Can Pests and Wildlife Carry Diseases?

Nuisance wildlife and pests—including rats, mice, raccoons, and mosquitoes—can carry many diseases that pose serious risks to your household.

If you have any nuisance wildlife populations in or near your home, it might be time to call in help from a professional to eliminate this potential threat to your health. You can easily avoid most of these zoonotic diseases with proper control of wildlife populations near your home.

Here’s a breakdown of the common zoonotic diseases that you should be concerned about if you have a nuisance wildlife population sharing your space.

• Zoonotic diseases are illnesses that can spread from animals to humans, often through direct contact, bites, or contaminated materials.
• Common carriers of these diseases include rats, mice, raccoons, mosquitoes, and other nuisance wildlife.
• Many of these diseases are preventable through proper wildlife control and hygiene practices.
• Early intervention and professional assistance can help reduce your risk of exposure to serious illnesses.
• Avoiding contact with wildlife and maintaining a clean environment are essential first steps in protecting your health.

Zoonotic Diseases Transmissible through Nuisance Wildlife

Zoonotic Diseases Transmissible through Ectoparasites

Ectoparasites are organisms that live on the skin of a host. Typical ectoparasites from nuisance wildlife include fleas and ticks.

Zoonotic diseases transmissible through the consumption of contaminated foods

Zoonotic Diseases from Nuisance Wildlife

Let’s take a closer look at the zoonotic diseases that can be contracted from an encounter with nuisance wildlife.

If you suspect that you have come in contact with a zoonotic disease, the best thing to do is work with a medical professional immediately.

Rabies

Any mammal can carry rabies. However, the disease is commonly found in wild animals such as raccoons, skunks, bats, coyotes, and foxes. In addition to wildlife, domesticated animals such as dogs, cats, and cattle can be rabid.

Rabid animals can transmit the disease through any form of direct contact, such as saliva touching any broken skin or mucous membranes. The most common transmission method is a bite from a rabid animal.

Although only 1 to 3 human cases are reported annually in the U.S., thousands of animals test positive for rabies each year, primarily bats and raccoons.

Avoiding contact with infected animals is the best line of defense against rabies. If an animal is behaving unusually, it’s best to avoid it and consult a professional if any contact occurs.

Hantavirus

Cotton rats, deer mice, rice rats, and white-footed mice are known carriers of hantavirus in the United States. This disease, transmitted by rodents, can lead to severe health complications in humans.

If a rodent carries the disease, it may spread it through its excrement or saliva. Hantavirus is more commonly spread through the aerosolized virus from the urine, feces, or saliva. However, you may also contract the virus when an infected rodent bites you. Fewer than 1,000 cases have been reported in the U.S. since 1993, most often in rural areas with rodent exposure.

The best way to prevent hantavirus is to avoid contact with rodents or their excrements. If you are cleaning a rodent-infested area, wear gloves and a mask to handle the task. Additionally, you should spray the entire area with detergent or diluted bleach before cleaning to avoid the threat of airborne particles as a result of dry sweeping or vacuuming.

Mosquito-borne Encephalitis

Mosquito-borne encephalitis is a disease that can be found anywhere in the United States. The disease is transmitted via mosquito bites. Though rare, infections from these viruses can lead to serious health outcomes.

West Nile Virus, the most common mosquito-borne illness in the U.S., is reported in nearly every state each year.

The only way to prevent this disease is to avoid mosquito bites. Preventative measures against mosquito bites include wearing bug spray and getting rid of any standing water around your home.

Tuberculosis

Tuberculosis is more commonly known as TB. The disease is caused by bacteria that can be easily spread from infected mammals to humans via close contact with the aerosolized bacteria or consumption of unpasteurized dairy products.

Over 10 million people worldwide fall ill with TB each year, though zoonotic transmission is rare in the U.S. As with all zoonotic diseases, you should contact a medical professional if you suspect an exposure.

Leprosy – Hansen’s Disease

Leprosy, also known as Hansen’s disease, is caused by bacteria that can spread from human to human. In addition to humans, armadillos are known carriers of the disease.

Each year, about 150–250 cases are reported in the U.S., with armadillo exposure considered a risk factor in the South. As a precaution, it is a good idea to avoid close contact with armadillos.

