10+ Dangerous Diseases Spread by Rats and Their Symptoms


Rats are types of rodents that are found in the home; apart from their destructive nature and disturbances and noises they create at night; they are carriers of deadly diseases hence they are called “deadly pests” or “disease ridden pests”. They were responsible for the outbreak of Black Death which killed millions of people in Europe in the 14th century.


Rats and mice are known to spread more than thirty five diseases; they are found in every continent of the world except Antarctica and they can adapt quickly to a wide range of habitat.

These diseases from rats are spread through direct contact with dead or live rats, through contact with their faeces (their fecal droppings triggers allergies and transmit food borne diseases), urine and saliva; their bites and scratches can also make one sick.

They can also spread diseases to humans indirectly through insects like fleas, ticks or mites that feed on infected rats and rodents.

The rate of diseases caused by rats are high during cold seasons; they come into homes to look for warmth and shelter, the National Pest Management Association estimated that twenty one million homes in the united states are invaded every winter.

This pests squeeze themselves through small spaces and opening to get into homes and they are said to be responsible for more deaths than all the wars put together over the last one thousand years. In this article, we will be looking at common and well known deadly diseases caused by rats.


Francisella tularensis is a bacterium that is haboured by rodents; it causes tularemia which is a medical condition that can be life threatening.

The bacterium can enter the human body through the skin, eyes, mouth, throat or lungs; this can occur through direct contact with infected pest, handling infected animals and meat, drinking contaminated water, eating contaminated food and inhaling contaminated dust or aerosols and this is one of the most serious infections known.

Fever is a common symptom of tularemia; there are other symptoms but it depends on the route of infection.

Ulceroglandular tularemia

Results when infected rodents bite or when they are handled without protection, symptoms are skin ulcer that appears at the site of bite or infection and swollen groin and lymph glands in the armpit.

Glandular tularemia

Symptom is swollen lymph gland without ulcers.

Pneumonic tularemia

This type occurs when the one breathes in contaminated dusts or aerosols; symptoms are cough, chest pain and serious difficulty and this is the most serious form of tularemia infections.

Occuloglandular tularemia

This type enters the body through the eyes and it results in inflammation of the eyes and swelling of the lymph glands near the ear.

Oropharyngeal tularemia

This type is caused by ingestion of contaminated food and water; symptoms are mouth ulcers, sore throat, tonsillitis and swelling of the lymph glands in the neck.

This infection is relatively rare and the symptoms can be mistaken for other diseases and it can last up to several weeks. It can be treated with antibiotics and if it is left untreated, it can lead to severe health complications and affects multiple organs like the lungs, spleen, liver and lymphatic system.


Rats and other types of rodents carry the Salmonella bacteria which can cause this illness for humans and their pets; people become infected with this disease when they take food and water contaminated with the faeces of rats.

Symptoms usually show 12 to 17 hours after infection and some of the symptoms are diarrhea, fever, vomiting and abdominal cramps. An infected person can also transfer this disease to healthy people through dirty hands and poor hygiene and sanitation.


Rodents carry a number of species of Bartonella bacteria which is responsible for Bartonellosis that cause a wide range of symptoms; Bartonella elizabethae has been found in rats in America, Asia and Europe.

This disease gives symptoms close to those of heart inflammation and eye diseases and it is treatable with antibiotics.


The specie of the tapeworm Echinococcus cause this disease and mice serve as the intermediate host; they pass on the cysts of the larval stage when they are eaten by cats and dogs and these domestic animals in turn pass it to man through their contaminated faeces.

When a human ingest this microbe; the larva hatches and bore holes through the walls of the intestine and goes into the bloodstream and from there it travels to important organs like the liver and the lungs, it also invades surrounding tissues and can remain there indefinitely.

This infection can be present in the body for years without showing any symptom or becoming obvious but the affected tissues begin to grow like tumors and it ends up causing organ infection and tissue rupture.

Infection of the liver and lungs are common in Echinococcosis and the symptoms are abdominal pain and chest pain, cough and bloody mucous respectively. Rupture tissues cause skin rash, fever, increase in the number of white blood cells and anaphylactic shock can occur in response to the large numbers of larvae released into the body.


Rats and other species of rodents are long term reservoirs of the bacteria Yersinia pestis which cause plague; this disease have caused many epidemic in history; it has wiped out large numbers of people over the years.

Coming in direct contact with infected animals and handling their tissues or fluid without protection can lead to bubonic plague or septicemic plague.

