Comparative Evaluation of Rose Bengal Plate test and ELISA in lab Diagnosis of Human Brucellosis

ABSTRACT

Human brucellosis is a major bacterial zoonosis reported worldwide. It is mainly an occupational disease reported in farmers, veterinarians, slaughterhouse workers, animal handlers and meat inspectors. Unavailability of automated blood culture systems makes isolation difficult and diagnosis mainly depends on serological and molecular methods. Materials and Methods: In a prospective study, a total of 127 serum samples, 28 from pyrexia of unknown origin (PUO) cases and 99 from high risk cases like veterinary personnel, butchers, nomads, farmers and gawalas, were serologically tested by Rose Bengal Plate Test (RBPT) and enzyme-linked immumosorbent assay (ELISA) and results were analyzed. Results: Out of 127 samples, 20 were tested positive by RBPT while 24 tested positive by ELISA. None of the PUO cases and veterinary personnel tested positive by RBPT or ELISA. Positivity was more among males, urban area, history of animal contact and consumption of raw milk. ELISA was found to be more sensitive and specific than RBPT. Conclusion: In our study significant prevalence of brucellosis was found among occupationally exposed persons. Most of the positive cases were found to be asymptomatic and those who were symptomatic had non-specific complaints. The findings signified silent presence of disease in our society. RBPT can be used as a rapid screening test in the peripheral resource poor labs and in absence of culture ELISA can be used for further confirmation.