How effective is the District’s playbook for fighting West Nile?
Illustration By Alison Elizabeth Taylor
It’s taken only three years for the West Nile virus to fly from New York to the District. These days, human cases are being reported in D.C., Baltimore, and Richmond. The city’s health department is so certain that the disease is here that they don’t collect bird carcasses anymore.
“It’s now endemic to our area,” Mayor Anthony A. Williams told ABC-7’s Capital Sunday on Aug. 18.
The specter of mosquito-borne disease is no longer a specter. The theoretical has become real.
The D.C. Department of Health (DOH) is taking action. As of Aug. 20, the department says, it has administered larvicide to 6,850 catch basins and other bodies of water.
And it’s spreading the word. By Aug. 20, DOH representatives had visited some 22,700 homes in the District, letting the citizenry know what it can do, block by block, yard by yard, to fight the West Nile virus.
Since the Northern house mosquito (Culex pipiens, a prime suspect in West Nile transmission) generally lays eggs in stagnant water, the general idea is to wage war on water. The DOH has promulgated a list of steps people can take to keep their back yards from becoming mosquito social clubs. Many are pretty simple: Clean up empties, take in the dog’s bowl when chow time is over. Some take more effort: Don’t let water collect under your geranium pots. Clean out your gutters regularly. Chuck old tires, or cover them with tarps when it rains. Freshen the birdbath every few days. Put screens over your doors and windows.
Sound like a hassle? The DOH also recommends that you always use a bug repellent with DEET (N,N-diethyl-m-toluamide) when you go outside—though DEET has been suspected of causing rashes and seizures. If reeking of bug spray in the thick of D.C. August isn’t oppressive enough, the authorities also suggest that you wear long-sleeved shirts and long pants. Also, the department’s Web site advises citizens to “[s]tay indoors at dawn, dusk, [and] early evening”—have fun explaining that to the kids—and “[a]void woodlands, wetlands, [and] marshy areas.”
And if the disease is endemic, will the final recommendation be to keep doing these things every day of every summer for the rest of your life? Is this a long-term habit change?
“It could well be,” DOH Chief of Animal Disease Prevention Peggy Keller says. “In other parts of the country where arboviruses [those borne by arthropods, such as mosquitoes] have existed for many years, certainly they’ve had to change their habits.” But West Nile in D.C. is “an emerging infectious disease.We don’t know what we’re going to find next year; we don’t know what we’re going to find the year after that.”
By spreading word that castoff Firestones give aid and comfort to the enemy, the health department is doing what a responsible municipal health agency ought to do: Keeping the public aware is part of keeping the public healthy.
Still, neighborhoods have yet to form anti-puddle brigades. The virus is certainly eerie—a row of dead birds lining your street makes for a chilling omen. And nationwide, the virus has claimed at least 20 lives this year. But the risks posed by West Nile hardly motivate you to haul out the household extension ladder and fish wet leaves out of the gutter.
According to Centers for Disease Control and Prevention (CDC) numbers, the danger for any one person is essentially nil: Fewer than 1 percent of people who become infected will become severely ill. Of those infected, 15 percent or fewer will die.
If the current public-health response seems to work, it may simply be because West Nile is not a worthy opponent.
The DOH’s strategy may prevent some West Nile cases. But ultimately, this is a plan for putting up with the disease, not for dealing with it.
Mosquito eradication is a long-standing and difficult problem. To the extent that elimination efforts have worked historically, they’ve tended to rely on mobilization, huge budgets, and, not infrequently, heavy doses of pesticides. Instead, the District is telling us to pull down our sleeves and dump out our kiddie pools.
No doubt, many people will do their part. But despite all the hubbub about the role of passenger cars in global climate change, traffic still floods the Beltway on a Monday morning. Voluntary compliance hasn’t always proved to be the best fix for shared problems.
Just ask Louisiana. One hundred seventy-one West Nile virus encephalitis cases—eight resulting in death—have been reported there in 2002 alone. Bob Johannessen, spokesperson for Louisiana’s Department of Health and Hospitals, says, “People still have not embraced this change of behavior to eliminate standing stagnant water”—even though the state has spent more than a quarter of a million dollars on an ad campaign, and generated about 10,000 news reports, since mid-July. “We’re still fighting,” he says.
Famed malaria foe Fred Soper, as Malcolm Gladwell noted last year in the New Yorker, succeeded by becoming “a disease fascist”—Soper’s eradication efforts in ’30s Brazil were greatly aided by the fact that the country was run by a dictator: Compliance with mosquito inspectors was mandatory.
The effects of a noncompliant person, Keller says, may be local and limited. “Mosquitoes don’t travel very far, and that’s a good thing,” she says. An area with a lot of breeding sites “would be problematic for the immediate properties, but not over a whole city.”
That may be all right, given the odds of contracting West Nile. But suppose West Nile is a warm-up for a more serious mosquito-borne disease to come. We’re in a dress rehearsal, and the city doesn’t know the whole script yet.
Consider the Aedes albopictus—commonly called the Asian tiger mosquito for its striped body. The Asian tiger mosquito, too, breeds in containers of water. But it can get down to business in vessels as small as a bottle cap, as well as in water-logged pockets of trees.
A recent arrival in this country, the Asian tiger is said to be flighty—harder to swat than other mosquitoes. And if staying inside at dusk and dawn gets you down, think about this: The Asian tiger is more active—it’s out for blood in the daytime, not just when the sun’s rising or setting.
And it is spreading quickly through the United States. Believed to have come to this country via Texas in the mid-’80s, the tiger mosquito has spread through most counties on the Gulf Coast; most or all counties in Louisiana, Florida, Georgia, South Carolina, North Carolina, and Tennessee; and parts of other states.
And it’s here in D.C.
“This one appears to be more aggressive,” says Dr. Eric Schreiber, project scientist for Florida’s Sarasota County Mosquito Management Services (which has enshrined the Asian tiger in its “Mosquito Hall of Shame”). “It’s more in-your-face.”
As the mosquito spreads, unforeseen diseases may spread with it. Were there to be a outbreak of a disease like dengue, DOH Senior Deputy Director for Public Health Assurance Theodore J. Gordon says, the District would consult with local authorities such as the Council of Governments and with the CDC—as it has done with West Nile.
Advisories about gutters and repellents would also likely be part of the response.
“That is a fundamental protective measure,” Gordon says. “The government can’t do this alone.” Legislation mandating compliance might be considered, he says, though he believes that most citizens would voluntarily follow recommendations.
Let’s hope so. The Asian tiger mosquito has tested positive for West Nile and may be a vector for other illnesses, including yellow fever. And last fall, the Hawaii Department of Health attributed transmission of dengue on Maui to tiger mosquitoes.
Though Americans tend to think of mosquito-borne plagues as a foreign problem, Joe Conlon, a technical advisor to the American Mosquito Control Association, points out that this country has a history of them. Dengue, for instance, was first identified not somewhere near the equator but in 18th-century Philadelphia.
“They’re not tropical diseases,” Conlon says. “They would be very much at home here in the United States. Our standard of living keeps them at bay.” CP
Art accompanying story in the printed newspaper is not available in this archive: Illustration By Alison Elizabeth Taylor.