Browsing by Author "Kimutai, Albert"
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Item A Review of Leishmaniasis in Eastern Africa.(Elsevier, 2009-03) Ngure, Peter Kamau; Ng'ang'a, Zipporah W.; Rukunga, Geoffrey; Kimutai, Albert; Tonui, Willy K.The review presents the epidemiology of leishmaniasis in the Eastern Africa region. We searched PUB MED and MEDLINE with several key words-namely, “leishmaniasis”;“cutaneous”, “diffuse cutaneous”, “mucosal”, and “visceral leishmaniasis”; “kala azar”, and “post kala azar dermal leishmaniasis”, -for recent clinical and basic science articles related to leishmaniasis in countries in the Eastern Africa region. Poverty, wars, conflicts and migration have significantly aggravated leishmaniases in Eastern Africa. Of particular concern is the increasing incidence of Leishmania-HIV co-infection in Ethiopia where 20∼40% of the persons affected by visceral leishmaniasis are HIV-co-infected. Sudan has the highest prevalence rate of post kala-azar dermal leishmaniasis(PKDL) in the world, a skin complication of visceral leishmaniasis(VL) that mainly afflicts children below age ten. In view of its spread to previously non-endemic areas and an increase in imported cases, leishmaniasis in Eastern Africa should be considered a health emergency.Item Evaluation of the Adjuvanticity of Artemisinin with Soluble Leishmania Major Antigens in BALB/C Mice(Elsevier, 2009) Karanja, Muhia Robert; Ngure, Peter Kamau; Ingonga, Johnstone; Gicheru, Michael M.; Kepha, Stella; Njeru, Laban Ireri; Wachira, Dorcas; Mwangi, Milkah; Nyamwamu, Lydia B.; Kimutai, Albert; Tonui, Willy K.Objective; To determine the adjuvant potential of artemisinin with a soluble leishmanial antigen in vaccinating BALB/c mice. Methods; Seventy two female BALB/c mice were randomly assigned into six groups. The mice were vaccinated with soluble leishmania antigens (SLA) alone, artemisinin co-administered with SLA, SLA and Bacille Calmette Guérin (BCG) vaccine, and artemisinin and BCG alone. Unvaccinated mice formed the control group. The induction of cell-mediated immunity following vaccination was determined by measuring in vitro lymphocyte proliferation and the production of interleukin (IL)-4, IL-5 and gamma interferon (IFN-γ) determined by flow cytometry. Protection against L. major was determined by quantifying parasite burdens in L. major infected footpads using a limiting dilution assay and by measuring lesion sizes of the infected footpad compared to the contralateral uninfected footpad. Results; Mice receiving SLA plus artemisinin produced significantly high levels of IL-4 and IL-5 (P < 0.05) and low levels of IFN-γ, resulting in exacerbated disease. In addition, subcutaneous administration of SLA + artemisinin, artemisinin alone or SLA alone resulted in the development of large footpad swellings and high parasite loads that were comparable to those of the control unvaccinated mice (P > 0.05), resulting in exacerbated disease. Conclusion; These data suggest that artemisinin is not a suitable adjuvant for Leishmania vaccines. However, since artemisinin has been shown to be effective against Leishmania parasites in vitro and in vivo, further studies ought to be conducted to determine its immunochemotherapeutic potential when co-administered with Leishmania antigens.Item Evaluation of the immunochromatographic strip test for the rapid diagnosis of antenatal syphilis in women in Eldoret, Kenya.(Elsevier, 2009) Nyamwamu, Lydia B.; Gicheru, Michael M.; Sharma, Rekha R.; Kimutai, Albert; Tonui, Willy K.; Kamau, Ngure PeterObjective; This study compared the performance of the immunochromatographic strip (ICS) to the Venereal Disease Research Laboratory (VDRL) test and Treponema pallidum hemagglutination assay (TPHA) at a primary health care setting. Methods; The study group was comprised of 150 females randomly drawn from a population of pregnant women attending their first antenatal visit or follow-up visits at West Maternity Hospital in Eldoret Kenya, but without a previous syphilis test during that pregnancy. On-site VDRL, ICS and TPHA tests were performed and immediate treatment provided where appropriate. The performance of the three tests was compared. Results; The zero-prevalence of syphilis as determined by the VDRL test was 3%. There was no significant difference between the ICS and the VDRL test (P > 0.05). The sensitivity and specificity of the ICS test were 80% and 98.6% respectively, while the negative predictive value (NPV) and positive predictive value (PPV) were both 100%. On the other hand, the sensitivity and specificity of the VDRL test were 66.7% and 99.3%, while the NPV and PPV were 80% and 98.6% respectively. The Treponema pallidum hemagglutination assay was used as a reference test and had sensitivity, specificity, NPV and PPV of 100%.Item Leishmaniasis in northern and western Africa: a review(Afr. J. Infect. Dis., 2009) Kimutai, Albert; Ngure, Peter Kamau; Tonui, Willy K.; Gicheru, Michael Muita; Nyamwamu, Lydia BonareriLeishmaniasis, one of the highly neglected diseases is currently a significant health problem in northern Africa with a rising concern in western Africa because of co-infection