Rat fever

What is rat fever?

Rat fever is an illness caused by a bacteria transmitted to humans from rat, mice and rodents. The fever is called rat bite fever.

Rat fever is commonly seen in Asia, Europe and South America.

How does rat fever spread?

The bacteria is spread through their urine and mucous secretions. The bacteria may be transmitted by their bites or through any cut or wound in the human body. It is an infectious disease caused by two different bacteria.

The disease can spread to humans through pet animals infected by rat bite also. The bacteria can be transmitted by bite and handling of the rodents infected. The disease do not spread from human to human. Humans are affected by the disease by just getting into contact of water, wet soil or vegetation contaminated by the urine of rats, mice or rodents that are infected.

Many diseases may spread due to rat bite or rodent bite and infections transmitted by them. Rat fever is one among them.

There are a number of rat varieties present world over and people in different geographical regions are known to be affected by different diseases. Humans are mostly affected by black rat and brown rat while infection from any type of rat is possible.

The origin of rat fever

Rat fever was first described in India about 2300 years ago but are known to the western world just about 200 years ago. The incidence of rat fever is more in children as rats have been popular pets in some nations. At the same time rats have been in use in laboratories for conducting various researches on food and medicines later used for human consumption. Such laboratory use is in vogue for more than a century and it is the brown rat which is mostly used. In recent times cancer research institutes use rat for various tests.

It is estimated that about 95 percent of animals used for research in laboratories are rats and mice. Starting from formulation of dietary supplements to cancer drugs, mice and rats play a crucial role.

Researchers rely on mice, rats and rodents for they are very small and can be easily handled. Moreover their life span is small, about two to three years only, and so many generations of the animals can be observed within a short period of time.


Rat fever is also called leptospirosis and is a serious infection which spreads to all parts of the body. The infection can get into the body either through skin or through oral consumption of items contaminated by rats.

There are two types of rat bite fever. They are spirillosis and streptobacillosis.

Spirillary rat bite or spirillosis is suspected and identified by symptoms like repetitive fever, formation of ulcer at the site of the rat bite, swelling, swelling of the lymph nodes and rashes in the body other than the bite site. Symptoms normally appear after one to three weeks of bite or transmission of the infection into the body.


In the case of the other type, namely streptobacillary, the symptoms are headache, body pain, muscle pain, vomiting sensation, fever and rash. Here also the symptoms appear after three to ten days of the bite or transmission.

All sorts of people who get into contact with rat or rodent either by their inhabitance at the dwelling places or in the laboratories where they are used for various tests can be infected by both types of diseases. So also during rainy days stagnant water or flowing water may have been infected by rat urine and mucus secretions which in turn transmit to humans on contact. People who are involved in scavenging activities and veterinarians who attend to the rats or other pet animals infected are also infected.

The disease has the potential to inflict damage to vital organs and can lead to life threating complications like renal failure, hypotension or hemorrhage. If not diagnosed early and appropriately treated the infection can even lead to the extent of death.

Diagnosis of rat fever

Diagnosis of rat fever is carried out by conducting laboratory tests. Blood test and fluid tests will reveal the type of bacteria that has affected the person. Fluids from the joints and lymph nodes are collected for testing. Skin and blood anti body tests are also conducted wherever required.

Cure for rat fever

Rat bite fever can get cured without any treatment but it may take more time, may be even a year. Since prolonged fever can cause severe damage to other organs of the body including the linings of the heart, treatment must be given urgently once diagnosed. Rat bite fever is treated with antibiotics only for quick cure.

Prevention of rat bite fever can be only by avoiding contact with rats, mice and rodents and their dwellings.

Ramya Srinivasan, PDGBA, earned her Master’s degree in Business. As a result of her passion in native medicine, she got her Diploma in Traditional Siddha Medicine from Bharat Sevak Samaj registered under the Indian Planning Commission. She is certified by Stanford University School of Medicine in Introduction to Food and Health.