In Brazil, a New Effort to Wipe Out Hookworm
Children living outside the Brazilian village of Americaninhas. - Children living outside the Brazilian village of Americaninhas. About 75 percent of people living in the area are infected with hookworm. The effects of the disease -- malnutrition and anemia -- are worse in children. (Brigid McCarthy, NPR)
The interior of the Brazilian state of Minas Gerais is gorgeous. Soaring black stone cliffs jut out from rolling hills. It's dry and dusty in early October, but vegetation is still lush. On small farms, you can see banana palms, coffee plants and manioc. Cattle are plentiful.
The people here are poor. Tucked among the hills are small clusters of one-room houses. Some are sturdy, made from adobe or dried mud. But others are just a rickety collection of logs with leaves and branches for roofs.
Children in T-shirts and shorts scamper around, blowing whistles or chewing on sugar cane. One little boy is pushing a bike wheel with a forked stick, clearly a prized toy. They are small for their age, and several have distended bellies -- a sign of malnutrition.
(Brigid McCarthy, NPR)
That's because there's a problem here: Three-fourths of the people in the region are infected with hookworm.
Jeff Bethony, a tropical disease expert at George Washington University in Washington, D.C., has been working in Minas Gerais for more than a year. He calls himself a foot soldier in the war on hookworm.
"Most people don't know when they became infected, and that they are infected, and that they will be for their entire life," says Bethony.
(Brigid McCarthy, NPR)
Hookworm is an intestinal parasite. The worm larvae live in the soil, and pass directly through the skin. Infection comes from acts as simple as walking barefoot on contaminated soil or kneeling down to pull a weed or plant a vegetable.
Once the larvae get in, they migrate to the intestines, where they clamp on with their sharp, jagged mouth parts and start sucking their victims blood like internal leeches. As adults, the worms are about a half-inch long.
The more worms a person is infected with, the more severe the anemia and malnutrition. To make matters worse, the worms lay eggs, which come out in the feces.
There are no bathrooms in these rural areas, not even outhouses, so the eggs spread through the soil. There they hatch into larvae, and the vicious cycle of infection continues.
Hookworm is unknown in the United States today, but that wasn't always the case. The parasite used to be endemic in the South and Atlantic coastal regions. Better sanitation and a higher standard of living have eradicated hookworm disease in this country, although dogs sometimes still get infected.
But worldwide it's a different story. By some estimates, 740 million people are infected. It rarely kills, but it causes a terrible burden of malnutrition and severe anemia, especially in children.
Hookworm is a chronic infection. In other words, it doesn't go away unless treated. Often, those infected don't realize how sick they are until they are treated.
Maria Jaraous, 67, has 13 children and scores of grandchildren, all living in walking distance. A year ago, Jaraous took drugs that killed the worms. Only after the treatment did she know what it was like to feel well.
"I couldn't walk up the hill, my arms and legs were very weak. And now I feel much better, and can walk everywhere," she says.
Children are even more vulnerable. The worm doesn't just stunt growth. The anemia and malnutrition caused by the parasitic infection affect the brain, making learning difficult.
Giovanni Mas Silva is a 26-year-old school teacher in the area. Her students were given medication a year ago. She sees a noticeable difference in her classroom.
"They're doing a lot better now, understand more what I explain, and are doing better on tests," she says. "And they're more active. They play football, they run around, they really enjoy playing more."
The drugs to treat hookworm are cheap, and they work. The trouble is they don't protect people from getting re-infected. And in remote areas like the north of the Minas Gerais state, people seldom, if ever, get treated.
Jeff Bethony believes what's needed is a vaccine to prevent infection.
But first he needs to know precisely how common hookworm is in this area. A year ago he provided drugs to about 1,700 people living here.
In a month, he'll start testing them to see how many are re-infected. He knows quite a few will be.
This is not easy work. Communities are not that far apart, but the roads connecting them are narrow, steep and badly rutted. In the rainy season, they're treacherous. Just getting blood samples to a lab takes hours.
