Leptospirosis

Causative agent

Leptospirosis is a disease caused by bacteria of the genus Leptospira and affects humans and animals. The numerous Leptospira strains can establish infections in a variety of animal hosts that includes rodents, livestock, and wildlife while humans serve as incidental hosts. Wild and domestic animals in the carrier state may excrete leptospires intermittently for many years. Leptospira is common worldwide, especially in tropical areas with heavy rainfall, and can live for a long time in fresh water, damp soil, vegetation and mud. Flooding after heavy rainfall helps spread of the bacteria in the environment. 

Clinical features

Common symptoms include high fever, severe headache, chills, muscle aches and vomiting. Other symptoms including jaundice, red eyes, abdominal pain, diarrhea or rash may also occur. If the disease is not treated, the patient could develop potentially fatal infections of the kidneys, liver, brain, lungs or heart and even death.

Mode of transmission

Humans usually become infected through contact with water, food or soil contaminated by urine from infected animals, especially rodents. This may happen through skin contact, especially with mucosal surfaces, such as the eyes or nose, or with broken skin or by swallowing contaminated food or water. The disease can also be transmitted through contact with other body fluids from infected animals or rodent bites. Person-to-person transmission is rare.

High risk groups

People who work outdoors or with animals and people who participate in outdoor water sports such as swimming and wading in contaminated lakes and rivers have higher risks for the disease.

Incubation period

The incubation period is usually 5 to 14 days, with a range of 2 to 30 days.

Management

Leptospirosis can be treated with antibiotics.

Prevention

• Avoid contact with fresh water, soil and vegetation that might be contaminated with the urine or bodily fluids of infected animals, especially rodents.
• Avoid directly touching urine or bodily fluids from an infected animal. Never touch a dead animal with bare hands.

• Wash or shower after exposure to contaminated water or soil.
• Clean wound immediately and cover properly with waterproof adhesive dressings until healed.
• Wear appropriate protective clothing or footwear when participating in recreational or work activities that might result in contact with contaminated soil or water.
• Perform hand hygiene frequently. Wash hands with liquid soap and water after handling pets or animals, and disinfect contaminated areas.
• Drink only boiled water from the mains or bottled drinks from reliable sources.

• Prevent rodent infestation by keeping food, water and trash in closed containers and maintaining the hygienic condition of the environment.
• Leptospirosis can be spread by contaminated soil and water during and after typhoons and storms. Whether practicable, stay indoor during typhoons and storms, avoid travelling to areas with potential flooding, and not to wade or contact with muddy water and soil.
• Travellers can contract the disease through outdoor water sports. Risk of infection can be minimised by limiting exposure to water sources, such as rivers, ponds or lakes that might be contaminated with the urine or bodily fluids of infected animals and avoiding swimming or wading in potentially contaminated water.