Is DDT Making a Comeback?

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.

On the medical front today, gene sequencing and molecular manipulation raise the real possibility that a vaccine, elusive for so long, may be on the horizon, but even optimistic researchers say practical results are many years away. In any case, even as science fuels hope, it also more fully illuminates the pathogenic intransigence of the parasite -- crucial yet sobering knowledge. A drug cocktail known as ACT (artemisinin-based combination therapy) works well provided patients are treated promptly. Artemisinin is derived from the leaf of China's sweet wormwood tree; the drug is formulated along with synthetic antimalaria agents in a single pill. The cocktail approach is designed as a hedge against resistance, though Sawa says he is already beginning to see signs that the drug is losing its edge.

Efforts to control malaria essentially have run along one of two lines: drugs, such as ACT, to kill the parasite or insecticides to kill the mosquito. But both targets are ruthlessly mutable, evolving quickly and in ways that leave them impervious to our most calculated chemical assaults. Chloroquine was hailed as a miracle drug 50 years ago for its ability to trounce the parasite, but is now all but useless. Post-World War II faith in DDT was once so strong that Paul Müller, the scientist who discovered its insecticidal properties, was awarded the 1948 Nobel Prize for medicine.

In 1955, armed with these two marvels, the World Health Organization (WHO) mounted a global malaria eradication campaign. Despite some successes, mostly in contained island environments such as in the West Indies, or in more prosperous regions such as parts of Australia and southern Europe, the effort failed. In Africa it never got off the ground. The campaign was finally abandoned in 1969, its collapse traceable to three main causes: the onset of mosquito resistance to DDT, the insuperable logistics of indoor spraying in endemic areas, and a dawning awareness that DDT was toxic to more than just mosquitoes and other pesky arthropods. In the void left by the discarded WHO operation, malaria slipped from the world's attention. Cloaked for 20 years in obscurity (to all but the suffering millions), the disease dug in and proliferated.

What brought malaria back to public consciousness was an unprecedented wave of epidemics, especially in Africa, in areas that had not previously been affected. This brought fresh infusions of cash and led to a campaign called Roll Back Malaria, which was cobbled together from an international cross-section of expertise involving major aid agencies, governments, the private sector, and NGOs. Promoting drugs, insecticides, and bed nets, the campaign was launched in 1998 with the goal of halving the incidence of the disease by 2010. A decade into that effort, however, there's little to show for it: malaria is far more pervasive today than it was when the campaign started.

In 2005 the Bush administration pledged $1.2 billion to fight the disease. And setting a new standard of engagement for private philanthropy, the Bill and Melinda Gates Foundation has been spending nearly $400 million a year, mostly on vaccine development; but it also directs funds to bed nets, drug research, and mosquito control. Meanwhile, malaria rages on--as does the debate over whether to bring back DDT to fight it.

International protocols governing the use of DDT are set by the 2001 United Nations-sponsored Stockholm Convention on persistent organic pollutants, or POPs. A POP is generally defined as a toxin that remains in the environment for years and often decades, is prone to bioaccumulate (collect in fatty tissue and become more concentrated as it moves up the food chain), and is readily conveyed around the globe by either air or water currents. DDT appears on the Stockholm Convention's original register of 12 banned toxins, but it is the only such item listed with an asterisk: nations meeting strict criteria of demonstrable need for fighting malaria are exempt from the DDT ban. This paradox, in which DDT is at once revered (for its real or perceived ability to save lives) and reviled (for its toxicity) has generated an often loud and unruly dispute.

In September 2006 the World Health Organization issued a press release headlined, "WHO Gives Indoor Use of DDT a Clean Bill of Health for Controlling Malaria." It was a startling announcement, apparently contradicting the position the agency had held on DDT since the 1970s, and numerous WHO malaria researchers resigned in protest.

Five years earlier the Stockholm Convention had sanctioned the use of DDT in prescribed circumstances. DDT tends to be most desperately needed, and most reliable, in epidemic conditions, where the break in the transmission cycle that it provides can be dramatically effective. In such instances, the immediate need to save lives trumps concerns about subsequent health or environmental complications (including the potential for mosquitoes to develop resistance to the toxin). It was recognition of this stark calculus that forged the 2001 compromise on DDT, which was agreed to by groups with histories of firm opposition to the insecticide, such as the World Wildlife Fund, the Natural Resources Defense Council (NRDC), and the Pesticide Action Network (PAN).

