Browsing by Author "Shija, Fortunate"

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Assessment of milk handling practices and bacterial contaminations along the dairy value chain in Lushoto and Handeni districts, Tanzania
(Sokoine University of Agriculture, 2013) Shija, Fortunate
Contaminated milk is responsible for up to 90% of all dairy-related diseases of humans. A cross sectional study was carried out in Lushoto and Handeni districts of Tanga, Tanzania to determine the milk handling practices, bacterial contamination and selected milk-borne zoonotic pathogens along the dairy value chain. A total of 93 respondents were interviewed and 184 milk and milk product samples were collected. Laboratory analysis of total and coliform plate counts, detection of Escherichia coli O157:H7 and Brucella abortus using polymerase chain reaction (PCR) were done. Results showed that, most farmers (57 %) milked their cows under unhygienic conditions. More than 60% of farmers did not clean their hands, wash cow teats and clean animal houses before milking. The majority (92.1%) of farmers were not trained on livestock keeping and milk handling. Although the mean TPC was within the East African Community (EAC) standards, general counts ranged between 3.3 to 5.8 log10. Eighty seven and 93% of milk from farmers and vendors, respectively, did not meet the TPC EAC standards. All the collected milk did not meet the CPC EAC standards, indicating contamination of milk with coliforms. PCR analyses did not detect E. coli O157:H7 in all the tested samples while B. abortus was detected in 37 out of 87 samples tested. It was concluded that unhygienic practices of milking and post-harvest handling along the dairy value chain possibly contributed to microbial contamination of milk. Detection of B. abortus in milk is of public health significance due to its zoonotic potential. It is recommended that veterinary/extension services be provided to livestock farmers on proper animal husbandry and control of zoonotic animal diseases. Public education should be given to all stakeholders in dairy industry on milking and post harvest handling of milk to curtail the likely losses due to rejection of spoiled milk and milk-borne pathogens resulting from contamination of milk.
Historical environmental change in africa drives divergence and admixture of aedes aegypti mosquitoes:aprecursor to successful worldwide colonization?
(John Wiley & Sons Ltd., 2016) Bennett, Kelly louise; Shija, Fortunate; Linton, Yvonne-marie; Misinzo, Gerald; Kaddumukasa, Martha; Djouaka, Rousseau; Anyaele, Okorie; Harris, Angela; Irish, Seth; Hlaing, Thaung; P r a k a s h, A n i l; L u t w a m a, J u l i u s; Walton, Catherine
Increasing globalization has promoted the spread of exotic species, including disease vectors. Understanding the evolutionary processes involved in such colonizations is both of intrinsic biological interest and important to predict and mitigate future dis- ease risks. The Aedes aegypti mosquito is a major vector of dengue, chikungunya and Zika, the worldwide spread of which has been facilitated by Ae. aegypti’s adaption to human-modified environments. Understanding the evolutionary processes involved in this invasion requires characterization of the genetic make-up of the source population (s). The application of approximate Bayesian computation (ABC) to sequence data from four nuclear and one mitochondrial marker revealed that African populations of Ae. aegypti best fit a demographic model of lineage diversification, historical admixture and recent population structuring. As ancestral Ae. aegypti were dependent on forests, this population history is consistent with the effects of forest fragmentation and expansion driven by Pleistocene climatic change. Alternatively, or additionally, histori- cal human movement across the continent may have facilitated their recent spread and mixing. ABC analysis and haplotype networks support earlier inferences of a single out-of-Africa colonization event, while a cline of decreasing genetic diversity indicates that Ae. aegypti moved first from Africa to the Americas and then to Asia. ABC analy- sis was unable to verify this colonization route, possibly because the genetic signal of admixture obscures the true colonization pathway. By increasing genetic diversity and forming novel allelic combinations, divergence and historical admixture within Africa could have provided the adaptive potential needed for the successful worldwide spread of Ae. aegypti.