Increasing Trends of Leptospirosis in Northern India

Leptospirosis is often not suspected by physicians in patients with acute febrile illnesses reported from north India. Researchers from Postgraduate Institute of Medical Education and Research, Chandigarh retrospectively reviewed the records of Leptospirosis cases diagnosed at the institute between 2004-2008. In all, 232 cases of Leptospirosis were detected in the five years of study period (9 in 2004, 17 in 2005, 25 in 2006, 74 in 2007, and 107 in 2008). There was a sustained rise of Leptospirosis cases from 0.5% to 11.7%.
Cases were more common in the months of July-October for most of the years. The patients resided in different states of north India, however majority of patients were from Punjab, Haryana and Himachal Pradesh.

The authors noted that major epidemiological risk factors in these patients included wet environmental living conditions, lack of protective footwear, infestation of dwelling with rats, working in farm lands, contact with animals, especially cattle, bathing in public places, history of unprotected contact with dirty stagnant water, alcohol addiction, and smoking. Most of the patients by occupation were farmers (28, 32.6%), followed by housewives (19, 22.1%), students (11, 12.8%), laborers (10, 11.6%), indoor non-manual workers (10, 11.6%), para-military personal (2, 2.3%), sweeper (1, 1.2%), carpenter (1, 1.2%).

Leptospirosis can lead to serious complications that can affect most organ systems, including liver, kidneys, lungs and the central nervous system. The most common complication found in these patients was renal failure. Also observed were respiratory failure requiring mechanical ventilation, neuroleptospirosis, ascitis and pleural effusion. Using the Microscopic agglutination test the researchers could demonstrate high antibody titres to Pomona, Ballum, Gryppotyphosa, and Autumnalis serovars.

According to the researchers, the stupendous rise in the number cases seen in this study should not come as a surprise. Previous reports from Chandigarh, Ludhiana, New Delhi, and Uttar Pradesh have also pointed to the fact that leptospirosis is present all over India. Though north India receives less rainfall compared to the coastal regions and the south, most areas still receive 100 cm rainfall in the monsoon season between July and October. Flooding, not so uncommon unseasonal heavy precipitation, large agrarian , intimate contact with animals, unprotected entry into waterlogged fields, and bathing in contaminated community ponds are across north India are some of the many conducive factors that allow for the survival and transmission of Leptospira.

Given the protean manifestations of Leptospirosis and high risk of life threatening complications that can affect most organ systems, timely diagnosis and specific therapy is important to reduce severity of illness and, in turn, mortality. The disease is easily confused with other viral, parasitic and bacterial infections. Lack of awareness, clinical suspicion and active surveillance have led to this much-neglected disease entity emerge as a major cause of acute febrile illness in a so called ‘‘non-endemic area. The authors thus recommend that clinicians even in so called non endemic areas should be more vigilant. The modified Faine's criterion is an efficient tool available that could be used by physicians when evaluating suspected cases of Leptospirosis.

Source: Sethi S, Sharma N, Kakkar N, Taneja J, Chatterjee SS, et al. (2010) Increasing Trends of Leptospirosis in Northern India: A Clinico-Epidemiological Study. PLoS Negl Trop Dis 4(1): e579. doi:10.1371/journal.pntd.0000579