Context: Leptospirosis has emerged as an important infectious disease in the world today. Alarmed by a rise in leptospirosis cases before monsoons, the civic health department in Mumbai has decided to study the 300-plus patients who tested positive. 

• It is a potentially fatal zoonotic bacterial disease that tends to have large outbreaks after heavy rainfall or flooding.

About Leptospirosis

• It is a contagious disease in animals but is occasionally transmitted to humans in certain environmental conditions.

• Caused by: A bacterium called Leptospira interrogans, or leptospira.

• Carriers of the disease: Wild or domestic animals, including rodents, cattle, pigs, and dogs, water buffaloes, goats, horses, and sheep.

• Misconception: The disease has been called “ili jwara” in Kannada and “eli pani” in Malayalam, both meaning “rat fever”. This usage has fed the common belief that rats are the sole cause of the disease, which is not true.

Disease Transmission

• The cycle of disease transmission begins with the shedding of leptospira, usually in the urine of infected animals. 

• According to the U.S. Centres for Disease Control and Prevention, infected animals can continue to excrete the bacteria into their surroundings for a few months, but sometimes up to several years.

Which people are at risk?

• Humans become part of the cycle when they come in direct contact with this urine or indirectly, through soil and water that contain leptospira bacteria. 

• A person is more likely to contract leptospirosis if they have cuts or abrasions on their skin.

• Symptoms: In milder cases, patients could experience a sudden onset of fever, chills, and headache – or no symptoms at all. 

• In severe cases, the disease can be characterised by the dysfunction of multiple organs, including the liver, kidneys, lungs, and the brain.

Major drivers of the disease

• Extreme weather events like floods and hurricanes

• Poor waste management

• A high density of stray animals

• Faulty drainage systems, and unhygienic sanitation facilities

• Contaminated paddy fields

• Dirty livestock shelters

Prevention of Leptospirosis

• Leptospirosis control can benefit from a ‘One Health’ approach. 

• ‘One Health’ is an interdisciplinary approach that recognises the interconnections between the health of humans, animals, plants, and their shared environment.

• Wearing personal protective equipment like gloves and boots while dealing with animals. 

• Sanitary animal keeping conditions.