DETECTION OF BRUCELLOSIS IN OCCUPATIONALLY EXPOSED WORKERS

Abstract

3rucellosis since the discovery of Brucella melitensis by Sir David Bruce in 1887 continues to Jose a human health risk globally, despite the control measures undertaken by national luthorities in many countries. Currently B. melitensis remains the principal cause of human Jrucellosis globally. The recent isolation of distinct strains of Brucella from marine mammals md humans is an indicator of an emerging zoonotic disease. Half a million of new cases of lUman brucellosis are reported annually worldwide, however the World Health Organization llU10unced that these numbers are greatly underestimate the true incidence of human brucellosis lS the actual number of cases is estimated to be at least 10 times the figures officially announced. n Pakistan, the disease is possibly endemic but unfortunately no data is available. A safe and :ffective vaccine in humans is not yet available. Prevention of human brucellosis is dependent on he control of disease in animals by vaccination, effective heat treatment of the milk and other \airy products and hygienic precautions to prevent occupational exposure. 3rucellosis in endemic and non-endemic areas remall1S a diagnostic puzzle due to unusual lresentations and misleading non-specific manifestations. Conventional diagnostic methods culture, serological tests etc.) are unable to diagnose the disease accurately. Therefore rapid and eliable, sensitive and specific and easy to perform assays (PCR etc.) are urgently needed to .llow early diagnosis and adequate antibiotic therapy in time to decrease morbidity and nortality. n the present study, PCR assay was developed for the diagnosis of brucellosis. The PCR assay vas applied for the detection of brucellosis in different individuals occupationally exposed to nimals. The results of PCR assay were also compared with that of Serum Agglutination Test. It vas found that PCR assay is more sensitive and specific and establishes the diagnosis of ·rucellosis earlier than the conventional diagnostic methods. For confirmation of the results, the mplified products (223 bp region of BCSP 31 gene of Brucella) were cloned and sequenced. The v 3LAST analysis showed that these sequences have 100% homology with the BCSP 31 gene of ]rucella reported from other countries. her fore , there is also a need to develop diagnostic facilities (especially PCR based) and lational surveillance programme to combat this re-emerging zoonosis in an agricultural country ike Pakistan where vast majority of population is involved in livestock farming. In the present tudy, confirmation of brucellosis in individuals exposed to animals, highlights the importance of urther research for establishing risk of brucellosis in occupationally exposed population.