Frequency of leptospirosis in patients of acute febrile illness in Uttar Pradesh.

OBJECTIVE

This study was performed to asses the disease burden of leptospirosis in and around Lucknow among patients presenting with acute febrile illness and conforming to the case definition of leptospirosis.

METHODS

A total of 346 serum samples (mostly paired) and an equal number of urine samples were collected from patients presenting with acute febrile illness and fulfilling the criteria of clinical diagnosis of leptospirosis from January 2001 to December 2001. Patients attending a tertiary care hospital as well as from various communities in and around Lucknow were included in this study. All sera and urine samples were tested for the presence of IgM antibody by Leptodipstick test and by dark-field microscopy (DFM) respectively. All positive and 10% negative sera were tested at national leptospirosis reference centre at Andaman and Nicobar Islands for microagglutination test (MAT).

RESULTS

IgM antibody was detected in 25/346 (7%) patients ranging in age from 9-65 years. DFM was positive in only in one case. MAT was positive in 4/17 cases tested and the prevalent serogroups were L. grippotyphosa and L. pomona in two each. Common presenting features in these patients were fever (25/25) and jaundice (17/25). History of contact with animal or water contaminated with animal urine was present in 96% cases.

CONCLUSION

Leptospirosis is not uncommon in Uttar Pradesh. However larger epidemiological studies are required to know the actual disease burden. Dark-field microscopy is an insensitive method for the diagnosis of leptospirosis and is not suitable for surveillance.