Pitfalls of Spraying for West Nile Virus

  • The Culex pipiens quinquefasciatus mosquito - one of the mosquitoes responsible for the transmission of West Nile virus. Photo courtesy of the USGS.

The West Nile virus has claimed 28 lives and at least 550 people have been infected in the nation so far this summer. And evidence of the virus has already been found in 41 states. The carriers of the virus, mosquitoes, have been a concern and a nuisance for public health officials. Many citizens are demanding more visible action on the officials’ part to get rid of the bad bugs…like spraying chemicals to kill adult mosquitoes. The Great Lakes Radio Consortium’s Annie MacDowell reports:

Transcript

The West Nile virus has claimed 28 lives and at least 550 people have been infected in the nation so far this summer. And evidence of the virus has already been found in 41 states. The carriers of the virus, mosquitoes, have been a concern and a nuisance for public health officials. Many citizens are demanding more visible action on the officials’ part to get rid of the bad bugs…like spraying chemicals to kill adult mosquitoes. The Great Lakes Radio Consortium’s Annie MacDowell reports:


You might not expect to find a breeding ground of controversy in the suburbs, but
then again, you wouldn’t expect to find an exotic disease breeding there, either.
With the West Nile virus threatening any place that has mosquitoes…which is almost
anywhere…people are fighting over whether to spray or not to spray.


Spraying means releasing pesticides into the air to kill adult mosquitoes.
Pro-sprayers say the threat of West Nile virus necessitates this chemical
treatment. But some people who live in spraying districts are worried about the
possible dangers of the pesticides. Dr. Kim Stone is the Executive Director of the
Safer Pest Control Project in Chicago. As we walk around a nature preserve, she
tells me they’ve started spraying in her neighborhood and she’s worried about her
kids. Passing the pond and a grove of trees, she says the pesticides could kill fish
that eat mosquito larvae and birds that eat the adults. But she’s more concerned
about their possible threat to humans.


“I believe that the health impacts of the pesticides are a greater danger than the health impacts of West Nile virus. A local hospital had seen many people who thought that they had West Nile virus, came in with headache, nausea, and the hospital said that they did not have West Nile virus, but suspected that it might be related to the pesticides, because it was the morning after pesticides were sprayed in those neighborhoods.”


Stone recommends a different form of mosquito abatement…larvaecide.
Larvaecide is a preventative form a treatment that kills mosquito larvae before they
hatch. Pellets of larvaecide are dropped into lagoons, or a blower is used to spread
granules over the water. The chemicals are less toxic, she says, and they’re
species-specific. That means they won’t kill other animals. Dr. William Paul is with
the Chicago Department of Public Health. He says the city of Chicago hasn’t started
spraying because larvaecide is much more effective.


“We would really, in terms of mosquito control, want to focus on the long run,
breeding sites, and larval breeding sites, because that’s in the long run what’s going to be more effective. Using sprays for adults to kill the northern house mosquito… it’s challenging, you need tightly spaced applications of the product. And it’s not just a going up and down the streets kind of thing.


But spraying is a more visible treatment than larvaecide. Paul says people like to
see their government doing something to combat the mosquitoes. It makes them
feel better, he says. Other government officials can relate. Dr. Kiahn Liem has
been the head of the South Cook County Mosquito Abatement District in the Chicago area for 28 years. He’s has been working with mosquitoes since he was a little boy. He says watching many of his fathers’ patients die of malaria in his native country led him to his current profession of killing mosquitoes.


“I grew up in Indonesia, and malaria is a big killer of people there. Almost six to ten million people every year get killed by malaria. And there’s probably ten times more mosquitoes there than here.”


Liem uses larvaecide in his district. He hasn’t sprayed since 1977, after the
outbreak of St. Louis encephalitis, another virus carried by mosquitoes. He says
spraying was not effective then, and it still isn’t now, as most mosquitoes hide out in
people’s back yards, in the bushes or under leaves. He says the spray released from
trucks in the street just doesn’t reach them. But many of his citizens demand a
visible fight against the mosquitoes.


“They want to see you working. But if you work and you don’t do anything for them, you’re just fooling them. We have many of them that call us, and say, I want you here, I want you to show me that you’re doing something for my money. And we do that just to appease them.”


If people really want peace of mind, personal protection is what most experts
recommend. They say to wear long sleeves and pants between dusk and dawn
when mosquitoes are out in force. If you’re going outside, use mosquito repellent.
And routinely change standing water on your property, such as kiddie pools and bird
baths, to cut down on available mosquito breeding sites.


For the Great Lakes Radio Consortium…I’m Annie MacDowell.