Bio

Prof Dalton Wamalwa, MB.ChB,M.Med, MPH

Associate Professor  in the Department of Paediatrics and Child Health and a Consultant paeditrician. Prof Wamalwa has experience in conducting research studies in Maternal Newborn and Child Health as well as Paediatric HIV .

PDF Upload: 

Publications


2013

Chohan, BH, Tapia K, Merkel M, Kariuki AC, Khasimwa B, Olago A, Gichohi R, Obimbo EM, Wamalwa DC.  2013.  Pooled HIV-1 RNA Viral Load Testing for Detection of Antiretroviral Treatment Failure in Kenyan children. Abstract

Pooled viral load (VL) testing with two different testing strategies was evaluated as a potential cost-saving method to monitor antiretroviral therapy (ART) in HIV-infected children receiving ART in a resource-limited setting. METHODS:: Archived samples collected from 250 HIV-1 infected children on first-line ART at various time-points post-ART initiation were evaluated for pooled VL testing using a minipool+algorithm strategy. Additionally, samples collected in real-time from 125 children on ART were assessed for virologic failure using a minipool strategy for pooled viral load testing. Virologic failure was determined as HIV-1 RNA viral loads >1500 copies/ml. RESULTS:: Minipool+algorithm strategy for pooled VL testing of archived samples had estimated viral failure of 13.6%, with a relative efficiency (RE) of 23.6% (95% CI; 18.5, 29.4), and negative predictive value (NPV) of 88%. This testing strategy would have resulted in 24% fewer assays needed, for a cost savings of $1,180 per 100 samples. The minipool strategy for pooled viral load testing of samples obtained in real-time yielded an estimated 23.2% of samples with viral failure and a RE of 8.0 % (95% CI; 3.9, 14.2); however had a minipool+algorithm pooling strategy been used the RE would increase to 20%. CONCLUSIONS:: The minipool+algorithm strategy for pooled VL testing to detect virologic failure in HIV-1 infected children on ART was determined to be relatively efficient in detecting virologic failure, had high NPV, with substantial cost savings. Pooling strategies may be important components of cost-effect strategies to reduce rates of viral failure and resistance, thus improving clinical outcomes.

Karanja, BW, Oburra HO, Masinde P, Wamalwa D.  2013.  Risk Factors for Hearing Loss in Children following Bacterial Meningitis in a Tertiary Referral Hospital. Abstractrisk_factors_for_hearing_loss_in_children_following_bacterial.pdf

This study aimed to examine hearing function in children admitted with bacterial meningitis to determine the risk factors for sensorineural hearing loss. Setting. The study was conducted in the audiology unit and paediatric wards of Kenyatta National Hospital. Subjects and Methods. The study involved 83 children between the ages of six months and twelve years admitted with bacterial meningitis. The median age for the children examined was 14. On discharge they underwent hearing testing to evaluate for presence and degree of hearing loss. Results. Thirty six of the 83 children (44.4%) were found to have at least a unilateral mild sensorineural hearing loss during initial audiologic testing. Of the children with hearing loss, 22 (26.5%) had mild or moderate sensorineural hearing loss and 14 (16.9%) had severe or profound sensorineural hearing loss. Significant determinants identified for hearing loss included coma score below eight, seizures, cranial nerve neuropathy, positive CSF culture, and fever above 38.7 degrees Celsius. Conclusions. Sensorineural hearing loss was found to be highly prevalent in children treated for bacterial meningitis. There is need to educate healthcare providers on aggressive management of coma, fever, and seizures due to their poor prognostic value on hearing.

Langat A, Benki-Nugent S, Wamalwa D, Farquhar C, Ngugi E, Diener L, Richardson BA, GC. J-S.  2013.  Lipid Changes in Kenyan HIV-1-Infected Infants Initiating Highly Active Antiretroviral Therapy by One Year of Age.. Pediatr Infect Dis J. 2013 Feb 4. [Epub ahead of print]. Abstract

Abstract
BACKGROUND:: Early highly active antiretroviral therapy (HAART) is recommended for HIV-1 infected infants. There are limited data on lipid changes during infant HAART. METHODS:: Non-fasting total (TC), low density lipoprotein (LDL), and high density lipoprotein (HDL) cholesterol, and triglycerides (TG) were measured at 0, 6 and 12 months. Correlates of lipid levels and changes post-HAART were assessed using linear regression. RESULTS:: Among 115 infants, pre-HAART median age was 3.8 months, CD4% was 19%, and weight-for-age z-score (WAZ) was -2.42. Pre-HAART median lipid levels were: TC, 108.7 mg/dl, LDL, 42.5 mg/dl, HDL, 29.4 mg/dl and TG, 186.9 mg/dl. Few infants had abnormally high TC (6.2%) or LDL (5.6%), but many had low HDL (76.5%) or high TG (69.6%). Higher pre-HAART WAZ and HAZ were each associated with higher pre-HAART TC (P=0.04 and P=0.01) and LDL (P=0.02 and P=0.008). From 0-6 months post-HAART, TC (P<0.0001), LDL (P<0.0001), and HDL (P<0.0001) increased significantly, and 23.1% (P=0.002), 14.0% (P=0.2), 31.3% (P<0.0001), and 50.8% (P=0.2) of infants had abnormally high TC, high LDL, low HDL, and high TG, respectively. Changes in TC and HDL were each associated with higher gain in WAZ (P=0.03 and P=0.01) and HAZ (P=0.01 and P=0.007). Increased change in LDL was associated with higher gain in HAZ (P=0.03). Infants on protease inhibitor (PI)-HAART had smaller HDL increase (P=0.004). CONCLUSIONS:: Infants had substantive increases in lipids, which correlated with growth. Increases in HDL were attenuated by PI-HAART. It is important to determine clinical implications of these changes.
PMID:
23385950
[PubMed - as supplied by publisher]

