Bio

PROF. IRUNGU, LUCY W.

Personal Information

Biography

Publications


Submitted

JP, E, S E, J K, LW I.  Submitted.  Biology of the coconut bug Pseudotheraptus wayi on French Beans. . Journal of Insect Science .

In Press

JP, E, J K, LW I, F H.  In Press.  Description of pre-adult stages of the coconut bug, Pseudotherapthus wayi .. Journal of Insect Science .

2012

PM, N, L. RL, LW. I, C. KJ, O. AC.  2012.  Nocturnal activities of phlebotomine sand flies (Diptera: Psychodidae) in Baringo County, Kenya.. African Journal of Health Sciences . 23:298-305.
CO, A, PM N, LW. I.  2012.  Natural and experimental studies on domestic animal infections with visceral and cutaneous Leishmaniasis in Kenya. African Journal of Health Sciences . 23:292-297.
TF, A, F. H, PN N, LW I.  2012.  Life history of Oplostomus haroldi (Coleoptera: Scarabaeidae) unde laboratory conditions and a description of its third instar larva.. International Journal of Tropical Insect Science. AbstractInternational Journal of Tropical Insect Science

The life history of Oplostomus haroldi (Witte), a recently reported pest of honeybee colonies in East Africa, was studied for the first time under laboratory conditions. Adult O. haroldi collected from beehives in the coastal part of Kenya were reared on a mixture of moist sterilized soil and cow dung. At 25 ± 2 °C, 50 ± 5% relative humidity and a 10 h light-14 h dark photoperiod, the laid eggs took 11.9 ± 1.3 days to hatch into a curved pear-shaped scarabaeiform larva with a well-developed head and thoracic legs. The first, second and third larval instars lasted 14.6 ± 2.6, 17.5 ± 2.4 and 34.6 ± 2.4 days, respectively. The pupal stage, which was marked by formation of a mud cocoon, lasted 31.1 ± 6.7 days with the adults surviving for 2–6 months under laboratory conditions, suggesting that the beetle is multivoltine. A detailed taxonomic description of the external morphology of the third instar larva is provided

M, MH, LW I, PN N.  2012.  The diseases of coffee under the changing climate: the established situation in Kenya. . Journal of Agricultural Science and Technolog. 2(2):265-267.
M, MH, LW I, PN N.  2012.  Population dynamics of predacious phytoseiid mites, Euseius kenyae and coffee thrips, Diarthrothrips coffeae and their Interactions in coffee agro ecosystems in Kenya.. International journal of Science and nature.. 3(2):316-323. AbstractInternational Journal of Science and Nature

Several strategies are employed in management of insect pests. Among these, chemical control is a priority to most farming communities where pest incidences occur while other existing options such as biological control are rarely considered. In coffee farming agro ecosystems, there are indigenous biological control agents such as the predacious phytoseiid mites, Euseius kenyae (Swirski and Ragusa) that have the potential to manage secondary pests like coffee thrips, Diarthrothrips coffeae Williams. This study was conducted to assess the population dynamics of E. kenyae and D. coffeae as well as their interactions under coffee agro ecosystems where various soil fertilizer sources and selective insecticides were applied as treatments. The populations of both E. kenyae and D. coffeae fluctuated during the three years study period. The E . kenyae suppressed the population of D. coffeae under various treated coffee blocks. There was negative correlation between E. kenyae and D. coffeae in year 2006 and 2008 where the increasing population of E. kenyae decreased that of D. coffeae. In year 2007, positive correlation between E
. kenyae and D. coffeae was observed in some of the treatments where increased population of D. coffeae
caused an increased population of E . kenyae. Euseius kenyae managed to contain the D. coffeae population to below economical injury levels (1- 2 thrips per leaf) during the three years under the various coffee agro ecosystems. The use of chlorpyrifos never affected E. kenyae. Their survival and increased in number under chlorpyrifos treated coffee blocks indicated the development of resistance by the population of
E. kenyae , hence the possibility of using them as a component in an Integrated Pest Management strategy in coffee.