Pet like cats can also become infected when they eat infected rats. Rats and other rodents carry infected fleas and when they die from the disease, these fleas look for new host to feed on and they end up spreading bubonic or septicemic plague.

This disease is highly contagious; when the bacteria reach the lungs and cause lung infection, the patient begins to cough and this produces infected air borne particles that when they are inhaled by healthy individuals who are close by, it can result in pneumonic plagues in those individuals.

Bubonic plague

Symptoms are swollen and painful lymph nodes (Buboes where the bacteria multiply and spread from if not treated promptly and properly), extreme weakness and sudden onset of fever.

Septicemic plagues

Symptoms are fever, diarrhea, extreme weakness, abdominal pain, delirium, shock and bleeding in the skin and other organs; the skin and other tissues can turn black and die, especially the fingers, toes and nose.

Pneumonic plagues

Symptoms are shock, chest pain, cough, difficulty breathing, bloody mucous, fever and other symptoms of pneumonia. Plagues can be treated with antibiotics but it has to be prompt and early because it can cause rapid death.

In bubonic plague, death can occur in less than two weeks while death can occur before symptoms occur in septicemic plague and all cases of untreated pneumonic plagues lead to death.


Rodents are carriers of Hantaviruses which cause infections in humans; humans get infected with this disease when they come in direct contact with the urine, saliva and faeces of infected rodents or when they touch them or take food and drinks that are contaminated or by breathing in aerosolized particles.

Rat tapeworm

There are two types of rat tapeworm; they are Hymenolepis nana and H. diminuta; both of these species use beetles as their secondary host.

Humans become infected with rat tapeworm by ingesting food and water that has been contaminated with the beetles or rat faeces; or they touch thing and food items contaminated by these microbes and eat with the same hand without washing them.

Symptoms of rat tapeworm are anal and nasal itching, restless sleep, abdominal pain, enteritis, diarrhea, loss of appetite, irritability and restlessness.  This infection is severe in children and can cause serious medical problems but they have no damaging effect on adults.

Rat bite fever (RBF):

When rats bite or scratch a human; they can infect them with Streptobacillus moniliformis and spirillum minus; these bacteria are also present in their faeces, urine and secretions from the nose, mouth and eyes.

Handling infected animals without gloves or other means of protection and taking food and drinks contaminated with their faeces or urine can also cause this infection.

Streptobacillus occurs 3 to 10 days after infection and the symptoms are fever, joint pain, skin rash, muscle pain, headache and vomiting while Spirillum occurs 7 to 21 days after infection and the symptoms are recurrent fevers, ulcer at the site of the bite wound, skin rash, swollen lymph nodes and swelling around the wound; both infections can be treated with anti-biotics and if these infections are not treated well and promptly.

It can lead to more serious health complications like abscesses in internal organs, lung infection (pneumonia), infection of the brain (meningitis) and heart infections.


The bacteria Leptospira cause this infection and they live in the kidneys of rats and are excreted through their urine; humans become infected when they come in direct contact with the urine of infected rodents, they can also be infected when they come in contact with contaminated body fluids of infected animals like their saliva or infected soil, food and water contaminated with their urine.

When infected rats urinates, these bacteria can survive for months in soil or water; these bacteria can also enter the body through broken skin, scratches, cuts and also through the mucous membranes of the eyes, nose or mouth.

Symptoms appear 7 to 14 days after infections and some of them are headache, chills, skin rash, muscle pain, diarrhea, nausea, vomiting and redness of the eyes.


Rodents are the main host of Capillaria hepatica; which is a nematode (roundworm) that causes this disease; this protozoan requires only one host in its lifecycle and it depends on the death of the host to disseminate its viable eggs.

When rats are infected with Capillaria hepatica; the eggs hatch into the first stage larvae in the intestines and the bore holes through the walls of the intestines and go straight to the liver through the bloodstream.

In the liver of the rats; the larvae matures into adults in 18 to 21 days and then lay eggs in the tissues of the liver and this eggs are excreted because they cannot develop into larvae without spending time in the environment.

Humans become infected when they ingest food and water contaminated with these eggs or play or touch a contaminated soil and don’t wash the hands.

Domestic animals like cats and dogs also excrete the eggs in their faeces when they eat contaminated rodents; If the eggs are excreted in the environment; it requires about four to five weeks to develop into larvae but it can also remain viable for several months.