"It's hard and it's time consuming and it uses a lot of material," says Bethony. "But the value is that this is an area where there was a lot of infection. And these are the people that really the vaccine is made for."
The job of making a vaccine belongs to Bethony's boss, Peter Hotez, a professor at George Washington University.
If Bethony is the foot soldier in the war on hookworm, Hotez is the general.
Ever since he was a schoolboy, Hotez has been fascinated by parasites. When he went for a combined M.D./Ph.D. degree, he decided to focus on hookworm because, basically, no on else was.
"The problem is let's remember who gets hookworm: It's the poorest of the poor," says Hotez. "So although there's a huge market for a hookworm vaccine, the commercial market is zero."
A few years ago, Hotez convinced the Bill and Melinda Gates Foundation to back his plans for a vaccine. So far, the foundation has given $40 million to the project. Before that money came through, Hotez didn't know how he was going to pay for a vaccine.
"We even considered developing a veterinary vaccine for dogs," says Hotez. Any profits would be siphoned off and used to make a human hookworm vaccine. "Sadly, the commercial market for veterinary products is far bigger than the market for products for neglected human tropical diseases," says Hotez.
Now he has developed a human vaccine. Instead of collaborating with a pharmaceutical company, Hotez is working with the non-profit Sabin Vaccine Institute. The vaccine is being tested now in healthy volunteers in America. If it proves safe, and things are looking good so far, Hotez will send the vaccine to Brazil where it will be tested on people exposed to hookworm.
China and India may have a bigger problem with hookworm than Brazil, but the Brazilian government has promised to manufacture the vaccine if it's successful, so Hotez and his colleagues decided to work there first.
Bethony is working long hours back in Brazil preparing for the upcoming vaccine study. Bethony knows there's a real possibility that the vaccine being tested now may not work.
"It would be really lucky," he says. There's a lot of hope for this vaccine, says Bethony, but rarely are the first incarnations of a vaccine successful. "We're learning a lot," he adds. "We're learning how to make this kind of vaccine, test this kind of vaccine, we're learning how to work in this kind of environment. And if it takes us 10 or 20 years, I think it's worth it."
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LINDA WERTHEIMER, host:
If you've never heard of hookworm, you're not alone. Today, the intestinal parasite is unknown in this country, but that was not always the case.
(Soundbite of music)
Ms. BLIND BLAKE: (Singing) Hookworm in your body, your food don't do you no good. Hookworm in your body, your food don't do you no good.
WERTHEIMER: When Blind Blake recorded that song in 1927, hookworm was everywhere in the American South and along the East Coast. Better sanitation, a better standard of living has eradicated hookworm disease in this country, although dogs sometimes get infected. But worldwide, it's a different story. By some estimates, 740 million people--that's one in eight people on the planet--are infected. Hookworm rarely kills but it causes a terrible burden of malnutrition and severe anemia, especially in children. A small band of scientists is working on a vaccine to relieve the suffering that hookworm causes. NPR's Joe Palca visited one of those scientists working in a remote part of Brazil.
JOE PALCA reporting:
The interior of the Minas Gerais state is gorgeous. Soaring blackstone cliffs jut out from rolling hills. It's dry and dusty this time of year, but vegetation is lush. On small farms, you can see banana piles, coffee plants and manioc. Cattle are plentiful. The people here are poor. Tucked among the hills are small clusters of one-room houses. Some are solid, made from adobe or dried mud, but others are just a rickety collection of logs with leaves and branches for roofs. Dogs, ducks and chickens roam freely. Children in T-shirts and shorts scamper around blowing whistles or chewing on sugar cane. One little boy is pushing a bike wheel with a forked stick. This is clearly a prized toy. These children are small for their age and several have distended bellies, a sign of malnutrition. That's because there's a problem here: 70 to 80 percent of the people are infected with hookworm.