2012

Diener; Slyker, J, Christine G, Dalton W, Lara C, Tapia KA, Richardson BA, Farquhar C, Overbaugh J, Elizabeth M-O, John-Stewart G.  2012.  Performance Of The Integrated Management Of Childhood Illness Algorithm For Diagnosis Of Hiv-1 Infection Among African Infants.
John-Stewart GC, Wariua G, Beima-Sofie KM, Richardson BA, Farquhar C, Maleche-Obimbo E, Mbori-Ngacha D, D. W.  2012.  Prevalence, perceptions, and correlates of pediatric HIV disclosure in an HIV treatment program in Kenya.. AIDS Care.2012 Dec 20. [Epub ahead of print]. Abstract

Abstract
Abstract Disclosure to HIV-infected children regarding their diagnosis is important as expanding numbers of HIV-infected children attain adolescence and may become sexually active. In order to define correlates of pediatric disclosure and facilitate development of models for disclosure, we conducted a cross-sectional survey of primary caregivers of HIV-1 infected children aged 6-16 years attending a pediatric HIV treatment program in Nairobi, Kenya. We conducted focus group discussions with a subset of caregivers to further refine perceptions of disclosure. Among 271 caregiver/child dyads in the cross-sectional survey, median child age was 9 years (interquartile range: 7-12 years). Although 79% of caregivers believed children should know their HIV status, the prevalence of disclosure to the child was only 19%. Disclosure had been done primarily by health workers (52%) and caregivers (33%). Caregivers reported that 5 of the 52 (10%) who knew their status were accidentally disclosed to. Caregivers of older children (13 vs. 8 years; p<0.001), who were HIV-infected and had disclosed their own HIV status to the child (36% vs. 4%; p=0.003), or who traveled frequently (29% vs. 16%, p=0.03) were more likely to have disclosed. Children who had been recently hospitalized (25% vs. 44%, p=0.03) were less likely to know their status, and caregivers with HIV were less likely to have disclosed (p=0.03). Reasons for disclosure included medication adherence, curiosity or illness while reasons for nondisclosure included age and fear of inadvertent disclosure. Our study found that disclosure rates in this Kenyan setting are lower than observed rates in the USA and Europe but consistent with rates from other resource-limited settings. Given these low rates of disclosure and the potential benefits of disclosure, strategies promoting health worker trainings and caregiver support systems for disclosure may benefit children with HIV.

2011

Ujiji, OA;, Rubenson B;, Ilako F;, Marrone G;, Wamalwa D;, Wangalwa G;, Ekström AM.  2011.  Is 'Opt-Out HIV Testing' a real option among pregnant women in rural districts in Kenya? Abstract

BACKGROUND: An 'opt-out' policy of routine HIV counseling and testing (HCT) is being implemented across sub-Saharan Africa to expand prevention of mother-to-child transmission (PMTCT). Although the underlying assumption is that pregnant women in rural Africa are able to voluntarily consent to HIV testing, little is known about the reality and whether 'opt-out' HCT leads to higher completion rates of PMTCT. Factors associated with consent to HIV testing under the 'opt-out' approach were investigated through a large cross-sectional study in Kenya. METHODS: Observations during HIV pre-test information sessions were followed by a cross-sectional survey of 900 pregnant women in three public district hospitals carrying out PMTCT in the Busia district. Women on their first antenatal care (ANC) visit during the current pregnancy were interviewed after giving blood for HIV testing but before learning their test results. Descriptive statistics and multivariate regression analysis were performed. RESULTS: Of the 900 women participating, 97% tested for HIV. Lack of testing kits was the only reason for women not being tested, i.e. nobody declined HIV testing. Despite the fact that 96% had more than four earlier pregnancies and 37% had been tested for HIV at ANC previously, only 17% of the women surveyed knew that testing was optional. Only 20% of those surveyed felt they could make an informed decision to decline HIV testing. Making an informed decision to decline HIV testing was associated with knowing that testing was optional (OR = 5.44, 95%CI 3.44-8.59), not having a stable relationship with the child's father (OR = 1.76, 95%CI 1.02-3.03), and not having discussed HIV testing with a partner before the ANC visit (OR = 2.64 95%CI 1.79-3.86). CONCLUSION: High coverage of HIV testing appears to be achieved at the cost of pregnant women not understanding that testing is optional. Good quality HIV pre-test information is central to ensure that pregnant women understand and accept the reasons for testing and will thus come back to collect their test results, an important prerequisite for completing PMTCT for those who test HIV-positive.

Mbori-Ngacha, DA, Wamalwa DC, Nderitu M, Maleche-Obimbo E, Githinji N.  2011.  Utility of total lymphocyte count as a surrogate marker for CD4 counts in HIV-1 infected children in Kenya. Abstract

In resource-limited settings, such as Kenya, access to CD4 testing is limited. Therefore, evaluation of less expensive laboratory diagnostics is urgently needed to diagnose immuno-suppression in children. Objectives: To evaluate utility of total lymphocyte count (TLC) as surrogate marker for CD4 count in HIV-infected children. Methods: This was a hospital based retrospective study conducted in three HIV clinics in Kisumu and Nairobi in Kenya. TLC, CD4 count and CD4 percent data were abstracted from hospital records of 487 antiretroviral-naïve HIVinfected children aged 1 month - 12 years. Results: TLC and CD4 count were positively correlated (r = 0.66, p < 0.001) with highest correlation seen in children with severe immuno-suppression (r = 0.72, p < 0.001) and children >59 months of age (r = 0.68, p < 0.001). Children were considered to have severe immuno-suppression if they met the following WHO set CD4 count thresholds: age below 12 months (CD4 counts < 1500 cells/mm3), age 12-35 months (CD4 count < 750 cells/mm3), age 36-59 months (CD4 count < 350 cells/mm3, and age above 59 months (CD4 count < 200 cells/ mm3). WHO recommended TLC threshold values for severe immuno-suppression of 4000, 3000, 2500 and 2000 cells/mm3 for age categories <12, 12-35, 36-59 and >59 months had low sensitivity of 25%, 23%, 33% and 62% respectively in predicting severe immuno-suppression using CD4 count as gold standard. Raising TLC thresholds to 7000, 6000, 4500 and 3000 cells/mm3 for each of the stated age categories increased sensitivity to 71%, 64%, 56% and 86%, with positive predictive values of 85%, 61%, 37%, 68% respectively but reduced specificity to 73%, 62%, 54% and 68% with negative predictive values of 54%, 65%, 71% and 87% respectively. Conclusion: TLC is positively correlated with absolute CD4 count in children but current WHO age-specific thresholds had low sensitivity to identify severely immunosuppressed Kenyan children. Sensitivity and therefore utility of TLC to identify immuno-suppressed children may be improved by raising the TLC cut off levels across the various age categories.

