Best practices for nuisance wildlife control operators in New York State

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Ch 4: Section four: What you need to know about wildlife diseases

How do you protect yourself from wildlife diseases?

Toxoplasmosis

Caused by: A parasite.

Most common way people catch it: Touch contaminated object, then unwashed hands touch mouth. Put contaminated object directly into mouth.

Worst-case scenario: Can cause miscarriages or serious birth defects.

How common in the Northeast? Common.

Most vulnerable groups: People with compromised immune systems; pregnant women; fetuses. Most infections are mild. Pregnant women can transfer the disease to their fetuses, but it usually doesn’t cause problems. Miscarriages and severe birth defects are possible.

Toxoplasmosis is an infection in mammals caused by a microscopic parasite, a protozoan called Toxoplasma gondii. Usually, the disease is mild and is often mistaken for a simple cold or viral infection.

There are several ways in which toxoplasmosis resembles histoplasmosis: most people who are infected never realize it; it often causes flu-like symptoms; people with compromised immune systems are at greater risk for developing a much more severe infection; and severe infections may result in brain damage or death.

But there's a significant difference between the two diseases. A pregnant woman can pass the toxoplasmosis infection to her unborn baby. Miscarriages, stillbirths, and severe birth defects, including blindness, cerebral palsy, and mental retardation, are possible. (The disease is more serious if passed on to the fetus in the first three months, however, it's more commonly transmitted later in the pregnancy.)

On average in the U.S., one out of a thousand babies is born with toxoplasmosis each year. But that doesn't tell the whole story. The March of Dimes reports that up to 90% of infected babies appear normal at birth, and 55–85% of them develop symptoms months to years later, suffering from eye infections, hearing loss, and learning disabilities.

Toxoplasmosis is common, but very few people have symptoms because the immune system usually keeps the parasite from causing illness. Symptoms in adults include swollen lymph glands, mild fevers, muscle aches, headaches, tiredness, confusion, and pains that last for a few days to several weeks. Severe infections can result in brain damage and damage to the eyes, and may become chronic.

How do you catch it?

People catch toxoplasmosis by eating or handling raw or undercooked meat that's infected with the parasite's eggs (especially pork, lamb, or venison) or through direct contact with infected feces (usually from cats) or contaminated soil. Most people are likely to become infected after cleaning a cat's litter box or gardening. They may touch contaminated soil or other fouled objects, forget to wash their hands, and then transfer the eggs to their mouths. Rarely, people contract toxoplasmosis through organ transplantation or transfusion.

Cats acquire the toxoplasma parasite by eating infected wild animals or raw meat. Most mammals can be infected with this parasite. The eggs take about two days to become infective.

According to the American Veterinary Medical Association, infected cats only shed the eggs for one to two weeks of their lives, right after their first exposure to the parasite. Like humans, cats rarely have symptoms when first infected, so most people don't know if their cat has been exposed to toxoplasma. There are no good tests available to determine if your cat is passing Toxoplasma in its feces.

Treatment

In an otherwise healthy person who is not pregnant, treatment is often not needed. Symptoms will usually go away within a few weeks. For pregnant women or people who have weakened immune systems, drugs are available to treat toxoplasmosis. There are tests to determine if a fetus is infected; if so, medication may prevent or reduce the severity of the effects of the infection.

Protection on the job

Even NWCOs who never handle a nuisance complaint involving cats might encounter this disease. Cats and wild animals frequent some of the same areas. Use your standard precautions to avoid contact with cat feces, and, as always, wash your hands well with soap and warm water, especially before you eat, smoke, or prepare any food.

Advice for customers

1. Relax, and consider this in perspective. First, toxoplasmosis is more of a concern if you're pregnant or have a compromised immune system. Even if you fit either of those categories, you can still wash your hands! That's a pretty simple way to avoid contracting this disease; no need to call out the cavalry.
    
2. There's no need to get rid of pet cats or avoid adopting a cat. To prevent infections, keep cats indoors and feed them dry or canned cat food.
    
3. Feral cats, stray cats, and pets who are allowed to roam outdoors may eat infected small mammals and defecate on your property. Remove food sources to discourage stray cats.
    
4. Avoid handling stray cats, especially kittens. If you want to adopt a stray, or don't know whether or not a cat you'd like to adopt roamed outdoors or was fed raw meat, talk to your veterinarian before you bring the cat into your home.
    
5. Cover sandboxes, and carefully wash your hands after working in your garden (or wear gloves).
    
6. If the litter box is cleaned daily, any eggs present would still be in the non-infective stage.
    
7. Ideally, someone who's healthy and not pregnant should clean the litter box and handle raw meat. If this isn't possible, wear gloves while doing either activity, then wash your hands well with soap and warm water. Remember to wash any cutting boards, sinks, knives, and other utensils that might have touched raw meat or unwashed vegetables.
    
8. Cook all meat thoroughly, at least to 150 degrees (no longer pink in the center, or until the juices run clear). Don't sample meat before it is fully cooked. Red meat that's been smoked, cured, or frozen for at least 24 hours is also safe from this parasite. Chicken, other fowl, and eggs almost never contain this parasite, according to the CDC.

For more information about toxoplasmosis

• CDC - Parasitic Disease Information - Toxoplasmosis Fact Sheet
   
• CDC - You Can Prevent Toxo - A Guide for People with HIV Infection
   
• March of Dimes - Medical References click "quick reference and fact sheet," then choose "toxoplasmosis."
   
• Care for Animals - General Illnesses and Diseases - Toxoplasmosis

Review questions

1. Toxoplasmosis is like histoplasmosis because
   1. they're both caused by a parasite
   2. both cause flu-like symptoms that are often mistaken for something else
   3. with both diseases, people with compromised immune systems are more likely to develop a severe infection than others
   4. a pregnant woman can pass either disease to her unborn child
   5. answers "b" and "c" are correct
   6. answers "a," and "c" are correct
       
2. How do people catch toxo?
   1. direct contact with cat feces
   2. eating or handling raw or undercooked meat
   3. breathe in the spores
   4. gardening
   5. answers "b" and "c" are correct
   6. answers "a," "b," and "d" are correct
       
3. NWCOs just need to know how to answer customers' questions about this disease, because they're not likely to be exposed to it. (Circle correct answer)
   True False

Answers

1. e
    
2. f
    
3. false (cats and wildlife use some of the same areas. Feral cats, strays, and pets that roam outdoors are also more likely to be infected than indoor house cats, because they eat more wild animals.)

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