Diseases Carried by Rats

Rat-borne diseases

Rats are undoubtedly one of the most dreaded rodents of all time, and for good reason. Known for residing in sewers, around garbage and in drains, it’s no surprise the critters carry many diseases that can be extremely harmful to humans. These can be transmitted in a number of ways, including coming into contact with rat droppings, saliva or urine, being bitten by a rat, handling a rat, or being bitten by an infected flea.


For this reason, these long-tailed rodents are even more dangerous than people first realise, making it crucial to get on top of the problem as quickly as possible if you do spot one in your home. You can check out our website for top tips and tricks for doing so, but for now let’s take a look at which diseases rats carry.

What disease do rats carry?

Rats carry many viruses and bacteria than can cause life-threatening illness for humans, but the three main ones are:

Weil’s disease (rat urine disease)

Weil’s disease is a bacterial infection that can be spread to humans through rat’s urine. The original infection is called leptospirosis, with Weil’s Disease being the name for this infection once it’s developed into its second phase. As rats can live with leptospirosis completely symptom-free, it means that their populations are often highly infected with the bacteria, making transmission to humans more likely. In fact, it’s the most widespread animal-to-human transmitted diseases in the world.


People usually contract the disease when swimming in open water where there is a presence of rat urine, especially if they have any cuts or open wounds while doing so. Once infected, symptoms can occur between three to 21 days and usually come in two phases.


The first of these include flu-like symptoms including high fever, chills, headaches, muscle aches and pains, vomiting and sometimes a rash. The second phase can include things like jaundice, diarrhoea and meningitis-like symptoms, as well as kidney and liver failure in severe cases. Phase two usually happens after a brief period of feeling well again, but in milder cases some people may recover fully without a phase two.

Lungworm Disease

Angiostrongylus cantonensis, otherwise known as rat lung worm disease, is a parasite that lives in rats and other rodents. It’s one of the diseases than can be caused by coming into contact with rat droppings, as these can contain the worms’ larvae. This is usually passed on to snails and slugs when they come in contact with rat faeces.


This can be transmitted to humans when the parasite larvae get onto things like lettuce due to snails crawling across it, and it can also be transmitted if children accidentally ingest infected snails or slugs in the garden.


Luckily the parasite isn’t typically dangerous for humans and most people don’t even show any symptoms. If symptoms do occur, they can include muscle aches, headaches, a stiff neck, a slight fever and vomiting, although they’ll usually resolve by themselves within a couple of weeks.


Hantaviruses are a variety of viruses that are known to live in rodents, and which can be spread to humans through rat urine, droppings and saliva. The type of Hantavirus the rat has will depend on its breed, but if the virus spreads to a person it can have severe consequences including Hantavirus Pulmonary Syndrome (HPS).


This is a dangerous respiratory disease which can, in some cases, be fatal, so it’s crucial to seek medical help immediately if you have any of the symptoms and suspect you have come into contact with rat urine, faeces or saliva. These include fatigue, fever, muscle aches, dizziness, chills, nausea and vomiting, and can progress to severe coughing and shortness of breath. There aren’t any known cases of this disease spreading from person-to-person.


Another illness caused by Hantavirus is haemorrhagic fever with renal syndrome (HFRS) which is actually the name for a group of diseases with similar symptoms including severe intense headaches, back and abdominal pain, nausea, fever and blurred vision. This set of diseases, too, can be fatal so urgent medical attention should be sought if you’re worried about symptoms such as these.


If you suspect you have rats living in your home, the above diseases are just a few of the reasons you should tackle the problem immediately. We believe the safest and most efficient way of doing so is with d-CON Corner Fit Bait Stations, but for more detailed information on everything you need to know about dealing with rats, browse the rest of our handy articles.