Publications


Submitted

B., PROFESTAMBALEBENSON.  Submitted.  Antibodies in the serum of golden hamsters experimentally infected with the intestinal trematode Echinostoma caproni. J Helminthol. 1991 Dec;65(4):239-47. Erratum in: J Helminthol 1992 Mar;66(1):78.. J Helminthol. 1991 Dec;65(4):239-47. Erratum in: J Helminthol 1992 Mar;66(1):78.. : Taylor & Francis Abstract
The serum antibody response in golden hamsters (Mesocricetus auratus) infected with the intestinal trematode Echinostoma caproni was examined with ELISA, SDS-PAGE and Western blot, and IFAT techniques. All methods showed that the hamsters responded slowly but developed a clear positive humoral response to the infection. In most hamsters, an antibody response to infection could not be detected earlier than 11-13 weeks after infection with 6 or 25 metacercariae, and responses were weak when compared to previous results from mice infected with the same parasite. IFAT with positive hamster sera on live juvenile E. caproni showed only fluorescence at the posterior tip, which is a different pattern from that seen using from infected mice, indicating a different response to antigens on the juvenile parasites by these two hosts. The results are discussed in relation to the limited selfcure and development of resistance which is observed in golden hamsters infected with E. caproni.

2013

raham, SM, Rajwans N, Tapia KA, Jaoko W, Estambale B, McClelland RS, Overbaugh J, Liles WC.  2013.  A prospective study of endothelial activation biomarkers, including plasma angiopoietin-1 and angiopoietin-2, in Kenyan women initiating antiretroviral therapy. Abstracta_prospective_study_of_endothelial_activation.pdf

HIV-1-related inflammation is associated with increased levels of biomarkers of vascular adhesion and endothelial activation, and may increase production of the inflammatory protein angiopoietin-2 (ANG-2), an adverse prognostic biomarker in severe systemic infection. We hypothesized that antiretroviral therapy (ART) initiation would decrease endothelial activation, reducing plasma levels of ANG-2. METHODS: Antiretroviral-naive Kenyan women with advanced HIV infection were followed prospectively. Endothelial activation biomarkers including soluble intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), and E-selectin, and plasma ANG-2 and angiopoietin-1 (ANG-1) were tested in stored plasma samples from 0, 6, and 12 months after ART initiation. We used Wilcoxon matched-pairs signed rank tests to compare endothelial activation biomarkers across time-points, generalized estimating equations to analyze associations with change in log10-transformed biomarkers after ART initiation, and Cox proportional-hazards regression to analyze associations with mortality. RESULTS: The 102 HIV-1-seropositive women studied had advanced infection (median CD4 count, 124 cells/muL). Soluble ICAM-1 and plasma ANG-2 levels decreased at both time-points after ART initiation, with concomitant increases in the beneficial protein ANG-1. Higher ANG-2 levels after ART initiation were associated with higher plasma HIV-1 RNA, oral contraceptive pill use, pregnancy, severe malnutrition, and tuberculosis. Baseline ANG-2 levels were higher among five women who died after ART initiation than among women who did not (median 2.85 ng/mL [inter-quartile range (IQR) 2.47--5.74 ng/mL] versus median 1.32 ng/mL [IQR 0.35--2.18 ng/mL], p = 0.01). Both soluble ICAM-1 and plasma ANG-2 levels predicted mortality after ART initiation. CONCLUSIONS: Biomarkers of endothelial activation decreased after ART initiation in women with advanced HIV-1 infection. Changes in plasma ANG-2 were associated with HIV-1 RNA levels over 12 months of follow-up. Soluble ICAM-1 and plasma ANG-2 levels represent potential biomarkers for adverse outcomes in advanced HIV-1 infection.

2012

Odem-Davis, K, Kavanaugh BE, Jaoko W, Estambale B, Kiarie JN, Masese LN, Deya R, Manhart LE, Graham SM, McClelland RS.  2012.  Prevalence and correlates of genital Warts in Kenyan female sex workers. Abstract

Understanding the prevalence and correlates of genital warts will help to determine whether coverage for the wart-inducing subtypes 6 and 11 in a human papillomavirus vaccine is an important consideration in resource-limited countries

Kinyuru, JN;, Konyole SO;, Kenji GM;, Onyango CA;, Owino VO;, Owuor BO;, Estambale BB;, Friis H;, Roos N.  2012.  Identification of Traditional Foods with Public Health Potential for Complementary Feeding in Western Kenya. Abstract

The diversity of traditional foods in Kisumu West District of Western Kenya was assessed with an aim to identify the foods with a potential for complementary feeding. Leaves were the most consumed plant part amongst vegetables, while a few fruits were consumed together with their seeds. Amaranthus cruentus L. was found to be consumed as a leafy vegetable while another variety, Amaranthus hybridus L. was found to be consumed as a grain. Four species of winged termites, a grasshopper, black ant and dagaa fish were also identified. Twelve of the traditional foods were found to be associated with nutritional and health benefits as perceived by the locals. Traditional food processing methods such as boiling, fermentation and sun drying were identified. Thus exploitation of the species possessing nutrient, health and processing benefits needs to be explored in complementary feeding.

Otieno, W, Estambale B, Odera MM, Aluoch JR, Stoute JA.  2012.  Red Blood Cell Immune Complex Binding Capacity in Children with Sickle Cell Trait (HbAS) Living in P. falciparum Malaria Holoendemic Region of Western. Abstract

Malaria infection leads to the formation of circulating immune complexes (CICs) which have been implicated in the pathogenesis of complicated malaria which includes severe malarial anemia. Children with sickle cell trait (HbAS) are less predisposed to getting severe manifestations of malaria. We carried out a study to determine the competence of the red blood cells (RBCs) of children with HbAS to bind immune complexes (ICs) and compared this with normal hemoglobin (HbAA). Methods: Children (aged 0-192 months) were enrolled in a nested case controlled study conducted in Kombewa Division, Kisumu West District, Kenya. Based on hemoglobin (Hb) type, children were stratified into those with HbAS (n=47) and HbAA (n=69). The 47 HbAS individuals were matched to 69 HbAA of similar age. The children were further categorized into three cohorts (0-12, 13-48 and 49-192 months). Immune complex binding capacity (ICBC) was quantified using a FACScan flow cytometer under normal and reduced oxygen saturation. Results: The mean immune complex binding capacity for the HbAS cells was significantly higher than that of HbAA cells (P=0.0191) under normal oxygen saturation or under reduced oxygen saturation (P=0.0050). When a matching variable (UNIANOVA) was done to control for age, gender, the presence or absence of malaria parasitaemia, the binding capacity was again significantly higher for the HbAS than for HbAA under normal oxygen saturation (P=0.025) and under reduced oxygen saturation (P=0.003). The binding capacity was lowest in the 7-12 months age group for both HbAS and HbAA; however, the overall picture showed that HbAS individuals had higher immune complex binding capacity than HbAA in all the age cohorts. Conclusion: These results demonstrate that the protection afforded by HbAS against severe manifestations of malaria may be partly due to higher immune complex binding capacity of the HbAS compared to the HbAA cells. This high binding capacity may lead to the mopping up of ICs formed during malaria attacks and therefore protect these cells from deposition and subsequent destruction.