Chohan BH, Froggett S, Emery S WD, G J-S, Majiwa M, Ng'ayo M, J. O.  2011.  8.Evaluation of a single round polymerase chain reaction assay using dried blood spots for diagnosis of HIV-1 infection in infants in an African setting. BMC Pediatr. 2011 Feb 18;11:18. doi: 10.1186/1471-2431-11-18.. Abstract

Abstract
BACKGROUND:
The aim of this study was to develop an economical 'in-house' single round polymerase chain reaction (PCR) assay using filter paper-dried blood spots (FP-DBS) for early infant HIV-1 diagnosis and to evaluate its performance in an African setting.
METHODS:
An 'in-house' single round PCR assay that targets conserved regions in the HIV-1 polymerase (pol) gene was validated for use with FP-DBS; first we validated this assay using FP-DBS spiked with cell standards of known HIV-1 copy numbers. Next, we validated the assay by testing the archived FP-DBS (N=115) from infants of known HIV-1 infection status. Subsequently this 'in-house' HIV-1 pol PCR FP-DBS assay was then established in Nairobi, Kenya for further evaluation on freshly collected FP-DBS (N=186) from infants, and compared with findings from a reference laboratory using the Roche Amplicor® HIV-1 DNA Test, version 1.5 assay.
RESULTS:
The HIV-1 pol PCR FP-DBS assay could detect one HIV-1 proviral copy in 38.7% of tests, 2 copies in 46.9% of tests, 5 copies in 72.5% of tests and 10 copies in 98.1% of tests performed with spiked samples. Using the archived FP-DBS samples from infants of known infection status, this assay was 92.8% sensitive and 98.3% specific for HIV-1 infant diagnosis. Using 186 FP-DBS collected from infants recently defined as HIV-1 positive using the commercially available Roche Amplicor v1.5 assay, 178 FP-DBS tested positive by this 'in-house' single-round HIV-1 pol PCR FP-DBS PCR assay. Upon subsequent retesting, the 8 infant FP-DBS samples that were discordant were confirmed as HIV-1 negative by both assays using a second blood sample.
CONCLUSIONS:
HIV-1 was detected with high sensitivity and specificity using both archived and more recently collected samples. This suggests that this 'in-house' HIV-1 pol FP-DBS PCR assay can provide an alternative cost-effective, reliable and rapid method for early detection of HIV-1 infection in infants.

2010

Wamalwa, DC, Obimbo EM, Farquhar C, Richardson BA, Mbori-Ngacha DA, Inwani I, Benki-Nugent S, John-Stewart G.  2010.  Predictors of mortality in HIV-1 infected children on antiretroviral therapy in Kenya. Abstract

Among children, early mortality following highly active antiretroviral therapy (HAART) remains high. It is important to define correlates of mortality in order to improve outcome. Methods: HIV-1-infected children aged 18 months-12 years were followed up at Kenyatta National Hospital, Nairobi after initiating NNRTI-based HAART. Cofactors for mortality were determined using multivariate Cox regression models. Results: Between August 2004 and November 2008, 149 children were initiated on HAART of whom 135 were followed for a total of 238 child-years (median 21 months) after HAART initiation. Baseline median CD4% was 6.8% and median HIV-1-RNA was 5.98-log10 copies/ml. Twenty children (13.4%) died at a median of 35 days post-HAART initiation. Mortality during the entire follow-up period was 8.4 deaths per 100 child-years (46 deaths/100 child-years in first 4 months and 1.0 deaths/100 child-years after 4 months post-HAART initiation). On univariate Cox regression, baseline hemoglobin (Hb) <9 g/dl, weight-for-height z-score (WHZ) < -2, and WHO clinical stage 4 were associated with increased risk of death (Hb <9 g/dl HR 3.00 [95% C.I. 1.21-7.39], p = 0.02, WHZ < -2 HR 3.41 [95% C.I. 1.28-9.08], p = 0.01, and WHO clinical stage 4, HR 3.08 [1.17-8.12], p = 0.02). On multivariate analysis Hb < 9 g/dl remained predictive of mortality after controlling for age, baseline CD4%, WHO clinical stage and weight-for-height z-score (HR 2.95 (95% C.I. 1.04-8.35) p = 0.04). Conclusion: High early mortality was observed in this cohort of Kenyan children receiving HAART, and low baseline hemoglobin was an independent risk factor for death.

Osano, BO, Kamenwa RW, Wamalwa D, Wangombe JK.  2010.  Short term clinical outcome of children with rotavirus infection at Kenyatta National Hospital, Nairobi. Abstract

Rotavirus infection is the single most common cause of acute gastroenteritis in children under five years of age. Rotavirus gastroenteritis has a high morbidity and mortality in children in Kenya. To determine the short term clinical outcome for children admitted to Kenyatta National Hospital with rotavirus gastroenteritis and the correlates of poor outcome. Short longitudinal survey. Kenyatta National Hospital from February to May 2008. Five hundred children were screened using a rapid antigen detection kit and ELISA. Of the 191 children who tested positive for rotavirus in stool; 172 children were recruited into the study. Eighty eight per cent of the patients were discharged within one week, 8.1% stayed for more than seven days while 4.1% died. Children who had co-morbidities such as malnutrition, rickets and pneumonia had worse outcomes. Rotavirus gastroenteritis has a long hospital stay and a high mortality. Children in shock on admission and those with co-morbid conditions should get priority for they have a poor outcome

Farquhar C, Overbaugh J, Wamalwa D, Farquhar C, Harris J, Bosire R, G. J-S.  2010.  Illness during pregnancy and bacterial vaginosis are associated with in-utero HIV-1 transmission.. AIDS. 2010 Jan 2;24(1):153-5. doi: 10.1097/QAD.0b013e32832326d8.. Abstract

Abstract
HIV-1 transmission in utero accounts for 20-30% of vertical transmission events in breast-feeding populations. In a prospective study of 463 HIV-1-infected mothers and infants, illness during pregnancy was associated with 2.6-fold increased risk of in-utero HIV-1 transmission [95% confidence interval (CI) 1.2-5.8] and bacterial vaginosis with a three-fold increase (95% CI 1.0-7.0) after adjusting for maternal HIV-1 viral load. Interventions targeting these novel risk factors could lead to more effective prevention of transmission during pregnancy.

