22 April 2004

A Growing Malaria Problem

In honor of Earth Day, last night's NewsHour with Jim Lehrer on PBS showed a segment about the possible danger of global temperatures rising enough to permit bird malaria to wipe out unique endangered species at higher elevations in Hawai‘i. As one who has experienced repeated bouts of human malaria (P. vivax, not the dreaded P. falciparum variety), I thought I might mark the occasion by reminding readers yet again that the human malaria problem is already here and growing fast, and that we do not lack the means to fight it, if we are persistent and careful and rethink old shibboleths about DDT.

Most of what Ellen Ruppel Shell wrote about the Resurgence of a Deadly Disease in The Atlantic back in 1997 still applies.
All but obliterated in the developed world half a century ago, and suppressed in the Third World in the 1950s and 1960s [thanks to DDT!], malaria has since returned in full force to North Africa, India, Southeast Asia, China, South America, and the Caribbean. Worldwide incidence of the disease has quadrupled in the past five years, and resistance to available drugs for prevention and treatment is growing rapidly. Nearly 40 percent of the world's population lives in regions where malaria is endemic, and millions more live in areas that are encountering the disease for the first time in decades....

Nonetheless, the United States has shown little interest in the problem. Malaria is transferable in blood, yet it is not screened for in the American blood supply. The country's Anopheles mosquito population has gone unmonitored for more than fifty years. "We just don't know the potential for transmission," says John Beier, a professor of tropical medicine at Tulane University. Temperature and humidity may well be among the most important factors in the rate of spread of the disease, yet we have only a vague notion of what effect, if any, climate change will have on malaria transmission -- if, for example, global warming can be expected to bring malaria and other mosquito-borne diseases north from Mexico. Most Americans seem to think the disease has been eradicated or, at worst, is confined to the tropics. In fact there are few places on earth that cannot sustain a malaria epidemic.
A much more iconoclastic take on Earth Day appeared in the San Francisico Chronicle, coauthored by Patrick Moore, apostate cofounder of Greenpeace who left to become chairman and chief scientist of Greenspirit, and Nick Schulz, editor of TechCentralStation.com.
Ironically, the very movement that made its presence felt in rallies across this country in 1970 and that thrives in the developed world today must shoulder much of the blame for the developing world's sorry state. It is impeding both economic and environmental progress due to an agenda that is anti-development, anti-technology and, in the final analysis, anti-human.

For example, today's eco-activists boast that they have blocked more than 200 hydroelectric projects in the developing world over the past two decades. It is true that hydro power has a large ecological footprint, creating lakes and filling valleys. But it is a renewable energy that makes it possible to read after the sun goes down, boosting literacy in poor areas. It provides controlled irrigation for better crop yields and mitigates flooding and the loss of life and property damage....

Or consider that the pesticide DDT has been proven to radically reduce malaria in South Africa, while activist groups such as the World Wildlife Fund push for a total ban on its use. It only needs to be sprayed inside houses, where it poses no threat to the external environment, to make it effective. Despite the ability to stop malaria in its tracks with DDT -- as the United States had already done before its use was prohibited here -- 300 million people will become infected every year and at least 1 million will die, according to the World Health Organization.
UPDATE: Abiola Lapite's Foreign Dispatches and Virginia Postrel's Dynamist blog jumped on this story before I did: Abiola on 11 April (where I found the NYT article); Postrel on 19, 20, 21, and again on 21 April (where I found the Atlantic article).

UPDATE 2: Now the Washington Post has weighed in.
A large portion of the blame for the increased incidence of malaria can be laid at the feet of WHO itself, as well as other aid agencies such as the Global Fund to Fight AIDS, Tuberculosis and Malaria, and the U.S. Agency for International Development (USAID).

These agencies' mosquito-prevention and drug-treatment policies in Africa are in tatters. A group of prominent malaria experts has even charged the agencies with malpractice for their reluctance to supply new, more expensive and better drugs for treatment [like artemisinin combination therapies (ACTs)], and for sticking instead with essentially ineffective medicines [like chloroquine and sulphadoxine-pyrimethamine]. But if WHO and its partners are serious about reducing the malaria threat, they need to reconsider their approach and start using all the weapons available to combat malaria -- and soon.

While AIDS gets all the attention for destroying the young adults of Africa, few Westerners are aware that malaria kills more children than any other disease....

Preventing malaria means creating a barrier between the mosquito, which is the carrier of the malarial parasite, and the parasite's primary host -- humans. Since malarial mosquitoes bite only between dusk and dawn, WHO's campaign has promoted bed nets, which can protect those who sleep beneath them. But this policy has had limited success. Nets for a whole family are expensive, and mosquitoes can take many blood meals between dusk and bedtime. Also, nets work best if treated with insecticide. But a recent survey in Kenya found that 21 percent of households had one single bed net, and only 5.6 percent of these were insecticide-treated. Moreover, mosquitoes are growing resistant to the type of insecticide with which the nets are coated.

By contrast, South Africa -- which is rich enough to fund its own public health programs and doesn't need to rely on WHO's largess -- has reduced malaria transmission by 90 percent in recent years, by a combination of returning to an old insecticide and investing in a new drug. It chose to spray insecticides, especially DDT, on the inside walls of dwellings to prevent mosquitoes from entering the buildings. This protects everyone inside all the time, not just when people might be sleeping.

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