Lucy, MW, Christine S-KB, Benson EBA, Marleen TT.  2012.  Risk Association between Human Leucocyte Antigens (HLA) and Cervical Neoplasia in Kenyan Women.
Konyole, SO, Kinyuru JN, Owuor BO, Kenji GM, Onyango CA, Estambale BB, Friis H, Roos N, Owino VO.  2012.  Acceptability of Amaranth Grain-based Nutritious Complementary Foods with Dagaa Fish (Rastrineobola argentea) and Edible Termites (Macrotermes subhylanus) Compared to Corn Soy Blend Plus among Young Children/Mothers Dyads in Western Kenya. AbstractWebsite

This paper reports on a prospective study conducted between June 1990 and June 1992 to determine method acceptability, user satisfaction and continuation rates for three highly effective and reversible contraceptive methods currently available in Kenya: the CuT 380A (IUCD), the injectable, Depo-Provera and the low-dose oral contraceptive pill, Microgynon. A non-randomised sample of volunteer participants was used. One thousand and seventy-six users were followed up for a period of one year or up to the time of discontinuation of the method, whichever came earlier. Analysis revealed method specific differences in users' characteristics. The OC users were younger and had fewer children than the IUCD or Depo-Provera users. The Depo-Provera users were older, and had the largest family sizes. Many OC users (almost 40%) were single, while almost three-quarters of IUCD and Depo-Provera users were married. IUCD users were also more educated compared to OC and Depo-Provera users. Survival analysis was used to calculate cumulative life table discontinuation rates by method for the 12 month period. Discontinuation rates were highest for OC users (80%) and lowest for IUCD users (20%) and intermediate for Depo-Provera users (39%). Ninety percent of OC and Depo-Provera users and 86% of IUCD users said they were satisfied with their respective methods. While OCs are among the most popular family planning methods in Kenya, they are also one of the most problematic, while IUCD has the fewest compliance problems. Service providers need to address the issue of high discontinuation rates among the young OC users.
PIP:
This paper reports on a prospective study conducted between June 1990 and June 1992 to determine method acceptability, user satisfaction, and continuation rates for three highly effective and reversible contraceptive methods currently available in Kenya: the CuT 380A IUD; the injectable Depo-Provera; and the low-dose oral contraceptive Microgynon. A nonrandomized sample of volunteer participants was used. 1076 users were followed up for a period of 1 year or up to the time of discontinuation of the method, whichever came earlier. Analysis revealed method-specific differences in users' characteristics. The OC users were younger and had fewer children than the IUD or Depo-Provera users. The Depo-Provera users were older and had the largest family sizes. Many OC users (almost 40%) were single, while almost three-quarters of the IUD and Depo-Provera users were married. IUD users were also more educated compared to OC and Depo-Provera users. Survival analysis was used to calculate cumulative life table discontinuation rates by method for the 12-month period. Discontinuation rates were highest for OC users (80%), lowest for IUD users (20%), and intermediate for Depo-Provera users (39%). 90% of OC and Depo-Provera users and 86% of IUD users said they were satisfied with their respective methods. While OCs are among the most popular family planning methods in Kenya, they are also one of the most problematic, while IUDs have shown the fewest compliance problems. Service providers need to address the issue of high discontinuation rates among young OC users

2009

Alusala, DN;, Estambale B.  2009.  Intermittent presumptive treatment of malaria to prevent low birth weight in newborns in a cohort of pregnant women from a malaria endemic area. Abstract

OBJECTIVE: To determine and describe the patterns of low birth weight in newborns of a cohort of mothers given intermittent presumptive treatment (IPT) for malaria prevention in a malaria endemic area of Kenya. DESIGN: A longitudinal prospective cohort study. SETTING: Got Agulu Health Centre in Usigu Division, Bondo District, Nyanza Province. SUBJECTS: Pregnant women of all parities attending antenatal care services. Only women who gave informed consent for themselves and their newborns after birth were eligible to participate in the study. RESULTS: Parity was highly predictive of birth weight in the study subjects. Primigravidae and secondigravidae had a significantly lower mean birth weight (2952g) than women of higher gravidity (3214g) p-value <0.0001. Regardless of IPT administration, women who became positive for malaria infection at any point during pregnancy delivered 73.7% of the LBW infants. There was no significant difference in mean birth weights between primigravidae and multigravidae who had parasitaemia at baseline and at delivery (means 2906g and 3062g respectively, p=0.11). However, there was a significant difference between the parasitaemia negative primigravidae and multigravidae at baseline and at delivery (means 2952g and 3204g respectively, p=0.006). Infection with helminths did not have an effect on birth weight. Overall, low birth weight was observed in 9% of the newborns and was most commonly found in primigravidae and secondigravidae (14.8% and 13.1% respectively). CONCLUSION: Although many factors have been known to play a role in the causation of low birth weight (LBW <2500g), parity status and malaria infection in malaria endemic areas still play a major role regardless of IPT administration.

Plummer, FA;, Ackers M;, Gelmon L;, Kimani J;, Thabane L;, Ball B;T, Ngugi E;, Estambale B;, Nguti R;, Barasa S;, Karanja S;, Habyarimana J;, Jack W;, Chung M;, Ritvo P;, Kariri A;, Mills EJ;, Lester RT.  2009.  The HAART cell phone adherence trial (WelTel Kenya1): a randomized controlled trial protocol. Abstract

The objectives are to compare the effectiveness of cell phone-supported SMS messaging to standard care on adherence, quality of life, retention, and mortality in a population receiving antiretroviral therapy (ART) in Nairobi, Kenya. A multi-site randomized controlled open-label trial. A central randomization centre provided opaque envelopes to allocate treatments. Patients initiating ART at three comprehensive care clinics in Kenya will be randomized to receive either a structured weekly SMS (’short message system’ or text message) slogan (the intervention) or current standard of care support mechanisms alone (the control). Our hypothesis is that using a structured mobile phone protocol to keep in touch with patients will improve adherence to ART and other patient outcomes. Participants are evaluated at baseline, and then at six and twelve months after initiating ART. The care providers keep a weekly study log of all phone based communications with study participants. Primary outcomes are self-reported adherence to ART and suppression of HIV viral load at twelve months scheduled follow-up. Secondary outcomes are improvements in health, quality of life, social and economic factors, and retention on ART. Primary analysis is by ‘intention-to-treat’. Sensitivity analysis will be used to assess per-protocol effects. Analysis of covariates will be undertaken to determine factors that contribute or deter from expected and determined outcomes. This study protocol tests whether a novel structured mobile phone intervention can positively contribute to ART management in a resource-limited setting.

