I happened to be watching a New York Knicks game on television the other night when the revolving billboard beneath the scorer’s table unfurled an advertisement for Propecia, the Merck drug that prevents hair loss. In one of those Proustian leaps of association that often come to me while I’m in couch-potato mode, I found myself thinking about April showers, and mosquitoes, and medicine. The connection may seem circuitous, but hang on-we’ll get there.
April showers will bring May mosquitoes in the New York City area, and with them renewed concerns about West Nile fever, the exotic mosquito-borne virus that caused an outbreak of encephalitis in the city last year. The question perplexing many public health officials is this: Will the virus survive the winter in infected mosquitoes, like other mosquito-borne viruses (or arboviruses) in this country? And will it reappear in the city this spring?
West Nile caught everyone by surprise when it made its debut in the Western Hemisphere last summer. The disease was at first misdiagnosed as St. Louis encephalitis. Seven people, all elderly, died of encephalitis, a brain infection; dozens became ill.
As someone who has written about arboviruses for nearly 20 years, I understand that the risk of becoming infected is low, and the risk of developing encephalitis lower still. As a resident of Brooklyn, though, I wasn’t exactly thrilled by the helicopters that droned overhead in September, dousing our backyard with malathion.And as the father of an 18-monthold boy, I remember the sudden fear when I went to fetch Sandro one morning from his crib and noticed that he was
covered with mosquito bites.
With a lull in the outbreak,we might ask what lessons can be learned from West Nile. One lesson it doesn’t seem to be imparting is the notion, indirectly suggested last fall, that the outbreak might be human-made.An article in The New Yorker last October implied that the CIA was concerned that the rise ofWest Nile “might have been an act of bioterrorism.” But if West Nile were an agent of biowarfare (BW), why use an arbovirus,with a complicated avian transmission cycle, instead of a directly transmissible agent like smallpox? And why would the first cases turn up in a distant corner of Queens rather than, say, Times Square or on Pennsylvania Avenue? “The BW angle is BS,” one knowledgeable government source told me.
Rather than a terrorist plot, the unexpected appearance of West Nile has the quality of Mother Nature clearing her throat. West Nile has been very much on the
move, spreading from Africa as far east as India and as far west as Romania. Dengue fever and yellow fever, to mention other mosquito-borne diseases, have happily colonized the Western Hemisphere. If the host is mobile, viruses are the ultimate hitchhikers.