Cryptococcosis

A fungus causes cryptococcosis, a rare fungal infection that primarily affects people with weakened immune systems, often after contact with contaminated soil or droppings. The most common way to contract the disease is through inhalation of the fungus. However, pigeon droppings are known to contain the fungus in question. With that, inhaling aerosolized bird droppings could lead to an infection. Luckily, it is extremely rare to become infected.

Raccoon Roundworm – Baylisascaris Infection

Raccoon roundworms can lead to Baylisascaris infection. The disease is transmitted through contact with raccoon feces. If infected, the roundworm can cause extensive and sometimes fatal neurological damage.

Baylisascaris procyonis is commonly found in raccoons, with studies showing that 70% or more of raccoons in some areas may carry the parasite. Humans can accidentally ingest the eggs when handling contaminated soil or objects.

To avoid the disease, avoid contact with raccoons. If you are in an area with known raccoon activity, frequent handwashing is the best preventative. It is always a good idea to work with a professional if you are dealing with a raccoon infestation.

Rat-bite Fever

Rat-bite fever (RBF) is caused by bacteria found on the teeth and gums of rats. When a rat bites you, an infection may occur. But you can also contract the disease by consuming food that has been contaminated by rat excrement.

RBF is a rare but serious disease. In the U.S., most reported cases are linked to contact with pet or wild rats, and infections have been associated with both bites and food contamination. The bacteria responsible are typically found in the mouths of healthy-appearing rats.

You can avoid the disease by avoiding contact with rats. If you have a rat population near your home, clearing clutter and removing food sources can help reduce the population. Additionally, avoid any food products that may contain rat excrement.

Rickettsialpox

Rickettsialpox is spread through mite bites of infected mice. While rare, Rickettsialpox cases have been documented in urban environments, particularly in densely populated cities like New York, where house mice are common. The disease is caused by Rickettsia akari, a bacterium spread by mites that live on mice.

Luckily, Rickettsialpox can be largely avoided by reducing contact with mice. You can reduce mouse populations around your home by clearing debris from your yard and eliminating potential food sources.

Histoplasmosis

Histoplasmosis is caused by a fungus that can be found in soil with large amounts of bird or bat droppings. The fungus spores will remain safely in the soil with regular fresh droppings. But as the droppings dry out, a dusty environment will cause the spores to spread. At that point, you can contract histoplasmosis by breathing in the spores.

This fungal disease is most commonly reported in areas surrounding the Ohio and Mississippi River Valleys, where conditions are ideal for spore development. According to the CDC, people can be exposed when disturbing contaminated soil or droppings, especially in attics, old barns, or under bird roosts.

To prevent histoplasmosis, reduce large roosts of bats or birds near your home. If you are cleaning out an old roost, enlist the help of professionals to remove the material safely.

Ornithosis

Ornithosis is caused by Chlamydophila psittaci. Birds of all kinds are known carriers of the illness. Humans can contract the disease by inhaling dust that contains the droppings or secretions of infected birds.

Also known as psittacosis when transmitted from parrots or other pet birds, this infection can spread from a wide range of bird species, including pigeons, doves, and poultry. Though relatively rare, outbreaks have occurred in both pet shops and poultry-processing facilities.

Prevention strategies include reducing large bird populations around your home. Additionally, wear protective masks when cleaning old bird droppings.

Psittacosis

Psittacosis is also caused by contact with the droppings or secretions of infected birds. The illness can pose health risks, especially in occupational or pet-related exposure settings. As with ornithosis, prevention strategies include reducing large bird populations around your home.

This disease is primarily associated with psittacine birds such as parrots, parakeets, and cockatiels, but pigeons, turkeys, and chickens can also carry it. Although human cases are uncommon, they are often linked to close contact with infected pet birds or occupational exposure.

Influenza – H1N1

H1N1 is one strain of the influenza virus that humans can contract from contact with infected animals. Although the disease is commonly known as the ‘swine flu’, you can contract the disease from contact with infected pigs or birds. Inhalation of the droppings or excrements of infected animals can cause illness.

The 2009 H1N1 pandemic highlighted the ability of this virus to spread from animals to humans, especially in environments where close contact with livestock is common. While most cases are now seasonal and mild, the virus continues to circulate globally.

This strain of flu continues to circulate globally and is included in ongoing public health surveillance.

Cercarial Dermatitis – Swimmer’s Itch

Cercarial dermatitis, or swimmer’s itch, is caused by microscopic parasites that can accidentally penetrate human skin. The parasites intend to infect birds and mammals. However, the parasite may burrow into the skin of a human if it comes into contact with it.