2008

B., PROFESTAMBALEBENSON.  2008.  Clarke SE, Jukes MC, Njagi JK, Khasakhala L, Cundill B, Otido J, Crudder C, Estambale BB, Brooker S.Effect of intermittent preventive treatment of malaria on health and education in schoolchildren: a cluster-randomised, double-blind, placebo-controlled tr. Lancet. 2008 Jul 12;372(9633):127-38.. : Taylor & Francis Abstract
BACKGROUND: Malaria is a major cause of morbidity and mortality in early childhood, yet its consequences for health and education during the school-age years remain poorly understood. We examined the effect of intermittent preventive treatment (IPT) in reducing anaemia and improving classroom attention and educational achievement in semi-immune schoolchildren in an area of high perennial transmission. METHODS: A stratified, cluster-randomised, double-blind, placebo-controlled trial of IPT was done in 30 primary schools in western Kenya. Schools were randomly assigned to treatment (sulfadoxine-pyrimethamine in combination with amodiaquine or dual placebo) by use of a computer-generated list. Children aged 5-18 years received three treatments at 4-month intervals (IPT n=3535, placebo n=3223). The primary endpoint was the prevalence of anaemia, defined as a haemoglobin concentration below 110 g/L. This outcome was assessed through cross-sectional surveys 12 months post-intervention. Analysis was by both intention to treat, excluding children with missing data, and per protocol. This study is registered with ClinicalTrials.gov, number NCT00142246. FINDINGS: 2604 children in the IPT group and 2302 in the placebo group were included in the intention-to-treat analysis of the primary outcome; the main reason for exclusion was loss to follow-up. Prevalence of anaemia at 12 months averaged 6.3% in the IPT group and 12.6% in the placebo group (adjusted risk ratio 0.52, 95% CI 0.29-0.93; p=0.028). Significant improvements were also seen in two of the class-based tests of sustained attention, with a mean increase in code transmission test score of 6.05 (95% CI 2.83-9.27; p=0.0007) and counting sounds test score of 1.80 (0.19-3.41; p=0.03), compared with controls. No effect was shown for inattentive or hyperactive-compulsive behaviours or on educational achievement. The per-protocol analysis yielded similar results. 23 serious adverse events were reported within 28 days of any treatment (19 in the IPT group and four in the placebo group); the main side-effects were problems of balance, dizziness, feeling faint, nausea, and/or vomiting shortly after treatment. INTERPRETATION: IPT of malaria improves the health and cognitive ability of semi-immune schoolchildren. Effective malaria interventions could be a valuable addition to school health programmes.
B., PROFESTAMBALEBENSON.  2008.  Koukounari A, Estambale BB, Kiambo Njagi J, Cundill B, Ajanga A, Crudder C, Otido J, Jukes MC, Clarke SE, Brooker S.Relationships between anaemia and parasitic infections in Kenyan schoolchildren: A Bayesian hierarchical modelling approach. Int J Parasito. Int J Parasitol. 2008 Jun 12. [Epub ahead of print]. : Taylor & Francis Abstract
Anaemia is multi-factorial in origin and disentangling its aetiology remains problematic, with surprisingly few studies investigating the relative contribution of different parasitic infections to anaemia amongst schoolchildren. We report cross-sectional data on haemoglobin, malaria parasitaemia, helminth infection and undernutrition among 1523 schoolchildren enrolled in classes 5 and 6 (aged 10-21 years) in 30 primary schools in western Kenya. Bayesian hierarchical modelling was used to investigate putative relationships. Children infected with Plasmodium falciparum or with a heavy Schistosoma mansoni infection, stunted children and girls were found to have lower haemoglobin concentrations. Children heavily infected with S. mansoni were also more likely to be anaemic compared with uninfected children. This study further highlights the importance of malaria and intestinal schistosomiasis as contributors to reduced haemoglobin levels among schoolchildren and helps guide the implementation of integrated school health programmes in areas of differing parasite transmission.
B., PROFESTAMBALEBENSON.  2008.  De Vuyst H, Gichangi P, Estambale B, Njuguna E, Franceschi S, Temmerman M.Human papillomavirus types in women with invasive cervical carcinoma by HIV status in Kenya. Int J Cancer. 2008 Jan 1;122(1):244-6.. Int J Cancer. 2008 Jan 1;122(1):244-6.. : Taylor & Francis Abstract
To evaluate the fraction of invasive cervical carcinoma (ICC) that could be prevented in HIV-infected women by vaccines currently available against human papillomavirus (HPV)16 and 18, we conducted a cross-sectional study in women with ICC in Nairobi, Kenya. Fifty-one HIV-positive women were frequency-matched by age to 153 HIV-negative women. Cervical cells were tested for HPV DNA using polymerase chain reaction-based assays (SPF10-INNO-LiPA). Comparisons were adjusted for multiplicity of HPV types. As expected, multiple-type infections were much more frequent in HIV-positive (37.2%) than in HIV-negative (13.7%) women, but the distribution of HPV types was similar. HPV16 was detected in 41.2% versus 43.8% and HPV16 and/or 18 in 64.7% versus 60.1% of HIV-positive versus HIV-negative women, respectively. The only differences of borderline statistical significance were an excess of HPV52 (19.6% versus 5.2%) and a lack of HPV45 (7.8% versus 17.0%) in HIV-positive women compared to HIV-negative women, respectively. We have been able to assess an unprecedented number of ICCs in HIV-positive women, but as we did not know the age of HIV acquisition, we cannot exclude that it had occurred too late in life to affect the type of HPV involved in cervical carcinogenesis. However, if our findings were confirmed, they would suggest that the efficacy of current vaccines against HPV16 and 18 to prevent ICC is similar in HIV-positive and HIV-negative women, provided vaccination is administered before sexual debut, as recommended. Copyright 2007 Wiley-Liss, Inc.
B., PROFESTAMBALEBENSON.  2008.  Temperley M, Mueller DH, Njagi JK, Akhwale W, Clarke SE, Jukes MC, Estambale BB, Brooker S.Costs and cost-effectiveness of delivering intermittent preventive treatment through schools in western Kenya.Malar J. 2008 Sep 30;7:196.. Malar J. 2008 Sep 30;7:196.. : Taylor & Francis Abstract
BACKGROUND: Awareness of the potential impact of malaria among school-age children has stimulated investigation into malaria interventions that can be delivered through schools. However, little evidence is available on the costs and cost-effectiveness of intervention options. This paper evaluates the costs and cost-effectiveness of intermittent preventive treatment (IPT) as delivered by teachers in schools in western Kenya. METHODS: Information on actual drug and non-drug associated costs were collected from expenditure and salary records, government budgets and interviews with key district and national officials. Effectiveness data were derived from a cluster-randomised-controlled trial of IPT where a single dose of sulphadoxine-pyrimethamine and three daily doses of amodiaquine were provided three times in year (once termly). Both financial and economic costs were estimated from a provider perspective, and effectiveness was estimated in terms of anaemia cases averted. A sensitivity analysis was conducted to assess the impact of key assumptions on estimated cost-effectiveness. RESULTS: The delivery of IPT by teachers was estimated to cost US$ 1.88 per child treated per year, with drug and teacher training costs constituting the largest cost components. Set-up costs accounted for 13.2% of overall costs (equivalent to US$ 0.25 per child) whilst recurrent costs accounted for 86.8% (US$ 1.63 per child per year). The estimated cost per anaemia case averted was US$ 29.84 and the cost per case of Plasmodium falciparum parasitaemia averted was US$ 5.36, respectively. The cost per case of anaemia averted ranged between US$ 24.60 and 40.32 when the prices of antimalarial drugs and delivery costs were varied. Cost-effectiveness was most influenced by effectiveness of IPT and the background prevalence of anaemia. In settings where 30% and 50% of schoolchildren were anaemic, cost-effectiveness ratios were US$ 12.53 and 7.52, respectively. CONCLUSION: This study provides the first evidence that IPT administered by teachers is a cost-effective school-based malaria intervention and merits investigation in other settings.
B., PROFESTAMBALEBENSON.  2008.  Brooker S, Akhwale W, Pullan R, Estambale B, Clarke SE, Snow RW, Hotez PJ.Epidemiology of plasmodium-helminth co-infection in Africa: populations at risk, potential impact on anemia, and prospects for combining control.Am J Trop Med Hyg. 2007 Dec;77(6 Sup. Am J Trop Med Hyg. 2007 Dec;77(6 Suppl):88-98.. : Taylor & Francis Abstract
Human co-infection with Plasmodium falciparum and helminths is ubiquitous throughout Africa, although its public health significance remains a topic for which there are many unknowns. In this review, we adopted an empirical approach to studying the geography and epidemiology of co-infection and associations between patterns of co-infection and hemoglobin in different age groups. Analysis highlights the extensive geographic overlap between P. falciparum and the major human helminth infections in Africa, with the population at coincident risk of infection greatest for hookworm. Age infection profiles indicate that school-age children are at the highest risk of co-infection, and re-analysis of existing data suggests that co-infection with P. falciparum and hookworm has an additive impact on hemoglobin, exacerbating anemia-related malarial disease burden. We suggest that both school-age children and pregnant women–groups which have the highest risk of anemia–would benefit from an integrated approach to malaria and helminth control.
B., PROFESTAMBALEBENSON.  2008.  Alusala DN, Estambale BB, Magnussen P, Friis H, Luoba AI, Mwaniki D.Predictors of serum ferritin and haemoglobin during pregnancy, in a malaria-endemic area of western Kenya.Ann Trop Med Parasitol. 2008 Jun;102(4):297-308.. Ann Trop Med Parasitol. 2008 Jun;102(4):297-308.. : Taylor & Francis Abstract
Between 2000 and 2004, a cross-sectional survey was conducted, as part of a prospective cohort study, among the women attending antenatal-care clinics in Bondo district, a malaria-endemic area of western Kenya. The aim was to assess the prevalence of iron deficiency and determine the predictors of haemoglobin and serum ferritin concentrations in the women who had a gestational age between 14 and 24 weeks. A standardized questionnaire was used to collect and store the relevant bio-data for the study. Haemoglobin and ferritin concentrations were evaluated, sickle-cell status was determined, and malarial parasitaemias were detected and evaluated, using blood samples collected at enrollment. Multiple regression analysis was then used to test for significant predictors of the haemoglobin and serum ferritin concentrations. Although 842 women were enrolled in the prospective cohort study, haemoglobin concentrations were evaluated for only 828 of them, serum ferritin levels for 621, and levels of parasitaemia for 812. The mean haemoglobin concentration recorded was 10.9 g/dl. Although 37.9% of the subjects had mild-moderate anaemia (7.0-10.5 g haemoglobin/dl), only 0.5% were severely anaemic (<7.0 g haemoglobin/dl). The geometric mean serum ferritin concentration recorded was 18.9 microg/litre, and 32.3% of the subjects evaluated had low serum concentrations of ferritin (<12 microg/litre). Among the parasitaemic primigravidae (but not the parasitaemic multigravidae), those found positive for sickle-cell trait had significantly lower haemoglobin concentrations than those found negative in a sickling test (P=0.01). Among the pregnant women of Bondo district, gravidity, malarial infection and sickle cell appear to be key predictors of haemoglobin concentration.
B., PROFESTAMBALEBENSON.  2008.  Alusala DN, Estambale BB, Magnussen P, Friis H, Luoba AI, Mwaniki D.Predictors of serum ferritin and haemoglobin during pregnancy, in a malaria-endemic area of western Kenya.Ann Trop Med Parasitol. 2008 Jun;102(4):297-308.. Ann Trop Med Parasitol. 2008 Jun;102(4):297-308.. : Taylor & Francis Abstract
Between 2000 and 2004, a cross-sectional survey was conducted, as part of a prospective cohort study, among the women attending antenatal-care clinics in Bondo district, a malaria-endemic area of western Kenya. The aim was to assess the prevalence of iron deficiency and determine the predictors of haemoglobin and serum ferritin concentrations in the women who had a gestational age between 14 and 24 weeks. A standardized questionnaire was used to collect and store the relevant bio-data for the study. Haemoglobin and ferritin concentrations were evaluated, sickle-cell status was determined, and malarial parasitaemias were detected and evaluated, using blood samples collected at enrollment. Multiple regression analysis was then used to test for significant predictors of the haemoglobin and serum ferritin concentrations. Although 842 women were enrolled in the prospective cohort study, haemoglobin concentrations were evaluated for only 828 of them, serum ferritin levels for 621, and levels of parasitaemia for 812. The mean haemoglobin concentration recorded was 10.9 g/dl. Although 37.9% of the subjects had mild-moderate anaemia (7.0-10.5 g haemoglobin/dl), only 0.5% were severely anaemic (<7.0 g haemoglobin/dl). The geometric mean serum ferritin concentration recorded was 18.9 microg/litre, and 32.3% of the subjects evaluated had low serum concentrations of ferritin (<12 microg/litre). Among the parasitaemic primigravidae (but not the parasitaemic multigravidae), those found positive for sickle-cell trait had significantly lower haemoglobin concentrations than those found negative in a sickling test (P=0.01). Among the pregnant women of Bondo district, gravidity, malarial infection and sickle cell appear to be key predictors of haemoglobin concentration.

