Seroepidemiological study of livestock brucellosis in a pastoral region.

A seroepidemiological study of Brucella infections in multiple livestock species in the Borana pastoral system of Ethiopia was performed between December 2007 and October 2008. A cross-sectional multi-stage sampling technique was employed to select 575 cattle, 1073 camels and 1248 goats from the target populations. Sera were collected from the animals, and serially tested using Rose Bengal test and complement fixation test. Overall prevalence and prevalence with respect to explanatory variables were established, and potential risk factors for seropositivity were analysed using a multivariable logistic regression. The results showed that 8·0% (95% CI 6·0-10·6), 1·8% (95% CI 1·1-2·8) and 1·6% (95% CI 1·0-2·5) of the tested cattle, camels and goats, respectively, had antibodies to Brucella antigen. Positive reactors were found in 93·8% of the villages with more frequent detection of positive cattle (93·3%) than camels (56·3%) and goats (37·5%). Risk factors identified for cattle were: keeping more livestock species at household level (OR 4·1, 95% CI 1·9-8·9), increasing age of the animal (OR 2·8, 95% CI 1·3-6·0) and wet season (OR 3·3, 95% CI 1·6-6·9). Increase in household-level species composition (OR 4·1, 95% CI 1·2-14·2) and wet season (OR 3·7, 95% CI 1·5-9·1) were found to be risk factors for seropositivity in camels and goats, respectively. Existence of more than one seroreactor animal species in most villages and association of increased livestock species composition with seropositivity may add more credence to the possibility of cross-species transmission of Brucella infections. Although no attempt to isolate Brucella spp. was made, our results suggest that cattle are more likely maintenance hosts of Brucella abortus which has spread to goats and camels. This should be substantiated by further isolation and identification of Brucella organisms to trace the source of infection and transmission dynamics in various hosts kept under mixed conditions. In conclusion, the present study suggests the need for investigating a feasible control intervention and raising public awareness on prevention methods of human exposure to brucellosis.

Prevalence of pulmonary tuberculosis and associated risk factors in Eastern Ethiopian prisons.

OBJECTIVES: To determine the prevalence of pulmonary tuberculosis (PTB) and associated risk factors among inmates in three major prison settings of Eastern Ethiopia. DESIGN: Between July and November, 2008, 371 prisoners with a history of cough of ≥ 2 weeks were screened for PTB using direct smear microscopy and culture. Data were analysed using descriptive statistics and multivariable logistic regression. RESULTS: Of 371 PTB suspects identified by active screening, 33 (8.9%) were confirmed as smear- or culture-positive PTB. Together with the 11 PTB patients already on treatment, the point prevalence of PTB was 1913 per 100,000 (95%CI 1410-2580), about seven times higher than that of the general population. Eleven newly diagnosed PTB patients were sharing a cell with known TB patients. Factors significantly associated with PTB were young age (15-44 years of age) (OR 3.73), urban residence (OR 3.59), having a cough >4 weeks (OR 3.15), and sharing a cell with a TB patient (OR 3.39) or a prisoner with chronic cough (OR 4.5). CONCLUSIONS: The study documented a high prevalence of PTB among Ethiopian prisoners. Socio-demographic and TB management factors were identified to be underlying causes of the high transmission rate and the acquisition of new cases. Active surveillance of TB and implementing prevention and control guidelines are imperative.

Assessment of knowledge and practice about tuberculosis among eastern Ethiopian prisoners.

OBJECTIVE: To assess the level of knowledge and practice related to TB and identify predictive factors in three prisons in eastern Ethiopia: Dire Dawa, Jijiga and Harar. DESIGN: Between July and November 2008, 382 TB patients and suspects were interviewed using a structured questionnaire. Data were analysed using descriptive statistics and ordinal logistic regression. RESULTS: Only six (1.6%) prisoners described the cause of TB as being bacterial, while a wind locally known as 'nefas' was frequently mentioned (36.1%); nearly 75% of the prisoners correctly described breath as a mode of TB transmission; 116 (30.7%) did not know any measures for TB prevention and control; and half of the participants did not know that anti-tuberculosis drugs were provided free of charge. Significant predictors of TB knowledge were: incarceration in the Jijiga (OR 9.62, P < 0.001) and Dire Dawa (OR 2.14, P = 0.016) prisons, those who did not consult and receive treatment for TB symptoms (OR 2.46, P < 0.001), and prisoners without a past history of TB (OR 2.72, P = 0.002). CONCLUSION: The study demonstrates that prisoners have a modest level of biomedical knowledge. As part of the National TB Programme, health education programmes need to be implemented to enhance prisoners' knowledge of TB.