"We fully support the Stockholm approach to DDT because we understand that DDT can be effective under certain circumstances," said Kristin Schafer, campaigns director for PAN, "but also because the convention stipulates that use of DDT must be accompanied by efforts to develop alternative approaches. That's the point that is so often lost in these discussions: the Stockholm Convention is meant specifically to mobilize funds and attention to develop capacities such that DDT will no longer be needed."

Asterisk notwithstanding, DDT remains on the convention's so-called dirty dozen list of banned chemicals. All signatories to the treaty agree to a goal of ultimate phaseout. Thus, the 2006 WHO announcement ran counter to both the spirit and the letter of the Stockholm Convention. However, at the most recent Stockholm conference, in Dakar, Senegal, in April 2007, WHO officials backed away from their earlier statement and reconfirmed their commitment to finding alternatives to DDT.

Today's most ardent proponents of DDT suggest that the sole obstacle to routing malaria half a century ago was the onset of the environmental movement. Mosquito resistance to DDT and the crippling logistics of effective spraying campaigns are overlooked in favor of the much juicier target of Rachel Carson and her green descendants. Carson's 1962 book, Silent Spring, was indeed a watershed. Invoking DDT as Exhibit A and sounding her alarms in graceful, elegiac prose, Carson awakened readers to the idea that pesticides might have a downside.

The use of DDT was banned in the United States in 1972. But while the chemical is no longer manufactured here, other organochlorine compounds are, and many are or are likely to be subject to scrutiny by regulators. This may be what really concerns DDT's more aggressive advocates in the private sector. In a chapter of a book on "message crafting," economist Roger Bate, a fellow at the Competitive Enterprise Institute, warns, "DDT may be today's target, but it's not going to be long before chemicals that the industry cares about are added to the POPs Convention and other chemicals regulations."

DDT proponents are generally reluctant to acknowledge the complicating and protean factor of mosquito resistance. Entomologist May Berenbaum finds this galling. An expert on insecticide metabolism, Berenbaum is director of the entomology department at the University of Illinois at Urbana-Champaign. "Read the entomological literature of the 1950s," she said in a telephone interview. "Way before Silent Spring, scientists were already trying to understand resistance. That's what insecticide toxicology was all about back then. Resistance to DDT was first detected in Italy, in houseflies, in 1947!"

Environmentalists' objections to DDT, Berenbaum said, were just one piece of an intricate puzzle. In a 2005 Washington Post article that discussed mosquito resistance to DDT, she warned: "Overselling a chemical's capacity to solve a problem can do irretrievable harm not only by raising false hopes but by delaying the use of more effective long-term methods."

After Berenbaum published the article, she said, she was barraged by e-mails demanding that she support her claims. "To get them off my back, I finally culled a list of peer-reviewed articles documenting resistance to DDT and other pesticides in pockets all over Africa. This is not my life's work. I spent 10 minutes--10 minutes--and I found 15 articles. What would I have found if I'd spent an hour?"

DDT kills by attacking a mosquito's nervous system. But in any given population, a random smattering of individuals will have a genetic mutation that renders them resistant to certain toxins. At first the number is insignificant, but over time it will grow until the only mosquitoes that continue to breed will be resistant ones.

ICIPE physician Patrick Sawa acknowledged that "DDT is a cheap and effective method of controlling malaria, with the capacity to drastically reduce infection rates." Initially.

People who live in malarial areas and survive bouts of the disease acquire a level of immunity that mitigates its severity in subsequent infections. When spraying campaigns temporarily suppress mosquitoes and malaria, human populations lose the immunity they once had. But where mosquito populations grow resistant to DDT, "the severity of the rebound will be inversely proportional to the span of time DDT has been effective," Sawa said.