Fombong, AT, Teal TE, Arbogast RT, Ndegwa PN, Irungu LW, Torto B.  2012.  Chemical communication in the honey bee scarab pest Oplostomus haroldi: role of (Z)-9-pentacosene.. Journal of Chemical Ecology. 38(12):1463-1473. AbstractPubMed link

Oplostomus haroldi Witte belongs to a unique genus of afro-tropical scarabs that have associations with honey bee colonies, from which they derive vital nutrients. Although the attributes of the honey bee nest impose barriers to communication among nest invaders, this beetle still is able to detect conspecific mates for reproduction. Here, we show, through behavioral studies, that cuticular lipids serve as mate discrimination cues in this beetle. We observed five steps during mating: arrestment, alignment, mounting, and copulation, and a post-copulatory stage, lasting ~40–70 % of the total mating duration, that suggested mate guarding. Chemical analysis identified the same nine straight-chain alkanes (C23–C31), six methyl-branched alkanes (6), and five mono-unsaturated alkenes in the cuticular lipids of both sexes. Methyl alkanes constituted the major component (46 %) of male cuticular lipids, while mono-unsaturated alkenes were most abundant (53 %) in females. (Z)-9-Pentacosene was twice as abundant in females than in males, and ~20 fold more concentrated in beetles than in worker bees. In mating assays, (Z)-9-pentacosene elicited arrestment, alignment, and mounting, but not copulation, by male beetles. These results represent the first evidence of a contact sex pheromone in a scarab beetle. Such contact pheromones may be an essential, cryptic mechanism for arthropods associated with eusocial insects.

2011

JP, E, S E, J K, LW I, B T.  2011.  Semiochemicals mediating behavioural response of the coconut bug, Pseudtheraptus wayi to conspecific volatile cues.. Book of abstracts, 19th conference of the African Association of Insect Scientists. :20-21., ICIPE, NAIROBI - KENYA: ICIPE
JP, E, S E, J K, LW I, B T.  2011.  Inter and intraspecific olfactory behaviour of the coconut bug, Pseudtheraptus wayi: do males search of the food then invite females?, 12 - 15 NOVEMBER Book of abstracts, Semio 11 workshop. , ICIPE, NAIROBI - KENYA
J.P., E, Ekesi S, Kabaru J, Irungu LW, Torto B.  2011.  Identification of sex pheromones of the coconut bug, Pseudtheraptus wayi, 16 November. icipe science day. , ICIPE, NAIROBI - KENYA
Egonyu, JP, Ekesi S, Kabaru J, Irungu LW, B. T.  2011.  Host Odour responses and experience induced learning in the coonut bug, Pseudotheraptus wayi Brown ( Heteroptera: Coriedae)., 13-18 August. Symposium on Insect-Plant Interactions. , Wageningen, The Netherlands
Anjili, CO, Ngumbi PM, Kaburi JC, Irungu LW.  2011.  The phlebotomine sandfly fauna (Diptera: Psychodidae) of Kenya. Journal of vector borne diseases. 48(4):183–189. AbstractJournal of vector borne diseases

Visceral and cutaneous leishmaniases are endemic in some parts of Kenya, where they are transmitted by phlebobotomine sandflies of genus Phlebotomus. This review is a compilation of the currently known distribution of phlebotomine sandflies in the parts of Kenya that have been studied, from the time sandflies were first reported in the country. So far 48 species of sandflies have been identified falling in the genera Phlebotomus Rondani & Berte and Sergentomyia Franca & Parrot. Genus Phlebotomus in Kenya is represented in five subgenera, namely Phlebotomus, Larroussius, Synphlebotomus, Paraphlebotomus and Anaphlebotomus. Genus Sergentomyia has the largest number of sandflies, and is represented in four subgenera, namely Sergentomyia, Sintonius, Grassomyia and Parvidens.

