Browsing by Author "Muluvi, Geoffrey M."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Detection of trypanosomes in small ruminants and pigs in western Kenya: important reservoirs in the epidemiology of sleeping sickness?
    (2005-07-14) Ng'ayo, Musa O.; Njiru, Zablon K.; Kenya, Eucharia U.; Muluvi, Geoffrey M.; Osir, Ellie O.; Masiga, Daniel K.
    Background: Trypanosomosis is a major impediment to livestock farming in sub-Saharan Africa and limits the full potential of agricultural development in the 36 countries where it is endemic. In man, sleeping sickness is fatal if untreated and causes severe morbidity. This study was undertaken in western Kenya, an area that is endemic for both human and livestock trypanosomosis. While trypanosomosis in livestock is present at high levels of endemicity, sleeping sickness occurs at low levels over long periods, interspersed with epidemics, underscoring the complexity of the disease epidemiology. In this study, we sought to investigate the prevalence of trypanosomes in small ruminants and pigs, and the potential of these livestock as reservoirs of potentially human-infective trypanosomes. The study was undertaken in 5 villages, to address two key questions: i) are small ruminants and pigs important in the transmission dynamics of trypanosomosis? and ii), do they harbour potentially human infective trypanosomes? Answers to these questions are important in developing strategies for the control of both livestock and human trypanosomosis. Results: Eighty-six animals, representing 21.3% of the 402 sampled in the 5 villages, were detected as positive by PCR using a panel of primers that identify trypanosomes to the level of the species and sub-species. These were categorised as 23 (5.7%) infections of T. vivax, 22 (5.5%) of T. simiae, 21 (5.2%) of the T. congolense clade and 20 (5.0%) of T. brucei ssp. The sheep was more susceptible to trypanosome infection as compared to goats and pigs. The 20 T. brucei positive samples were evaluated by PCR for the presence of the Serum Resistance Associated (SRA) gene, which has been linked to human infectivity in T. b. rhodesiense. Three samples (one pig, one sheep and one goat) were found to have the SRA gene. These results suggest that sheep, goats and pigs, which are kept alongside cattle, may harbour human-infective trypanosomes.
  • Thumbnail Image
    Item
    Distribution of indigenous strains of atoxigenic and toxigenic Aspergillus flavus and Aspergillus parasiticus in maize and peanuts agro‑ecological zones of Kenya
    (Springer (BioMed Central Ltd), 2015-09) Okun, Daniel O.; Kenya, Eucharia U.; Khamis, Fathiya M.; Muluvi, Geoffrey M.; Ngeranwa, Joseph J.; Ombura, Fidelis O.; Yongo, Moses O.
    Background Grains of important food and export crops in Africa are susceptible to contamination by toxin-producing moulds. Aflatoxins are mycotoxins associated with liver damage and cancer in humans and animals. These toxic substances are produced by fungi (such as Aspergillus flavus and Aspergillus parasiticus) in food and feed exposed to poor conditions during crop cultivation, storage or processing of harvest. The presence of aflatoxins in especially maize and peanuts in Kenya is of great concern. Recent developments in the application of atoxigenic strains of these fungi as biological control agents against toxigenic strains could be a solution to the problem. The objective of this study was to isolate, identify and characterize atoxigenic and toxigenic strains of A. flavus and A. parasiticus in Kenya, and investigate possible application of atoxigenic strains in control of aflatoxin levels in maize and peanuts. Fungal communities in soils of maize and peanut fields were examined to determine the distributions of aflatoxin-producing Aspergillus species and to identify endemic atoxigenic strains. 220 isolates belonging to A. flavus and A. parasiticus were collected randomly from soils of maize and peanuts fields in seven agro-ecological zones and characterized using morphological and physiological examination. Results Aspergillus section Flavi was detected in all the 57 soil samples collected in Kenya. Members of Aspergillus section Flavi L strain was the most common (54 %), followed by S-strains (35 %). Among Aspergillus, A. flavus was the most predominant (63.2 %), followed by A. parasiticus (27.7 %), A. tamari (5.5 %) and A. nomius (2.7 %). The mean CFU of the Aspergillus colonies per gram of soil was highly variable among the districts, ranging from 3.0 × 103 to 1.72 × 106 (p < 0.05). The mean pH across the collection sites also varied according to the respective agroecological zones (pH 5.5–6.8) which is within the optimal pH requirement for the members of section Flavi. There was no significant variation in temperature across the sampling sites (p > 0.05). The results also showed that A. flavus was detected in all the zones examined. Conclusions Each of the regions had atoxigenic strains of potential value which can be employed as biological control agents in the management of aflatoxicoses.