Mycotoxins are toxic fungal metabolites naturally found in food and feed as contaminants. Animal feed and human food samples (n=1818) from three major Kenyan laboratories were categorized as ...compliant and non-compliant according to Kenya, America (USA) and Europe (EU) mycotoxin regulatory limits. Quantitative risk assessment of dietary aflatoxin intake in maize, wheat, peanut and dairy products in relation to human hepatdegreesCellular carcinoma was carried out employing deterministic approach. Non-compliant samples' proportions were calculated, and logistic regression and chi-square test used to compare different commodities. Animal feed were least compliant, with 64% and 39% having total aflatoxin (AFT) levels above Kenya and USA standards, respectively. Peanuts were the most non-compliant food, with 61% and 47% samples failing Kenya and USA AFT standards respectively, while wheat was least compliant (84%) according to EU threshold for AFT. Half of baby food sampled had AFT level above Kenya and EU standards. High non-compliance rate with Kenya, USA and EU regulatory thresholds with respect to seven different mycotoxins (summarized as "mycotoxins"), and also AFT and aflatoxin Ml alone in edible materials is reported. Significant non-compliance is reported for compound animal feed, peanuts, wheat, baby food, feed ingredients, herbal healthy drink, maize and fodder feed in that order. High levels of aflatoxin residues in animal feed and human food was also observed. Lifetime human consumption of wheat and maize leads to high additional risk for primary liver cancer, human hepatdegreesCellular carcinoma (HCC) assdegreesCiated with dietary aflatoxin, wheat and its products causing the highest disease burden. Subsequent implications and limitations of current food safety standards are discussed. Humans and animals in Kenya appear to be chronically exposed to mycotoxin hazards: this calls for surveillance and risk management. There is urgent need for enhanced and consistent surveillance of the dietary mycotoxin hazards observed in this study employing representative sampling plans. Regulation and future research need to fdegreesCus on reliable analysis techniques, collection of data on toxicological effects of mycotoxins and food consumption pattern, and regulatory limits accordingly set and compliance enforced to protect vulnerable groups such as paediatric, geriatric and sick members of the sdegreesCiety to reduce cancer burden in Kenya.
Four thousand nine hundred and seventy-one trypanosomosis-surveillance records from an open population of Orma Boran cattle raised under natural trypanosomosis challenge in Galana Ranch, Kenya ...between the years 1990 and 2000 were analysed. The objective of the analysis was to identify epidemiological factors that influenced time-to-treatment of trypanosomosis cases. Under the surveillance programme, blood was being examined fortnightly for trypanosomosis using buffy coat technique. Infected animals were treated when their packed cell volumes (PCV) fell to 25% or lower. The number of days between the first diagnosis and treatment of trypanosomosis cases was obtained from the difference between diagnosis and treatment dates. Days-to-treatment clustered around the screening periods; therefore, time-to-treatment was represented by a series of time points 0–8 at 14-day intervals. Factors postulated to affect the outcome (time-to-treatment) were age of an animal at time of diagnosis, sex, number of trypanosome infections, trypanosome species and season of the year. Five animal generations were generated from birth dates and treated as nuisance parameters. Conditional logistic regression and Cox proportional hazards models were fitted to the data, the former to analyse factors that influenced treatment after time 0 (outcome dichotomised as time 0 or >0) and the latter to analyse factors that influenced time-to-treatment for cases that were treated after time 0, excluding all cases treated on time 0. The majority of the cases (89.5%) were treated on the same day of diagnosis. Trypanosome infections were more likely to be treated after time 0 in dry than in wet season. Similarly, the rate of treatment was lower in the dry than the wet season. An increase in number of previous trypanosome infections reduced the odds of an animal being treated after time 0. Animals that had been exposed to many infections before had higher rates of treatment than those that had minimal experiences. We offer possible reasons for these observations and conclude that selection of animals for breeding purposes in programmes geared towards improving trypanotolerance should take into consideration the environmental factors that affect classification of an animal as being resistant or susceptible.
