The Department of Microbiology, Parasitology, and Biotechnology is delighted to announce to the scientific community and extend its congratulations to Dr. Ivy Sylvia Okello, on the successful defense of her PhD on 6th May 2024 at Sokoine University of Agriculture (SUA). His PhD thesis is titled “Epidemiology, Drug Sensitivity Pattern and Control Practices of African Animal Trypanosomes in Western Kenya, Lambwe Region.”
Dr. Ivy Sylvia Okello began her PhD program at the Department of Microbiology, Parasitology, and Biotechnology within the College of Veterinary Medicine and Biomedical Sciences (CVMBS) in October 2020. Employed by Pwani University, Dr. Okello served as an Adjunct Lecturer in Molecular Biology and Population Genetics within the Biology department. She was guided and supervised by Dr. Eliakunda Mafie (SUA), Dr. Jahashi Nzalawahe (SUA), and Prof. Gillian Eastwood of Virginia Polytechnic Institute and State University (VT). Dr. Okello’s primary research focuses on Molecular Biology.
List of members of the panel for the viva voce examination
| 1 | Chairperson | Prof. Abdul Katakweba |
| 2 | Appointee of the Principal, CVMBS | Dr. Ernatus Mkupasi |
| 3 | Appointee of the Head of Department | Dr. Emma Njau |
| 4 | Independent Internal Examiner 1 who did not supervise | Dr. Elisa Mwega |
| 5 | Independent Internal Examiner 2 who did not supervise | Dr. Benigni Temba |
Summary of findings
The research was carried out in Lambwe, region of Homabay in Kenya. The region is endemic to African animal trypanosomiasis (AAT). The aim of the study was to determine the current prevalence of cattle AAT, what are the factors leading to persistence of AAT in the region, prevalence of drug resistant trypanosomes from the region and changes of tsetse flys’ density and infection rates in different seasons. Hence, the study investigated all these factors. The study reported cattle AAT prevalence of 15.63%, and that farmers have good knowledge of AAT but use inappropriate control practices which contributes to persistence of AAT in the region, other risk factors were proximity of farms to the National Park and communal grazing of livestock by farmers. There were T. congolense isolates associated with homidium, diminazene and isometamidium resistance from the region based on molecular and in vivo mice tests. TcoAde2 tranporter gene is unlikely involved in drug sensitivity and this was confirmed by molecular assays backed with in vivo mice tests. Drop in packed cell volume (PCV) in host infected with drug-resistant trypanosomes and later treated is more pronounced than in those infected with drug-sensitive trypanosomes and treated. Tsetse vector density and infection rates were more in wet than dry seasons. Female tsetse flies harbored more Trypanosoma infections than male tsetse flies. Tsetse flies were also considered to be the main transmitter of animal trypanosomes in Lambwe region.
Publications:
- Seasonal Variation in Tsetse Fly Apparent Density and Trypanosoma spp. Infection Rate and Occurrence of Drug-Resistant Trypanosomes in Lambwe, Kenya, Ivy Okello, Eliakunda Mafie, Jahashi Nzalawahe & Gillian Eastwood, Parasitology Research, 123, Volume 2024 Article number 46. FULL TEXT
- Trypanosoma Congolense Resistant to Trypanocidal Drugs Homidium and Diminazene and their Molecular Characterization in Lambwe, Kenya, Ivy Okello, Eliakunda Mafie, Gillian Eastwood, Jahashi Nzalawahe, Leonard E. G. Mboera, Jean Nepomuscene Hakizimana & Kennedy Ogola, Acta Parasitologica. FULL TEXT
- Prevalence and associated risk factors of African Animal Trypanosomiasis in Cattle in Lambwe, Kenya, Ivy Okello, Eliakunda Mafie, Gillian Eastwood, Jahashi Nzalawahe, Leonard E. G. Mboera, & Samuel Onyoyo, Journal of Parasitology Research, Volume 2022, Article ID 5984376, 12 pages. FULL TEXT
- African Animal Trypanosomiasis: A Systematic Review on Prevalence, Risk Factors and Drug Resistance in Sub-Saharan Africa, Ivy Okello, Eliakunda Mafie, Gillian Eastwood, Jahashi Nzalawahe, & Leonard E. G. Mboera. Journal of Medical Entomology, Volume, 2022, 145 FULL TEXT