Explained | Leptospirosis, a disease that surges in the monsoon months

Leptospirosis has emerged as an important infectious disease in the world today. It is a potentially fatal zoonotic bacterial disease that tends to have large outbreaks after heavy rainfall or flooding. This article explains its character, symptoms, risk factors, and precautions.

Leptospirosis has emerged as an important infectious disease in the world today. It is a potentially fatal zoonotic bacterial disease that tends to have large outbreaks after heavy rainfall or flooding.

The disease is more prevalent in warm, humid countries and in both urban and rural areas. It affects an estimated 1.03 million people every year, killing around 60,000. The burden of leptospirosis is expected to increase in the future as the urban poor population in tropical countries increases even as sanitary infrastructure falls shorter. In India, thousands of people are affected by leptospirosis every year.

However, the numbers at the global and regional levels aren’t exact because of misdiagnosis (its symptoms mimic those of dengue, malaria, and hepatitis), limited access to reliable diagnostics, lack of awareness among treating physicians, and lack of environmental surveillance.

Within India, studies have found that leptospirosis is more common in the south, although this could be due to the region’s better healthcare and thus better disease detection.

What causes the disease?

The disease is caused by a bacterium called Leptospira interrogans, or leptospira. It is a contagious disease in animals but is occasionally transmitted to humans in certain environmental conditions.

The carriers of the disease can be either wild or domestic animals, including rodents, cattle, pigs, and dogs.