"If DDT remains effective, say, for five years," he continued, "we'll have a generation of children who, without the DDT intervention, would at least have developed some immunity had they been exposed to malaria; instead they'll be susceptible to the most severe manifestations of the disease." It is cruelly ironic that a temporary respite from malaria is, ultimately, more pernicious than no respite at all.

Theoretically, five years should be long enough to interrupt the cycle of malaria transmission. Plasmodium falciparum does not survive for more than a few months in the human bloodstream (the other three, less lethal, malaria parasites last longer). Using DDT to suppress Anopheles gambiae mosquitoes for half a year would seem enough to clear the blood of everyone in a community. One might suppose that even as mosquitoes start breeding again, no parasites would remain for them to distribute.

But towns like Mbita that are "holo-endemic"-- meaning that just about anyone you meet carries the parasite--are neighbor to countless other such towns and villages where migration is the norm because of farming cycles, civil unrest, or any number of other factors. In order to succeed, a DDT eradication campaign would require a synchronized, fail-safe effort that is nearly impossible to pull off anywhere, let alone across contiguous, cross-border endemic zones that cover thousands of square miles deep in destitute Africa.

Nairobi-based physician Paul Saoke is chairman of Kenya's DDT and Malaria Expert Committee on implementation of the Stockholm Convention and head of the country's chapter of the international health advocacy group Physicians for Social Responsibility. He has his eye on another serious concern about the toxin: its effects on human health. I first met Saoke in April 2007 at the POPs conference in Dakar. The man has an impish grin and a way with a crowd. To an audience of buttoned-up delegates representing all sides of the POPs question and all corners of the globe, he introduced a presentation on the health risks of DDT with an anecdote from his childhood.

Born in 1961, Saoke grew up in an area near Mbita that used to be "fumigated," as he put it. Through the 1960s and 1970s DDT periodically rained down to control agricultural pests and to combat mosquitoes, ticks, and tsetse flies. Saoke and his boyhood pals would often peel off their clothes to swim in Lake Victoria, and as they grew older they dared one another to leap off a high, rocky ledge into the water. Some of the kids were afraid to jump.

So, in a kind of rough-and-tumble, let's-see-what-you're-made-of scramble, they would reach between one another's legs to check. Lo and behold, Saoke recalled to the group of fidgeting dignitaries, by this crude measure a number of the boys were not made of much. His serious point: according to a growing body of evidence, cryptorchidism -- undescended testes -- and other genital malformations can result from in utero exposure to DDT.

Saoke now lives in Nairobi with his wife, a neonatologist, and their three children. Walking on the streets of the capital, or grabbing lunch in a restaurant, he appeared to know just about everyone he meets, from the shoeshine man to the government minister. Over the course of several conversations, Saoke recounted to me the parliamentary machinations by which Kenya very nearly changed course and resumed spraying DDT for disease-vector control.

The pro-DDT lobby was powerful, and while Saoke was not alone in raising opposition, it's easy to imagine he was among the more outspoken. He's wary of the influence that global corporate interests can bring to bear on Kenyan national policy. His particular concern is that the international chemicals industry and its promoters are using the millions of African babies they claim DDT can save as a "human shield" behind which to begin rehabilitating an industry with a long history of lousy PR.

In the end, Saoke concedes, it was not concern about the health effects of DDT that carried the day; it was fears about lost trade. The European Union tests agricultural imports for traces of banned chemicals, and it refuses goods that test positive. DDT was not being considered for agricultural use, but wind and water can carry the stuff; moreover, in Kenya, as in most African countries, once the chemical is in distribution it is nearly impossible to monitor and control the manner in which it's deployed (a vexing problem for the Stockholm Convention). The Kenyan government was not about to adopt a policy that could threaten exports. This was fine with Saoke, but it is the health issues that consume him.

Some say that these concerns are based on purely anecdotal evidence. But the science has been accumulating for years, and policy makers are beginning to take note. At a high-level Stockholm Convention meeting in October 2007, for example, convened to discuss plans for alternatives to DDT in the fight against malaria, one agenda item read: "New information on DDT toxicity -- is it time to press the panic button?"

