Seroprevalence studies of human brucellosis in pyrexia of unknown origin (PUO) patients by various diagnostic modalities.

Abstract

Background: Brucellosis is a re-emerging zoonosis with global distribution. In India, it remains common but often neglected. In Rajasthan, where agriculture is prevalent, frequent contact with infected animals such as goats, sheep, and cattle leads to brucellosis-like clinical symptoms. This study aims to determine the seroprevalence of brucellosis in patients presenting with PUO (Pyrexia of Unknown Origin).

Materials and methods: This cross-sectional observational study was conducted on 170 suspected PUO patients from January 2019 to December 2019 in Western Rajasthan to detect the seroprevalence of Brucella. Patients with Widal, MP, and RA test positive were kept in exclusion criteria. All samples were tested by using screening test: Stained Febrile Antigen for Brucella abortus and Brucella melitensis by using, RBPT, Standard tube Agglutination Method (STAT). All samples were processed for ELISA IgM and ELISA IgG titers using Cal biotech kit, and the results were analyzed statistically.

Results: Out of 170 samples, 9 (5.29%), 8 (4.70%), and 11 (6.47%) were positive by RBPT, SAT and STAT, respectively, while 14 (8.23%) positive by ELISA. Positivity was higher in males 9 out of 14, urban area 8 out of 14, >60 years 5 (22.72%) of age, occupational risk of animal contact was in 10 (15.55%). Out of 170 cases had histories of animal contact 170 (100%), consumption of raw dairy products 23 (13.52%), and meat consumption 17 (10%). The most common clinical feature was fever 125 (73.52%) followed by headache and back pain. ELISA IgM and IgG antibodies were positive in 3 (1.76%) and 7 (4.11%) patients, respectively, and both ELISA IgM and IgG were positive in 4 (2.35%) patients.

Conclusion: Brucellosis is prevalent in Western Rajasthan, due to its dry climatic conditions. It should be considered in PUO diagnosis, with all preventive measures applied. A safe and effective vaccine in human is not yet available. Prevention relies on public awareness, safe livestock practices, and health-veterinary cooperation.