2007

B., PROFESTAMBALEBENSON.  2007.  Orech FO, Christensen DL, Larsen T, Friis H, Aagaard-Hansen J, Estambale BA.Mineral content of traditional leafy vegetables from western Kenya.Int J Food Sci Nutr. 2007 Dec;58(8):595-602.. Int J Food Sci Nutr. 2007 Dec;58(8):595-602.. : Taylor & Francis Abstract

Socio-economic changes that have taken place in Africa have influenced people's eating habits in both rural and urban set-ups. Most people prefer introduced foods to traditional foods, including plant foods whose consumption is widely regarded as a primitive culture manifesting poor lifestyles. However, recent studies on traditional plant foods have shown that some are highly nutritious; containing high levels of both vitamins and minerals. They also have potential as a remedy to counter food insecurity since most are well adapted to the local environment, enabling them to resist pests, drought and diseases. This paper describes the mineral (calcium, iron and zinc) contents in some 54 traditional vegetable species collected from Nyang'oma area of Bondo district, western Kenya. Atomic absorption spectroscopy was used to determine the mineral content. We found that most traditional leafy vegetables, domesticated and wild, generally contain higher levels of calcium, iron and zinc compared with the introduced varieties such as spinach (Spanacia oleracea), kale (Brassica oleracea var. acephala) and cabbage (Brassica oleracea var. capitata). The results of this study could contribute towards identification, propagation and subsequent domestication and cultivation promotion of nutrient-rich and safe species within the farming systems of the local communities in Kenya, sub-Saharan Africa or elsewhere.

B., PROFESTAMBALEBENSON.  2007.  Jaoko WG, Michael E, Meyrowitsch DW, Estambale BB, Malecela MN, Simonsen PE.Immunoepidemiology of Wuchereria bancrofti infection: parasite transmission intensity, filaria-specific antibodies, and host immunity in two East African communities. Infect Immun. Infect Immun. 2007 Dec;75(12):5651-62. Epub 2007 Oct 1.. : Taylor & Francis Abstract
We compared the age profiles of infection and specific antibody intensities in two communities with different transmission levels in East Africa to examine the contribution of humoral responses to human immunity to the vector-borne helminth Wuchereria bancrofti. The worm intensities were higher and exhibited a nonlinear age pattern in a high-transmission community, Masaika, in contrast to the low but linearly increasing age infection profile observed for a low-transmission community, Kingwede. The mean levels of specific immunoglobulin G1 (IgG1), IgG2, IgG4, and IgE were also higher in Masaika, but intriguingly, the IgG3 response was higher in Kingwede. The age-antibody patterns differed in the two communities but in a manner apparently contrary to a role in acquired immunity when the data were assessed using simple correlation methods. By contrast, multivariate analyses showed that the antibody response to infection may be classified into three types and that two of these types, a IgG3-type response and a response measuring a trade-off in host production of IgG4 and IgG3 versus production of IgG1, IgG2, and IgE, had a negative effect on Wuchereria circulating antigen levels in a manner that supported a role for these responses in the generation of acquired immunity to infection. Mathematical modeling supported the conclusions drawn from empirical data analyses that variations in both transmission and worm intensity can explain community differences in the age profiles and impacts of these antibody response types. This study showed that parasite-specific antibody responses may be associated with the generation of acquired immunity to human filarial infection but in a form which is dependent on worm transmission intensity and interactions between immune components.