The efficacy of a bull cryopreservation medium Triladyl® in preservation of the various pathogenic trypanosomes was evaluated against the commonly used glycerol ethylenediamine tetraacetic acid ...(EDTA) saline glucose (ESG). Trypanosoma brucei rhodesiense, T. evansi, T. b. brucei and T. congolense were first propagated in Swiss White mice. At peak of parasitemia, blood was collected from the mice by cardiac puncture and 1 x 102 trypanosomes/ml dilution made. This dilution was then divided into 2 equal portions which were cryopreserved in either ESG 10% glycerol or Triladyl® 50%. After 1 month of cryopreservation, 2 irradiated mice were intraperitoneally administered with 0.2 ml of the cryopreserved sample and then monitored for parasitemia development. Triladyl-cryopreserved T .evansi and ESG-cryopreserved T. congolense had shorter although not significant prepatent period (PPP) compared to their counterparts in the alternate medium. The peak parasitemia was significantly higher for Triladyl®-cryopreserved T. evansi trypanosomes compared to that preserved in ESG. The parasitemia pattern for T. evansi, T. b. brucei and T. congolense were characterized by 1 wave while T. b. rhodesiense had 2 waves. For T. b. brucei, T. b rhodesiense and T. congolense the number of days taken to develop peak parasitemia were shortest for ESG cryopreserved trypanosomes and this was opposite for T. evansi. In conclusion, Triladyl® can be used as an alternative cryopreservative medium for trypanosomes and would be the cryopreservative medium of choice for T. evansi trypanosomes based on the PPP, peak parasitaemia and days to peak parasitaemia.
The efficacy of Triladyl®, a commercial cryomedium for bull semen, in the cryopreservation of both humanand animal infective trypanosomes as compared to EDTA Saline Glucose (ESG) 10% glycerol was ...evaluatedin the current study. Cryopreserved Trypanosoma brucei rhodesiense, T. evansi, T. b. brucei and T.congolense were first propagated in irradiated mice. At the peak of parasitemia, parasites were harvested bycardiac puncture and 106,105,104103,102 and 10 dilutions made using whole blood bled from clean mice.These dilutions were divided into two equal portions of 0.5 ml each and cryopreserved in both ESG 10%glycerol and neat Triladly®. The procedure was also repeated with T. congolense and T. vivax species oftrypanosomes directly isolated from naturally infected cattle. After 1 month of cryopreservation, 0.4 ml eachportion of this dilution was injected intraperitonially into irradiated Swiss white mice. Results on pre-patentperiod (ppp) and progression of parasitemia showed no difference in the recovery of samples cryopreservedusing the 2 media. However, mice injected with T. b. brucei cryopreserved in the 2 media showed highlysignificantly (p < 0.01 by t-test) lower ppp when compared to the other species of trypanosomes which hadno significant difference. However, the ppp in mice injected with trypanosomes cryopreserved in ESG 10%glycerol was significantly lower (p < 0.05 by t-test) when compared to those cryopreserved in Triladyl®.The interaction between media and species was highly significant indicating therefore that the difference incryopreservation between the two media varies from one species of trypanosome to the other. Theinteraction between dose and species was also highly significant (p < 0.01 by t-test) implying therefore thatthe effect of the inoculum dose varied from one species to the other leading to the conclusion therefore thatalthough Triladyl® appears as good a cryopreservative medium as ESG 10% glycerol, the choice will bedetermined by the species of trypanosome.
A total of 17 head of cattle presenting with typical "Elephant skin disease" were isolated from the rest of the herd within a beef ranch for further clinical observation. On physical examination, all ...the animals had characteristic sclero-conjunctival cysts of Besnoitia besnoiti. In addition, some of the animals had characteristic skin nodules on the legs, ears and back. Histological examination of skin sections revealed typical large Besnoitia cysts. Microscopic examination of crush preparations of skin scrapings revealed crescent-shaped organisms with a more pointed anterior than posterior end (banana-shaped morphology) confirming that the cysts belong to the genus Besnoitia.
