EPIDEMIOLOGY OF BOVINE TUBERCULOSIS AND ITS PUBLIC HEALTH SIGNIFICANCE IN PESHAWAR

Abstract

A cross-sectional study of bovine tuberculosis (bTB) was carried in Peshawar, Pakistan. A total of 556 cattle and buffalo were screened for bovine tuberculosis. Out of 556 animals screened, 5.75% (3.9-8.0%) were found positive. The prevalence was higher in old animals (P= 0.001) as compared to younger animals. Prevalence also varied with source of animal (either raised on farm or purchased), stay of animals at night (indoor or outdoor) and herd size. Farmer’s knowledge about transmission of TB from animals to human as well as signs and symptoms of TB was extremely low. Only 3.6% farmers correctly stated the combination of three major symptoms of TB. For assessment of presence of Mycobacterium bovis (M. bovis) in milk sold at retail shops, milk samples were obtained from 92 milk shops and analysed for presence of M. bovis. Data on socio-demographic characteristics and KAP about TB was obtained from 800 M. bovis contaminated milk consumers. Mycobacterium bovis was detected in 8.7% (8/92) milk samples. Although 97.4% of the participants had heard of TB but only 39.6% knew that cough lasts for more than 3 weeks was one symptom. Only 79.2% have awareness that TB can be prevented and the most frequently stated (48.4%) method of TB prevention was good nutrition. Participants believed that TB can be cured by prayers/ eating well (41.8%) and also by herbal cures/ consulting Hakeem (35.7%). Mean knowledge score for the participants was 12.1± 2.47 out of maximum 22. Mean knowledge score varied significantly with ethnicity, level of education and residential status (Urban vs rural). Overall knowledge about TB was low. Next part of the study was conducted to determine the occurrence of active pulmonary tuberculosis due to M. bovis in abattoir workers, butchers, livestock farmers and veterinarians and to document the Knowledge and practices of these professional regarding bTB. The cross sectional study included 141 abattoir workers, 317 butchers, 50 livestock farmers, 5 veterinary doctors and vii3 veterinary assistants. Sputum samples were collected from those respondents who had chronic cough that last for more than 2 weeks. Four out of 16 suspected abattoir workers and 1 out of 50 livestock farmers were found positive for M. bovis by Polymerase chain reaction analysis. Duration of work as abattoir worker was found significantly associated (p<0.05) with occurrence of zoonotic TB. The knowledge of abattoir workers, butchers, livestock farmers and veterinary assistants regarding transmission of bTB from animal to human and symptoms of TB in human was very low. Most of these professional did not use protective material/ techniques and are considered at high risk of acquiring zoonotic tuberculosis. The last part of study aimed to determine the proportion of zoonotic TB cases out of overall human TB patients and school children, drug resistance of M. bovis isolates and knowledge, attitude and practices about TB. Total 300 human TB patients and 100 school children were included in the study. Sputum samples were processed by PCR for presence of Mycobacterium tuberculosis and M. bovis. Sputum samples from TB patients were cultured and M. bovis isolates were subjected to drug susceptibility testing. Data on knowledge, attitude and practices were obtained from TB patients by administering pre-tested questionnaire. Among TB patietns 4% (12/300) were infected with M. bovis. None of the school children was positive for M. bovis. Residence, occupation, presence of animals at home and sleeping in shed at night was found significantly associated with occurrence of zoonotic TB. Except one all M. bovis isolates were resistant to Pyrazinamide. Among other drugs resistance to streptomycin and isoniazid was high. Low level of knowledge and practices were observed.