IRUNGU, LUCYW.  2011.  Plasmodium falciparum transmission and aridity: a Kenyan experience from the dry lands of Baringo and its implications for Anopheles arabiensis control. Malaria Journal. 2011;10(1):121. Acarologia, XLIX, 3-4 : 121-137. : Mala AO, Irungu LW, Shililu JI, Muturi EJ, Mbogo CC, Kiambo JK, Mukabana WR, Githure JI
PROF. IRUNGU, LUCYW.  2011.  Pathogenicity of Metarhizium anisopliae (Metch) Sorok and Beauveria bassiana (Bals) Vuill to adult Phlebotomus duboscqi (Neveu-Lemaire) in the laboratory. Acarologia, XLIX, 3-4 : 121-137. : Philip M. Ngumbi 1,2, Lucy W. Irungu2, Paul N. Ndegwa2 & Nguya K. Maniania3 1Kenya Medical Research
PROF. IRUNGU, LUCYW.  2011.  Factors influencing differential larval habitat productivity of Anopheles gambiae complex mosquitoes in a western Kenyan village. Acarologia, XLIX, 3-4 : 121-137. : Albert O. Mala & Lucy W. Irungu Abstract
Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Background & objectives: The study was undertaken to characterize factors influencing differential productivity of Anopheles gambiae complex mosquitoes at larval habitats in a rural village in western Kenya . Methods: Longitudinal larval sampling was done using an area sampler for 3 months. Emerged adults were identified to species level morphologically using taxonomic keys and to sub-species by polymerase chain reaction (PCR). Nutrient content was analyzed using persulphate oxidation method. Water pH was measured using an Orion pH/conductivity meter. Turbidity was measured using a Hach 2100A turbidity meter. Algal count density was estimated using a sedge-wick rafter cell.   Results: A total 3367 larvae were harvested. Out of 500 adults subjected to PCR analysis 358 (71.6%) were Anopheles gambiae s.s., 127 (25.4%) An. arabiensis while PCR amplification failed for 15 (3%) specimens.  Rainwater pools were the most productive habitat type. There was a positive association between algal density and larval density (p<0). Total nitrogen, water pH and turbidity were positively correlated with larval density (p<0.01) and pH was negatively associated with larval density.   Conclusion: Results indicate water nutrient and algal content in larval habitats of An. gambiae play crucial, dual roles in the resource ecology of these mosquitoes. Overall, the findings of this study support the notion that anti-larval source reduction measures aimed at manipulating physicochemical variables in larval habitats to eliminate larval production have a chance of succeeding in an integrated vector control program.   Key words Anopheles gambiae; larval productivity, nutrients; rainwater pools
PROF. IRUNGU, LUCYW.  2011.  Dry season ecology of Anopheles gambiae complex mosquitoes at larval habitats in two traditionally semi-arid villages in Baringo, Kenya. Acarologia, XLIX, 3-4 : 121-137. : Albert O Mala 1,2* Abstract
{ Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Background: Pre-adult stages of malaria vectors in semi-arid areas are confronted with highly variable and challenging climatic conditions. The objective of this study was to determine which larval habitat types are most productive in terms of larval densities in the dry and wet seasons within semi-arid environments, and how vector species productivity is partitioned over time.   Methods: Larval habitats were mapped and larvae sampled longitudinally using standard dipping techniques. Larvae were identified to species level morphologically using taxonomic keys and to sub-species by polymerase chain reaction (PCR) methods. Physical characteristics of larval habitats, including water depth, turbidity, and presence of floating and emergent vegetation were recorded. Water depth was measured using a metal ruler. Turbidity, pH, conductivity, dissolved oxygen, temperatures salinity and total dissolved solids (TDS) were measured in the field using the hand-held water chemistry meters.   Results: Mean larval densities were higher in the dry season than during the wet season but the differences in density were not statistically significant (F = 0.04

