Doctor's Diagnosis: West Nile Virus

Most people I know want nothing to do with the West Nile virus. What few people realize is that West Nile virus wants nothing to do with them, either.

Birds are the intended victims of West Nile virus. Mosquitoes transmit the virus from bird to bird, enabling the virus to survive, essentially forever. Occasionally mosquitoes will transmit the virus to other mammals such as horses or humans. But people are “dead end” hosts; even if we are infected, we will not pass on the virus if a mosquito bites us. The cycle is broken and the virus dies off, but not before it may have caused considerable harm.

There’s a reasonable chance that you have been infected with West Nile and do no know it. Most people never develop any symptoms at all. About one in five will develop transient fever, headache, body aches and fatigue. Usually enough to make you feel like you have “the flu,” but not enough to make you seek medical attention.

Less than 1 percent of infected people develop severe complications. The brain and spinal cord become inflamed, causing such problems as seizures, coma, paralysis and possibly even death. Those that survive may be left with permanent injuries.

There is no specific treatment available and no vaccine, either. Instead, prevention is aimed at attacking the mosquitoes that spread the disease.

On a personal level, this can involve proper use of insect repellents, wearing long sleeves and pants, and fixing broken screens. Emptying areas of standing water where mosquitoes can lay their eggs, such as flowerpots, gutters, birdbaths and pool covers, is also essential.

On a county level, this involves active surveillance of mosquitoes and birds to determine levels of West Nile activity, which can fluctuate considerably from year to year. When significant activity is detected, difficult decisions have to be made. For example, over the summer Suffolk County had to close several parks in the evenings — when mosquitoes are most active — due to increased West Nile activity. Decisions about spraying with insecticides can be especially challenging, having to balance people’s concerns of potential harm from the insecticides against the threat of disease caused by West Nile virus.

West Nile virus was first detected in this country in New York City in 1999 and has spread throughout the continental United States. Mosquitoes are no longer just annoying; they can be deadly, too.