A growing number of peer-reviewed studies suggest links between DDT exposure and a range of ills, such as breast and liver cancer, neurological and developmental abnormalities, and a variety of hormonal effects. Some of these conditions may not manifest themselves for years, but others may take a more immediate toll.

DDT can interfere with the feedback loop in the pituitary gland, which releases the milk-producing hormone prolactin. Studies show that exposure to DDT at critical points in pregnancy or just after childbirth can reduce the output of breast milk, or even dry it up. In such instances the mother will turn to formula, which is expensive.And in Africa formula feeding often leads to another death sentence for babies: diarrhea (infants have no immunity to the microbes that abound in contaminated drinking water throughout much of the continent). Here, then, exposure to DDT may cause as swift and bleak an outcome as exposure to a mosquito.

Many of today's DDT promoters concede that the toxin cannot eliminate malaria all by itself. They endorse the idea of Integrated Vector Management (IVM), which combines indoor house spraying with bed nets, larvicides, and whatever other control measures may be applicable in a given area. But they insist that DDT can and should be part of a comprehensive, multifaceted response.

They correctly point out that the amount of DDT necessary to keep mosquitoes from biting inside a house is far less than the amount required for agricultural pest control. However, according to Gina Solomon, associate clinical professor of medicine at the University of California at San Francisco and a senior scientist with NRDC, "There's not much reassurance in that argument. These applications occur where people live and therefore involve direct human exposures, so there's still a human health concern."

Moreover, she says, "Hormone concentrations are minuscule, by definition. That's the entire point." Hormones are chemical signals released by glands at varying intervals to initiate and modulate an organism's development, and there is compelling evidence that DDT and its metabolite DDE can interfere with that delicate process. Encountered at the wrong time, at a critical moment in the growth of a fetus or a baby, the smallest amount may disrupt the messages that hormones exist to convey.

In Africa, airtight longitudinal health studies of any kind are extremely difficult to execute, given the continent's ramshackle health care infrastructure, its migratory populations, and the sheer multiplicity of medical issues that challenge any long-term attempt to isolate and track the factors involved in disease. But a crowded spectrum of reports, studies, and anecdotes like Paul Saoke's link DDT exposure to low birth weight, increased miscarriages, impaired neural development in children, low sperm count in men, and a long list of other ailments.

Kennedy Agwanda makes at least 100 mud bricks a day. He accomplishes this backbreaking task with his hands and just a few crude tools. Barefoot and shirtless, he bends at the waist and applies a mold to the muck, transforming a tiny slice of floodplain, brick by brick, into an income for him and his family. Agwanda is 23 years old, with a wife and a child. His daily output can fetch between 300 and 400 Kenya shillings ($4.50 to $6), more if he bakes the bricks, but in that case he has to shell out a percentage to kiln operators and other middlemen.

I asked Agwanda if he'd ever had malaria. He interrupted the rhythm of his work to look at me. "Yes," he said. "A few times. When I was younger." These days he worries about his baby boy, who has not yet contracted the disease.

Every brick Agwanda extracts from the saturated earth leaves a negative image of itself that quickly fills with seeping groundwater. One by one, as he stacks the bricks into pyramids to dry, each brick-shaped puddle forms a ready-made larva nursery for local mosquitoes. These miniature sun-warmed pools are consummate breeding sites for Anopheles gambiae, a species that likes to lay its eggs in shallow, placid, temporary reservoirs, undisturbed by plant or predator. Here was a man laboring to sustain his family, while a by-product of that labor perpetuated a breeding cycle that could destroy his family. The awful symmetry was not lost on Agwanda.

From where we stood, on a 12-square-mile floodplain at the base of the first swell in Kenya's western highlands, I could see other brickmaking sites and a kiln belching smoke. These features appeared randomly distributed on the flat expanse, but upon closer inspection I could see that they were linked by a network of trenches. These had been put in to drain the puddles and ditches, thus drying up the mosquito nurseries, and to generate a current. If water is flowing or even trickling, Anopheles gambiae won't deposit its eggs. The mosquito's demand for tranquility is an exploitable weakness.

