Pennsylvania state officials have confirmed that their first positive test of West Nile Virus of the year has been found in a mosquito from the city of Altoona, Blair County. This is the first time the virus has been found so early in the year in the state.
West Nile Virus (WNV) first appeared in Pennsylvania in 2000 where it was found in mosquitoes, birds and a horse.
WNV was first found in North America in 1999, in New York. Since then it has spread rapidly throughout 48 US continental states, seven Canadian provinces and all of Mexico. Signs of the virus have also been found in Puerto Rico, the Dominican Republic, Jamaica, Guadeloupe and El Salvador.
Before 1999 WNV had only been found in Africa, Eastern Europe and western parts of Asia.
WNV is carried by mosquitoes and causes inflammation of the brain, or encephalitis.
According to the US Centers for Disease Control and Prevention (CDC), over 15,000 confirmed cases have occured in the US since 1999, of which 500 resulted in death. It is likely that the actual number of infected people is much higher, because most of them will have only mild symptoms, if any.
The chances of a person becoming infected is quite low, and fewer than 1 per cent of those infected will get seriously ill. People most at risk are likely to be elderly or sick. However, it is still possible, if only less so, to be healthy and become infected, so the sensible thing to do is take precautions and protect yourself from mosquito bites.
WNV is a close relative of the St Louis encephalitis virus (SLEV), also found in the US, and the Kunjin virus (KV) which occurs in Australia, a few Western Pacific islands and some parts of South East Asia.
Infections occur because mosquitoes carrying WNV pass it onto birds, animals and people. Cases of infection in Pennsylvania are usually reported in mid summer or early fall, although mosquitoes start appearing around April and last until October.
The ideal breeding ground for mosquitoes is water that has been standing for a period of four days or more, for example in a puddle.
Today’s find has prompted officials to remind the public about the dangers of the virus and how to reduce the opportunities for mosquitoes to breed.
To reduce the chances that mosquitoes will breed in standing water on your property you should:
- Remove tin cans, containers, pots or anything that collects water.
- Look out for discarded tires; these can also accumulate water when it rains.
- Clear out clogged gutters and drains.
- Turn over paddling or wading pools, birdbaths, wheelbarrows so they don’t collect water when not in use.
- Make sure outdoor containers drain any water they collect; drill holes in the bottom.
- Don’t drill holes only in the sides, the water that collects in the bottom is enough for mosquitoes to breed.
- Make sure your garden pond is well aerated with a water pump or put fish in it if it is big enough.
- Eliminate any areas on your property where large puddles might accumulate; fill them in or re-landscape.
- Clean your swimming pool regularly and make sure it is chlorinated.
Pennsylvania’s 2007 West Nile Control Program website has details of a naturally occuring bacterial product called “Bti” that kills mosquito larvae and is not harmful to people, pets, aquatic life (such as fish) or plants.
Click here for more information on Pennsylvania’s 2007 West Nile Control Program.
Written by: Catharine Paddock
Writer: Medical News Today