Tiny germs can make us sick. 
Tiny germs can make people and animals sick. 
Leptospirosis is a sickness caused by tiny germs. We call these germs bacteria. 
Most people feel mild symptoms. They may have a fever, headache, or muscle pain. Some people get yellow skin or eyes. This is called jaundice. A severe form is known as Weil's disease. It can cause kidney failure or bleeding. Some people may even bleed in their lungs. This is very serious. Doctors can find the germs by testing blood. They use antibiotics to treat the sickness. Antibiotics are medicines that fight germs. To stay safe, people should wash well after contact with animals. It also helps to keep rodents away from homes and work areas.
Leptospirosis is a blood infection caused by tiny living things called bacteria. These bacteria belong to a group named Leptospira. 
The way this infection spreads follows a specific path. The bacteria live in the urine or feces of animals. They can stay alive in moist soil or stagnant water. Humans get sick when they touch this contaminated water or soil. The germs enter the body through the eyes, mouth, or nose. They can also enter through small breaks or cuts in the skin.
A doctor named Adolf Weil first described the disease in 1886. He worked in Germany. 
There are many important facts about how the bacteria behave. Scientists have identified 66 different species of Leptospira. 
Understanding this disease helps us see how humans, animals, and nature are linked. This connection is called One Health. 

Leptospirosis is a serious blood infection caused by bacteria of the genus Leptospira. 

The bacteria move through the environment using a unique biological mechanism. Leptospira are spirochaete bacteria, which means they have a spiral or helical shape. 
Transmission of the infection follows a specific pathway from animals to humans. The bacteria are spread through the urine or feces of infected animals. Rodents are the most common animals to spread the disease. The bacteria can survive for long periods in moist environments like stagnant water or soil. Humans become infected when they come into contact with this contaminated material. The bacteria enter the body through the eyes, mouth, or nose. They can also enter through breaks or cuts in the skin.
Symptoms of leptospirosis often appear in two distinct stages, known as a biphasic illness. The first stage is the acute or leptospiremic phase, which lasts five to seven days. During this time, patients experience sudden fever, chills, intense headaches, and muscle aches. Pain is often felt in the calves and the lower back. A very characteristic sign is conjunctival suffusion, which is redness in the eyes without discharge. 
Severe cases of the disease can lead to life-threatening complications. One severe form is called Weil's disease, named after physician Adolf Weil who described it in 1886. 

Scientists classify the 66 known species of Leptospira into different groups. They are divided into two main clades, which are large evolutionary branches. These are further divided into four subclades: P1, P2, S1, and S2. The P1 subclade contains 19 members, including eight species that cause severe disease in humans. The P2 clade includes 21 species that may only cause mild illness. The S1 and S2 subclades contain saprophytes. These are organisms that live by consuming decaying matter in the environment.
Managing leptospirosis requires a strategy known as One Health. This approach recognizes that human health is connected to animal health and the environment. 

🖼️ Images & Media (12)
More to explore
✨ What else?
Related topics you might enjoy
🔬 Go deeper
More advanced topics to explore
🪜 Step back
Simpler topics to build understanding
What is Nepedia?
A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.