Today's Story
As reports are coming in of birds and mosquitoes across the state testing positive for West Nile Virus, zoo workers are doing all they can to protect the animals in their care. Brad Linder has more.

West Nile Virus
Keeping you and your pets safe from the virus.
August 23, 2002

By Dan Simon

If you're concerned about the risks of catching mosquito-borne illnesses, such as West Nile Virus, there are precautions you can take to protect both yourself and your pets.

The first thing to do is minimize your potential contact with mosquitoes. You can start with an appropriate insect repellant for both yourself and your pet. Make sure you check with your veterinarian to make sure the repellent you're using is also safe for your pet (not all human insect repellents are safe for dogs and cats).

Whatever insect repellent you choose, the Centers for Disease Control and Prevention recommend it contain DEET, which the agency describes as "the most effective and best-studied insect repellent available." DEET is an insect repellent ingredient, not a brand. The higher the concentration of DEET, the longer lasting the repellant effectiveness will be although concentrations higher than 50 percent haven't been proven to provide protection any longer than 50 percent strength applications.

The CDC also recommends staying inside during peak mosquito biting times, which include dawn, dusk and early evenings. Also check windows, doors and screens to be sure there's no potential mosquito entry points.

Getting rid of any standing water on your property is also high on the list of mosquito prevention measures. Even a tiny amount of water can serve as a breeding ground for these insects. If you want to keep a small pond filled, add some mosquito dunks that contain a naturally-occurring bacteria that stops mosquito larvae from developing. These "BT" (which stands for "Bacillus thuringiensis") are a naturally occurring soil bacteria that's proved effective against certain gardening pests. A version known as "Bt Israelensis," is the strain used for these dunks. This product, usually called "mosquito dunks" is available at many garden supply or lawn and garden shops and each one lasts for about a month.

When it comes to your pets and a disease such as the West Nile Virus, there's no set answer that works for every type of animal. One thing does appear to be consistent though. The disease can only be transmitted via a mosquito bite and not from pet to human or pet to pet.


While family pets can also be infected with West Nile Virus, most cats and dogs will suffer few effects from the disease. Just like with humans though, older pets face a greater risk from the disease. ©Photo by Dan Simon for GreenWorks.

The best current evidence suggests that dogs and cats may be able to become infected with the virus, but are at low risk of dying from it. Dogs and cats that do become infected can recover from it with normal supportive care. Just as in humans, an older or infirm pet will be more at risk from the disease than one in the prime of life.

The virus is more of a threat for horses, with some fatalities from the disease occurring in the United States. An experimental vaccine has been developed to offer horses some protection from the virus. Just as with humans and other pets, the best protection seems to be taking measures to avoid mosquito bites.

Remember that West Nile Virus is only one disease that can be carried by mosquitoes. The disease is also far less dangerous to humans than other mosquito-borne diseases, such as malaria or St. Louis Encephalitis. Most people who become infected suffer flu-like symptoms for a few days, recover and enjoy future immunity from the disease (although this may diminish over the years) according to a CDC web site on the disease. People over 50 years of age are the most likely to develop severe illnesses from the disease.

"Even if the mosquito is infected, less than one percent of people who get bitten and become infected will get severely ill. The chances you will become severely ill from any one mosquito bite are extremely small," according to information on the disease at the CDC.

A trial is currently underway to test the effectiveness of alpha-interferon in treating the West Nile Virus in infected humans. There is some optimism this drug may be effective against the disease because it's helped lessen the symptoms of St. Louis Encephalitis, a similar disease. There is also work in progress on a human vaccine for the disease, with the possibility of its availability as early as next year.

In the meantime, the easiest, and most pleasant, approach is to just avoid getting bit. While the risk of catching a mosquito-borne disease is pretty low, those bites still itch!


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Pennsylvania's West Nile Surveillance Program
Learn about West Nile virus and the latest surveillance update from Pennsylvania.

Environmental Reporter for August 21, 2002
Stories about mosquitoes and their enemies, the bat.

University of Tennessee School of Veterinary Medicine
Q&A on West Nile Virus issues.

Center for Disease Control
Federal site with Q&A information.

Medline
A medical web site for your pets.

The Humane Society of the United States
The Society's site provides information on the disease and how to help keep your pet safe.





The Environmental Reporter is a partnership of GreenWorks.tv and WHYY Radio, which makes all reports available to public radio stations throughout Pennsylvania.