Isolation of Mycobacterium bovis from human cases of cervical adenitis in Tanzania: a cause for concern?

SETTING

Pastoralist communities in the Northern and Southern zones of Tanzania.

DESIGN

Observational study.

OBJECTIVES

To determine the involvement of Mycobacterium bovis in tuberculosis cases presenting at tuberculosis (TB) clinics in rural areas in these zones.

METHODS

A total of 149 tuberculosis cases identified on the bases of clinical manifestation were sampled. Appropriate specimens were cultured on two Löweinstein Jensen slants with respectively glycerol and pyruvate added. Forty-one isolates were cultured and subjected to biochemical typing.

RESULTS

Overall, 31 (70.5%) of the mycobacterial isolates recovered from all forms of tuberculosis were identified as M. tuberculosis, seven (16.0%) were identified as M. bovis, and six (13.6%) were other mycobacterial species. There was a significantly higher isolation rate (P < 0.05) of M. bovis among strains recovered from extra-pulmonary (26.8%) than pulmonary tuberculosis samples (4.3%).

CONCLUSION

Based on these findings, it is imperative that M. bovis be considered as a pathogen of concern to people living in rural areas of Tanzania. Further work is required to establish a zoonotic link between cattle and the people in these communities who rear them.