2010

PROF. IRUNGU, LUCYW.  2010.  Nocturnal activities of Phlebotomine sandflies (Diptera: Psydhodidae) in Baringo District, Kenya. Submitted to TAF Preventive Medicine Bulletin. Acarologia, XLIX, 3-4 : 121-137. : Ngumbi PM, Robert LL, Irungu LW, Kaburi JC, Githure JI
PROF. IRUNGU, LUCYW.  2010.  IN VITRO EFFECTS OF WARBURGIA UGANDENSIS, PSIADIA PUNCTULATA AND CHASMANTHERA DEPENDENS ON LEISHMANIA MAJOR PROMASTIGOTES. Afr. J. Trad. CAM 7 (3): 264-275. : Edward K. Githinji, Lucy W. Irungu, Willy K. Tonui, Geoffrey M. Rukunga, Charles Mutai, Charles N. M Abstract

Plant extracts from Warburgia ugandensis Sprague (Family: Canellaceae), Psiadia punctulata Vatke (Family: Compositae) and Chasmanthera dependens Hoschst (Family: Menispermaceae) were tested for activity on Leishmania major promastigotes (Strain IDU/KE/83 = NLB-144) and infected macrophages in vitro. Plants were collected from Baringo district, dried, extracted, weighed and tested for antileishmanial activity. Serial dilutions of the crude extracts were assayed for their activity against Leishmania major in cell free cultures and in infected macrophages in vitro. Inhibitory concentrations and levels of cytotoxicity were determined. Warburgia ugandensis, Psiadia punctulata and Chasmanthera dependens had an IC(50) of 1.114 mg/ml, 2.216 mg/ml and 4.648 mg/ml, respectively. The cytotoxicity of the drugs on BALB/c peritoneal macrophage cells was insignificant as compared to the highly toxic drug of choice Pentostam(®). The supernatants from control and Leishmania infected macrophages were analyzed for their nitrite contents by Griess reaction and nitrite absorbance measured at 540 nm. Warburgia ugandensis (stem bark water extract), Chasmanthera dependens (stem bark water extract) and Psiadia punctulata (stem bark methanol extract) produced 112.3%, 94% and 88.5% more nitric oxide than the untreated infected macrophages respectively. Plant crude extracts had significant (p<0.05) anti-leishmanial and immunomodulative effects but insignificant cytotoxic effects at 1mg/ml concentration. All experiments were performed in triplicate. Statistical analysis of the differences between mean values obtained from the experimental group compared to the controls was done by students't test. ANOVA was used to determine the differences between the various treatment groups. The analysis program Probit was used to determine IC(50)s.

2009

IRUNGU, LUCYW.  2009.  SURVEY OF PREDACIOUS PHYTOSEIID MITES (ACARI: PHYTOSEIIDAE) INHABITING COFFEE TREES IN KENYA WITH DESCRIPTIONS OF SOME NEW SPECIES. Acarologia, XLIX, 3-4 : 121-137. : ELSAYED EL BANHAWY,1 L. IRUNGU1 & H. MUGO2 Abstract

SUMMARY:  During a comprehensive survey of predacious mites in the different coffee zones of Kenya 33 species of phytoseiid mites were reported from 122 coffee farms: eight species of Euseius Wainstein, three Ueckermannseius Chant & McMurtry, seven Amblyseius Berlese, two Typhlodromalus Muma, nine Typhlodromus Scheuten, and four species from different genera.  The number of species and abundance of mites greatly varied among coffee agrozones: 14 species in UMI, 22 in UMII, and 21 in UMIII.  The predacious mite E. kenyae Swirski & Ragusa was the most common species in any zone.  Although Typhlodromus species showed a greater diversity, they were recorded at low abundance.  The study included the description of 6 new species: Amblyseius hamisi n. sp., Euseius majengo n. sp., Uckermannseius lugula n. sp., Transeius maragoli n. sp., Phytoseius kaimosi n. sp. And Typhlodromus ruiru n. sp.; Amblyseius italicus Chant and A. sundi (Pritchard & Baker) were reported for the first time from Kenya and descriptions are included.