Mackelprang RD, Carrington M, G J-S, Lohman-Payne B, Richardson BA, Wamalwa D, Farquhar C, Gao X, Majiwa M, Mbori-Ngacha D, C. F.  2010.  Maternal human leukocyte antigen A*2301 is associated with increased mother-to-child HIV-1 transmission. . J Infect Dis. 2010 Oct 15;202(8):1273-7. doi: 10.1086/656318. 10. . Abstract

Abstract
We examined associations between maternal human leukocyte antigen (HLA) and vertical human immunodeficiency virus type 1 (HIV-1) transmission in a perinatal cohort of 277 HIV-infected women in Nairobi. HLA class I genes were amplified by using sequence-specific oligonucleotide probes, and analyses were performed using logistic regression. Maternal HLA-A*2301 was associated with increased transmission risk before and after adjusting for maternal viral load (unadjusted: odds ratio [OR], 3.21; 95% confidence interval [CI], 1.42-7.27; P = .005; Pcorr = 0.04; adjusted: OR, 3.07; 95% CI, 1.26-7.51; P =.01; Pcorr is not significant). That maternal HLA-A*2301 was associated with transmission independent of plasma HIV-1 RNA levels suggests that HLA may alter infectivity through mechanisms other than influencing HIV-1 load.

Jonnalagadda S, Lohman Payne B, Brown E, Wamalwa D, Farquhar C, Maleche Obimbo E, Majiwa M, Ng'ayo M, Otieno P, Mbori-Ngacha D, John-Stewart.  2010.  Latent tuberculosis detection by interferon γ release assay during pregnancy predicts active tuberculosis and mortality in human immunodeficiency virus type 1-infected women and their children.. J Infect Dis. 2010 Dec 15;202(12):1826-35. doi: 10.1086/657411. Epub 2010 Nov 10.. Abstract

Abstract
BACKGROUND:
We evaluated the prognostic usefulness of interferon γ release assays (IGRAs) for active tuberculosis and mortality in Kenyan human immunodeficiency virus type 1 (HIV-1)-infected women and their infants.
METHODS:
Prevalence and correlates of Mycobacterium tuberculosis-specific T-SPOT.TB IGRA positivity were determined during pregnancy in a historical cohort of HIV-1-infected women. Hazard ratios, adjusted for baseline maternal CD4 cell count (aHR(CD4)), were calculated for associations between IGRA positivity and risk of active tuberculosis and mortality over 2-year postpartum follow-up among women and their infants.
RESULTS:
Of 333 women tested, 52 (15.6%) had indeterminate IGRA results. Of the remaining 281 women, 120 (42.7%) had positive IGRA results, which were associated with a 4.5-fold increased risk of active tuberculosis (aHR(CD4), 4.5; 95% confidence interval [CI], 1.1-18.0; P = .030). For immunosuppressed women (CD4 cell count, <250 cells/μL), positive IGRA results were associated with increased risk of maternal mortality (aHR(CD4), 3.5; 95% CI, 1.02-12.1;), maternal active tuberculosis or mortality (aHR(CD4), 5.2; 95% CI, 1.7-15.6; P = .004), and infant active tuberculosis or mortality overall (aHR(CD4), 3.0; 95% CI, 1.0-8.9; P = .05) and among HIV-1-exposed uninfected infants (aHR(CD4), 7.3; 95% CI, 1.6-33.5; P = .01).
CONCLUSIONS:
Positive IGRA results for HIV-1-infected pregnant women were associated with postpartum active tuberculosis and mortality among mothers and their infants.

2009

Shiroya-Wandabwa, M, Yuko-Jowi C, R W Nduati, Githanga J, Wamalwa D.  2009.  Risk factors for cardiac dysfunction in children on treatment for cancer at Kenyatta National Hospital, Nairobi. Abstract

To determine the point prevalence of abnormal cardiac function and to assess the risk factors for cardiac dysfunction in paediatric oncology patients on treatment at Kenyatta National Hospital. DESIGN: Descriptive cross-sectional study with a nested case control. SETTING: Kenyatta National Hospital between February and April 2006. MAIN OUTCOME MEASURES: Left ventricular dysfunction if ejection fraction (EF) <55% or fractional shortening (FS) <29% defined cases. Controls had EF >55% or FS >29%. RESULTS: One hundred and eleven patients were enrolled of whom 32 had abnormal cardiac function and were classified as cases while 79 had normal cardiac function. About a third, point prevalence 29% (95% CI 21.2-37.9), had cardiac dysfunction. Cumulative anthracycline dose was a risk factor for cardiac dysfunction in this population. Above 200 mg/m2 the attributable risk percentage of cardiac dysfunction was 77%. CONCLUSIONS: Serial echocardiography should be performed to identify patients at risk. Alternative treatment protocols should be used when the cumulative anthracycline dose exceeds 200 mg/m2 due to the high attributable risk. Studies to further assess the other associated risk factors and long term effects of anthracycline are recommended.