2006

B., PROFESTAMBALEBENSON.  2006.  Gichangi P, Bwayo J, Estambale B, Rogo K, Njuguna E, Ojwang S, Temmerman M.HIV impact on acute morbidity and pelvic tumor control following radiotherapy for cervical cancer.Gynecol Oncol. 2006 Feb;100(2):405-11. Epub 2005 Nov 4.. Gynecol Oncol. 2006 Feb;100(2):405-11. Epub 2005 Nov 4.. : Taylor & Francis Abstract
OBJECTIVE: To determine the impact of HIV infection on acute morbidity and pelvic tumor control following external beam radiotherapy (EBRT) for cervical cancer. METHOD: 218 patients receiving EBRT who also had HIV testing after informed consent was obtained were evaluated. Acute treatment toxicity was documented weekly during treatment and 1 month post-EBRT. Pelvic tumor control was documented at 4 and 7 months post-EBRT. Clinicians were blinded for HIV results. RESULTS: About 20% of the patients were HIV-positive. Overall, 53.4% of the patients had radiation-related acute toxicity (grade 3-4). HIV infection was associated with a 7-fold higher risk of multisystem toxicity: skin, gastrointestinal tract (GIT) and genitourinary tract (GUT) systems. It was also an independent risk factor for treatment interruptions (adjusted relative risk 2.2). About 19% of the patients had residual tumor at 4 and 7 months post-EBRT. HIV infection was independently and significantly associated with 6-fold higher risk of residual tumor post-EBRT. The hazard ratio of having residual tumor after initial EBRT was 3.1-times larger for HIV-positive than for HIV-negative patients (P = 0.014). CONCLUSION: HIV is associated with increased risk of multisystem radiation-related toxicity; treatment interruptions and pelvic failure (residual tumor) following EBRT. HIV infection is an adverse prognostic factor for outcome of cervical cancer treatment.
B., PROFESTAMBALEBENSON.  2006.  Gichangi P, Estambale B, Bwayo J, Rogo K, Ojwang S, Njuguna E, Temmerman M.Acceptability of human immunodeficiency virus testing in patients with invasive cervical cancer in Kenya.Int J Gynecol Cancer. 2006 Mar-Apr;16(2):681-5.. Int J Gynecol Cancer. 2006 Mar-Apr;16(2):681-5.. : Taylor & Francis Abstract
Invasive cervical cancer (ICC) is common in areas where human immunodeficiency virus (HIV) is also prevalent. Currently, HIV seroprevalence as well as acceptability of HIV testing in ICC patients in Kenya is unknown. The objective of this study was to determine the acceptability of HIV testing among patients with ICC. Women with histologically verified ICC at Kenyatta National Hospital participated in the study. A structured questionnaire was administered to patients who gave informed consent. HIV pre- and posttesting counseling was done. Blood was tested for HIV using enzyme-linked immunosorbent assay. Overall, 11% of ICC patients were HIV seropositive. The acceptance rate of HIV testing was 99%; yet, 5% of the patients did not want to know their HIV results. Patients less than 35 years old were two times more likely to refuse the result of the HIV test (odds ratio [OR] 2.2). Patients who did not want to know their HIV results were three times more likely to be HIV seropositive (OR 3.1). Eighty four percent of the patients were unaware of their HIV seropositive status. The HIV-1 seroprevalence in ICC patients was comparable to the overall seroprevalence in Kenya. ICC patients were interested in HIV testing following pretest counseling. Offering routine HIV testing is recommended in ICC patients.
B., PROFESTAMBALEBENSON.  2006.  Jaoko WG, Simonsen PE, Meyrowitsch DW, Estambale BB, Malecela-Lazaro MN, Michael E.Filarial-specific antibody response in East African bancroftian filariasis: effects of host infection, clinical disease, and filarial endemicity.Am J Trop Med Hyg. 2006 Jul. Am J Trop Med Hyg. 2006 Jul;75(1):97-107.. : Taylor & Francis Abstract
The effect of host infection, chronic clinical disease, and transmission intensity on the patterns of specific antibody responses in Bancroftian filariasis was assessed by analyzing specific IgG1, IgG2, IgG3, IgG4, and IgE profiles among adults from two communities with high and low Wuchereria bancrofti endemicity. In the high endemicity community, intensities of the measured antibodies were significantly associated with infection status. IgG1, IgG2, and IgE were negatively associated with microfilaria (MF) status, IgG3 was negatively associated with circulating filarial antigen (CFA) status, and IgG4 was positively associated with CFA status. None of the associations were significantly influenced by chronic lymphatic disease status. In contrast, IgG1, IgG2, and IgG4 responses were less vigorous in the low endemicity community and, except for IgG4, did not show any significant associations with MF or CFA status. The IgG3 responses were considerably more vigorous in the low endemicity community than in the high endemicity one. Only IgG4 responses exhibited a rather similar pattern in the two communities, being significantly positively associated with CFA status in both communities. The IgG4:IgE ratios were higher in infection-positive individuals than in infection-negative ones, and higher in the high endemicity community than in the low endemicity one. Overall, these results indicate that specific antibody responses in Bancroftian filariasis are more related to infection status than to chronic lymphatic disease status. They also suggest that community transmissi
B., PROFESTAMBALEBENSON.  2006.  Filarial-specific antibody response in East African bancroftian filariasis: effects of host infection, clinical disease, and filarial endemicity. Am J Trop Med Hyg. 2006 Jul;75(1):97-107.. Am J Trop Med Hyg. 2006 Jul;75(1):97-107.. : Taylor & Francis Abstract
The effect of host infection, chronic clinical disease, and transmission intensity on the patterns of specific antibody responses in Bancroftian filariasis was assessed by analyzing specific IgG1, IgG2, IgG3, IgG4, and IgE profiles among adults from two communities with high and low Wuchereria bancrofti endemicity. In the high endemicity community, intensities of the measured antibodies were significantly associated with infection status. IgG1, IgG2, and IgE were negatively associated with microfilaria (MF) status, IgG3 was negatively associated with circulating filarial antigen (CFA) status, and IgG4 was positively associated with CFA status. None of the associations were significantly influenced by chronic lymphatic disease status. In contrast, IgG1, IgG2, and IgG4 responses were less vigorous in the low endemicity community and, except for IgG4, did not show any significant associations with MF or CFA status. The IgG3 responses were considerably more vigorous in the low endemicity community than in the high endemicity one. Only IgG4 responses exhibited a rather similar pattern in the two communities, being significantly positively associated with CFA status in both communities. The IgG4:IgE ratios were higher in infection-positive individuals than in infection-negative ones, and higher in the high endemicity community than in the low endemicity one. Overall, these results indicate that specific antibody responses in Bancroftian filariasis are more related to infection status than to chronic lymphatic disease status. They also suggest that community transmission intensity play a dominant but subtle role in shaping the observed response patterns.

2005

Gichangi, P, Estambale B, Bwayo JJ, Rogo KO, Ojwang S, Njuguna E, Temmerman M.  2005.  Acceptability of human immunodeficiency virus testing in patients with invasive cervical cancer in Kenya. AbstractWebsite

Invasive cervical cancer (ICC) is common in areas where human immunodeficiency virus (HIV) is also prevalent. Currently, HIV seroprevalence as well as acceptability of HIV testing in ICC patients in Kenya is unknown. The objective of this study was to determine the acceptability of HIV testing among patients with ICC. Women with histologically verified ICC at Kenyatta National Hospital participated in the study. A structured questionnaire was administered to patients who gave informed consent. HIV pre- and posttesting counseling was done. Blood was tested for HIV using enzyme-linked immunosorbent assay. Overall, 11% of ICC patients were HIV seropositive. The acceptance rate of HIV testing was 99%; yet, 5% of the patients did not want to know their HIV results. Patients less than 35 years old were two times more likely to refuse the result of the HIV test (odds ratio [OR] 2.2). Patients who did not want to know their HIV results were three times more likely to be HIV seropositive (OR 3.1). Eighty four percent of the patients were unaware of their HIV seropositive status. The HIV-1 seroprevalence in ICC patients was comparable to the overall seroprevalence in Kenya. ICC patients were interested in HIV testing following pretest counseling. Offering routine HIV testing is recommended in ICC patients.

B., PROFESTAMBALEBENSON.  2005.  Luoba AI, Wenzel Geissler P, Estambale B, Ouma JH, Alusala D, Ayah R, Mwaniki D, Magnussen P, Friis H. Earth-eating and reinfection with intestinal helminths among pregnant and lactating women in western Kenya. Trop Med Int Health. 2005 Mar;10(3):220-7.. Trop Med Int Health. 2005 Mar;10(3):220-7.. : Taylor & Francis Abstract
We conducted a longitudinal study among 827 pregnant women in Nyanza Province, western Kenya, to determine the effect of earth-eating on geohelminth reinfection after treatment. The women were recruited at a gestational age of 14-24 weeks (median: 17) and followed up to 6 months postpartum. The median age was 23 (range: 14-47) years, the median parity 2 (range: 0-11). After deworming with mebendazole (500 mg, single dose) of those found infected at 32 weeks gestation, 700 women were uninfected with Ascaris lumbricoides, 670 with Trichuris trichiura and 479 with hookworm. At delivery, 11.2%, 4.6% and 3.8% of these women were reinfected with hookworm, T. trichiura and A. lumbricoides respectively. The reinfection rate for hookworm was 14.8%, for T. trichiura 6.65, and for A. lumbricoides 5.2% at 3 months postpartum, and 16.0, 5.9 and 9.4% at 6 months postpartum. There was a significant difference in hookworm intensity at delivery between geophagous and non-geophagous women (P=0.03). Women who ate termite mound earth were more often and more intensely infected with hookworm at delivery than those eating other types of earth (P=0.07 and P=0.02 respectively). There were significant differences in the prevalence of A. lumbricoides between geophagous and non-geophagous women at 3 (P=0.001) and at 6 months postpartum (P=0.001). Women who ate termite mound earth had a higher prevalence of A. lumbricoides, compared with those eating other kinds of earth, at delivery (P=0.02), 3 months postpartum (P=0.001) and at 6 months postpartum (P=0.001). The intensity of infections with T. trichiura at 6 months postpartum was significantly different between geophagous and non-geophagous women (P=0.005). Our study shows that geophagy is associated with A. lumbricoides reinfection among pregnant and lactating women and that intensities built up more rapidly among geophagous women. Geophagy might be associated with reinfection with hookworm and T. trichiura, although these results were less unequivocal. These findings call for increased emphasis, in antenatal care, on the potential risks of earth-eating, and for deworming of women after delivery.

