Serologic Evidence of Leptospirosis in Patients Attending a Tertiary Care Hospital, Central Kerala, India- A Retrospective Study.

Leptospirosis is a zoonotic disease seen all over the world caused by pathogenic members of the genus Leptospira. Humans are infected by direct or indirect contact with an environment contaminated by urine of infected animals such as rodents, cattle and dogs. As the clinical manifestations of leptospirosis are nonspecific, laboratory diagnostic methods are needed for definitive diagnosis.METHODSThis is a retrospective study conducted in the Department of Microbiology, Government Medical College, Kottayam, Kerala, in patients with clinical features of acute febrile illness from January 2015 to December 2018. A total of 2941 blood samples were received for leptospira serology. They were subjected to specific anti leptospira IgM ELISA by Panbio Diagnostics, Brisbane, Australia. In the year 2018, 43 samples received during flood period were subjected to PCR, in addition to antileptospira IgM ELISA. For PCR, blood in EDTA, CSF and urine were sent to Manipal Centre for Virus Research, Karnataka. Twenty-five blood samples were sent for Microscopic Agglutination Test to Department of Veterinary Microbiology, College of Veterinary and Animal sciences, Mannuthy, India. Modified Faine’s criteria were assessed based on clinical, epidemiological and laboratory findings.RESULTSAmong 2941 cases of acute febrile illness, 777 (26.4 %) cases were serologically positive (IgM ELISA) for leptospirosis. Among 777 cases, maximum cases 481 (61.9 %) were seen during the year 2018, followed by 106 (13.64 %) cases during the year 2016, 104 cases (13.38 %) during the year 2015 and 86 (11.06 %) cases during the year 2017. Maximum cases were seen during the month of August, September, and October. Among 43 cases during flood 2018, 35 were (81.4 %) males and 8 (18.6%) were females. Maximum cases were seen in the age group of 41-50 years. Among the 43 cases, fever was present in all the 43 (100%) cases followed by myalgia in 36 (83.7 %) cases. Headache was seen in 22 (51.16%) cases, jaundice in 16 (37.2%) cases, cough and breathlessness in 15 (34.9%) cases, conjunctival suffusion in 13 (30.2% ), oliguria in 13 (30.2%) cases, vomiting in 11 (25.6 %) cases, abdominal pain in 7 (16.3%) cases, diarrhoea in 4 (9.3% ) cases, altered sensorium in 3 (6.9%) cases. Among complications, acute kidney injury was seen in 13 (30.2%) cases, followed by respiratory injury (ARDS) requiring mechanical ventilation in 10 (23.3%) cases and myocarditis in 4 (9.3%) cases.CONCLUSIONSLeptospirosis is a zoonotic disease of protean clinical manifestations with difficulty in diagnosis. Confirmation by diagnostic test is essential so that early diagnosis helps in early treatment and prevention of complications in turn reducing mortality.