Leptospirosis In Humans: Risk Factors, Symptoms, Treatment, and Prevention
Sun, April 18, 2021

Leptospirosis In Humans: Risk Factors, Symptoms, Treatment, and Prevention


Leptospirosis is a bacterial infection that affects both animals and humans, explained Yvette Brazier of Medical News Today, a web outlet for medical news. Several species of the Leptospira genus of bacteria cause this disease and Weil’s disease or meningitis, which can be fatal. The bacteria is transmitted in the body through open wounds, the eyes or mucous membranes. Animals such as rats, foxes, and more can pass on the disease to humans.

Leptospirosis is more prevalent in tropical areas. According to the World Health Organization (WHO), the UN’s health agency, leptospirosis affects 10 or more people in every 100,000 every year. In temperate climates, leptospirosis affects between 0.1 and 1 per 100,000 people. It can affect 100 or more in every 100,000 people in an epidemic.

A Knowledge Assessment Survey of Leptospirosis in Post-Outbreak Sri Lanka (2010)

Suneth B. Agampodi and colleagues of life science and biomedical journal portal PMC wrote that a total of 601 participants responded to the survey from 63 clusters from 13 districts representing seven of nine provinces in Sri Lanka.  When asked “How many cases of leptospirosis have been reported from your area recently,” 35.3% of respondents in endemic and 33.7% of those in non-endemic areas answered “no idea.”

The respondents said they have never heard of the disease in the area (24.5% versus 32.1%). 26.2% of those from endemic areas answered “very few cases” compared to 22.4% of respondents in non-endemic areas. More respondents in endemic areas (10.8%) than in non-endemic areas (9.9%) answered “several cases.” 3.1% of those in endemic areas and 1.9% of individuals in non-endemic areas answered “large number of cases,” respectively.

When asked “What are the animals that can harbor ‘rat fever’ infection,” 93.7% of respondents said rats, followed by other rodents (22%), buffaloes (1.7%), and cattle (1.5%). None of the respondents answered dogs. As for the question, “What are the ways that you can get infection from those animals,” 57.9% answered contact with contaminated water, 47.7% said direct contact with infected urine, 25.4% stated drinking contaminated water, and 23.6% answered contact with contaminated wet soil.

When asked about the common symptoms of leptospirosis, the respondents said fever (86%), malaise (30.8%), headache (29.6%), muscle tenderness (28.8%), oliguria (14.8%), jaundice (14.6%), and red eyes (20%). 

When asked about the complications of the disease, 73.7% said death, followed by renal problems (39.5%), heart failure (15.3%), and hemorrhages (8.6%). According to the respondents, the methods that could be useful in preventing the disease were wearing boots and gloves (53.9%), using chemoprophylaxis before paddy field work (50.3%), disposing of waste properly (26.2%), avoiding flood water (20.2%), and drinking boiled cool water (20.1%). Agampodi and colleagues concluded that knowledge on leptospirosis is poor in Sri Lanka despite the disease’s massive outbreak and control programs initiated by the epidemiology unit.



What Are the Symptoms of Leptospirosis?

Symptoms usually appear about five to 14 days after infection. Public health institution CDC (Centers for Disease Control and Prevention) said the incubation period ranges from two to 30 days, cited Brazier. Symptoms of mild cases of leptospirosis include fever, chills, coughing, diarrhea or vomiting (or both), headache, muscle pain, rashes, red and irritated eyes, and jaundice. Most people recover from mild leptospirosis within a week, but 10% of patients may develop severe leptospirosis, said CDC.

On the other hand, the signs of severe leptospirosis appear after mild symptoms of mild leptospirosis disappear. Severe cases of leptospirosis depend on which vital organs are involved. Such cases cause kidney or liver failure, respiratory distress, and meningitis— which can be fatal.

If leptospirosis affects the heart, liver, and kidneys, the individual will experience fatigue, irregular (often fast) heartbeat, muscle pains, nausea, nosebleeds, pain the chest, poor appetite, jaundice, panting, and more. If not treated, this can cause kidney failure.

If it affects the brain or spinal cord, the person may develop meningitis, encephalitis, or both. If meningitis or encephalitis is untreated, it can cause serious brain damage. If leptospirosis affects the lungs, the person may experience high fever, panting, and coughing up blood.

Who Is At Risk?

A person is at risk of contracting leptospirosis if they spend a lot of time outdoors or around animals, said WebMD, a website on health and medicine. Farmers, veterinarians, underground workers, slaughterhouse workers, and military personnel are at risk of being infected. Flooding increases the likelihood of a leptospirosis outbreak.



How Is Leptospirosis Treated?

The disease can be treated with antibiotics such as penicillin and doxycycline. Doctors may also prescribe ibuprofen for fever and muscle pain. A person may require hospitalization in severe cases. Antibiotics may also be injected into the body.

How to Prevent Leptospirosis

People who do water sports during the holidays or those who regularly swim in freshwater should take precautionary measures. One example is to ensure that any cuts in the skin are covered with a waterproof dressing, protecting the person from a variety of infections, including giardiasis and hepatitis A. Showering thoroughly after swimming in fresh water should be done to prevent leptospirosis.

Individuals who work with animals or potentially contaminated water or soil should wear gloves, masks, boots, and goggles to reduce their risk of being infected. They may also need to follow local or national rules and regulations. For those who travel to areas where leptospirosis is prevalent, tourists and travelers should clean and cover any open wounds with a waterproof dressing, drink boiled water or water from a sealed bottle, and avoid swimming in fresh water (as much as possible). If visiting a developing country, don’t drink water unless it is clean and safe for consumption.



Do note that leptospirosis is more likely to occur in South and Southeast Asia, the Caribbean and Central America, Australia, the Andres and tropical Latin America, and East Sub-Saharan Africa. Emergency workers or military personnel deployed in disaster response initiatives might need to ingest antibiotics. 

Other useful tips include controlling pets, notably rodents, washing hands after handling animals and animal products, cleaning skin wounds and covering them with waterproof dressings, wearing protective gear at work, ensuring that dogs are vaccinated against leptospirosis, and more.


People should exercise caution and proper hygiene when handling animals or traveling to countries where leptospirosis is prevalent. Dogs should be vaccinated against the disease, as they can also be infected by the Leptospira bacteria.