Health Risks From Rat Disease

Many people are aware that rats spread disease. I am not a doctor or an expert on zoonotic diseases, so I'm just repeating some other information that I've found on the web about rat diseases, as collected from the Centers for Disease Control and other sources. I list seven of the more serious diseases below, but it's my understanding that rats are associated with many more diseases, many not so serious.

I can personally say that in my experience working as a rat removal specialist, I've never contracted a serious disease from contact with rats or rat feces. I do, however, always wear protection, and you can see me in the photos on this website wearing gloves, a filter mask, and often biohazard suits. I always wash my hands. My anecdotal thought is that health risks from wild rats and other rodents like mice are relatively rare. But just as I wear a seatbelt in the car, I am careful around rats and rat feces.

 Eosinophilic Meningitis

An infection of the brain occurring in association with an increase in the number of white blood cells that are associated with infection by worms that penetrate into the body. The rat lung worm is called angiostrongylus cantonensis, and can be contracted by ingesting (even from hands) the worms from rat feces.

 Rat-bite fever (RBF)

A systemic bacterial illness caused by Streptobacillus moniliformis that can be acquired through the bite or scratch of a rodent or the ingestion of food or water contaminated with rat feces.


A bacterial disease that affects humans and animals who come into contact with rat poop. It is caused by bacteria of the genus Leptospira. In humans it causes a wide range of symptoms including high fever, headache, chills, muscle aches, and vomiting, and may include jaundice (yellow skin and eyes), red eyes, abdominal pain, diarrhea, or a rash. If the disease is not treated, the patient could develop kidney damage, meningitis, liver failure, and respiratory distress. In rare cases death occurs.

 Hantavirus Pulmonary Syndrome (HPS)

A deadly disease transmitted by infected rodents through urine, droppings, or saliva. Humans can contract the disease when they breathe in aerosolized virus. Although rare, HPS is potentially deadly.

 Murine Typhus

Caused by infection with R. typhi. It occurs worldwide and is transmitted to humans by rat fleas.

 Salmonella enterica serovar Typhimurium

In humans S. Typhimurium does not cause as severe disease as S. Typhi, and is not normally fatal. The disease is characterized by diarrhea, abdominal cramps, vomiting and nausea, and generally lasts up to 7 days. Unfortunately, in immunocompromized people, that is the elderly, young, or people with depressed immune systems, Salmonella infections are often fatal if they are not treated with antibiotics.

 Bubonic Plague

A zoonotic disease, circulating mainly among small rodents and their fleas. Caused by Yersinia pestis, which belongs to the family Enterobacteriaceae. Without treatment, the plague kills about 66% of infected humans within 4 days. Swollen lymph nodes (buboes) especially occur in the armpit and groin in persons suffering from bubonic plague. Read more about Biology of Black Rat.

 Help! I've been infected with rat disease!

Well, don't jump to any conclusions. Medicine is a tricky topic. I, and amazingly, many medical doctors that I've spoken with in my life, have a lot to learn, and are ultimately unaware of many aspects of the human body and pathogens. But, if you are sick, I still of course do recommend that you see a doctor, and you can cite rodents as a potential cause of the symptoms you are experiencing. Again, it's my general thought that health risks from rats, mice, and other rodents are relatively low, so long as you are careful. A mask to protect against respiratory diseases, gloves against those that are contracted via direct contact with wild rat feces.


Although I wrote this site with rats in mind, such as the Roof Rat and Norway Rat, the same principles apply to other rodents, such as the house mouse. Mice are very similar to rats, they're just smaller. Email me if you have any questions about mouse diseases, health risks associated with mice, bacterial disease, virus and viral diseases, rodent disease and risks to health.

Read more about rats:
Do cats keep rats away?
Do rats carry rabies?
Can Rats Chew Through Wires in a Car?
Does car insurance cover rat damage?
Do rats live in more urban areas, or wild areas?
Rats in New York subway
How do you remove a rat stuck in a dumpster?
Why are there so many rats in NYC?

If you have any questions or comments, e-mail me at