Leptospirosis: Seroprevalence, risk factors, and diagnostic view in a tertiary care center in North India

INTRODUCTION: Leptospirosis is a zoonotic disease with clinical manifestations, ranging from subclinical infection to fulminant disease. OBJECTIVE: To study the seroprevalence, various epidemiological risk factors, and diagnostic aspects of leptospirosis. MATERIALS AND METHODS: One hundred and seventy-one clinically suspected individuals were enrolled in the study at Jawaharlal Nehru Medical College and Hospital, AMU, Aligarh, during January 2013-May 2014. A detailed history of patients was taken on a predesigned pro forma. Blood sample was collected from the patients, and immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and microscopic agglutination test (MAT) were done for diagnosis. The patients' details were also scored according to the modified Faine's criteria. RESULTS: Of 171 patients, 24 (14.1%) cases were diagnosed positive by IgM ELISA. Contact with dirty surroundings, fieldworkers, history of animal contact, and use of public bathing facilities/ponds were associated with 20 (83.3%), 20 (83.3%) 19 (79.2%), and 18 (75%) cases, respectively. Fifteen (62.5%) cases were diagnosed during July-September (P = 0.004). Fever, myalgia, and abdominal pain were the common symptoms. Calf tenderness was seen in 22 cases (P < 0.0001). Of 24 seroreactive cases, 20 (83.3%) cases were positive by PCR. MAT was performed for only 15 serologically reactive patients. A titer of 1:40 was observed in only two cases. Faine's score (Part A + Part B + Part C) was calculated for all ELISA-reactive patients. Only one case had score between 20 and 25 and the rest had >25. CONCLUSIONS: Dirty surroundings, fieldworkers, animal contact, and heavy rainfall are the major epidemiological risk factors for leptospirosis. Modified Faine's criteria may play a useful role in diagnosis for a patient with low clinical score.