Mr. JEFF BETHONY (Tropical Disease Expert, George Washington University): Most people don't know when they became infected and that they are infected and that they will be for their entire life.
PALCA: Jeff Bethony is a tropical disease expert at George Washington University. He calls himself a foot soldier in the war on hookworm. Jeff's been working in Minas Gerais for more than a year. He's become a familiar figure, a swarthy man with an easy-going manner and a permanent five o'clock shadow. He speaks fluent Portuguese, although everyone makes fun of his accent. A group of curious children follow as he walks among the houses.
Mr. BETHONY: (Portuguese spoken)
Unidentified Child: (Portuguese spoken)
Mr. BETHONY: (Portuguese spoken)
PALCA: These kids don't look sick, but if you stood them next to American kids the same age, you'd see how small they were. Part of the reason is hookworm. You just can't avoid it here. The worm larvae live in the soil. They pass directly through the skin. Walk barefoot on contaminated soil, you're infected. Kneel down to pull a weed or plant a vegetable, you're infected. Once the larvae get in, they migrate to the intestines, where they clamp on with their sharp jagged mouth parts and start sucking their victims' blood, like internal leeches. As adults, the worms are about a half-inch long. The more worms, the more severe the anemia and malnutrition. To make matters worse, the worms lay eggs. The eggs come out in the feces. There are no bathrooms in these rural areas, not even outhouses, so the eggs spread through the soil, where they hatch into larvae, and the vicious cycle of infection continues.
Hookworm is a chronic infection. In other words, you just live with it, and in a way, you don't know how sick you were until you get treated. Maria Jarauj(ph) is 67 years old. She has 13 children and scores of grandchildren all living in walking distance. A year ago, Maria took drugs that killed the worms.
Tell me how you felt before you had the treatment.
Ms. MARIA JARAUJ (Treated for Hookworm): (Through Translator) My legs and arms were weak. I couldn't lift things or even walk up the hill. Now I can walk anywhere and I feel much stronger.
PALCA: Children are even more vulnerable. The worm doesn't just stunt growth; the anemia and malnutrition dull the brain, making learning difficult.
(Soundbite of bell)
PALCA: Schools are out on this day. It's the Festival of Our Lady Aparecida, one of Brazil's patron saints. In the nearby village of Americaninez(ph), people tend church services and somewhat incongruously set off firecrackers from the steps of the Catholic Church in the main square.
(Soundbite of firecrackers; people chanting)
PALCA: Jovani Mossilva(ph) is a 26-year-old school teacher in the area. Her students were given medication a year ago. She sees a noticeable difference in her classroom.
Ms. JOVANI MOSSILVA (Teacher): (Through Translator) They're learning a lot more, they understand more what I explain and are doing better on tests, and they're a lot more active. They play soccer, they run around and they really enjoy playing outside more. Before, they just sat around, not doing much of anything.
PALCA: The drugs that treat hookworm are cheap and they work. The trouble is they don't protect people from getting reinfected. And in remote areas like this, people seldom, if ever, get treated. So Jeff Bethony believes what's needed is a vaccine to prevent infection. But first, he needs to know precisely how common hookworm is in this area. A year ago, he provided drugs to about 1,700 people living here, including Jovani Mossilva's students. In a month, he'll start testing them to see how many are reinfected. He knows quite a few will be. This is not easy work. Communities are not that far apart but the roads connecting them are narrow, steep and badly rutted. In the rainy season, they're treacherous. Communication is difficult. Just getting blood samples to a lab takes hours.
Mr. BETHONY: It's hard and it's time consuming and it uses a lot of material. So it took about a 40-minutes driving through really tough terrain and then we ended up walking 20 minutes to come to this small group of houses. But, you know, the value is that all of these people--this was an area where there was a lot of infection, and these are the people that, really, the vaccine is made for.
PALCA: The job of making a vaccine belongs to Jeff's boss, Peter Hotez, a professor at George Washington University in Washington, DC. If Jeff Bethony is the foot soldier in the war on hookworm, Hotez is the general. Ever since he was a schoolboy, Hotez has been fascinated by parasites. When he went for a combined MD-PhD degree, he decided to focus on hookworm because basically no one else was.