2004

B., PROFESTAMBALEBENSON.  2004.  Mukoko DA, Pedersen EM, Masese NN, Estambale BB, Ouma JH. Bancroftian filariasis in 12 villages in Kwale district, Coast province, Kenya - variation in clinical and parasitological patterns. Ann Trop Med Parasitol. 2004 Dec;98(8):801-15.. Ann Trop Med Parasitol. 2004 Dec;98(8):801-15.. : Taylor & Francis Abstract
As part of a larger study on the effects of permethrin-impregnated bednets on the transmission of Wuchereria bancrofti, subjects from 12 villages in the Coastal province of Kenya, south of Mombasa, were investigated. The aims were to update the epidemiological data and elucidate the spatial distribution of W. bancrofti infection. Samples of night blood from all the villagers aged i 1 year were checked for the parasite, and all the adult villagers (aged >/= 15 years) were clinically examined for elephantiasis and, if male, for hydrocele. Overall, 16.0% of the 6531 villagers checked for microfilariae (mff) were found microfilaraemic, although the prevalence of microfilaraemia in each village varied from 8.1%-27.4%. The geometric mean intensity of infection among the microfilaraemic was 322 mff/ml blood. At village level, intensity of the microfilaraemia was positively correlated with prevalence, indicating that transmission has a major influence on the prevalence of microfilaraemia. Clinical examination of 2481 adults revealed that 2.9% had elephantiasis of the leg and that 19.9% of the adult men (10.8%-30.1% of the men investigated in each village) had hydrocele. Although the overall prevalence of microfilaraemia in the study villages had not changed much since earlier studies in the 1970s, both prevalence and intensity varied distinctly between the study villages. Such geographical variation over relatively short distances appears to be a common but seldom demonstrated feature in the epidemiology of bancroftian filariasis, and the focal nature of the geographical distribution should be carefully considered by those mapping the disease.
B., PROFESTAMBALEBENSON.  2004.  S. Brooker, S. Clarke, JK Njagi, S. Polack, B. Mugo, B. Estambale, E. Muchiri, P. Magnussen, J. Cox (2004). Spatial clustering of malaria and associated risk factors during an epidemic in a highland area of western Kenya. Trop Med & Int. Health 9 (7) 757 . Trop Med & Int. Health 9 (7) 757 . : Taylor & Francis Abstract
We conducted a longitudinal study among 827 pregnant women in Nyanza Province, western Kenya, to determine the effect of earth-eating on geohelminth reinfection after treatment. The women were recruited at a gestational age of 14-24 weeks (median: 17) and followed up to 6 months postpartum. The median age was 23 (range: 14-47) years, the median parity 2 (range: 0-11). After deworming with mebendazole (500 mg, single dose) of those found infected at 32 weeks gestation, 700 women were uninfected with Ascaris lumbricoides, 670 with Trichuris trichiura and 479 with hookworm. At delivery, 11.2%, 4.6% and 3.8% of these women were reinfected with hookworm, T. trichiura and A. lumbricoides respectively. The reinfection rate for hookworm was 14.8%, for T. trichiura 6.65, and for A. lumbricoides 5.2% at 3 months postpartum, and 16.0, 5.9 and 9.4% at 6 months postpartum. There was a significant difference in hookworm intensity at delivery between geophagous and non-geophagous women (P=0.03). Women who ate termite mound earth were more often and more intensely infected with hookworm at delivery than those eating other types of earth (P=0.07 and P=0.02 respectively). There were significant differences in the prevalence of A. lumbricoides between geophagous and non-geophagous women at 3 (P=0.001) and at 6 months postpartum (P=0.001). Women who ate termite mound earth had a higher prevalence of A. lumbricoides, compared with those eating other kinds of earth, at delivery (P=0.02), 3 months postpartum (P=0.001) and at 6 months postpartum (P=0.001). The intensity of infections with T. trichiura at 6 months postpartum was significantly different between geophagous and non-geophagous women (P=0.005). Our study shows that geophagy is associated with A. lumbricoides reinfection among pregnant and lactating women and that intensities built up more rapidly among geophagous women. Geophagy might be associated with reinfection with hookworm and T. trichiura, although these results were less unequivocal. These findings call for increased emphasis, in antenatal care, on the potential risks of earth-eating, and for deworming of women after delivery.
B., PROFESTAMBALEBENSON.  2004.  Luoba AI, Geissler PW, Estambale B, Ouma JH, Magnussen P, Alusala D, Ayah R, Mwaniki D, Friis H. Geophagy among pregnant and lactating women in Bondo District, western Kenya. Trans R Soc Trop Med Hyg. 2004 Dec;98(12):734-41.. Trans R Soc Trop Med Hyg. 2004 Dec;98(12):734-41.. : Taylor & Francis Abstract
Geophagy was studied among 827 pregnant women in western Kenya, during and after pregnancy. The women were recruited at a gestational age of 14-24 weeks and followed-up to 6 months post-partum. The median age (range) of the women was 23 years and median parity 2. At recruitment, 378 were eating earth, of which most (65%) reported earth-eating before pregnancy. The preferred type of earth eaten was soft stone, known locally as odowa (54.2%) and earth from termite mounds (42.8%). The prevalence remained high during pregnancy, and then declined to 34.5% and 29.6% at 3 and 6 months post-partum respectively (P < 0.001). The mean daily earth intake was 44.5 g during pregnancy, which declined to 25.5 g during lactation (P < 0.001). A random sample of 204 stools was collected from the women and analysed for silica content as a tracer for earth-eating. The mean silica content was 2.1% of the dry weight of stool. Geophagous women had a higher mean silica content than the non-geophagous ones (3.1% vs. 1.4%, P < 0.001). Faecal silica and reported geophagy were strongly correlated (P < 0.001).
B., PROFESTAMBALEBENSON.  2004.  Clarke SE, Brooker S, Njagi JK, Njau E, Estambale B, Muchiri E, Magnussen P. Malaria morbidity among school children living in two areas of contrasting transmission in western Kenya. Am J Trop Med Hyg. 2004 Dec;71(6):732-8.. Am J Trop Med Hyg. 2004 Dec;71(6):732-8.. : Taylor & Francis Abstract
Research in malaria-endemic areas is usually focused on malaria during early childhood. Less is known about malaria among older school age children. The incidence of clinical attacks of malaria was monitored, using active case detection in primary schools, in two areas of western Kenya that differ in the intensity of transmission. Clinical malaria was more common in schools in the Nandi highlands, with a six-fold higher incidence of malaria attacks during the malaria epidemic in 2002, compared with school children living in a holoendemic area with intense perennial transmission during the same period. The high incidence coupled with the high parasite densities among cases is compatible with a low level of protective immunity in the highlands. The malaria incidence among school children exposed to intense year-round transmission (26 per 100 school children per year) was consistent with reports from other holoendemic areas. Taken together with other published studies, the data suggest that malaria morbidity among school age children increases as transmission intensity decreases. The implications for malaria control are discussed.