An investigation was made into whether recent vaccination of cattle with tissue culture rinderpest virus would cause immunosuppression and lead to more frequent or more severe infection with ...trypanosomes in animals grazing in tsetse-infested areas. Herds of cattle on Galana Ranch in Kenya were divided, with approximately half of each herd being vaccinated with tissue culture rinderpest virus strain Kabete 'O', while the rest remained unvaccinated. The herds were then exposed to the risk of natural infection with trypanosomes on the ranch. Three experiments were performed during different seasons. Infections with Trypanosoma congolense and Trypanosoma vivax were frequently detected but there was no evidence that vaccinated animals were more likely to acquire trypanosome infections or to show a more severe disease than unvaccinated cattle. It is concluded that tissue culture rinderpest vaccine does not cause immunosuppression and can safely be used in cattle likely to be exposed to tsetse flies and trypanosomosis.
The concentrations of isometamidium circulating in poorly nourished Zebu cattle which showed morbidity, mortality, and biochemical and histopathological evidence of hepatotoxicity, following frequent ...treatments with isometamidium chloride and diminazene aceturate were investigated using the isometamidium‐ELISA. As few as two isometamidium treatments one month apart were associated with significant weight loss, and cattle treated with diminazene aceturate after three or four isometamidium treatments suffered a 50% mortality.
Although there were no obvious, marked elevations in isometamidium concentration which might have allowed the use of the ELISA as a predictor of a potential toxicity problem, concentrations did increase significantly with the number of monthly treatments administered, suggesting drug accumulation, and the increases were significantly higher in cattle to which diminazene had also been administered. In cattle treated with both trypanocides, weight loss and serum glutamate dehydrogenase levels were correlated with isometamidium concentrations. These observations, together with the histopathological findings, support the hypothesis that the morbidity and mortality observed were related to the repeated treatment with isometamidium in conjunction with diminazene aceturate, and that the pathogenesis involved a component of hepatic damage.
It is therefore recommended that cattle, particularly those under nutritional stress, are not subjected to repeated treatments with isometamidium at intervals as short as one month, and particularly not with concurrent administration of diminazene.
A survey was undertaken on the prevalence of heartwater in Narok district, Kenya as a component of a broader study to establish constraints to livestock production in a Maasai pastoral production ...system. Serum samples were collected on a single occasion from 147 Red Maasai sheep and 149 Small East African goats aged 6 months to 3 years from three sites in the district. The sera were tested for antibodies to Ehrlichia ruminantium, by a MAP1 B ELISA. The sero-prevalence of E. ruminantium ranged from 62% to 82.5% in sheep, while in goats the range was 42.5% to 52%. Brain crush smears prepared from a dead sheep on the study site were positive for E. ruminantium organisms thus confirming the presence of the disease. The most prevalent tick species observed on the animals was Rhipicephallus appendiculatus with a mean tick count per animal of 3.98 to 5.67 while the mean tick count for Amblyomma variegatum, the vector of heartwater, was 0.015 to 0.12 per animal. The results of the study do suggest that the farmers need to adopt a regular tick control programme to prevent the susceptible animals from getting infected with heartwater. Keywords: seroprevalence, survey, pastoral production system, sheep and goats, Ehrlichia ruminantium Bulletin of Animal Health and Production in Africa Vol. 54(1) 2006: 23-33
A cross-sectional study was carried out in two villages (Emorijoi and Ngoswani) in Lemek group ranch and one village (Enkoje) situated in Koyaki group ranch in Narok District to investigate parasitic ...infections in small ruminants. Blood and faecal samples were collected from 150 sheep and an equal number of goats during wet season (May-June) and dry season (August-September) and analyzed using different parasitological methods. The findings showed that parasites infecting small ruminants in the area were helminthes, Cowdria ruminantium, ticks and trypanosomes. The most prevalent genera of nematodes identified were Strongyles, which usually occurred concurrently in most animals. The percentage of animals with at least one or more helminth eggs detected during the wet season in sheep and goats was 36% (54) and 52% (78) respectively before deworming with Nilzan plus (1.5% levamisole plus refoxanide hydrochloride). Approximately two months after deworming the animals, this percentage of animals declined to 18% (27) and 24.6% (37) in sheep and goats respectively during the dry season. During the wet season the overall trypanosome prevalence in sheep and goats was 1.3% (2) and 4.6% (7) respectively and decreased significantly to 0% (0, goats) (P0,05). Le taux de prvalence globale de la cowdriose tait beaucoup plus lev (P
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