NICHOLAS D. KRISTOF: Attack of the Worms

RUTSHURU, Congo

Quiz time: So what do hundreds of millions of ordinary schoolchildren around the world possess that American kids almost never get?

Answer: Worms.

My win-a-trip journey to Africa, with a teacher and a student, has taken us to regions where most people are “poly-parasitized.” So while in Congo, I picked up doses of deworming medicine for myself and those travel partners who wanted it. (It’s over-the-counter here. In the U.S. the simplest approach is to ask a vet for medication to deworm a St. Bernard.)

AIDS is the disease in the global spotlight, capturing celebrity attention and billions of dollars in treatment programs — and that’s terrific, because it still kills almost three million people a year. But it’s also time to recalibrate our efforts and devote more money to other ailments.

Some 40 million people have H.I.V. or AIDS, and 600 million have hookworms. Here in Congo, one study found that 82 percent of children have worms, and partly as a consequence 70 percent are anemic.

It often costs hundreds of dollars a year to treat a person with AIDS, continuing for as long as the person lives. But it costs 3 cents per year per person for medicine to prevent elephantiasis, which is caused by worm-like creatures and is on my personal top-three list of diseases never to develop.

Elephantiasis causes one’s legs to become grotesquely swollen, looking like an elephant’s, hence its name. And a man’s scrotum balloons so monstrously that in extreme cases the victim needs a wheelbarrow to support it as he walks.

Not knowing the local word for the disease, we had some trouble at first; it was awkward inquiring about men with oversized genitalia. But once we conveyed our meaning, villagers quickly pointed us to many sufferers.

Justine Nyinobajambere, 30, can barely walk, because both feet are leathery, pus-oozing stumps with flies feasting on them. She has already lost two of her four children, perhaps in part because her deformity makes it difficult to get food and water for them. All that suffering could have been prevented for 3 cents a year.

In addition, the disease is spread by mosquito bites, so the bed nets and mild DDT spraying that protect against malaria also help prevent elephantiasis.

I’m not criticizing the AIDS effort at all. Indeed, there should be an even bigger push for AIDS prevention measures such as condoms, education, male circumcision and drugs to block transmission in childbirth. All those steps are incredibly cost effective and should be expanded.

But Western support for health in poor countries right now has to be broadened to include more attention to malaria and especially to what are called the neglected tropical diseases.

The Global Network for Neglected Tropical Diseases estimates that more easily preventable and treatable ailments, including worms, elephantiasis and trachoma, kill 500,000 people annually. Indeed, ordinary worms kill 130,000 people a year, through anemia and intestinal obstruction.

More generally, these diseases prevent children from achieving their intellectual or physical potential.

“Why are millions of kids getting enough to eat but are still malnourished?” asks Josh Ruxin, who runs the program in Rwanda against neglected tropical diseases. “Because they have worms.”

These ailments together can be prevented or treated for just 50 cents per person per year.

“This is a chunk of global health that we can fix for almost nothing,” says Michael Kempner, chairman of the board of the Sabin Institute, which hosts the global network. (The network is an outgrowth of Bill Clinton’s work on international health.)

The benefits are also economic. One study found that chronic hookworm infections in childhood reduced future earnings by 40 percent. And a landmark study in Kenya found that deworming reduced school absenteeism by one-quarter.

Indeed, the cheapest way to increase school attendance in poor countries isn’t to build more schools, but to deworm children. Yet almost no government aid goes to deworming.

“The average American spends $50 a year to deworm their dog,” notes Peter Hotez, president of the Sabin Institute. “In Africa, you can deworm a child for 50 cents.”

This win-a-trip journey is an excuse to examine issues that are so basic that they usually get ignored. And so as we look at the international agenda, in addition to energy, war and nuclear proliferation, it’s time to add something that affects more people more intimately than almost anything else in the world.

Yes, worms.

You are invited to comment on this column at Mr. Kristof’s blog, www.nytimes.com/ontheground.