These parasites are released by infected snails into fresh and saltwater sources. While humans are not suitable hosts, accidental contact during swimming or wading can trigger a reaction. The condition is reported worldwide, especially in shallow, warm waters where birds and snails are present.

As with all allergic reactions, repeated contact may increase sensitivity to the parasites. The best way to prevent this rash is to avoid swimming in infested waters.

Colorado Tick Fever

Colorado Tick Fever (CTF) is a viral disease caused by the bite of an infected Rocky Mountain wood tick. This tick is commonly found at elevations between 4,000 and 10,000 feet in the western United States, especially in mountainous areas.

While the illness is generally mild and rarely life-threatening, it is still important to take precautions in areas where ticks are active. Cases are most frequently reported during the spring and early summer months when adult ticks are most active.

The only real way to prevent CTF is to avoid tick bites. You can use permethrin to treat your boots and clothing to repel ticks if you are in a heavily wooded area. Additionally, it is smart to check for ticks within two hours of returning from the outdoors.

Tularemia

Tularemia can be spread by ticks and deer fly bites. Additionally, tularemia can be transmitted via contact with infected animals, including rabbits, hares, rodents, and domestic cats.

This bacterial disease is considered potentially serious and is found throughout the United States. It can infect more than 100 different animal species, with rabbits and rodents among the most common carriers. Tularemia is classified as a Tier 1 select agent due to its potential use in bioterrorism, highlighting the need for caution around potentially infected wildlife.

You can prevent this disease by avoiding tick and deer fly bites. Beyond that, use gloves to handle any potentially infected animals.

Rocky Mountain Spotted Fever

As the name suggests, two of the most pronounced symptoms of Rocky Mountain Spotted Fever are a fever and rash. Infected ticks transmit the disease via bites. With that, the only way to prevent the illness is to prevent tick bites.

This potentially fatal tick-borne illness is most commonly reported in the southeastern and south-central United States.

Relapsing Fever

Ticks or lice can cause relapsing fever. The disease is primarily found in the western United States and is most often linked to rustic cabins or rodent-infested structures.

Typically, tick-borne relapsing fever occurs when humans are sleeping in rodent-infested dwellings. The ticks live within rodent burrows and usually feed on the rodents while they sleep. But if there are humans present, the tick may leave the rodent nest to feed on a sleeping human.

If you own a cabin or dwelling with a rodent infestation, contact a professional to remove the rodents. With the removal of the rodents, the ticks should be taken care of as well.

Lyme Disease

Lyme disease is the most common vector-borne illness in the United States, especially in the Northeast and upper Midwest. It’s a bacterial infection that ensues after a bite from an infected tick. Typically, humans who contract Lyme disease are infected by a nymph, a tiny tick that feeds in the spring and summer months.

In approximately 70% of infected individuals, rash results around the tick bite in a ‘bull’s-eye’. Fever, chills, fatigue, and headaches may also occur. The only way to prevent Lyme disease is to prevent tick bites and regularly check yourself for ticks.

Plague

Plague is caused by bacteria that circulate within wild rodent populations, with fleas as the carrier. Within the United States, rural and semi-rural rodent populations are especially vulnerable. A few known carriers include rock squirrels, woodrats, ground squirrels, prairie dogs, chipmunks, mice, voles, and rabbits.

You can contract this disease via the bite of an infected tick. Additionally, handling the tissue or body fluids of an infected animal can lead to an infection. Plague is rare today, but it still causes a handful of cases in the U.S. each year, primarily in the Southwest.

The best preventative strategy is to reduce the rodent population around your home. This can include removing brush, clutter, and possible food supplies for the rodents in your area. If you are handling a potentially infected animal, wear gloves to avoid any flea bites. Finally, dogs and cats should be treated with flea medication to avoid bringing the infected fleas into your home.

Murine Typhus Fever

Murine Typhus Fever is a flea-borne illness that can be found in small mammal populations. It’s most often reported in warm coastal regions, including southern Texas and southern California. Humans who come in regular contact with small mammals are at risk. Known carriers of the disease include opossums, mice, rats, and cats.

As with all flea-borne illnesses, the only way to avoid murine typhus fever is to avoid flea bites. You can do this by medicating your pets against fleas, removing rodents and other small mammal populations from around your home, and wearing gloves when handling stray pets or wild animals.