with the Human Immunodeficiency Virus (HIV). In this review, we present a summarized analysis of the epidemiology, infective species, parasites reservoirs, diagnosis, treatment and control measures of leishmaniasis in northern and western Africa region. In northern Africa, the disease is prevalent in Morocco, Algeria, Tunisia, Egypt and Libya. Comparatively, there are low prevalence rates of the disease in West African countries including Cameroon, Ghana, Burkina Faso, Niger, Mali, Nigeria and Senegal. In North Africa, visceral leishmaniasis (VL) is caused by L. infantum and transmitted by Phlebotomus perniciosus and P. longicuspis. On the other hand, cutaneous leishmaniasis (CL) is mainly caused by L. major and transmitted by P. papatasi, P. duboscqi and P. pedifer with L. infantum and L. tropica causing lower incidences of the disease. Notably, Algeria is one of the countries that constitute 90% of CL cases worldwide. In Western Africa; CL is caused by L. major while VL is caused by L. donovani. In these regions, zoonotic and anthroponotic cutaneous and visceral leishmaniasis is a health problem that should be addressed urgently.Item Potential Effects Of Pyrethrin Incorporated In Sucrose Baits Against Phlebotomus Duboscqi Neveu Lemaire (diptera: Psychodidae) In Leishmaniasis Control Strategies(Webmedcentral, 2010-11-06) Ireri, Laban N.; Mucheru, Obadiah; Ngure, Peter Kamau; Kepha, Stella; Kimutai, Albert; Cirindi, Josyline; Tonui, Willy K.Background: Due to challenges of controlling leishmaniasis in Kenya through the vector, the efficacy of pyrethrin EC (Pymos™ 0.6% W/V) a mosquito adulticide was evaluated against Phlebotomus duboscqi while incorporated in sucrose as a possible complementary method. Methods: Pyrethrin was prepared into concentrations of 0.08, 0.25and 0.5 mg/ml using 10% sucrose. Ten male and female sand flies were each aspirated into jars and fed separately with the prepared solutions using cotton wool pads placed atop experimental jars and mortality monitored each day. The experiments were replicated three times. Results: Significant mortality (P< 0.05) for both sexes was observed. The concentration of 0.08mg/ml gave low adult mortality in 24 hours but amplified with time. In the 0.25 bioassay, mortality of females were 10 (33.3%) and males had 21 (70%) in 24 hours. The LD50 for females and males tied at 0.1 mg/ml in 48 hours of exposure. The concentration of 0.25 mg/ml was ideal at 48 hours of feeding where majority of the sand flies succumbed to the insecticide. There were significant mortality differences (P <0.05) between the concentrations but no significant difference (P>0.05) was observed in male and female mortality at 48 hours of exposure however. Although we cannot rule out sand fly mortality due to contact with the test material, the results of this study however suggest that control strategies using low-dose pyrethrin-sugar combinations as baits may be effective against phlebotomine sand flies and other sugar feeding pests of medical importance.Item The potential of the extracts of Tagetes minuta Linnaeus (Asteraceae), Acalypha fruticosa Forssk (Euphorbiaceae) and Tarchonanthus camphoratus L. (Compositae) against Phlebotomus duboscqi Neveu Lemaire (Diptera: Psychodidae), the vector for Leishmania major Yakimoff and Schokhor(Journal of Vector Borne Diseases, 0201-09) Ireri, Laban N.; Kongoro, Jedida; Ngure, Peter Kamau; Mutai, Charles; Langat, Bernard; Tonui, Willy K.; Kimutai, Albert; Mucheru, ObadiahBackground & objectives: Harmful effects of synthetic chemical insecticides including vector resistance, environmental pollution and health hazards have necessitated the current significance in the search for plant-based insecticide products that are environmentally safe and effective to leishmaniases control. The insecticidal activity of Tagetes minuta Linnaeus (Asteraceae), Acalypha fruticosa Forssk (Euphorbiaceae) and Tarchonanthus camphoratus L. (Compositae) extracts were investigated against Phlebotomus duboscqi Neveu Lemaire (Diptera: Psychodidae). Methods: The extracts were prepared from dried aerial parts soaked in methanol and ethyl acetate twice until the filtrates became clear, filtered and dried out by rotary evaporation at 30–35oC. The solid extracts obtained were later prepared into 2.5, 5 and 10 mg/ml. Two millilitres of the solutions were blotted on filter papers, which were dried overnight and placed into jars where adult sandflies were aspirated. Males and females were assayed separately. Results & conclusion: The extracts had significant mortality (p<0.05) in both males and females bioassays but were not significantly different between sexes. The extracts of Acalypha fruticosa and Tagetes minuta had significantly higher mortality rates than those of Tarchonanthus camphoratus and the different concentrations used showed significantly different mortality rates and 10 mg/ml was the most effective concentration. Cent percent mortality was obtained at 96 h of exposure to 5 and 10 mg/ml concentrations except for Tarchonanthus camphoratus which had a mortality of only 46.7% in 10 mg/ml bioassay. These extracts were found to be insecticidal to adult sandflies.