The Modern Guide To Human-Transmissible Wildlife Diseases

Wild animals can be vectors for many different diseases, and in the height of Summer, there’s an increased likelihood of humans and wildlife crossing paths and transmitting illnesses. For the safety of humans and animals alike, it’s best to avoid contact with wild animals, know the signs and symptoms of wildlife diseases, and take appropriate precaution to avoid contracting diseases.


Rabies

Rabies Virus Enlarged

Odds are that the first thing that comes to mind when you think of wildlife diseases is rabies, and with good reason. It is a very serious disease that is almost 100% fatal if not treated in time.  It causes otherwise normal people and animals to become aggressive and erratic and has been cited as an inspiration for zombie movies.

What is Rabies?

Rabies is a virus that attacks the nervous system of mammals, including humans. It is fatal in 99% of cases in which medical intervention does not occur before symptoms emerge.  Globally, unvaccinated dogs cause 99% of human rabies cases, but in the United States, 7 out of 10 fatal rabies cases (of which there are less than 10 per year) originate from infected bats, followed by raccoons, skunks, and foxes. Some animals, such as possums and small rodents are resistant to rabies and rarely carry or contract it.

Rabies is primarily spread through bites and scratches from an infected animal, but can also be spread through contact with mucous or open wounds.

What Happens To A Person With Rabies?

Rabies incubation periods can vary from one week to one year, depending on the location the virus entered the body and the viral load.

Early Rabies symptoms can consist of:

  • Fever
  • Headaches
  • Loss of appetite
  • Fatigue
  • Muscle aches
  • Tingling, itching, prickling, or burning sensation at the site of the bite

If not treated, the virus will spread through the nerves to the brain, where it multiplies and causes severe, irreparable damage and death.

Two different rabies presentations occur in humans: Furious Rabies and Paralytic Rabies. Furious rabies is the image that most people conjure when they think of rabies. It comprises around 80% of rabies cases. As the virus attacks and multiplies in the nervous system and brain, the host becomes aggressive, manic, avoid water and fresh air, and dies a few days later.

Paralytic rabies comprises the other 20% of rabies cases. This is a longer-term illness that still results in fatality. As the virus spreads from the site of the infection, it paralyzes muscles until the host becomes comatose and eventually dies.

How Can Rabies Be Prevented in Humans?

The best rabies prevention is to avoid contact with infected animals. Avoid approaching wild animals, particularly if they are behaving abnormally or aggressively, walking in circles, or appear to be lethargic or having issues with motor control. If you see an animal displaying these symptoms, contact a professional immediately. Children are the most at risk of rabies, so it is critical to educate them to not approach wild or stray animals.

As previously mentioned, dogs cause 99% of global human rabies deaths, but since mass rabies vaccinations have been implemented in the United States, dogs make up only 1% of rabid animals reported each year. Vaccinating pets is a crucial step in stopping the spread of rabies to humans.

Human vaccination is also effective at preventing rabies both pre and post-exposure. Pre-exposure prophylaxis is recommended for people whose jobs put them at high risk of contact with infected animals as well as people who are traveling to areas with high rates of rabies.

If you suspect a bite has occurred, or that contact with a bat has been made:

  • Wash wounds or potential contact areas with soap and water. Use hand sanitizer if soap and water are not available.
  • Call a medical professional immediately
  • Call local animal control to find and catch the animal

Even if you have received preventative rabies vaccines, post-exposure prophylaxis vaccines are still necessary if you believe you have been in contact with a rabid animal.


Histoplasmosis

Bat or bird feces can release airborne histoplasmosis spores when disturbed

Thinking about cleaning out your barn or attic? Make sure to take precautions if you notice bird or bat droppings. The aforementioned excrement can carry histoplasmosis, which can be serious if you have existing health conditions.

What Is Histoplasmosis?

Histoplasmosis is a fungal infection that usually occurs in the lungs but has been known to spread to other body parts.  Bird and bat droppings are a favored substrate for the histoplasmosis fungus, and spreads to humans when bat droppings are disturbed, releasing airborne spores that are then inhaled.

What Are the Signs and Symptoms of Histoplasmosis?

 According to The CDC, symptoms occur 3-17 days after exposure and include:

  • Fever and chills
  • Dry Cough
  • Chest Pain
  • Muscle aches
  • Fatigue
  • Headaches

Can Histoplasmosis Be Cured?
Yes! Most mild cases will resolve on their own and many people never develop symptoms at all.  Severe cases can occur and will require medical intervention. People who are immune-compromised are at a higher risk of long-term symptoms

How To Prevent Histoplasmosis

Minimize your risk of exposure to histoplasmosis by avoiding enclosed environments with a high concentration of birds and bats. If you must enter these spaces, wear a mask and protective clothing. Wetting the area can also weigh down particles so they do not become airborne and enter your lungs.

Raccoon Roundworm

A close-up of a worm

Description automatically generated
Magnified picture of a raccoon roundworm

If you have seen raccoons or tell-tale signs of their mischief on your property, you may also unknowingly be host to their designated toilet area, which can be dangerous. Raccoon excrement can carry Raccoon Roundworm, a rare but serious parasite that is especially concerning for young children.