2003

B., PROFESTAMBALEBENSON.  2003.  Estambale BB.Microbial infections in the twenty first century: a continuous challenge.East Afr Med J. 2003 Aug;80(8):393-4.. East Afr Med J. 2003 Aug;80(8):393-4.. : Taylor & Francis Abstract
As part of a larger study on the effects of permethrin-impregnated bednets on the transmission of Wuchereria bancrofti, subjects from 12 villages in the Coastal province of Kenya, south of Mombasa, were investigated. The aims were to update the epidemiological data and elucidate the spatial distribution of W. bancrofti infection. Samples of night blood from all the villagers aged i 1 year were checked for the parasite, and all the adult villagers (aged >/= 15 years) were clinically examined for elephantiasis and, if male, for hydrocele. Overall, 16.0% of the 6531 villagers checked for microfilariae (mff) were found microfilaraemic, although the prevalence of microfilaraemia in each village varied from 8.1%-27.4%. The geometric mean intensity of infection among the microfilaraemic was 322 mff/ml blood. At village level, intensity of the microfilaraemia was positively correlated with prevalence, indicating that transmission has a major influence on the prevalence of microfilaraemia. Clinical examination of 2481 adults revealed that 2.9% had elephantiasis of the leg and that 19.9% of the adult men (10.8%-30.1% of the men investigated in each village) had hydrocele. Although the overall prevalence of microfilaraemia in the study villages had not changed much since earlier studies in the 1970s, both prevalence and intensity varied distinctly between the study villages. Such geographical variation over relatively short distances appears to be a common but seldom demonstrated feature in the epidemiology of bancroftian filariasis, and the focal nature of the geographical distribution should be carefully considered by those mapping the disease.
B., PROFESTAMBALEBENSON.  2003.  Kiambo N., Magnussen, P., Estambale B., Ouma J.H., Mugo B (2003). Prevention of anaemia in pregnancy using insecticide-treated bednets and sulfadoxine-pyrimethamine in a highly malarious are of Kenya: A randomized controlled trial. Trans. R Soc. Trop. Med. Trans. R Soc. Trop. Med. Hyg. 97: 277 . : Taylor & Francis Abstract
As part of a larger study on the effects of permethrin-impregnated bednets on the transmission of Wuchereria bancrofti, subjects from 12 villages in the Coastal province of Kenya, south of Mombasa, were investigated. The aims were to update the epidemiological data and elucidate the spatial distribution of W. bancrofti infection. Samples of night blood from all the villagers aged i 1 year were checked for the parasite, and all the adult villagers (aged >/= 15 years) were clinically examined for elephantiasis and, if male, for hydrocele. Overall, 16.0% of the 6531 villagers checked for microfilariae (mff) were found microfilaraemic, although the prevalence of microfilaraemia in each village varied from 8.1%-27.4%. The geometric mean intensity of infection among the microfilaraemic was 322 mff/ml blood. At village level, intensity of the microfilaraemia was positively correlated with prevalence, indicating that transmission has a major influence on the prevalence of microfilaraemia. Clinical examination of 2481 adults revealed that 2.9% had elephantiasis of the leg and that 19.9% of the adult men (10.8%-30.1% of the men investigated in each village) had hydrocele. Although the overall prevalence of microfilaraemia in the study villages had not changed much since earlier studies in the 1970s, both prevalence and intensity varied distinctly between the study villages. Such geographical variation over relatively short distances appears to be a common but seldom demonstrated feature in the epidemiology of bancroftian filariasis, and the focal nature of the geographical distribution should be carefully considered by those mapping the disease.
B., PROFESTAMBALEBENSON.  2003.  P.Gichangi, B. Estambale, J. Bwayo, K. Rogo, A. Opiyo, M. Temmerman (2003). Knowledge and practice about cervical cancer and Pap smear testing among patients at Kenyatta National Hospital Nairobi, Kenya. Int. J. Gynecol. Cancer. 13: 1 . Int. J. Gynecol. Cancer. 13: 1 . : Taylor & Francis Abstract
As part of a larger study on the effects of permethrin-impregnated bednets on the transmission of Wuchereria bancrofti, subjects from 12 villages in the Coastal province of Kenya, south of Mombasa, were investigated. The aims were to update the epidemiological data and elucidate the spatial distribution of W. bancrofti infection. Samples of night blood from all the villagers aged i 1 year were checked for the parasite, and all the adult villagers (aged >/= 15 years) were clinically examined for elephantiasis and, if male, for hydrocele. Overall, 16.0% of the 6531 villagers checked for microfilariae (mff) were found microfilaraemic, although the prevalence of microfilaraemia in each village varied from 8.1%-27.4%. The geometric mean intensity of infection among the microfilaraemic was 322 mff/ml blood. At village level, intensity of the microfilaraemia was positively correlated with prevalence, indicating that transmission has a major influence on the prevalence of microfilaraemia. Clinical examination of 2481 adults revealed that 2.9% had elephantiasis of the leg and that 19.9% of the adult men (10.8%-30.1% of the men investigated in each village) had hydrocele. Although the overall prevalence of microfilaraemia in the study villages had not changed much since earlier studies in the 1970s, both prevalence and intensity varied distinctly between the study villages. Such geographical variation over relatively short distances appears to be a common but seldom demonstrated feature in the epidemiology of bancroftian filariasis, and the focal nature of the geographical distribution should be carefully considered by those mapping the disease.
B., PROFESTAMBALEBENSON.  2003.  P.B. Gichangi, J. Bwayo, B. Estambale, H. De Vyust, S. Ojwang, K. Rogo, H. Abwao, M. Temmerman (2003). The Impact of HIV infection on invasive cervical cancer in Kenyan women. AIDS 17: 1963 . AIDS 17: 1963 . : Taylor & Francis Abstract
As part of a larger study on the effects of permethrin-impregnated bednets on the transmission of Wuchereria bancrofti, subjects from 12 villages in the Coastal province of Kenya, south of Mombasa, were investigated. The aims were to update the epidemiological data and elucidate the spatial distribution of W. bancrofti infection. Samples of night blood from all the villagers aged i 1 year were checked for the parasite, and all the adult villagers (aged >/= 15 years) were clinically examined for elephantiasis and, if male, for hydrocele. Overall, 16.0% of the 6531 villagers checked for microfilariae (mff) were found microfilaraemic, although the prevalence of microfilaraemia in each village varied from 8.1%-27.4%. The geometric mean intensity of infection among the microfilaraemic was 322 mff/ml blood. At village level, intensity of the microfilaraemia was positively correlated with prevalence, indicating that transmission has a major influence on the prevalence of microfilaraemia. Clinical examination of 2481 adults revealed that 2.9% had elephantiasis of the leg and that 19.9% of the adult men (10.8%-30.1% of the men investigated in each village) had hydrocele. Although the overall prevalence of microfilaraemia in the study villages had not changed much since earlier studies in the 1970s, both prevalence and intensity varied distinctly between the study villages. Such geographical variation over relatively short distances appears to be a common but seldom demonstrated feature in the epidemiology of bancroftian filariasis, and the focal nature of the geographical distribution should be carefully considered by those mapping the disease.
B., PROFESTAMBALEBENSON.  2003.  A. Blackwell, A.E Stuart, B.A. Estambale (2003). The repellent and antifeedant activity of Myrica Gale oil against Aedes aegypti mosquitoes and its enhancement by the addition of salicyluric acid. J.R. Coll. Physicians Edinb. 33: 209 . J.R. Coll. Physicians Edinb. 33: 209 . : Taylor & Francis Abstract
As part of a larger study on the effects of permethrin-impregnated bednets on the transmission of Wuchereria bancrofti, subjects from 12 villages in the Coastal province of Kenya, south of Mombasa, were investigated. The aims were to update the epidemiological data and elucidate the spatial distribution of W. bancrofti infection. Samples of night blood from all the villagers aged i 1 year were checked for the parasite, and all the adult villagers (aged >/= 15 years) were clinically examined for elephantiasis and, if male, for hydrocele. Overall, 16.0% of the 6531 villagers checked for microfilariae (mff) were found microfilaraemic, although the prevalence of microfilaraemia in each village varied from 8.1%-27.4%. The geometric mean intensity of infection among the microfilaraemic was 322 mff/ml blood. At village level, intensity of the microfilaraemia was positively correlated with prevalence, indicating that transmission has a major influence on the prevalence of microfilaraemia. Clinical examination of 2481 adults revealed that 2.9% had elephantiasis of the leg and that 19.9% of the adult men (10.8%-30.1% of the men investigated in each village) had hydrocele. Although the overall prevalence of microfilaraemia in the study villages had not changed much since earlier studies in the 1970s, both prevalence and intensity varied distinctly between the study villages. Such geographical variation over relatively short distances appears to be a common but seldom demonstrated feature in the epidemiology of bancroftian filariasis, and the focal nature of the geographical distribution should be carefully considered by those mapping the disease.