2008

Muriu, SM, Muturi EJ, Shililu JI, Mbogo CM, Mwangangi JM, Jacob BG, Irungu LW, Mukabana RW, Githure JI, Novak RJ.  2008.  Host choice and multiple blood feeding behaviour of malaria vectors and other anophelines in Mwea rice scheme, Kenya. Malaria Journal . 7(43):7-43. Abstract1475-2875-7-43.pdfMalaria journal link

Abstract
Background
Studies were conducted between April 2004 and February 2006 to determine the blood-feeding pattern of Anopheles mosquitoes in Mwea Kenya.

Methods
Samples were collected indoors by pyrethrum spay catch and outdoors by Centers for Disease Control light traps and processed for blood meal analysis by an Enzyme-linked Immunosorbent Assay.

Results
A total of 3,333 blood-fed Anopheles mosquitoes representing four Anopheles species were collected and 2,796 of the samples were assayed, with Anopheles arabiensis comprising 76.2% (n = 2,542) followed in decreasing order by Anopheles coustani 8.9% (n = 297), Anopheles pharoensis 8.2% (n = 272) and Anopheles funestus 6.7% (n = 222). All mosquito species had a high preference for bovine (range 56.3–71.4%) over human (range 1.1–23.9%) or goat (0.1–2.2%) blood meals. Some individuals from all the four species were found to contain mixed blood meals. The bovine blood index (BBI) for An. arabiensis was significantly higher for populations collected indoors (71.8%), than populations collected outdoors (41.3%), but the human blood index (HBI) did not differ significantly between the two populations. In contrast, BBI for indoor collected An. funestus (51.4%) was significantly lower than for outdoor collected populations (78.0%) and the HBI was significantly higher indoors (28.7%) than outdoors (2.4%). Anthropophily of An. funestus was lowest within the rice scheme, moderate in unplanned rice agro-ecosystem, and highest within the non-irrigated agro-ecosystem. Anthropophily of An. arabiensis was significantly higher in the non-irrigated agro-ecosystem than in the other agro-ecosystems.

Conclusion
These findings suggest that rice cultivation has an effect on host choice by Anopheles mosquitoes. The study further indicate that zooprophylaxis may be a potential strategy for malaria control, but there is need to assess how domestic animals may influence arboviruses epidemiology before adapting the strategy.

2007

29. Irungu, LW.  2007.  Neglected Tropical Diseases. POST. 13(1):1-3.
Odiere, M, Bayoh MN, Gimnig J, Vulule J, Irungu LW, Walker E.  2007.  Sampling Outdoor, Resting Anopheles gambiae and Other Mosquitoes (Diptera: Culicidae) in Western Kenya with Clay Pots. Journal of medical entomology. 44(1):14-22. AbstractPubMed link

Clay pots were analyzed as devices for sampling the outdoor resting fraction of Anopheles gambiae Giles (Diptera: Culicidae) and other mosquito species in a rural, western Kenya. Clay pots (Anopheles gambiae resting pots, herein AgREPOTs), outdoor pit shelters, indoor pyrethrum spray collections (PSC), and Colombian curtain exit traps were compared in collections done biweekly for nine intervals from April to June 2005 in 20 housing compounds. Of 10,517 mosquitoes sampled, 4,668 An. gambiae s.l. were sampled in total of which 63% were An. gambiae s.s. (46% female) and 37% were An. arabiensis (66% female). The clay pots were useful and practical for sampling both sexes of An. gambiae s.l. Additionally, 617 An. funestus (58% female) and 5,232 Culex spp. (males and females together) were collected. Temporal changes in abundance of An. gambiae s.l. were similarly revealed by all four sampling methods, indicating that the clay pots could be used as devices to quantify variation in mosquito population density. Dispersion patterns of the different species and sexes fit well the negative binomial distribution, indicating that the mosquitoes were aggregated in distribution. Aside from providing a useful sampling tool, the AgREPOT also may be useful as a delivery vehicle for insecticides or pathogens to males and females that enter and rest in them.