Inwani I, Nduati R, Obimbo E, Wamalwa D, Farquhar C, G J-S, C. F.  2009.  Performance of clinical algorithms for HIV-1 diagnosis and antiretroviral initiation among HIV-1-exposed children aged less than 18 months in Kenya. . J Acquir Immune DeficSyndr. 2009 Apr 15;50(5):492-8. doi: 10.1097/QAI.0b013e318198a8a4.. Abstract

Abstract
BACKGROUND:
Ninety percent of HIV-1-infected children live in sub-Saharan Africa. In the absence of diagnosis and antiretroviral therapy, approximately 50% die before 2 years.
METHODS:
We evaluated sensitivity and specificity of clinical algorithms for diagnosis of HIV-1 infection and antiretroviral therapy initiation among HIV-1-exposed children aged less than 18 months. Children were identified with routine HIV-1 testing and assessed using 3 sets of criteria: (1) Integrated Management of Childhood Illnesses (IMCI), (2) World Health Organization Presumptive Diagnosis (WHO-PD) for HIV-1 infection, and (3) CD4 T-lymphocyte cell subsets. HIV-1 infection status was determined using DNA polymerase chain reaction testing.
FINDINGS:
A total of 1418 children (median age 5.4 months) were screened for HIV-1 antibodies, of whom 144 (10.2%) were seropositive. Of these, 134 (93%) underwent HIV-1 DNA testing and 80 (60%) were found to be HIV-1 infected. Compared with HIV-1 DNA testing, sensitivity and specificity of the IMCI criteria were 19% and 96% and for WHO-PD criteria 43% and 88%, respectively. Inclusion of severe immune deficiency determined by CD4% improved sensitivity of IMCI and WHO-PD criteria to 74% and 84%, respectively; however, specificity declined to 43% and 41%, respectively.
INTERPRETATION:
Diagnosis of HIV-1 infection among exposed children less than 18 months in a high-prevalence resource-limited setting remains a challenge, and current recommended algorithms have low sensitivity. This underscores the need for rapid scale-up of viral assays for early infant diagnosis.

Farquhar C, Selig S, John-Stewart G, Mabuka J, Majiwa M, Sutton W, Haigwood N, Wariua G L-PB.  2009.  Immune responses to measles and tetanus vaccines among Kenyan human immunodeficiency virus type 1 (HIV-1)-infected children pre- and post-highly active antiretroviral therapy and revaccination.. Pediatr Infect Dis J. 2009 Apr;28(4):295-9. doi: 10.1097/INF.0b013e3181903ed3. 14. Abstract

Abstract
BACKGROUND:
: HIV-1-infected children have lower response rates after measles and tetanus immunization than uninfected children. We determined the extent to which highly active antiretroviral therapy (HAART) augments vaccine immunity and promotes responses to revaccination.
METHODS:
: Previously immunized, antiretroviral-naive HIV-1-infected children were evaluated for immunity against measles and tetanus. After 6 months on HAART, children meeting CD4% criteria (>15%) who were persistently antibody negative were revaccinated and immunity was reassessed.
RESULTS:
: At enrollment, among 90 children with mean age of 4.9 years, 67% had negative measles IgG and 22% negative tetanus IgG. Among 62 children completing 6 months on HAART, 17 (40%) of 43 without protective measles IgG converted and 10 (53%) of 19 positive children lost measles responses (P = 0.3). Children who lost responses had significantly lower measles antibody concentrations than those who remained measles IgG positive during follow-up (7.1 vs. 20.3 mg/mL; P = 0.003). Three (23%) of 13 children negative for tetanus IgG spontaneously seroconverted on HAART, while 15 (31%) of 49 children lost tetanus antibody (P = 0.008). There was a nonsignificant trend for an association between spontaneous measles seroconversion and lower baseline HIV-1 viral load (P = 0.06). Tetanus seroconversion was associated with older age (P = 0.03). After revaccination, positive responses were observed in 78% and 75% of children reimmunized against measles and tetanus, respectively.
CONCLUSIONS:
: After 6 months of HAART, more than half of previously immunized children still lacked positive measles antibody. With increased use of HAART in pediatric populations, revaccination against measles and tetanus should be considered to boost response rates and immunization coverage.

Obimbo EM, Wamalwa D, Richardson B, Mbori-Ngacha D, Overbaugh J, Otieno P, Bosire R, Payne BL, John-Stewart.  2009.  Pediatric HIV-1 in Kenya: pattern and correlates of viral load and association with mortality.. J Acquir Immune DeficSyndr. 2009 Jun 1;51(2):209-15.. Abstract

Abstract
BACKGROUND:
There is limited information regarding the pattern and correlates of viral replication in vertically HIV-1-infected children and its role on their outcomes in resource-limited settings.
METHODS:
HIV-1-infected infants were followed from birth to 24 months. Serial HIV-1 RNA levels were compared in infants infected in utero (<48 hours), peripartum (48 hours-1 month), and late postnatal (after 1 month). Cofactors for viral peak [highest viral load (VL) within 6 months of infection] and set point and mortality were determined.
RESULTS:
Among 85 HIV-1-infected infants, 24 were infected in utero, 41 peripartum, 13 late postnatal; 7 had no 48-hour assay. HIV-1 VL set point was significantly lower in infants infected >1 month vs. < or = 1 month (5.59 vs. 6.24 log10 copies per milliliter, P = 0.01). Maternal VL correlated with peak infant VL (P < 0.001). Univariately, infant peak and set point VL and 6-month CD4% <15% predicted mortality; and 6-month CD4% <15% remained independently predictive in multivariate analyses (hazard ratio = 4.85, 95% confidence interval: 1.90 to 12.36).
CONCLUSIONS:
Infants infected after the age of 1 month contained virus better than infants infected before 1 month of age. Maternal VL predicted infant VL, which, in turn was associated with early mortality.