What is Raccoon Roundworm?

Raccoon Roundworm is caused by parasites known as Baylisascaris worms found in raccoons. It is transmitted through direct or indirect contact with raccoon feces and can infect humans as well as pets and livestock. The disease is rare, with fewer than 25 cases having been documented in the United States

Young children are the most likely to contract the disease due to their propensity to put their hands in their mouths after playing in soil and also due to raccoons using children’s sandboxes as litter boxes.

How Do You Tell if You Have Raccoon Roundworm?

Humans become infected with raccoon roundworms by consuming their eggs. 

 According to The CDC, symptoms present after an incubation period of 1-4 weeks from exposure and can include:

  • Fatigue
  • Nausea
  • Coordination issues
  • Loss of muscle control
  • Enlarged liver
  • Blindness
  • Coma

What Kills Raccoon Roundworm?

Any material that has been potentially contaminated with raccoon feces should be carefully burned, buried, or otherwise removed. Use protective gear when handling contaminated material. See the CDC guide for safe raccoon waste disposal

Cryptococcosis

High concentrations of bird feces can breed Cryptococcosis fungus

What is Cryptococcosis?

Cryptococcosis is caused by a fungus known as Crytptococcus neoformans. This fungus incubates in bird feces and is most commonly found in pigeon roosts. It is particularly dangerous to people with existing immune issues, such as HIV.

What Are The Symptoms of Cryptococcosis?

Cryptococcosis can have several different presentations, which can appear similar to pneumonia, meningitis, or some skin conditions.
 Some symptoms include:

  • Cough
  • Chest pain
  • Shortness of breath
  • Fever
  • Headache
  • Neck pain/neck stiffness
  • Nausea
  • Vomiting
  • Light-sensitivity
  • Plaques on skin
  • Rashes
  • Sores
  • Bumps
  • Blisters

How Can I Prevent Cryptococcosis?

 Like Histoplasmosis, the best way to minimize your risk of exposure is by avoiding enclosed environments with a high concentration of birds or bird droppings. If you must enter these spaces, wear a mask and protective clothing. Wetting the area can also weigh down particles so they do not become airborne and enter your lungs.


Leptospirosis

Floodwater can contaminate soil with animal urine and spread Leptospirosis

Leptospirosis is on the rise in the United States, particularly in urban areas that have been affected by flooding, a trend which climate change is likely to accelerate.

Leptospirosis is caused by when humans and other animals come into contact with water or soil that his been contaminated by Leptospira bacteria. This is spread from the infected urine of many different types of wild and domestic animals, including rodents such as rats, mice, and squirrels.

What are The Signs of leptospirosis?

According to the CDC, symptoms of leptospirosis emerge within 2-30 days of contact and include:

  • Fever
  • Chills
  • Headache/ body aches
  • Vomiting, nausea, diarrhea,
  • Jaundice
  • Red eyes
  • Stomach pain
  • Rash

Symptoms can last up to several weeks and full recovery can take months. Some people carry the disease without symptoms

Who is Most at Risk for Leptospirosis?

As previously mentioned, flooding puts humans at an increased risk of contracting leptospirosis.  People who partake in outdoor activities such as swimming, rafting, kayaking, hiking, and gardening are at increased risk of contracting the disease as well as those who work with animals.

Can Leptospirosis be Cured in Humans?
 
 Yes. Leptospirosis is treated with antibiotics such as doxycycline and penicillin. Most people recover fully in a week, but serious infections should be treated in a hospital.



Salmonellosis

Salmonella Bacteria Under Magnification

Salmonellosis is not fun. Commonly referred to as food poisoning,  Salmonellosis is caused by a bacteria found in animal intestines known as salmonella. Most people think of salmonella as simply caused by unhygienic food handling and preparation, but it can also be transmitted through direct or indirect contact with wildlife.


What Happens If a Person Gets Salmonella?

According to the CDC person infected with salmonella may experience:

  • Nausea
  • Fever
  • Vomiting
  • Chills
  • Diarrhea
  • Stomach cramps
  • Headaches
  • Bloody stool


Is Salmonella a Serious Disease?

Most people stop experiencing symptoms after a week, but it can affect bowel movements for months afterward. If serious infections are left untreated, salmonella bacteria can spread to infect blood, bones, joints, and nervous system, causing severe damage.

How Do I Prevent Salmonella?

According to the CDC:

  • Avoid handling wild animals
  • Wash your hands
    • after handling animals or potentially contaminated materials
    • before preparing food
    • after cleaning animal droppings or coming in contact with animal feces
  • Do not allow children to put hands in their mouths after touching animals
  • Do not eat or drink in areas with high-risk animals (birds, rodents, etc.)
  •  Sterilize any cooking equipment that may have come in contact with rodents. If you notice signs of rodent infestation in your home, especially your kitchen, have a professional address them immediately.

Conclusion:

Hearing scratching noises, noticing droppings, or sensing unusual smells? Don’t wait! These could all be signs of wildlife instruction. Protect your family and pets from transmissible wildlife diseases. Contact Modern Pest today!