2006

Okech, BA, Irungu LW, J.E. C.  2006.  Heliminthiasis in Free-Ranging Indigenous Poultry in Kenya. . Bulletin of Animal Health and Production. 54(2):92-99. AbstractAJOL

In Kenya data on poultry helminthiasis are scarce and its research has received little attention owing to the less visible and chronic symptoms of helminthiasis that are difficult to discern. To bridge this gap, we examined 604 chicken guts from local slaughter houses in Kenya and then visited 22 homesteads in Central Province rearing indigenous free ranging chicken. A questionnaire dealing with clinical signs of helminthiasis and poultry management practices to assess whether the farmers discerned ill health in their flock was administered. Ninety percent of the slaughter house guts were positive for one or more helminth parasites, including Heterakis spp (28%), Strongyloides spp (24%), Ascaridia galli (14%), Acuaria spp (13.6%), Tetrameres spp (2.5%) and Davainea spp (2.1%) among others. Of the 22 homesteads, one or more reported abnormal conditions in their flock. Ninety percent observed depressed egg-laying, 59% saw weakness in legs and slimy/bloody stool, while 46% observed late maturity (>8months). Eighty two percent of the homesteads feedback tallied with the clinical signs associated with the helminth parasites identified from their poultry at coprology

Oketch, GBA, Irungu LW, Anjili CO, Munyua J, Njagi ENM, Rukunja G.  2006.  In vitro activity of the total aqueous ethanol leaf extracts of Ricinus communis ( on Leishmania major promastigotes.. Kenya Journal of Sciences, Series A& B .Special Edition . 1(1):1-4.

2005

Odiere, M, Irungu L, Vulule J, Bayoh N, Gimnig J, Hawley W, Walker E.  2005.  Sampling resting Anopheles gambiae with clay pots. 54th American Society of Tropical Medicine and Hygiene Conference. , Washington D.C.
Mathenge, EM, Misiani GO, Oulo DO, Irungu LW, Ndegwa PN, Smith TA, Killeen GF, Knols BGJ.  2005.  Comparative performance of the Mbita trap, CDC light trap and the human landing catch in the sampling of Anopheles arabiensis, An. funestus and culicine species in a rice irrigation in western Kenya. Malaria Journal . 4(doi:10.1186/1475-2875-4-7):4-7. AbstractMalaria journal link

Abstract
Background
Mosquitoes sampling is an important component in malaria control. However, most of the methods used have several shortcomings and hence there is a need to develop and calibrate new methods. The Mbita trap for capturing host-seeking mosquitoes was recently developed and successfully tested in Kenya. However, the Mbita trap is less effective at catching outdoor-biting Anopheles funestus and Anopheles arabiensis in Madagascar and, thus, there is need to further evaluate this trap in diverse epidemiological settings. This study reports a field evaluation of the Mbita trap in a rice irrigation scheme in Kenya

Methods
The mosquito sampling efficiency of the Mbita trap was compared to that of the CDC light trap and the human landing catch in western Kenya. Data was analysed by Bayesian regression of linear and non-linear models.

Results
The Mbita trap caught about 17%, 60%, and 20% of the number of An. arabiensis, An. funestus, and culicine species caught in the human landing collections respectively. There was consistency in sampling proportionality between the Mbita trap and the human landing catch for both An. arabiensis and the culicine species. For An. funestus, the Mbita trap portrayed some density-dependent sampling efficiency that suggested lowered sampling efficiency of human landing catch at low densities. The CDC light trap caught about 60%, 120%, and 552% of the number of An. arabiensis, An. funestus, and culicine species caught in the human landing collections respectively. There was consistency in the sampling proportionality between the CDC light trap and the human landing catch for both An. arabiensis and An. funestus, whereas for the culicines, there was no simple relationship between the two methods.

Conclusions
The Mbita trap is less sensitive than either the human landing catch or the CDC light trap. However, for a given investment of time and money, it is likely to catch more mosquitoes over a longer (and hence more representative) period. This trap can therefore be recommended for use by community members for passive mosquito surveillance. Nonetheless, there is still a need to develop new sampling methods for some epidemiological settings. The human landing catch should be maintained as the standard reference method for use in calibrating new methods for sampling the human biting population of mosquitoes.