Gichuhi S, Wamalwa D, Farquhar C, Maleche-Obimbo E, Farquhar C, Otieno P J-SGC.  2009.  Risk factors for neonatal conjunctivitis in babies of HIV-1 infected mothers.. Ophthalmic Epidemiol. 2009 Nov-Dec;16(6):337-45. doi: 10.3109/09286580903144746.. Abstract

Abstract
PURPOSE:
To determine the prevalence and correlates of neonatal conjunctivitis in infants born to human immunodeficiency virus type 1 (HIV-1) infected mothers.
METHODS:
This was a nested case-control study within a perinatal HIV-1 cohort. HIV-1 seropositive mothers were enrolled during pregnancy and mother-infant pairs followed after delivery with assessment for neonatal conjunctivitis at 48 hours and up to 4 weeks after birth. Genital infections (chlamydia, gonorrhea, syphilis, trichomonas, bacterial vaginosis, and candida) were screened for at 32 weeks gestation. Mothers received treatment for genital infections diagnosed during pregnancy and short-course zidovudine. Newborns did not receive ocular prophylaxis at hospital deliveries. Multivariate logistic regression models were used to determine cofactors for neonatal conjunctivitis overall and stratified for infant HIV-1 status.
RESULTS:
Four hundred and fifty-two infants were assessed and 101 (22.3%) had neonatal conjunctivitis during the first month postpartum. In multivariate analyses using odds ratios (OR) and confidence intervals (CI), neonatal conjunctivitis was associated with neonatal sepsis (adjusted OR 21.95, 95% CI 1.76, 274.61), birth before arrival to hospital (adjusted OR 13.91, 95% CI 1.39, 138.78) and birth weight (median 3.4 versus 3.3 kilograms, p=0.016, OR 1.79, 95% CI 1.01, 3.15). Infant HIV-1 infection was not associated with conjunctivitis.
CONCLUSIONS:
Despite detection and treatment of genital infections during pregnancy, neonatal conjunctivitis was frequently diagnosed in infants born to HIV-1 infected mothers suggesting a need for increased vigilance and prophylaxis for conjunctivitis in these infants. Neonatal sepsis, birth before arrival to hospital, and higher birthweight are factors that may predict higher risk of neonatal conjunctivitis in this population.

2008

Awiti, UO, Ekström AM, Ilako F.  2008.  Reasoning and deciding PMTCT-adherence during pregnancy among women living with HIV in Kenya. Abstract

This study explores type identities among rural and urban slum women on antiretroviral therapies who become pregnant. Narrative structuring was chosen to develop type narratives that illustrate how rural and urban women handle their HIV-infection and how they reason and decide about PMTCT-adherence during pregnancy and childbirth. Women in rural areas described their lives as 'secure and family controlled'. This gave the women security and predictability in life, but also meant that it was difficult to keep secrets about HIV infection. For women in the urban slum area the narratives were a tale of the uncertain and hard to predict reality in the slum, but also about self-reliance and decisiveness. They portrayed themselves as 'vulnerable and striving to survive' thus managing a tough situation without long-term solutions. We conclude that pregnancy poses different social challenges in rural and urban areas affecting how women choose to manage their adherence to PMTCT, which is also affected by HIV stigma and lack of disclosure

sponsored by UNICEF,(DHE).  2008.  Essential drugs and rational use of antibiotics AND Childhood Asthma : Primary health Care manual . Essential drugs and rational use of antibiotics AND Childhood Asthma . : unicef

2007

Wamalwa, D, Benki-Nugent S, Langat A, Tapia K, Ngugi E, Slyker JA, Richardson BA, John-Stewart GC.  2007.  Survival benefit of early infant antiretroviral therapy is compromised when diagnosis is delayed. Abstract

Late presentation is common among African HIV-1-infected infants. Incidence and correlates of mortality were examined in 99 infants with HIV-1 diagnosis by 5 months of age. Twelve-month survival was 66.8% (95% confidence interval: 55.9-75.6%). World Health Organization stage 3 or 4, underweight, wasting, microcephaly, low hemoglobin, pneumonia and gastroenteritis predicted mortality. Early HIV-1 diagnosis with antiretroviral therapy before symptomatic disease is critical for infant survival.

