How Can I Catch A Rodent Disease?

• inhalation or direct contact with rodent excreta (urine, faeces, saliva);
• handling or inhaling microorganism particles aerosolized from hay, woodpiles or other materials contaminated with infectious rodent urine;
• particles aerosolized by sweeping rodent infested spaces;
• handling of infected rodents by hunters or other people;
• bites from rodents — microorganisms carried in saliva can infect both humans and other rodents;
• scratches from rodents;
• drinking contaminated water or eating contaminated food;
• rodents acting as sources for infecting ectoparasites (ticks, fleas, mites, lice) with various pathogens;
• dogs, cats and foxes (especially urban) eating rodents and then catching parasites such as tapeworms that can be passed on to humans by them; and
• rodents can also act as reservoirs for various flying-insect-borne diseases.

Leptospirosis

Leptospirosis is an infection caused by species of Leptospira bacteria. It is caught from the urine of infected animals, which include rodents and also cattle, pigs and dogs.

Humans can become infected by:

• direct contact with urine or other animal body fluids (except saliva) of infected animals;
• contact with soil, water or food contaminated with the urine of infected animals.

The bacteria live inside the animal’s kidneys and are passed out in urine. They can survive for weeks or months in soil or water.

The bacteria do not only enter the body through the mouth, they can also enter through the skin, especially if broken by a scratch or cut, and the mucus membranes of the eyes, nose and mouth.

Risk

Leptospirosis occurs throughout temperate and tropical zones, but is more common in tropical and subtropical areas where the temperature and humidity are more favourable for its growth.

The risk of catching it is low for most people. However, occupations or activities that have contact with animals or freshwater sources have a higher risk.

Occupations & activities at higher risk

• farming;
• abattoir workers;
• vets;
• sewer workers;
• mine workers;
• fish workers;
• fishing;
• sailing;
• swimming

Symptoms of Leptospirosis

Symptoms of Leptospirosis show in around 7-14 days and can include mild to severe flu-like symptoms including:

• headache;
• chills;
• muscle pain;
• nausea; vomiting;
• redness of the eyes;
• diarrhoea; and
• skin rash.

It can be treated with antibiotics.

Bartonellosis

Bartonellosis is caused by a number of species of Bartonella bacteria, several of which can be carried by rodents and which cause a wide range of symptoms.

The disease can be transmitted between animals by biting arthropods such as ticks, fleas, sandflies, lice and mosquitoes.

Trench fever

The most well-known species is B. Quintana which was the cause of trench fever during the First World War and spread by the body louse. This species is not known to have an animal reservoir, however. Cat scratch disease is also caused by several Bartonella species.

Geographic distribution

Bartonella elizabethae has been found in rats in America, Asia and Europe. Several other species that can infect humans have been found in ground squirrels and deer mice in Thailand.

Patients with these infections have shown symptoms of heart inflammation (endocarditis, myocarditis) and eye disease (neuroretinitis).

Treatment is with antibiotics.

Capillariasis

Capillariasis involving rodents is caused by one species of nematode (roundworm), Capillaria hepatica. It is unusual in that the lifecycle of the nematode requires only one host and it depends on the death of the host to disseminate viable eggs.

Rodents are the main host, but it can also be other mammals, including humans.

Lifecycle

Infection starts with ingestion of food, water or soil contaminated with “environmentally conditioned” eggs.

• The eggs hatch into first stage larvae in the intestines where they bore through the intestinal wall into the blood system and the liver.
• In the liver the larvae mature into adults in 18-21 days and then lay eggs in the liver tissue. These cannot mature into larvae until they have spent time in the environment, which is usually on the death of the animal or if the rodent is eaten by a predator or scavenger.
• It the rodent is eaten, the eggs do not hatch but are passed out into the environment in the faeces of the predator. The eggs then require 4-5 weeks to develop but can remain viable for several months.

Symptoms

The adult nematodes feed on the liver, slowly causing loss of liver function, inflammation (hepatitis) and abnormal fibrous tissue production as the liver responds to the death of the adults and the presence of eggs.