2004

LW, I, RN K, SM K.  2004.  Helminth parasites in the intestinal tract of indigenous poultry in parts of Kenya.. Journal of the South African Veterinary Association. 75(1):58-59. AbstractPubMed link

A study was carried out on 456 indigenous poultry intestinal specimens from various towns in Kenya to determine the occurrence and distribution of helminth parasites in the intestinal tract of the birds. Of the specimens examined, 414 had parasites whereas the remaining 42 had none, which is an infection rate of 90.78%. The main species of helminths found in the intestines were Raillietina sp. (47.53%), Heterakis gallinarum (21.33%), Ascaridia galli (10.03%), Strongyloides avium (9.96%), Choanotaenia infundibulum (4.61%), Cotugnia digonopora (3.6%), Capillaria sp. (1.5%), Trichostrongylus tenius (1.04%) and Syngamus trachea (0.40%). Most helminths were present in both the mid- and hindguts. Syngamus trachea and C. digonopora were only found in the foregut and midgut, respectively. Although chickens from which the specimens were collected appeard healthy, the high prevalence of helminthiasis observed shows the poor level of helminth infection control practiced by the indigenous poultry keepers in the country, which might affect the health status of the birds and their growth rates. Poultry keepers should be encouraged to prevent, control and treat such cases.

Mathenge, EM, Omweri GO, Irungu LW, Ndegwa PN, Walczak E, Smith TA, Killeen GF, Knols BG.  2004.  Comparative field evaluation of the Mbita trap, the Centers for Disease Control light trap, and the human landing catch for sampling of malaria vectors in western Kenya.. The American journal of tropical medicine & hygiene. 70(1):33-37. AbstractThe American journal of tropical medicine &amp; hygiene

The mosquito sampling efficiency of a new bed net trap (the Mbita trap) was compared with that of the Centers for Disease Control miniature light trap (hung adjacent to an occupied bed net) and the human landing catch in western Kenya. Overall, the Mbita trap caught 48.7 +/- 4.8% (mean +/- SEM) the number of Anopheles gambiae Giles sensu lato caught in the human landing catch and 27.4 +/- 8.2% of the number caught by the light trap. The corresponding figures for Anopheles funestus Giles were 74.6 +/- 1.3% and 39.2 +/- 1.9%, respectively. Despite the clear differences in the numbers of mosquitoes caught by each method, both the Mbita trap and light trap catches were directly proportional to human landing catches regardless of mosquito density. No significant differences in parity or sporozoite incidence were observed between mosquitoes caught by the three methods for either An. gambiae s.l. or An. funestus. Identification of the sibling species of the An. gambiae complex by a polymerase chain reaction indicated that the ratio of An. gambiae Giles sensu stricto to An. arabiensis Patton did not vary according to the sampling method used. It is concluded that the Mbita trap is a promising tool for sampling malaria vector populations since its catch can be readily converted into equivalent human biting catch, it can be applied more intensively, it requires neither expensive equipment nor skilled personnel, and it samples mosquitoes in an exposure-free manner. Such intensive sampling capability will allow cost-effective surveillance of malaria transmission at much finer spatial and temporal resolution than has been previously possible.

2002

Odongo, DO, IRUNGU LUCYW.  2002.  A Simple Method for Storing Mosquito Bloodmeals for Human DNA Profiling. AbstractWebsite

A simple method for storing mosquito bloodmeal samples, which permits extraction and detection of human DNA after polymerase chain reaction (PCR) amplification of target DNA sequences, was tested. Abdomens of bloodfed field-collected Anopheles gambiae s.l. and An. funestus mosquitoes (Diptera: Culicidae) were directly expressed onto filter paper, air-dried and stored at room temperature. DNA was extracted and amplified at human hypervariable loci TC11, VWA and D1S80. The amplified products were separated using polyacrylamide gel electrophoresis, visualised by silver staining, and results compared with those from mosquitoes that had been preserved in liquid nitrogen. DNA from blooded abdomens stored on dried filter papers could be amplified with greater than 95 % success for any locus, storage temperature, mosquito species or storage duration. Collection and drying of mosquito bloodmeals directly onto filter paper appears to be a more convenient method for sample transportation and storage than the conventional method involving cryopreservation.