Trichinosis

The larvae of Trichinella worms cause trichinosis. The larvae can be found in undercooked meat from wild game or domestic animals, with most human infections in the U.S. linked to consuming wild game. In particular, bears, boars, domestic pigs, felines, foxes, dogs, wolves, horses, seals, and walruses are all known carriers of this parasite.

Brucellosis

Brucellosis is a globally widespread zoonotic disease, with over 500,000 human cases estimated each year. It often affects domestic animals such as sheep, goats, cattle, pigs, horses, and dogs. Additionally, it can infect wild mammals such as rodents, deer, bison, elk, moose, camels, and water buffalo.

The most common way for humans to contract the disease is by consuming undercooked meat or unpasteurized dairy products of an infected animal. But you may also contract the disease by breathing the aerosolized bacteria.

You can prevent this disease by avoiding undercooked meat and unpasteurized products from infected animals.

Anthrax

Anthrax is a rare but high-risk disease caused by bacteria which is found naturally in the soil. Grazing animals are at risk of anthrax infection. However, most livestock in the United States is regularly vaccinated against this threat.

Humans can contract the disease by breathing in the spores, getting spores in an open wound, or consuming undercooked meat that is contaminated with spores. One surprising way that you may contract the disease is by handling animal hides or furs of infected animals.

Escherichia Coli – E. coli

E. coli is naturally found in the intestinal tracts of many domestic animals, including cattle, sheep, and goats. The bacteria are normally part of a healthy human intestinal tract, but some strains of this bacterium can cause disease. Certain E. coli strains—like O157:H7—are especially dangerous and commonly linked to contaminated food or water.

Some strains of E. coli can cause serious illness if ingested. Unfortunately, the disease can be fatal for young children and older adults.

The best way to prevent infection is to cook meat to safe temperatures and avoid unpasteurized dairy products. Additionally, you should wash your hands regularly before preparing food.

Q Fever

Q Fever is caused by a bacterium that infects domestic animals, including goats, sheep, and cattle. The bacteria can be spread by inhaling spores from an infected animal’s urine, feces, birth products, or milk.

You are most likely to contract this disease if you work closely with livestock. Additionally, more than one-third of reported cases were in California, Texas, and Iowa. If you don’t work directly with livestock, avoiding unpasteurized dairy products should prevent the contraction of this disease.

Variant Creutzfeldt-Jakob Disease (vCJD)

In 1996, researchers determined that Variant Creutzfeldt-Jakob Disease (vCJD) was causally related to BSE, or bovine spongiform encephalopathy, more commonly known as ‘mad cow disease.’ Since this discovery, the rare vCJD disease has been associated with humans who frequently consume beef products that are likely to contain mechanically recovered meat or head meat.

Currently, vCJD is extremely rare due to extensive monitoring systems. However, there are one or two cases per every one million people each year.

Salmonellosis

Salmonellosis is a type of bacteria that lives in the intestinal tract of a wide range of animals and causes over a million infections in the U.S. each year, mostly through contaminated food. Known carriers of Salmonella include reptiles, amphibians, poultry, wild birds, rodents, small mammals, cattle, horses, goats, sheep, pigs, dogs, and cats.

You can avoid salmonellosis by washing your hands after handling any of the animals above. Additionally, it’s a good idea to store food properly to prevent accidental rodent excrement contamination.

Leptospirosis

Leptospirosis is spread through the urine of infected animals. The disease spreads through cattle, pigs, horses, dogs, rodents, and other wild animals. Typically, leptospirosis is associated with swimming or wading in contaminated waters. It’s more common in warm climates and after heavy rainfall or flooding. If possible, avoid contact with potentially contaminated waters.

How to Avoid Diseases from Pests & Wildlife

The vast majority of these zoonotic diseases are relatively uncommon in the United States. However, close proximity to a nuisance wildlife population can dramatically increase your risk of contracting one of these diseases.

If you are concerned about any particular critter that is too close for comfort, take action by working with a professional to remove the potential problem.

Critter Control has decades of experience in safely and humanely removing nuisance wildlife from residential and commercial properties. Whether you’re dealing with squirrels in the attic, raccoons in the garage, rats and mice in the walls, or bats in the chimney, our trained technicians know how to handle the situation and help reduce your risk of disease. Don’t wait—reach out to Critter Control to protect your home and your health.