Investigation of the prevalence of bovine tuberculosis and risk factors for human infection with bovine tuberculosis among dairy and non-dairy farming neighbour households in Dagoretti Division, Nairobi, Kenya.

OBJECTIVE: To determine the prevalence of bovine tuberculosis in urban dairy cattle and examine possible risk factors for human infection with bovine tuberculosis (BTB). DESIGN: Cross sectional study. SETTING: Urban and peri-urban dairy and non-dairy farming neighbour households. SUBJECTS: One hundred forty three dairy cattle and 299 and 149 dairy and non-dairy neighbour households respectively. RESULTS: Ten percent of the animals (15/143) were found to be reactors to the tuberculin test. The majority of the respondents 57% (168/295) and 72% (106/147) in dairy farming and non-farming households respectively, had limited knowledge of the disease in cattle thus making them unable to adopt any precautionary measures to protect themselves from contracting bovine tuberculosis. Distance from the main house and cattle shed, the time spent attending to the cattle, (on average 4.8 hours), and making of traditionally fermented milk were considered to be the major risk factors. CONCLUSION: Due to the presumed high background prevalence of human tuberculosis, the specificity of the test employed was unknown. Therefore no definite estimate of the prevalence of BTB was made. It is therefore necessary for further investigation involving culture, isolation and molecular typing from reactors to establish the prevalence of M. bovis in this setting.

Investigation on the prevalence of antimicrobial residues in milk obtained from urban smallholder dairy and non-dairy farming households in Dagoretti Division, Nairobi, Kenya.

OBJECTIVES: To assess the prevalence and the level of awareness of the risk posed by antibiotic residues among the urban dairy and non-dairy farming households using a household survey and laboratory analysis of milk samples. DESIGN: A cross sectional study. SETTING: Urban small holder dairy farming and non-farming households in Dagoretti division, Nairobi. RESULTS: The prevalence of antibiotic residues in dairy household milk samples was 4% (11/259) and in milk samples from non-dairy neighbouring households the prevalence was 0.07% (1/136). One sample was detected to belong to beta lactam and one to the tetracycline group of antibiotics. The remaining 10 were not categorised. Approximately 20% of dairy and non-dairy respondents were unsure of the risk that may be posed by the presence of antibiotic residues in milk. A high proportion of the respondents said they would be able to protect themselves from risk posed by antibiotic residues by following advice given by veterinary officers on the withdrawal periods after treatment of animals. CONCLUSION: Education of the farmers, continuous surveillance and understanding of the socio-economic incentives that would be traded off at farm level would help to reduce or eliminate the risk posed by the residues in marketed or consumed milk.

Investigations into the prevalence of bovine brucellosis and the risk factors that predispose humans to infection among urban dairy and non-dairy farming households in Dagoretti Division, Nairobi, Kenya.

OBJECTIVE: To explore the knowledge, attitudes and practices of dairy and non-dairy farming households in Dagoretti in regard to the risk posed by bovine brucellosis and determine the prevalence of the disease in urban dairy cattle. DESIGN: A cross sectional study. SETTING: Urban and Peri-urban dairy farming and non dairy farming households in Dagoretti division, Nairobi. SUBJECTS: Two hundred ninety nine dairy farming and 149 non dairy farming households. INTERVENTION: Segregated focus group discussions, administration of a household questionnaire and collection of unboiled milk from dairy and non dairy farming households were the instruments used to gather data on the practices, attitudes, perceptions and prevalence of bovine brucellosis. RESULTS: Three hundred and ninety three milk samples were collected and analysed for the presence of antibodies to Brucella abortus in an indirect ELISA. The apparent prevalence of bovine brucellosis from milk was estimated at 1% for the samples collected while in dairy farming households the prevalence was 1.1% [0.2, 3.4%] and 0.7% [0.4%] in non dairy farming households.. Thirty percent (90/296) of dairy respondents and 22% (32/147) of non-dairy respondents knew of the existence of brucellosis. Risk of contracting brucellosis was very low considering that milk is boiled together with other ingredients used in making tea and porridge. However, 31% (93/296) and 22% (31/143) of dairy and non dairy farming households respectively made traditionally fermented milk without first boiling the milk. This practice may predispose this group to brucellosis. CONCLUSION: The low prevalence of bovine brucellosis requires constant surveillance in case the prevalence rates do change. Education of dairy farming households who are more at risk of contracting brucellosis on the transmission pathways and risk factors is required in order to lower further the prevalence of bovine brucellosis in Dagoretti.