Risk factors, clinical characteristics and seasonal trends in Brucella seropositive cases presenting as Pyrexia of Unknown Origin/or Undifferentiated Febrile Illness at a tertiary care center from Rajasthan

: Background Brucellosis is a zoonotic disease identified as a public health concern with worldwide distribution. This study was undertaken to determine its prevalence and to identify potential risk factors associated with the disease among individuals reporting with Pyrexia of Unknown Origin (PUO)/Undifferentiated Febrile Illness (UFI) Material and methods The present work was carried out between 2019 - 2022 at a tertiary care hospital located in eastern part of Rajasthan. Patients presenting with PUO/UFI who were reported/ tested to be negative for SARS-Cov-2, Influenza, Tuberculosis, Typhoid, Malaria, Dengue and Chikungunya were tested for Brucella, Orientia tsutsugamushi and Leptospira antibodies by IgM capture ELISA. Results Among 2996 patients tested, 8.50% (255) were positive for Brucella IgM antibodies. Male: Female ratio was 1.14 among Brucella-positive patients. Maximum number of positive cases were reported from Jaipur with positivity peaking in November (13.89%) and December (14.44%). Majority of patients reported fever, myalgia, and headache (95-100%). Male gender, rural population, consumption of raw milk, contact with animals, and lack of awareness about zoonotic diseases were major risk factors significantly associated with sero-positivity. Conclusion We observed 7.8% to 11.8% sero-positivity for brucellosis. Positivity was higher during November and December, individuals with history of animal contact and consumption of raw milk. There is a need to carry out large-scale sero-surveillance for estimating the burden of disease, and create awareness among clinicians for early detection to reduce morbidity and mortality. It is also important to identify region-wise risk factors responsible for disease transmission to plan control measures.