Leptospirosis is a bacterial disease of animals that can also affect humans. Exposure through water contaminated by urine from infected animals (most commonly rats) is the most common route of infection. Outdoor and agricultural workers (rice-paddy and sugarcane workers for example) are particularly at risk.
In India it is recognized as being one of the most common causes of fever in many parts of the country but not in the north, where it is regarded as being “non-endemic”. New research (1), however, confirms that it has become much more common in this part of India in recent years.
During the period 2004 to 2008 the Post-Graduate Institute of Medical Education and Research (PGIMER) in Chandigarh received 1391 blood samples from suspected patients with fever of unknown origin, from several parts of northern India, which they tested for leptospirosis. They found there was a sustained rise of leptospirosis cases from 11.7% to 20.5% across the period.
The researchers followed up 86 of the leptospirosis cases in more detail. Infestation of dwellings with rats (53.7%), working in farm lands (44.2%), and contact with animals (62.1%) emerged as the most common risk factors. Five of the 86 patients died and many more suffered severe complications: kidney failure (60.5%), respiratory failure (20.9%), blood clotting (11.6%), and damage to the nervous system (11.6%).
Leptospirosis, say the researchers, is often not suspected by physicians in patients with fever in supposedly non-endemic areas. They argue that doctors in northern India should be more aware of the possibility of the disease in their patients, as early diagnosis and treatment may reduce the number of complications and the death rate.
Reference
1. 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