C., DRWAMALWADALTON, MBORI- PROFNGACHADOROTHYA, ELIZABETH DROBIMBO.  2007.  High uptake of postpartum hormonal contraception among HIV-1-seropositive women in Kenya. Sex Transm Dis . 2007 Jan; 34 ( 1 ): 25-9 . PMID: 16691159 [PubMed - indexed for MEDLINE] Balkus J, Bosire R, John-Stewart G, Mbori-Ngacha D, Schiff MA, Wamalwa D, G. Sex Transm Dis . 2007 Jan; 34 ( 1 ): 25-9 .. : Wasonga, C, Sheila O. Okoth, Joseph C. Mukuria and Charles C.O.A. Abstract
Department of Epidemiology, University of Washington, Seattle, Washington 98104, USA. jbalkus@u.washington.edu OBJECTIVES: The objectives of this study were to determine patterns of contraceptive utilization among sexually active HIV-1-seropositive women postpartum and to identify correlates of hormonal contraception uptake. GOAL: The goal of this study was to improve delivery of family planning services to HIV-1-infected women in resource-limited settings. STUDY DESIGN: HIV-1-infected pregnant women were followed prospectively in a perinatal HIV-1 transmission study. Participants were referred to local clinics for contraceptive counseling and management. RESULTS: Among 319 HIV-1-infected women, median time to sexual activity postpartum was 2 months and 231 (72%) women used hormonal contraception for at least 2 months during follow-up, initiating use at approximately 3 months postpartum (range, 1-11 months). Overall, 101 (44%) used DMPA, 71 (31%) oral contraception, and 59 (25%) switched methods during follow-up. Partner notification, infant mortality, and condom use were similar between those using and not using contraception. CONCLUSIONS: Using existing the healthcare infrastructure, it is possible to achieve high levels of postpartum hormonal contraceptive utilization among HIV-1-seropositive women. PMID: 16691159 [PubMed - indexed for MEDLINE]
C., DRWAMALWADALTON, MBORI- PROFNGACHADOROTHYA, ELIZABETH DROBIMBO.  2007.  Early response to highly active antiretroviral therapy in HIV-1-infected Kenyan children. J Acquir Immune Defic Syndr . 2007 Jul 1; 45 ( 3 ): 311-7 . PMID: 17356470 [PubMed - indexed for MEDLINE] Wamalwa DC, Farquhar C, Obimbo EM, Selig S, Mbori-Ngacha DA. J Acquir Immune Defic Syndr . 2007 Jul 1; 45 ( 3 ): 311-7 .. : Wasonga, C, Sheila O. Okoth, Joseph C. Mukuria and Charles C.O.A. Abstract
OBJECTIVES: To describe the early response to World Health Organization (WHO)-recommended nonnucleoside reverse transcriptase inhibitor (NNRTI)-based first-line highly active antiretroviral therapy (HAART) in HIV-1-infected Kenyan children unexposed to nevirapine. DESIGN: Observational prospective cohort. METHODS: HIV-1 RNA level, CD4 lymphocyte count, weight for age z score, and height for age z score were measured before the initiation of HAART and every 3 to 6 months thereafter. Children received no nutritional supplements. RESULTS: Sixty-seven HIV-1-infected children were followed for a median of 9 months between August 2004 and November 2005. Forty-seven (70%) used zidovudine, lamivudine (3TC), and an NNRTI (nevirapine or efavirenz), whereas 25% used stavudine (d4T), 3TC, and an NNRTI. Nevirapine was used as the NNRTI by 46 (69%) children, and individual antiretroviral drug formulations were used by 63 (94%), with only 4 (6%) using a fixed-dose combination of d4T, 3TC, and nevirapine (Triomune; Cipla, Mumbai, India). In 52 children, the median height for age z score and weight for age z score rose from -2.54 to -2.17 (P<0.001) and from -2.30 to -1.67 (P=0.001), respectively, after 6 months of HAART. Hospitalization rates were significantly reduced after 6 months of HAART (17% vs. 58%; P<0.001). The median absolute CD4 count increased from 326 to 536 cells/microL (P<0.001), the median CD4 lymphocyte percentage rose from 5.8% before treatment to 15.4% (P<0.001), and the median viral load fell from 5.9 to 2.2 log10 copies/mL after 6 months of HAART (P<0.001). Among 43 infants, 47% and 67% achieved viral suppression to less than 100 copies/mL and 400 copies/mL, respectively, after 6 months of HAART. CONCLUSION: Good early clinical and virologic response to NNRTI-based HAART was observed in HIV-1-infected Kenyan children with advanced HIV-1 disease. PMID: 17356470 [PubMed - indexed for MEDLINE]
C., DRWAMALWADALTON, MBORI- PROFNGACHADOROTHYA.  2007.  Breast milk alpha-defensins are associated with HIV type 1 RNA and CC chemokines in breast milk but not vertical HIV type 1 transmission. AIDS Res Hum Retroviruses . 2007 Feb; 23 ( 2 ): 198-203 . PMID: 17331027 [PubMed - indexed for MEDLINE] Bosire R, Joh. AIDS Res Hum Retroviruses . 2007 Feb; 23 ( 2 ): 198-203 .. : Wasonga, C, Sheila O. Okoth, Joseph C. Mukuria and Charles C.O.A. Abstract
{ Department of Pediatrics, University of Nairobi, Nairobi, Kenya. Alpha-defensins are proteins exhibiting in vitro anti-HIV-1 activity that may protect against mother-to-child transmission of HIV-1 via breast milk. Correlates of alpha-defensins in breast milk and transmission risk were determined in a cohort of HIV-1-infected pregnant women in Nairobi followed for 12 months postpartum with their infants. Maternal blood was collected antenatally and at delivery for HIV-1 viral load and infant HIV-1 infection status was determined < 48 h after birth and at months 1, 3, 6, 9, and 12. Breast milk specimens collected at month 1 were assayed for alpha-defensins, HIV-1 RNA, subclinical mastitis, and CC and CXC chemokines. We detected alpha-defensins in breast milk specimens from 108 (42%) of 260 HIV-1-infected women. Women with detectable alpha-defensins (> or =50 pg/ml) had a median concentration of 320 pg/ml and significantly higher mean breast milk HIV-1 RNA levels than women with undetectable alpha-defensins (2.9 log(10) copies/ml versus 2.5 log(10) copies/ml
C., DRWAMALWADALTON, MBORI- PROFNGACHADOROTHYA.  2007.  Herpes simplex virus type 2 and risk of intrapartum human immunodeficiency virus transmission. Obstet Gynecol . 2007 Feb; 109 ( 2 Pt 1 ): 403-9 . Erratum in: Obstet Gynecol. 2007 Apr;109(4):1002-3. PMID: 17267842 [PubMed - indexed for MEDLINE] Drake AL, J. Obstet Gynecol . 2007 Feb; 109 ( 2 Pt 1 ): 403-9 . Erratum in: Obstet Gynecol. 2007 Apr;109(4):1002-3.. : Wasonga, C, Sheila O. Okoth, Joseph C. Mukuria and Charles C.O.A. Abstract

OBJECTIVE: To determine whether herpes simplex virus type 2 (HSV-2) infection was associated with risk of intrapartum human immunodeficiency virus type 1 (HIV-1) transmission and to define correlates of HSV-2 infection among HIV-1-seropositive pregnant women. METHODS: We performed a nested case control study within a perinatal cohort in Nairobi, Kenya. Herpes simplex virus type 2 serostatus and the presence of genital ulcers were ascertained at 32 weeks of gestation. Maternal cervical and plasma HIV-1 RNA and cervical HSV DNA were measured at delivery. RESULTS: One hundred fifty-two (87%) of 175 HIV-1-infected mothers were HSV-2-seropositive. Among the 152 HSV-2-seropositive women, nine (6%) had genital ulcers at 32 weeks of gestation, and 13 (9%) were shedding HSV in cervical secretions. Genital ulcers were associated with increased plasma HIV-1 RNA levels (P=.02) and an increased risk of intrapartum HIV-1 transmission (16% of transmitters versus 3% of nontransmitters had ulcers; P = .003), an association which was maintained in multivariable analysis adjusting for plasma HIV-1 RNA levels (P=.04). We found a borderline association for higher plasma HIV-1 RNA among women shedding HSV (P=.07) and no association between cervical HSV shedding and either cervical HIV-1 RNA levels or intrapartum HIV-1 transmission (P=.4 and P=.5, [corrected] respectively). CONCLUSION: Herpes simplex virus type 2 is the leading cause of genital ulcers among women in sub-Saharan Africa and was highly prevalent in this cohort of pregnant women receiving prophylactic zidovudine. After adjusting for plasma HIV-1 RNA levels, genital ulcers were associated with increased risk of intrapartum HIV-1 transmission. These data suggest that management of HSV-2 during pregnancy may enhance mother-to-child HIV-1 prevention efforts. LEVEL OF EVIDENCE: II

