Introduction 
Leptospirosis is a zoonosis a disease acquired from animals. Rats and dogs are reservoir of infection. It can occur in domestic animals and few wild animals. Rats are asymptomatic and shed organisms in urine for a life time. Alkaline pH of urine helps in the growth of organism. They also are present in soil for many days. They enter humans through skin or through eyes conjunctiva or through mouth. They particularly enter man through wounds. It is an occupational disease for people working in slaughter house or in drains or in veterinarians.
Symptoms
The presentation varies from an asymptomatic infection to very severe disease. The incubation period that is the period from exposure to an infection to appearance of the first symptoms is usually 7 to 13 days but may vary from 4 to 20 days. Mostly it is an asymptomatic infection. But few experience severe disease. In mild cases there is flu like illness with fever, headache, muscle pain and eye redness. There may be sore throat or rash on skin. The symptoms stop after 5 to 7 days. After 1 to 3 days the symptoms recur. Immunological symptoms may occur after many days eg eye disease Severe disease is complicated by jaundice and kidney disease. Acute kidney disease occurs many patients . There may be bleeding in nose, or coughing of blood or intestinal bleeding . The patient may die due to shock, Acute Respiratory Distress Syndrome (ARDS) or due to multiple organ failure or due to bleeding in intestines.
Prevention
Prevention and control includes susceptible people wearing protective personal equipment,decontamination of surfaces, rat control and also prevention of exposure to contaminated water. Drug used to prevent leptospirosis is by taking 200 mg doxycycline per week.