Assessment of Staphylococcus aureus along milk value chain and its public health importance in Sebeta, central Oromia, Ethiopia.

BACKGROUND: Staphylococcus aureus is one of the leading causes of gastroenteritis acquired from contaminated foods such as milk and milk products. However, such information is limited in Ethiopia. A cross-sectional study was conducted to assess the contamination of milk with S. aureus and knowledge, attitudes and practices (KAP) of actors along the milk value chain in Sebeta, Central Oromia, Ethiopia. A total of 291 samples collected from dairy farms, milk collection centers (MCCs) and processing plant were examined using standard microbiological techniques. The antimicrobial susceptibility profiles of the isolates were also investigated. The KAP of actors in milk value chain were evaluated through a structured questionnaire. RESULTS: Overall, 23.4% (n = 68) of the samples were positive for S. aureus. The prevalence of S. aureus was 19.6% (95% CI: 14.5-25.6) and 80.0% (95% CI: 14.5-25.6) at farm level and MCCs, respectively. Higher isolation rate was observed in the MCCs (p = 0.000) than the farms. The contamination rates of hands of milkers' and milking buckets with S. aureus were 32% and 11.1%, respectively. S. aureus was not isolated from pasteurized milk samples. The isolates were found to be resistant to cefoxitin (100%), penicillin G (98.5%), and streptomycin (77.9%). Among 23 interviewed farmers, 35% of them consumed raw milk, none of them wash their hands and 82.6% did not wash udder and teat before milking. Six percent of consumers had the habit of raw milk consumption. Eighty seven percent of dairy farmers and 54% of consumers had no awareness about milk borne diseases and staphylococcal food poisoning. CONCLUSIONS: The study revealed a high prevalence of S. aureus along the milk value chain, poor milk handling practices, raw milk consumption behavior, lack of awareness about milk borne diseases and occurrence of antimicrobials resistant S. aureus. S. aureus seems to pose a public health risk in Sebeta. Authors recommended the urgent need of public awareness creation about the importance of hygienic milk production and proper handling and adequate heat treatment of milk before consumption and further study to assess cost-effective preventive and control options.

Ectoparasites of sheep in three agro-ecological zones in central Oromia, Ethiopia.

A cross-sectional study was conducted to determine the prevalence and risk factors for ectoparasites infestation in sheep in three agro-ecological zones in central Oromia, Ethiopia, from October 2009 to April 2010. The study revealed that 637 (48.1%) of the 1325 sheep examined were infested with one or more ectoparasites. The ectoparasites identified were Bovicola ovis (27.2%), Melophagus ovinus (16.4%), Ctenocephalides sp. (2.3%), Linognathus africanus (1.2%), Linognathus ovillus (0.3%), Sarcoptes sp. (1.2%), Amblyomma variegatum (4.4%), Rhipicephalus evertsi evertsi (1.9%), Rhipicephalus pravus (1.9%), Rhipicephalus (Boophilus) decoloratus (1.1%), Rhipicephalus sanguineus (0.9%), Rhipicephalus praetextatus (1.1%) and Hyalomma truncatum (1.6%). Statistically significant difference was observed in prevalence of B. ovis amongst study agroecological zones: highland 36.6%, midland 20.9% and lowland 14.0%. Significantly higher prevalence was recorded in highland agroecological zone. A significantly (OR = 0.041, p < 0.001) higher prevalence of M. ovinus in the highland (31.7%) than in both the lowland (0%) and midland (1.9%) was observed. The risk of tick infestation in the lowland and midland was 9.883 times and 13.988 times higher than the risk in the highland, respectively. A significantly higher prevalence of Ctenocephalides species was encountered in both the lowland (OR = 4.738, p = 0.011) and midland (OR = 8.078, p = 0.000) than in the highland agro-ecological zone. However, a significant difference (p = 0.191) amongst agro-ecological zones was not found for the prevalence of Linognathus and Sarcoptes species. Statistically significant variation (p > 0.05) was never recorded in the prevalence of all the identified species of ectoparasites between male and female sheep hosts. However, a significantly (p = 0.006) higher prevalence of B. ovis was recorded between young and adult sheep. The risk of B. ovis infestation was 1.45 times higher in young than the adult sheep. Furthermore, a significantly (p < 0.001) higher prevalence of M. ovinus, B. ovis and Sarcoptes sp. was found between sheep with poor and a good body condition. The ever increasing threat of ectoparasites on overall sheep productivity and tanning industry in Ethiopia warrants urgent control intervention. Further studies on the role of ectoparasites in transmission of diseases to sheep, zoonotic importance, comparative prevalence and load, and the importance of sheep as alternative hosts in different agroecological zones, breeds and management systems in Ethiopia are recommended so as to design applicable control programme in the country.