C., DRWAMALWADALTON, MBORI- PROFNGACHADOROTHYA, ELIZABETH DROBIMBO.  2007.  Morbidity among HIV-1-infected mothers in Kenya: prevalence and correlates of illness during 2-year postpartum follow-up. J Acquir Immune Defic Syndr . 2007 Oct 1; 46 ( 2 ): 208-15 . PMID: 17667334 [PubMed - indexed for MEDLINE] Walson JL, Brown ER, Otien. J Acquir Immune Defic Syndr . 2007 Oct 1; 46 ( 2 ): 208-15 .. : Wasonga, C, Sheila O. Okoth, Joseph C. Mukuria and Charles C.O.A. Abstract
Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya. walson@u.washington.edu BACKGROUND: Much of the burden of morbidity affecting women of childbearing age in sub-Saharan Africa occurs in the context of HIV-1 infection. Understanding patterns of illness and determinants of disease in HIV-1-infected mothers may guide effective interventions to improve maternal health in this setting. METHODS: We describe the incidence and cofactors of comorbidities affecting peripartum and postpartum HIV-1-infected women in Kenya. Women were evaluated by clinical examination and standardized questionnaires during pregnancy and for up to 2 years after delivery. RESULTS: Five hundred thirty-five women were enrolled in the cohort (median CD4 count of 433 cells/mm) and accrued 7736 person-months of follow-up. During 1-year follow-up, the incidence of upper respiratory tract infections was 161 per 100 person-years, incidence of pneumonia was 33 per 100 person-years, incidence of tuberculosis (TB) was 11 per 100 person-years, and incidence of diarrhea was 63 per 100 person-years. Immunosuppression and HIV-1 RNA levels were predictive for pneumonia, oral thrush, and TB but not for diarrhea; CD4 counts <200 cells/mm(3) were associated with pneumonia (relative risk [RR] = 2.87, 95% confidence interval [CI]: 1.71 to 4.83), TB (RR = 7.14, 95% CI: 2.93 to 17.40) and thrush. The risk of diarrhea was significantly associated with crowding (RR = 1.86, 95% CI: 1.19 to 2.92) and breast-feeding (RR = 1.71, 95% CI: 1.19 to 2.44). Less than 10% of women reported hospitalization during 2-year follow-up; mortality risk in the cohort was 1.9% and 4.8% for 1 and 2 years, respectively. CONCLUSIONS: Mothers with HIV-1, although generally healthy, have substantial morbidity as a result of common infections, some of which are predicted by immune status or by socioeconomic factors. Enhanced attention to maternal health is increasingly important as HIV-1-infected mothers transition from programs targeting the prevention of mother-to-child transmission to HIV care clinics. PMID: 17667334 [PubMed - indexed for MEDLINE]

2005

C., DRWAMALWADALTON, MBORI- PROFNGACHADOROTHYA, ELIZABETH DROBIMBO.  2005.  Predictors of mortality in HIV-1 exposed uninfected post-neonatal infants at the Kenyatta National Hospital, Nairobi. East Afr Med J . 2005 Sep; 82 ( 9 ): 447-51 . PMID: 16619717 [PubMed - indexed for MEDLINE] Gichuhi C, Obimbo E, Mbori-Ngacha D, Mwatha A. East Afr Med J . 2005 Sep; 82 ( 9 ): 447-51 .. : Wasonga, C, Sheila O. Okoth, Joseph C. Mukuria and Charles C.O.A. Abstract
{ Department of Clinical Pharmacology and Therapeutics, College of Health Sciences, University of Nairobi, P.O. Box 19676, Nairobi, Kenya. OBJECTIVES: To identify potential predictors of mortality, to determine mortality rate and to identify prevalent causes of death in a cohort of HIV-1 exposed uninfected infants. DESIGN: Prospective cohort study. SETTING: Kenyatta National Hospital, Nairobi, Kenya. SUBJECTS: Three hundred and fifty one HIV-1 exposed uninfected post-neonatal infants who survived to one year of age. RESULTS: Sixteen infants died (post-neonatal mortality rate of 47/1000 live births), 14 (88%) before six months of age. The most frequently identified medical conditions at death included bronchopneumonia, diarrhoea and failure to thrive. In multivariate analysis, prematurity (RR=10.5, 95%CI 3.8-29.1, p<0.001), teenage motherhood (RR=3.6, Cl 1.0-13.2

2002

C., DRWAMALWADALTON, FLORENCE DRMURILA, C. DRWAMALWADALTON, MASIBO PROFWAFULAEZEKIEL.  2002.  Pattern of use of skin care products in children with and without eczematous skin lesions. East Afr Med J. 2002 Dec;79(12):645-50. Wamalwa DC, Wafula EM, Munyao TM, Murila FV.. East Afr Med J. 2002 Dec;79(12):645-50.. : Wasonga, C, Sheila O. Okoth, Joseph C. Mukuria and Charles C.O.A. Abstract
OBJECTIVE: To compare the pattern of use of skin care products between children with eczematous skin lesions and those without. DESIGN: Case control study. SETTING: Two well baby clinics at the Kenyatta National Hospital and the Mbagathi District Hospital in Nairobi. SUBJECTS: Eighty nine infants with eczematous skin lesions and 89 age and sex matched controls without skin lesions. MAIN OUTCOME MEASURES: Presence and severity of skin lesions related to the type of skin care products used by the child. RESULTS: Exposure to various products was not significantly different between infants with skin lesions and those without. However, more mothers whose children had a skin rash had made a change in the type of soap and or skin cream used for their child (p<0.0001). The principal reason for changing products was skin rash in the baby and most mothers made changes away from scented baby soap products. CONCLUSION: The study found no significant difference between the cases and controls regarding the type of skin care products used.

UoN Websites Search