In the human body; the adult nematodes feeds on the liver and this ultimately leads to inflammation of the liver (hepatitis), impaired liver functions and abnormal fibrous tissue production occurs as the liver responds to presence of the eggs and the death of the adults.


Rodents are carriers of Salmonella typhi which can cause severe infection in man; it spreads from the intestines to the blood, lymphatic systems and other parts of the body.


The nematode worm is responsible for this infection and rats and other rodents help in maintaining their presence in the environment; T. spiralis and T. britovi are the main roundworm species that cause this infection.

Humans get infected when undercooked meat infected with this pathogen; other animals that are host to this disease causing nematode are domestic and wild pigs and in developing countries undercooked pork is the problem but for the sake of this article we will be looking at how it spreads through rats.

This infection is characterized by failure of the respiratory systems and it is rare in developed countries.


This is a very common infection caused by the protozoan Toxoplasma gondii. Rodents carry this microbe and infect both cats and humans; cats get infected when they eat rodents carrying the microbe and the cat excrete the virus through its faeces, humans get infected when they come in contact with contaminated cat faeces or infected rodents.

This infection gives no symptoms in some people but it is severe in people with weakened immune systems and pregnant women, it causes severe consequences in pregnant women like miscarriage, stillbirth and other dangers it poses to the fetuses.

Some people experience flu like symptoms with swollen glands and if left untreated it can be severe and can cause damage to the brain, eyes or other organs.

Weli’s disease

10% of leptospirosis cases lead to weli’s disease, which is a serious medical condition that can lead to internal bleeding, organ failure and death if leptospirosis is not treated promptly and properly. It needs urgent hospitalization where ventilator, dialysis treatments and intravenous antibiotics and fluids are given.

Symptoms of this severe infection are jaundice, coughing up blood, swollen feet, ankles and hands, headaches, vomiting, nausea, seizures, chest pain and other symptoms close to that of meningitis.


Particular species of rodents are known to carry or are associated with specific virus species of Arenaviruses which cause serious diseases in humans that usually appear as fever and acute haemorrhagic illnesses, example of a diseases caused by an Arenavirus is Lassa fever, the virus is spread by the multi-mammate mouse in west Africa.

The house mouse harbours the virus that spreads Lymphocytic choriomeningitis worldwide; the dry lands vesper mouse spreads Argentine haemorrhagic fevers; large vesper mouse spreads Bolivian hemorrhagic fever, the rodent vectors that spreads Chapare haemorrhagic fever and sabia associated haemorrhagic fever are unknown while the short tailed cane mouse cause the Venezuelan haemorrhagic fever.

There are no vaccines or specific treatments for infections caused by Arenaviruses because their biochemistry and physiology is not well understood; humans get infected with these deadly ailments when they come in contacted with contaminated food or other contaminated items or when they inhale contaminated particles.

Some can also be spread from person to person by direct contact with the blood or body fluids of infected persons; or when they touch infected objects such as medical equipment in a hospital.

How to prevent contracting diseases from rats

  • Regularly clean your home and surrounding environment as this will make this rodent unwelcomed and uncomfortable.
  • Properly cover your food stuffs, cooking utensils and cooked food, this will prevent contamination, starve them and force them out of the house.
  • Regularly practice hand washing; you might not know when you have come in contact with anything that has been contaminated by an infected rat.
  • If possible, do not let your pets eat rodents; it is okay if they kill it so that your pet won’t transfer rodent borne diseases to you.
  • Properly handle the dead bodies of rodents; don’t touch their carcasses with your bare hands, wear gloves on your hands and use tools like shovel or hoe to take it far from your home.
  • Avoid having dark and inaccessible corners in your home and try to keep the temperature of your home cool. This is to prevent them from having hideout.
  • Since these creatures are nocturnal; avoid leaving foods exposed in the kitchen when going to bed; clear the kitchen, wash the plate and clean the slabs.
  • If you see rat faeces, sweep it away and don’t try using your hands to pick it.

These deadly pests also have high rate of reproduction as they reproduce rapidly; they can produce half a billion offspring in three years; if conditions are suitable, the brown rats can bread throughout the year.

A female rat can mate as many as 500 times with various males during a six hours period of receptivity and she can experience this about 15 times a year; therefore a pair of brown rats can produce up to 2,000 offspring in a year.

The average lifespan of a rat is two to three years and a rat is sexually mature at three to four months old of age. Here are some effective home remedies to get rid of these dangerous.

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