Browsing by Author "Ndungu, J.M."
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Item Changes in atrial natriuretic factor and plasma renin activity in dogs infected with Trypanosoma brucei(1992) Ndungu, J.M.; Wright, N.G.; Jennings, F.W.; Murray, M; Kenya Trypanosomiasis Research Institute; Kenya Trypanosomiasis Research Institute, Muguga P.O. Box 362, Kikuyu, Kenya, University of Glasgow Veterinary School, Bearsden Road, Bearsden, G61 1 QH, Glasgow, ScotlandWhen beagle dogs were infected with Trypanosoma brucei, a marked reduction in the plasma concentration of atrial natriuretic factor (ANF) occurred in the terminal stage of the disease during weeks 3 and 4. At the same time there was an increase in plasma renin activity (PRA) after infection. Ultra structural studies of the atria of these dogs demonstrated a reduction in ANF granules. The changes in ANF and PRA Occurred in association with severe pancarditis and the development of heart failure. By impairing the ability of the heart and kidneys to regulate blood volume, the alterations in ANF and PRA could be involved in the pathogenesis of heart failure in T. brucei-infected dogs.Item Economic assessment of the performance of trypanotolerant cattle breeds in a pastoral production system in Kenya(2009) Maichomo, M.W.; Kosura, W.O.; Gathuma, J.M.; Ndungu, J.M.; Nyamwaro, S.O.Cattle are the major source of food security and income for pastoral farmers in sub-Saharan Africa. However, infectious and parasitic diseases remain a major constraint to improved cattle productivity in the region. The use of animal health economics to support decision making on cost-effective disease control options is increasingly becoming important in the developing world. Trypanotolerant indigenous Orma/zebu cattle in a trypanosomosis endemic area of Kenya were evaluated for economic performance using gross-margin analysis and partial-farm budgeting. Orma/zebu and SahiwaVzebu cross-bred cattle were exposed to similar husbandry practices and monitored for growth rate, incidence of common infections (trypanosomosis, anaplasmosis, babesiosis, East Coast Fever and helminthosis) and the cost of treatment assessed. Interview questionnaires were also used to assess the preference rating of the 2 breeds. Results indicated that incidence of infection was trypanosomosis 3 %, anaplasmosis 58 %, babesiosis 11 %, East Coast Fever 22 % and helminthosis 28 %, with no significant difference between breeds. The Orma/zebu and SahiwaVzebu breeds had comparable economic benefits, hence a pastoralist in Magadi division is likely to get similar returns from both breeds. This study therefore recommends adoption of not only the SahiwaVzebu but also the Orma/zebu breed for cattle improvement in trypanosomosis endemic areas and conservation of indigenous genetic resources.Item Effectiveness of Information Flows in Livestock(University of Nairobi, 2003) Ndungu, J.M.The agricultural sector in Kilifi district has been faced by poor performance due to insufficient rainfall, poor prices, and poor rural access roads. The poor performance is also reflected in the inability of the district to satisfy its food needs thus remaining a net food importer (KDDP2002-2008). Barriers to information have played a role in low uptake of dairy technologies and an understanding of the various factors will help in unraveling this circumstances surrounding the low levels of dairy technologies uptake.Item Efficacy of Trypan(Diminazene Di-Aceturate)in Camels Infected with Trypanosoma Evansi(2003) Maina, N.; Ngotho, J.M.; Njiru, Z.K.; Karanja, W M.; Gem, O.C.; Karanja, S.M.; Kibugu, J.K.; Ndungu, J.M.; Kenya Trypanosomiasis Research Institute; Kenya Trypanosomiasis Research Institute (KETRI), P.O. Box 362, Kikuyu, KenyaThe efficacy of a diminazene aceturate formulation•, Trypan® (Ataros GmbH and Co.) which was recently developed and recommended for camel trypanosomosis, was tested in 11 (1 to 3 year old) dromedary camels. The animals, .were divided into 3 groups; 1, 2 and 3, comprising 4, 3 and 4 camels, respectively. Groups 2 and 3 Camels were inoculated with Trypanosoma evansi KETRI 2455 (1 x •10' trypanosomes) via intravenous injection while group 1 \vas left uninfected. Clinical examination and parasitaemia determination were done daily whereas Blood for haematology was collected weekly. Camels in group 2 and 3 were treated with Trypan at 3.5 mg/kg bwt intramuscularly (1M) at the onset of parasitaemia (day 8 post infection) and at peak parasitaemia (day 10 post infection), respectively. The .control animals (group 1) were treated with Trypan® at 3.5 mg/kg bwt 1M and