2002

B., PROFESTAMBALEBENSON.  2002.  Simonsen PE, Meyrowitsch DW, Jaoko WG, Malecela MN, Mukoko D, Pedersen EM, Ouma JH, Rwegoshora RT, Masese N, Magnussen P, Estambale BB, Michael E.Bancroftian filariasis infection, disease, and specific antibody response patterns in a high and a low endemi. Am J Trop Med Hyg. 2002 May;66(5):550-9.. : Taylor & Francis Abstract
Bancroftian filariasis infection, disease and specific antibody response patterns in a high and a low endemicity community in East Africa were analyzed and compared to assess the relationship between these parameters and community transmission intensity. Overall prevalences of microfilaremia and circulating filarial antigenemia were 24.9% and 52.2% in the high and 2.7% and 16.5% in the low endemicity community, respectively. A positive history of acute attacks of adenolymphangitis was given by 12.2% and 7.1% of the populations, 4.0% and 0.9% of the adult (> or = 20 years old) individuals presented with limb lymphedema, and 25.3% and 5.3% of the adult males had hydrocele, in the high and the low endemicity community, respectively. Both infection and disease appeared earlier and reached much higher levels in the high than in the low endemicity community. The observed overall and age-specific infection and disease patterns in the two communities were in agreement with the view that these are primarily shaped by transmission intensity. No statistically significant relationships between infection status of fathers and mothers and that of their children were observed in any of the communities for either microfilaremia or for circulating filarial antigenemia. The overall levels (prevalence and geometric mean intensity) of filarial-specific IgG1, IgG2, IgG4, and IgE were significantly higher in the high endemicity community than in the low endemicity dommunity. Surprisingly, the opposite pattern was found for IgG3. Community transmission intensity thus appears to be an important determinant of observed inter-community variation in infection, disease, and host response patterns in Bancroftian filariasis.
B., PROFESTAMBALEBENSON.  2002.  P. Gichangi, H. De Vyust, P. Claeys, B. Estambale, J. Bwayo, K. Rogo, M. Temmerman (2002). HIV and cervical cancer in Kenya: A 10 year retrospective study at Kenyatta National Hospital. Int. J Gynaecol Obst. 76 (1), 55-63.. Int. J Gynaecol Obst. 76 (1), 55-63.. : Taylor & Francis Abstract
As part of a larger study on the effects of permethrin-impregnated bednets on the transmission of Wuchereria bancrofti, subjects from 12 villages in the Coastal province of Kenya, south of Mombasa, were investigated. The aims were to update the epidemiological data and elucidate the spatial distribution of W. bancrofti infection. Samples of night blood from all the villagers aged i 1 year were checked for the parasite, and all the adult villagers (aged >/= 15 years) were clinically examined for elephantiasis and, if male, for hydrocele. Overall, 16.0% of the 6531 villagers checked for microfilariae (mff) were found microfilaraemic, although the prevalence of microfilaraemia in each village varied from 8.1%-27.4%. The geometric mean intensity of infection among the microfilaraemic was 322 mff/ml blood. At village level, intensity of the microfilaraemia was positively correlated with prevalence, indicating that transmission has a major influence on the prevalence of microfilaraemia. Clinical examination of 2481 adults revealed that 2.9% had elephantiasis of the leg and that 19.9% of the adult men (10.8%-30.1% of the men investigated in each village) had hydrocele. Although the overall prevalence of microfilaraemia in the study villages had not changed much since earlier studies in the 1970s, both prevalence and intensity varied distinctly between the study villages. Such geographical variation over relatively short distances appears to be a common but seldom demonstrated feature in the epidemiology of bancroftian filariasis, and the focal nature of the geographical distribution should be carefully considered by those mapping the disease.

2001

B., PROFESTAMBALEBENSON.  2001.  Estambale BBA (2001). Parasitic infestations in children. An Editorial: E. Afr. Med. J. 78. 277-278.. E. Afr. Med. J. 78. 277-278.. : Taylor & Francis Abstract
Bancroftian filariasis infection, disease and specific antibody response patterns in a high and a low endemicity community in East Africa were analyzed and compared to assess the relationship between these parameters and community transmission intensity. Overall prevalences of microfilaremia and circulating filarial antigenemia were 24.9% and 52.2% in the high and 2.7% and 16.5% in the low endemicity community, respectively. A positive history of acute attacks of adenolymphangitis was given by 12.2% and 7.1% of the populations, 4.0% and 0.9% of the adult (> or = 20 years old) individuals presented with limb lymphedema, and 25.3% and 5.3% of the adult males had hydrocele, in the high and the low endemicity community, respectively. Both infection and disease appeared earlier and reached much higher levels in the high than in the low endemicity community. The observed overall and age-specific infection and disease patterns in the two communities were in agreement with the view that these are primarily shaped by transmission intensity. No statistically significant relationships between infection status of fathers and mothers and that of their children were observed in any of the communities for either microfilaremia or for circulating filarial antigenemia. The overall levels (prevalence and geometric mean intensity) of filarial-specific IgG1, IgG2, IgG4, and IgE were significantly higher in the high endemicity community than in the low endemicity dommunity. Surprisingly, the opposite pattern was found for IgG3. Community transmission intensity thus appears to be an important determinant of observed inter-community variation in infection, disease, and host response patterns in Bancroftian filariasis.

2000

B., PROFESTAMBALEBENSON.  2000.  K. Fonck, N. Kidula, W. Jaoko, B. Estambale, P. Claeys, J. Ndinya-Achola, P. Kirui, J. Bwayo, M. Termmerman (2000). Validity of vaginal discharge algorithm among pregnant and non-pregnant women in Nairobi, Kenya. Sexually Transmitted Infections 76, 33-38.. Sexually Transmitted Infections 76, 33-38.. : Taylor & Francis Abstract
Bancroftian filariasis infection, disease and specific antibody response patterns in a high and a low endemicity community in East Africa were analyzed and compared to assess the relationship between these parameters and community transmission intensity. Overall prevalences of microfilaremia and circulating filarial antigenemia were 24.9% and 52.2% in the high and 2.7% and 16.5% in the low endemicity community, respectively. A positive history of acute attacks of adenolymphangitis was given by 12.2% and 7.1% of the populations, 4.0% and 0.9% of the adult (> or = 20 years old) individuals presented with limb lymphedema, and 25.3% and 5.3% of the adult males had hydrocele, in the high and the low endemicity community, respectively. Both infection and disease appeared earlier and reached much higher levels in the high than in the low endemicity community. The observed overall and age-specific infection and disease patterns in the two communities were in agreement with the view that these are primarily shaped by transmission intensity. No statistically significant relationships between infection status of fathers and mothers and that of their children were observed in any of the communities for either microfilaremia or for circulating filarial antigenemia. The overall levels (prevalence and geometric mean intensity) of filarial-specific IgG1, IgG2, IgG4, and IgE were significantly higher in the high endemicity community than in the low endemicity dommunity. Surprisingly, the opposite pattern was found for IgG3. Community transmission intensity thus appears to be an important determinant of observed inter-community variation in infection, disease, and host response patterns in Bancroftian filariasis.

1998

B., PROFESTAMBALEBENSON.  1998.  Mirza NB, Estambale BB, Wamola IA, Kariuki N, Onyono E, Kabiru P, Piollet M.Bacterial meningitis in children admitted in hospitals within Nairobi.East Afr Med J. 1998 Feb;75(2):73-6.. East Afr Med J. 1998 Feb;75(2):73-6.. : Taylor & Francis Abstract
Four hundred and ninety nine children (aged between one month and five years) admitted with clinical features of meningitis were recruited in cross-sectional survey of bacterial meningitis in hospitals within Nairobi. Lumbar punctures were done on all of them and the cerebrospinal fluid (CSF) analysed bacteriologically and serologically for the common causative organisms. Two hundred and fifty (50.1%) cases were diagnosed clinically as having meningitis. Of these, 132 (52.8%) had turbid CSF specimens, while 118 (47.2%) were clear. When turbid CSF specimens were cultured, 83 (62.8%) yielded three common bacterial micro-organisms namely; Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae in that order of frequency. The implications of these findings in paediatric meningitis together with the drug sensitivity patterns is presented and discussed.

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