In Nyabondo, a town perched on a rise overlooking the plain, a group is working under the auspices of ICIPE to press that advantage. Operating on a shoestring budget out of an annex in a convent hospital, Swiss entomologist François Omlin and his team of field-workers and educators are trying to bridge the gap between what's necessary and what's possible, focusing on the interface among vector, parasite, and community. It's the kind of work that can get lost in plain sight. Some 90 percent of local mosquitoes breed in man-made environments, and a civic initiative to raise awareness and control breeding sites would seem elementary. Be that as it may, Africa's scarce resources have a way of obscuring the most obvious and compelling ideas.

A parable can be found in the events that finally routed malaria in the United States. By the early twentieth century, the disease had been eliminated everywhere except in the deep South, where the climate was warm and wet and many of the people were poor. Cash-strapped local governments had been unwilling or unable to fund malaria programs, but during World War I heads were turned by the army's successful mosquito-elimination campaigns at arsenals and bases in the South. When the war was over, and with assistance from the Rockefeller Foundation, municipal governments revved up their own programs.

Two essential tactics were to drain swamps and to install screens in windows and doors. Even through the Depression, FDR's Works Progress Administration dug thousands of miles of ditches and drained hundreds of thousands of swampy acres. Quinine (the drug of choice back then), combined with greater prosperity and education, delivered the final blow. Some historians assert that DDT rescued the American South from malaria, but the spraying campaigns of the 1950s merely ran up the score on a game that had already been decided.

No one is spraying DDT in Kenya's western highlands. Nor is anyone installing screens in the doors and windows of the houses built from Kennedy Agwanda's bricks. But the Ministry of Health and NGOs are distributing bed nets treated with deltamethrin and other insecticides that are harmless to humans; Omlin's team is spraying Bti (a naturally occurring microbial larvicide, see page 34); and the Ministry of Roads is excavating trenches to link the arteries dug at brickmaking sites to larger watercourses. Africa has long been deemed a less than ideal setting for environmental management programs of this sort: too much unpredictable rain; too many potential breeding sites, from big swamps to small hoofprints; no safe or effective larvicide to target those breeding sites (Bti is only now beginning to catch on); and, perhaps most significant, a lack of political and institutional will to overcome the obstacles.

"When larva counts go down, so do queues at the clinic for malaria treatment," Simon Osire Owuor told me as we stood watching kiln operators fire up a load of bricks. In his sixties (he couldn't precisely give his age) and an ex-brickmaker himself, Owuor now conducts barasas, community meetings in which he lays out the ABCs of malaria transmission and larva control and hammers home to brickmakers the importance of filling puddles and maintaining irrigation sluices at the end of a day's work. Owuor was among the first wave of brickmakers in the area, trained by a Dutch missionary who introduced the technology, along with the teachings of Christ, to select members of his flock. Not so long ago, Owuor said, popular belief held that disease-carrying mosquitoes came in from Lake Victoria, some 25 miles away. It's this kind of inertia-inducing misinformation that he works to eliminate. Wearing a threadbare suit and a beat-up felt fedora, the retired laborer gestured grandly across the floodplain. "There used to be thousands of breeding sites here. Not anymore. But there are still too many. We want none."

A long, man-made stream led away from the kiln, past some brickmaking sites and through an undisturbed field, as far as the eye could see. It snaked by a school that now has a soccer pitch in its backyard rather than a mosquito-infested swamp. We sat in on a class where the kids were being drilled on all matters malaria. The session included a primer on how to recognize potential breeding sites at home and what to do about them, a show-and-tell Bti pump demonstration, a refresher on the importance of sleeping under bed nets, and some basic vector/parasite science.

The charismatic instructor, Elijah Nyarangi, explained that a mosquito was like a matatu, the customized, tricked-out minivans that careen heedlessly around Kenyan cities and towns, crammed to bursting with humanity. Like the matatu, the mosquito is a transport vehicle. It must pick up a parasite from an infected individual before it can unload it elsewhere, into another person, causing another infection. Nyarangi turned sideways and slapped one elbow flat against his ribs, as if slamming shut a door, then revved up a whining engine in his throat before peeling out in wobbly matatu circles before the class. When he stopped and hinged his elbow open, he modulated the throaty whine to a mosquito buzz. The kids were laughing but the message could not have been clearer: bed nets keep uninfected people from receiving a fateful mosquito bite and passing the parasite along to others.