Observed daily for overt signs of toxicity. The camels did not show any sign of toxicity during the 3 months experimental period. Treatment with Trypanl/l) at the onset of parasitaemia (group 2) resulted in clearance of trypanosomes• within 18 hours. The animals however relapsed ten days after treatment and were treated Curatively with 0.25 mg/kg bwt melarsomine. Camels treated at peak parasitaemia with Trypan® also became aparasitaemic within 18 hours. The clinical condition of the camels severely deteriorated despite no relapse. The camel were euthaniased 5 days post treatment to alleviate further suffering. At post-mortem there was exudative Pneumonia. Haemorrhagic gastroenteritis and myocarditis. Histopathology revealed involvement of the central nervous system, with heavy cellular infiltration and congestion of blood vessels This Implies that Trypan'" suspension may not be effective in curing camels with acute T. evansi infections.Item Establishment of a partly DFMO-sensitive primate model of Trypanosoma rhodesiense sleeping sickness(1995) Burudi, E.M.E.; Karanja, S.M.; Njue, A.I.; Githiori, J.B.; Ndungu, J.M.; Kenya Trypanosomiasis Research Institute; Kenya Trypanosomiasis Research Institute (KETRI), Kikuyu.Human African Trypanosomiasis (HAT) caused by Tb. rhodesiense occurs mainly in Eastern and Central Africa (Manson-Bahr and Bell, 1989). Unlike the West African form caused by Tb. gambiense that manifests as a chronic disease, the East African type is an acute complex of syndromes lasting less than a year. It has a three-phase course; first as the haemo-stage when parasites are in blood circulation with no central nervous system (CNS) invasion, then the second phase which is a transitional one when the parasites are present in the cerebrospinal fluid (CSF) with no CNS parenchymal infection and, thirdly the late stage, also called the meningoencephalitic phase, when the CNS parenchyma is invaded by parasites. For the management of the haemo-phase of the disease, suramin is the drug of choice for Tb. rhodesiense and Tb. gambiense infections whereas pentamidine may also be used in early Tb. gambiense infections. The late stage form is dependent on melarsoprol (Gutteridge, 1985). Treatment with melarsoprol is often associated with a potentially fatal and unpredictable encephalopathy in 5-10% of patients.Item Extent and implications of incorrect offspring-sire relationships in pastoral production system in Kajiado District, Kenya(2008) Maichomo, M.W.; Gitau, G.K.; Gathuma, J.M.; Ndungu, J.M.; Kosura, O.; Oliver, H.O.The aim of this study was to evaluate accuracy of farmer's paternity identification which determines success of future breed selection and hence genetic gain. Patemity of269 Ormalzebu and Sahiwallzebu calves was evaluated using genetic markers and the likelihood based method.Item Haematological and Serological Changes During Acute Trypanosoma Evansi Infection in Drome Dary Camels (Camerus Dromedarius)(2000) Njiru, Z.K.; Mukani, W.O.; Khaemba, B. M.; Ochieng, R.S.; Ndungu, J.M.; ; Kenya Trypanosomiasis Research Institute; Kenya Trypanosomiasis Research Institute (KETRI), P.O.Box 362, Kikuyu, KenyaThe pathological effects of acute T. evansi infection in camels, haematological and serological parameters were assessed in 5 experimentally infected camels. The role of these parameters in immunosuppression and sudden death in sick camels was also investigated. Following infection, there was a massive leukocytosis characterised by lymphocytosis, neutrophilia and a mild eosinophilia. Monocyte, basophil and packed cell volume changes were negligible. There was a significant reduction (p<0.05) in haemolytic complement and an increase in complement fixing antibodies. These parameters returned to pre-infection levels after i.m. treatment with melarsomyl (Cymerlsan) at 0.25 mg/kg body weight. These results indicate that the activation of haemolytic complement during acute infection may be a major factor contributing to death in camels infected with trypanosomosis.Item KALRO - Horticulture Research Institute Financial Year 2022/2023 Annual Report(KALRO Horticulture Research Institute, 2024) Njuguna, J.; Ndungu, J.M.; Ngugi, C.; Thuranira, D.; Gathambiri, C.W.; Watani, G.W.; Nyaanga, S.; Amati, G.; KALRO - Horticulture Research InstituteHorticulture Research Institute (HRI) has the mandate to conduct research programmes in support of the National Horticultural Industry in Kenya. These include development of appropriate technologies and improvement, Integrated Management and postharvest of fruits, vegetables, flowers, medicinal and aromatic plants (MAPS), macadamia nuts and beans. The technologies developed at KALRO-HRI undergo adaptive research to render them suitable for specific regions.Item Nitric oxide production in vervet monkeys (Cercopithecus aethiops) Infected with Thypanosoma brucei(1998) Sternberg, J.M. ; Maina, N.N.; Gikhuki, C.W.; Ndungu, J.M.; Kenya Trypanosomiasis Research Institute; Department of Zoology, University of Aberdeen, Tilydrone Avenue, Aberdeen AB29 2TZ, Scotland, UK, Kenya Trypanosomiasis Research Institute, PO Box 362, Kikuyu, Kenya,A retrospective study of nitrate concentration in serum and cerebrospinal fluid (CSF) from vervet monkeys (Cercopithecus aethiops) infected with Trypanosoma brucei was undertaken. Serum nitrate was significantly elevated in parasitaemic animals. CSF nitrate detection correlated with the presence of parasites in the CNS, The results provide evidence for the production of nitric oxide (NO) in response to infection in a primate model of human African trypanosomiasis and provide the basis for the use of such a model in studies of the immunopathological effects of NO in human trypanosomiasisItem Total Protein and White Cell Changes in the Cerebrospinal Fluid of Vervet Monkeys Infected with Trypanosoma rhodesiense and the Post-treatment Reaction(The Research Centre for Protozoan Molecular Immunology, 1994) Ndungu, J.M.; Ngure, R.M.; Ngotho, J.M.; Sayer, P.D.; Omuse, J.K.; Kenya Trypanosomiasis Research Institute; Kenya Trypanosomiasis Research Institute, P. O. Box 362, Kikuyu, KenyaIn an attempt to elucidate the events leading to the development of post treatment reactve encephalopathy in human Africa trypanosomiasis (HAT),a group of vervet monkeys (ceropithecus aethiops)were experimentally indfected with Trypanosoma rhodesiense. When terminally sick on day 12, they were treated with either diminazene aceturate, suramin or melarsoprol. Trypanosomes appeared in the cerebrospinal fluid(CSF)by day 1 of infection and increased in numbers with progress of the disease. However, only marginal increases in CSF total protein and white cels ocured during the same period. Treatment with Berenil resulted in persistence and increase in numbers of CSF.Trypanosomes, a dramaric increase in proteins and white cells up to 8 weeks after treatment,calminating in clinical encephalitis. Suramin cleared CSF trypanosomes within 4 weeks with marginal increase in proteins and white cells up to 8 weeks after treatment, folowes thereafter by a grasual and prolonged fall to pre-infection levels, Melarsoprol eliminated trypanosomes from the CSF in less than a week but the white cell and protein levels increased for another 4 weeks before finally falling. The pos-treatment increased in white cell numbers and total protein was therefore dependent on the trypanocidal drug, and was highest and most prolonged when Berenil was used and lowest with Suramin. The present studies demonstrate tha trypanocidal treatment of infected animals is followed by a post-treatment reaction in the central nervous system, the severity of which is related to the drug used and the presence of trypanosomes in the CSF.The vervet monkey therefore appears to be a good model for studying the reaction in HAT.Item Trypanosomosis and Helminthosis in Camels: Comparison of Ranch and Traditional Camel Management Systems in Kenya(2002) Njiru, Z.K.; Bett, B.; Ole-Mapeny, I.M.; Githiori, J.B.; Ndungu, J.M.; Kenya Trypanosomiasis Research Institute; Kenya Traypanosomiasis Research Institute (KETRI), P.O.Box 362, Kikuyu, KenyaTwo camel rearing systems were compared, using trypanosomiasis and helminthosis prevalence as indicators of disease constraint. Biting flies were trapped to assess their role in transmission of trypanosomiasis. Data was collected during the wet and dry seasons. The prevalences of trypanosomiasis were 17.65 and 8.5% in ranch and traditional systems, respectively, and varied with age, sex and season. On average, single helminthic infection (67.3%) was higher than mixed infection (32.7%) in both systems, while Trichostrongylus spp. were the most prevalent. The mean egg count per gram of faeces (epg) was 220±78.20 and 1750±102.67 in ranch and traditional systems, respectively. The ranch camels required more veterinary attention than the traditionally grazed ones. The biting flies caught consisted of Haematobia minuta (94.8%), Tabanus taeniola (4%) and Hippobosca camelina and H. variegata (1.2%). Most flies were caught during the wet season and around the camel sheds. From this study, it appears that camels kept under ranch management have a higher disease burden than those kept in a traditional system.