Professor PETER HOTEZ (George Washington University): The problem is let's remember who gets hookworm. It's the poorest of the poor. And so we're talk--although there's a huge market for hookworm vaccine, the commercial market is zero.
PALCA: A few years ago, Hotez convinced the Bill and Melinda Gates Foundation to back his plans for a vaccine. So far, the foundation has given $40 million to the project. Before that money came through, Hotez didn't know how he was going to pay for a vaccine.
Prof. HOTEZ: We're even toying with the idea of developing a veterinary vaccine for dogs. With--any profits that we could make, we would use to siphon off into what I really wanted to do, which is to make a human hookworm vaccine. Sadly, the market for veterinary products is far bigger than the market for products for human-neglected diseases.
PALCA: Now he has developed a human vaccine. Instead of collaborating with a pharmaceutical company, Hotez is working with the non-profit Sabin Vaccine Institute. The vaccine is being tested now in healthy volunteers in America. If it proves safe, and things are looking good so far, Hotez will send the vaccine to Brazil, where it will be tested on people exposed to hookworm.
Fighting hookworm is not glamorous, either in the field or in the laboratory. Researchers can get far more money and prestige by studying the killers of the developed world, like cancer or heart disease. Yet, Hotez has assembled an international team of scientists to work on the vaccine. Several of them have personal experience with hookworm. Maria Elena Bottazzi is the cell biologist on the vaccine team. She's from Honduras.
Ms. MARIA ELENA BOTTAZZI (Cell Biologist): I remember when I was little and growing up, playing out in the fields and in the grass. And my father always used to complain to me. He was, like, `Don't walk without shoes because you're gonna get worms.' So it's always, you know, very common for us.
PALCA: Biochemist Gaddam Goud is in charge of making the proteins that make up the vaccine. He's from India.
Mr. GADDAM GOUD (Biochemist): I also suffered from these infections. Recently, I went back, and same conditions.
PALCA: And molecular biologist Bin Zhan grew up in Southern China.
Mr. BIN ZHAN (Molecular biologist): There are a lot of people suffer from hookworm infection, and I saw a lot of people that cannot walk, that feel like they are very weak.
PALCA: China and India may have a bigger problem with hookworm than Brazil, but the Brazilian government has promised to manufacture the vaccine if it's successful. So Hotez and his colleagues decided to work there first.
(Soundbite of birds)
PALCA: Back in Brazil, Jeff Bethony is working long hours preparing for the upcoming vaccine study.
What do you think? I mean, just in your gut, do you think you're gonna have a vaccine in 10 years?
Mr. BETHONY: I haven't been in this business long enough to have those kind of gut feelings. I mean, of course, I hope, but it takes a lot of trial and error to make a good vaccine. It would be really amazing if we had one in 10 years. It would be really lucky. I mean, we have a lot of hope for this vaccine, but nobody goes and gets it the first time. We're learning a lot. We're learning how to make a vaccine, we're learning how to test this kind of vaccine, we're learning how to work in this kind of environment. And if it takes us 10 or 20 years, I think it's worth it.
PALCA: Well, I'll tell you what. It's an incredibly beautiful place to live.
Mr. BETHONY: It's incredibly beautiful and, of course, it's in--the people are incredibly sick, too. In such a beautiful place, there's a lot of misery.
PALCA: A successful vaccine would not only relieve a lot of misery here but the hundreds of millions of people around the world infected with hookworm. Joe Palca, NPR News.
WERTHEIMER: Our story on hookworm was produced by Bridgid McCarthy. For more stories about global health, look for "Rx For Survival," a special public television series premiering Tuesday, November 1st. Check your local listings for times.
You're listening to WEEKEND EDITION from NPR News. Transcript provided by NPR, Copyright National Public Radio.
