Leptospirosis outbreak in 2005: L.T.M.G. hospital experience

Nine hundred and forty two serum samples from clinically suspected cases of leptospirosis admitted in Lokmanya Tilak Municipal General Hospital, Mumbai during July-September 2005 were tested by LeptoTek Dri-dot/Leptocheck. One hundred and sixty five positive sera by these tests were sent to I.R.R., Mumbai, for detection of leptospira IgM antibodies by ELISA (PanBio). Eighty seven positive sera were also sent to B.J. Medical College, Pune, for microscopic agglutination test (MAT) for serovar identification. Seropositivity with LeptoTek Dri-dot/Leptocheck was 34.3%. Adults and males predominated. All patients were febrile. The commonest presentation in adults was jaundice (81.4%), followed by oliguria (37.6%). In children, myalgia was commonest (75.6%), followed by conjunctival suffusion (54.7%). IgM ELISA positivity was 69.1% and MAT positivity was 29.9%. Commonest serovar detected in this geographical area was Leptospira icterohaemorrhagiae (42.9%), followed by L. bataviae, L. tarassovi, and L. pomona . Considering at least two of the above three serological tests positive, 127 cases could be diagnosed and only 89.8% of them could be diagnosed by ELISA and rapid test. Therefore, along with rapid serological tests, IgM ELISA should be routinely done for laboratory diagnosis of leptospirosis.