Rodent-borne diseases

As human and rodent habitats continually expand and overlap, we come into closer contact with more species of rodents and more rodent-borne diseases each day. Rodents play a significant role in the transmission of many disease-causing pathogens to humans. In fact, rodents are thought to be responsible for more deaths than all the wars over the last 1,000 years.

Rentokil specialists are here to protect your business from the many rodent-borne diseases that may put your patrons and employees in harm's way. Our specialists are trained to effectively remove mice or rats from your business, giving you the peace of mind you need that your building is a safe environment for all who enter.

Parasites

Research has shown that rats can harbor multiple infectious parasites at one time. They are reservoirs for many diseases including those carried by ectoparasites such as fleas, ticks, lice and mites.

One study found parasites that had rarely or never previously been investigated in wild rats (e.g. Cryptosporidium, Pasteurella, Listeria, Yersinia, Coxiella and Hantavirus) were a greater threat to human health than previously thought.

Allergens and asthma

An infestation of mice or rats also means the introduction of allergens. A protein found within their urine has been reported to trigger asthma and closely-related allergic conditions in susceptible people. The residue from rodent urine can easily spread all over a facility, with the highest concentrations usually in kitchens, and lead to potentially serious asthma attacks.

Because mice typically urinate in micro-droplets wherever they are nesting, eating and traveling, mouse urine can literally be found on thousands of surfaces throughout a building. This means employees and patrons can easily be exposed to rodent allergens whether they realize it or not.

How can I contract a rodent-transmitted disease?

Since many rodent-transmitted diseases are dangerous and have the potential to make you seriously ill, it is important to understand the ways in which they are contracted by humans.

• Inhalation or direct contact with rodent excreta (urine, feces, saliva);
• Handling of or close contact with infected rodents;
• Getting bitten or scratched;
• Consuming water or food contaminated by rodent droppings or urine.

Hantavirus

Many species of rodent carry hantaviruses, especially voles and mice.

Symptoms: Different species carry different viruses, so the virulence varies but all show similar flu-like symptoms.

Transmission: In the U.S., most cases are caused by humans breathing in aerosolized particles. However, there is also a slight risk of catching the disease through direct contact with an infected rodent, rodent urine, saliva or feces, or through consumption of contaminated food or drink.

Bartonellosis

Bartonellosis is caused by a number of species of Bartonella bacteria, several of which can be carried by rodents.

Symptoms: Symptoms of Bartonellosis include a low-grade fever, enlarged lymph nodes, a pustule at the site of the scratch or bite, and muscle pain.

Transmission: Zoonotic diseases (those transmitted from animal to human) are commonly transmitted to pets or other animals through the bites of infected vectors like fleas or lice. The disease is then transmitted to humans through a scratch or a bite, thus earning the name “Cat Scratch Disease.”

Rats are known reservoirs for Bartonella. Fleas found on rats can potentially vector these bacteria to humans who come into close contact with them.

Salmonellosis

In the US, probably one of the most common maladies associated with mice is food-borne illness. Mice have a tendency to live in or frequent unsanitary places such as sewers or garbage piles where they acquire bacteria such as salmonella and then harbor it in their digestive tracts. Mice then enter buildings and contaminate food and food surfaces with their infected droppings, which can lead to acute food-poisoning in humans.

Symptoms: Diarrhea, fever, vomiting, and abdominal cramps may begin 12-72 hours after infection.

Transmission: Once a person is infected, salmonella is easily transmitted to other people through poor hand hygiene and sanitation.

Leptospirosis

Leptospirosis is an infection caused by a bacteria called Leptospira. It is found in the blood and urine of animals, including rodents, cattle, pigs and dogs.

Symptoms: Anytime between 2 days and 4 weeks after exposure, mild to severe flu-like symptoms may arise including:

• headache
• chills
• muscle pain
• nausea
• vomiting
• redness of the eyes
• diarrhea
• skin rash

Transmission: Leptospira bacteria live inside the animal’s kidneys and are passed out in urine. They can survive for weeks or months in soil or water. Humans can become infected by:

• bites by infected mice or rats
• ingestion of food or water that was contaminated by the urine of infected mice or rats
• skin contact with water, soil or vegetation that was contaminated with the urine of mice, rats or other infected animals

Leptospirosis is found worldwide, including the U.S. In the U.S., rodent-associated leptospirosis has been shown to be quite prevalent in some areas.

The risk of contracting leptospirosis is low for most people. However, occupations or activities that involve frequent contact with freshwater sources or moist environments have a higher risk.

Rat-bite fever

In the United States, Rat-bite fever (RBF) is caused by the bacteria Streptobacillus moniliformis. In infected rodents, the bacteria are present in feces, urine and secretions from the mouth, nose and eyes.

Symptoms: 3-10 days after infection, symptoms such as fever, vomiting, muscle pain, headache, joint pain, and rash may arise.

More serious complications can include:

• heart infections
• meningitis (brain infection)
• pneumonia (lung infection)
• abscesses in internal organs

Transmission: RBF is usually caused by a bite or scratch from an infected rat or other rodent such as a mouse, squirrel or gerbil. It can also be caught by ingesting food or drink contaminated with rodent feces or urine.

Reports of rat-bite fever are rare in North America. However, many experts believe that rat-bite fever is under-reported and that numbers of actual human cases are much higher than what the literature shows.

Lymphocytic choriomeningitis (LCM)

Lymphocytic choriomeningitis (LCM) is one of the most common viruses, widely reported worldwide. It is part of the Arenaviridae family of viruses, which are generally associated with rodent-borne diseases in humans.

Transmission: The primary vector of LCM is the house mouse. Like many other rodent-borne diseases, infection can occur after exposure to items contaminated with rodent excretions or inhalation of contaminated particles. It is not known to spread person-to-person, with the exception of mother to fetus.

Symptoms: LCM infection can range rom asymptomatic to cases that produce mild meningitis. A typical infection involves fever, headache, and muscle pains that resemble typical flu and other common viral ailments arising 8-13 days after exposure. The mortality rate is less than 1%, but it can be quite dangerous for human fetuses if the mother is infected while pregnant.

Plague

Plague is the possibly the most notorious disease linked to rats in the human environment. In the 14th century Europe, it was better known as the “Black Death,” killing 25 million people over a 50-year period.

Plague is caused by the bacteria Yersinia pestis, which cycles between rodents and fleas. Several species of rodents, including rats, ground squirrels, prairie dogs and chipmunks are reservoirs of plague bacteria in the wild.

Transmission:

In the United States, the plague is primarily transmitted one of two ways:

1. Bites from fleas: rats and other rodents can carry infected fleas — as can cats.
2. Contact with infected animals: handling tissue or fluid of an infected animal. Cats (and other carnivores) can also acquire plague-causing bacteria by eating infected rodents.

Symptoms:

• Bubonic plague: This is the most common form, acquired by the bite of an infected flea. The bacteria travel through the bloodstream and concentrate within lymph glands. Signs include swollen and painful lymph nodes (called buboes) in the groin and under the armpits. It is accompanied by a sudden onset of fever and extreme weakness.
• Septicemic plague: When bubonic plague is left untreated, the bacteria will continue to spread throughout the body, leading to this deadly form. Symptoms include fever, extreme weakness, diarrhea, delirium, abdominal pain, and shock. Bleeding occurs under the skin, turning it black. This is the reason why plague was referred to as the “Black Death”.