Unnerving as West Nile is, Zaki, a married father of two, says it is only one of many exotic insect-and tick-borne diseases Americans can expect to see in years to come—and by no means the most serious. He discussed West Nile and other afflictions with contributor Matt Birkbeck.
Why is there so much concern about the West Nile virus?
Because it was newly introduced into this country—no one likes to see a new virus that can cause deaths and severe illness. But that is no reason to push the panic button.
What are the symptoms?
In 95 percent of cases they are like those of any other viral or bacterial infection. You may have some fever, headaches, muscle pain and vomiting. There is sometimes a rash on the trunk, or enlarged lymph glands. In children there can be a little fever with muscle aches. Many people don't even have symptoms.
Why are older people so susceptible?
Their immune systems are sometimes compromised, or they may have other predisposing factors that make them prone to encephalitis.
Do young adults or middle-aged people get serious complications from the virus?
No, very few.
If someone does contract West Nile, how long does it usually last?
Not longer than a week. The real problem is that there is no standard treatment. You hope the immune system will fight it out and recover.
What precautions can a person take?
Avoid being outdoors during periods of heavy mosquito activity, which are early in the morning and at dusk. Also, use repellents.
Will spraying insecticide in places like Manhattan or Boston really help keep the virus from spreading beyond the Northeast?
Any effective mosquito-control operation will definitely decrease the chances of human transmission.
Can West Nile be carried by other means?
In some countries in Africa, ticks transmit the virus. That can be a problem—mosquitoes can be controlled. They also have a short life span—a male lives one to two weeks, a female five or six weeks. But a tick can live for a year or two and proliferate. An infected tick will give you 500 to 1,000 infected daughter ticks. And ticks are very difficult to control because they spend a good deal of their life cycle attached to animals and are not out in the open.
Do other insect-or tick-borne diseases pose as much of a threat as the West Nile virus?
There are many such viruses and bacteria in the U.S. similar to West Nile—or worse. At first, you'll recall, West Nile was mistaken for the St. Louis virus, which is also mosquito-borne and causes encephalitis. In fact, the St. Louis virus is more serious. There was a huge epidemic in the Midwest and parts of the South in 1975. Ehrlichiosis, a tick-borne affliction, which produces fever, chills and headaches and has been fatal in some instances, is prevalent in the Southeast, Northeast and Midwest. And of course there is Lyme disease—in New York's Suffolk County alone, we have between 700 and 1,000 cases a year.
How about more exotic diseases? Are they the wave of the future?
I'm afraid so. I'll give you a simple example. For years here in Suffolk County, we'd get only one or two cases of malaria every year. Last year we had 14. Why? We have an influx of immigrants from areas such as Africa and the Middle East, where malaria is prevalent, and we have the mosquitoes to transmit the parasite. From now on, between immigration and a dramatic rise in international travel, we can expect to see in the U.S. any disease that is endemic in any other part of the world.
When Dr. Mahfouz Zaki first came to the U.S. in 1959 to pursue a doctorate at New York City's Columbia University, Americans had never seen the West Nile virus—so named for having been discovered in his native Egypt. Yet four decades later, Zaki, then director of public health for Suffolk County, N.Y., found himself confronting a disturbing outbreak of the virus, which is carried by birds and passed on to humans through mosquitoes. Last summer West Nile infected 62 people in the New York area, causing 7 deaths from encephalitis, a swelling of the brain, and inciting enormous public anxiety as authorities unleashed military-scale pesticide attacks. Dormant for months, the virus resurfaced this July among birds and mosquitoes as far north as Boston. Last week brought the year's first confirmed human case, a 78-year-old New York City man. Indeed, West Nile is especially worrisome for the elderly: All those who have died so far were over 60.