Is DDT Making a Comeback?

By Kim Larsen, OnEarth Magazine. Posted February 1, 2008.

This story first appeared in OnEarth Magazine and was written by Kim Larsen.

Only three of the 20-odd beds at Mbita District Hospital are occupied. This surprises me. After all, we are in the heart of an impoverished, malaria-ravaged region, on the shores of Lake Victoria along Kenya's remote western border. When I ask a medical assistant if it's unusual for the ward to be so sparsely populated, he laughs grimly. "In two or three weeks we will have several patients to a bed, with more on the floor," he explains. "We'll be turning people away." Here's why: malaria infections can occur any day of the year, but surge outbreaks are cyclical, the disease blooming lushly in the wake of a rainy season. It's late June now, and the winter rains are just about spent. Roads, fields, and footpaths are strewn with puddles large and small, ideal breeding sites for the Anopheles gambiae mosquito, malaria's endlessly regenerating delivery system.

Just beyond the hospital walls, battalions of Anopheles gambiae larvae were incubating in their warm, clear, sun-drenched baths. Upon maturity each mosquito, weighing in at a strapping 2.25 millionths of a pound, would fly off in search of sugar, the metabolic fuel provided by certain plants; and then, thus fortified, the female would move on to extract her blood meal, the protein feast that primes her to reproduce. In a matter of days, new malaria patients would begin streaming into the hospital, by foot or in wheelbarrows or splayed across the backs of donkeys, but mostly cradled in their mothers' arms. The immature immune systems of babies and toddlers are particularly vulnerable to the disease, and in this region cerebral malaria -- the deadliest variant, marked by seizures and coma -- is endemic.

Silver bullet, anyone? Vaccine, larvicide, insecticide, bed net, hex? Why should this disease, eradicated in the lucky zones of the world, continue to flourish elsewhere, in unlucky places like Mbita?

David Soti, the hospital's medical director, shook my hand briskly, unsmiling. Our meeting was a brief formality to secure permission to tour the hospital. I was with Hortance Manda, an entomologist investigating plant and mosquito interactions. She works nearby at the Mbita campus of ICIPE, a research facility headquartered in the capital, Nairobi, that, among other things, pursues methods for managing insect-borne disease in environmentally neutral ways. (The name was formerly the International Center for Insect Physiology and Ecology, but it's now known as African Insect Science for Food and Health.)

Recently Manda's work had involved malaria patients at the hospital. Soti nodded at her. "Very nice research: What is the mosquito? What does it eat? When? Why? Good. But I don't want to know the mosquito," he shrugged. "I want to kill it. DDT would kill it." He muttered this last point under his breath. ICIPE opposes the reintroduction of the pesticide DDT in the fight against malaria, and Kenyan law forbids its use under any circumstances. But Soti, apparently, would deploy the insecticide in a heartbeat.

He is not alone. Dichloro-diphenyl-trichloroethane has made a comeback. In Kenya, throughout Africa, in malarial regions around the globe, and perhaps most vociferously in certain pockets of the pundit-happy West, scientists, policy makers, and commentators are revisiting the merits and demerits of the iconic neurotoxin. Few would advocate a return to the strategies used in DDT's heyday in the United States, when crop dusters unloaded blizzards of the chemical--675,000 tons from the 1940s through the 1960s -- to control agricultural pests. But some argue that the judicious application of DDT is precisely what's needed to loosen malaria's death grip, particularly in sub-Saharan Africa.

Enter Patrick Sawa, head doctor at the St. Jude's medical clinic on the ICIPE campus in Mbita, less than a mile from the district hospital. I caught up with Sawa in a supply room, the only semi-quiet spot at a facility swarming with patients and activity. Word had got out that the clinic would be waiving its usual nominal fee while a group of visiting American doctors were in place, and patients -- many with confirmed or suspected malaria -- had arrived in droves.

I asked Sawa about the DDT option. "It's the wrong approach, an act of desperation," he said, gesturing toward the clinic's densely packed waiting area. "Desperate times, desperate measures?" I offered. His answer was immediate: "Not when the measures make matters worse."

There you have it. Two Kenyan doctors, working in the same grievously malarial and medically underserved outpost, each with a very different take on the role DDT might play in reducing the burden of the disease.

The burden is profound. Globally, more than 500 million individuals are infected with malaria every year, of whom more than a million die, mostly babies and pregnant women. More than 90 percent of the deaths occur in sub-Saharan Africa, where the most virulent form of the disease resides. Malaria is caused by a single-celled parasite -- Plasmodium -- which is transmitted by Anopheles mosquitoes. Of the four Plasmodium species that infect humans, P. falciparum, carried by the Anopheles gambiae mosquito, is by far the most lethal. This deadly duo has brought Mbita, and regions like it throughout vast swaths of Africa, to their knees.

See more stories tagged with: africa, ddt, malaria

Freelance writer Kim Larsen's work examines the intersection of culture, conservation and national identity. Her last piece for OnEarth reported on the bushmeat crisis in Congo.

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