Mathenge EM, GF K, DO O, LW I, PN N, BG K.  2002.  Development of an exposure-free bednet trap for sampling Afrotropical malaria vectors.. Medical and veterinary entomology. 16(1):67-74. AbstractWiley Online Library

An exposure-free bednet trap (the 'Mbita trap') for sampling of Afrotropical malaria vectors was developed during preliminary studies of mosquito behaviour around human-occupied bednets. Its mosquito sampling efficiency was compared to the CDC miniature light-trap and human landing catches under semi-field conditions in a screen-walled greenhouse using laboratory-reared Anopheles gambiae Giles sensu stricto (Diptera: Culicidae). When compared in a competitive manner (side by side), the Mbita trap caught 4.1+/-0.5 times as many mosquitoes as the CDC light-trap, hung beside an occupied bednet (P < 0.000 1) and 43.2+/-10% the number caught by human landing catches (P < 0.0001). The ratio of Mbita trap catches to those of the CDC light trap increased with decreasing mosquito density. Mosquito density did not affect the ratio of Mbita trap to human-landing catches. In a non-competitive comparison (each method independent of the other), the Mbita trap caught 89.7+/-10% the number of mosquitoes caught by human landing catches (P < 0.0001) and 1.2+/-0.1 times more mosquitoes than the CDC light trap (P = 0.0008). Differences in Mbita trap performance relative to the human landing catch under noncompetitive vs. competitive conditions were explained by the rate at which each method captured mosquitoes. Such bednet traps do not expose people to potentially infectious mosquito bites and operate passively all night without the need for skilled personnel. This trap is specifically designed to catch host-seeking mosquitoes only and may be an effective, sensitive, user-friendly and economic alternative to existing methods for mosquito surveillance in Africa.

2001

Mathenge EM, JE G, M K, M O, LW I, WA H.  2001.  Effect of permethrin-impregnated nets on exiting behavior, blood feeding success, and time of feeding of malaria mosquitoes (Diptera: Culicidae) in western Kenya.. Journal of medical entomology. 38(4):531-536. AbstractPubMed link

The impact of permethrin-treated bednets on the feeding and house entering/exiting behavior of malaria vectors was assessed in two studies in western Kenya. In one study, matched pairs of houses were allocated randomly to receive bednets or no bednets. Exiting mosquitoes were collected in Colombian curtains hung around half of each house; indoor resting mosquitoes were collected by pyrethrum spray catches. The number of Anopheles gambiae Giles and An. arabiensis Patton estimated to have entered the houses was unaffected by the presence of bednets; Anopheles funestus Giles was less likely to enter a house if bednets were present. Anopheles gambiae and An. funestus were less likely to obtain a blood meal and significantly more likely to exit houses when bednets were present. No difference was detected in An. arabiensis rates of blood feeding and exiting. In a second experiment, hourly night biting collections were done on 13 nights during the rainy season to assess whether village-wide use of permethrin-treated bednets caused a shift in the time of biting of malaria vectors. A statistically significant shift was detected in the biting times of An. gambiae s.l., although the observed differences were small. No change was observed in the hourly distribution of An. funestus biting. Our study demonstrated that, at least in the short-term, bednets reduced human-vector contact and blood feeding success but did not lead to changes in the biting times of the malaria vectors in western Kenya.

1999

Oketch, GBA, Anjili CO, Irungu LW, Munyua J, Njagi E, Rukunga G.  1999.  In Vivo effects of the crude aqueous leaf extracts and seed oil of Rucinus communis (Euphorbiaceae) on Leishmania major lesions in inbred Balb/c mice. . Proceedings of 20th African Health Sciences Congress. , Accra, Ghana

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