"That silver bullet thing is an idea of the past," François Omlin said to me in his office after a long day in the field. Hunched and sweating and coughing, Omlin was recovering from his own bout of malaria. No one really believes any longer that a single, monolithic solution will one day vanquish the disease, with the exception perhaps of vaccine researchers. But even if a malaria vaccine is one day formulated -- by no means a sure thing -- the challenge of inoculating millions in remote locations all over Africa may be insurmountable. Quinine, DDT, chloroquine, past vaccine quests, bed nets -- each, to one degree or another, has held out passing hope that it might singlehandedly save the day. But today most experts embrace the concept of integrated malaria management, along with its subset, integrated vector management.

Resistance, even to our most cleverly designed weapons, is malaria's ace in the hole. This is why policy makers in Geneva and field-workers in Nyabondo tend to agree: the best strategy for outmaneuvering the wily disease is to hit it and the mosquito it rode in on with as wide a range of ammo as possible.

Omlin is convinced that an integrated approach must include environmental management and local participation. Take fishponds. About 1,500 concrete ponds for fish-farming were installed years ago in the western highlands, but due to lack of money and training in their use they are now defunct, serving as de facto mosquito breeding sites. Omlin has conducted studies showing that restocking the ponds with Nile tilapia, a tasty local fish that happens to be a mosquito-vacuum, would vastly reduce the malaria burden as well as provide jobs and add a vital protein source to nearby markets. But the cash, education, and maintenance infrastructure the project would need to get off the ground are all still in short supply -- a scarcity that is hard to square with a world spending billions on malaria.

Burton Singer is a tropical disease specialist, a professor at Princeton's Woodrow Wilson School of Public and International Affairs, and author of numerous studies on both the history and contemporary challenges of environmental management in fighting malaria. He would like to see more money channeled into IVM, convinced that it can work in Africa. After all, it's worked there before -- when there has been sufficient motivation and funding. In Northern Rhodesia (now Zambia), from 1930 to 1950, colonial copper mines were located in a malaria-endemic region. The British owners could not have turned a profit with a sick and dying labor force, so they cleared vegetation, drained swamps, screened houses, and distributed bed nets and quinine. Within a few years malaria had ceased to threaten the economic stability of the enterprise.

Scientists are accustomed to tracking specific links between an individual method and its outcome, Singer says, but by definition environmental management programs pool approaches and look at aggregate results. Omlin told me that over the course of two years the effort in the brickmaking area, comprising water management, bed net distribution, larvicides, and community education, reduced malaria infections in children under the age of 5 by more than 50 percent. But, Omlin said, "It's impossible to discern the effect of an individual intervention since the whole approach is integrated."

Malaria parasites were first identified in human blood cells in 1880. Surveying a history of eradication efforts since then can feel like viewing a "You Are There" newsreel. We see test tubes and derring-do, improbable breakthroughs and scalding setbacks, good intentions and missed chances -- all set against a backdrop of brown skin, thatched roofs, and the incessant hum of the mosquito. What has changed? Today the concentration of international money and expertise uniting to confront malaria is unprecedented. It is as if a global indignation has set in -- part shame, part sputtering disbelief -- over our failure to relieve Africa, for all its woes, of this signature plague.

Not long ago, the late and esteemed Harvard entomologist Andrew Spielman was asked to name one item he would, if he could, supply to every malarial village in Africa. Spielman's unhesitating reply? A cement mixer -- for drainage canals, of course. They could certainly use one in Nyabondo, where the dirt trenches require constant upkeep.

What's been missing from this fight is long-term investment and a commitment by national authorities to programs that address the specific needs of affected communities. So, for now and the foreseeable future, DDT will continue to play some role as a front-line weapon in the malaria wars. But it is also a distraction. DDT won't pave a watercourse or feed a child or provide a job, and at the end of the day, malaria is a development issue. How well we understand this may determine whether the current crusade produces merely one more spool for the newsreel, or -- at long last -- an epic denouement.