For 30 years, scientists have fought to eliminate a horrifying parasite. Suddenly, it has begun infecting dogs in Chad, threatening to undo decades of progress. Martoussia, the celebrity of the moment in this remote fishing village, pants heavily under the awning where he lies chained. Still, he remains calm and sweet-tempered as the crowd presses in.
Children gawk as volunteers in white surgical gloves ease a foot-long Guinea worm from the dog’s leg and American scientists quiz his owner, a fisherman, about how many worms Martoussia has had.
The village chief, Moussa Kaye, 87, is asked the last time one of his people had a worm.
“Not since 40 years ago,” he says.
In this arid central African country, the long global struggle to eliminate a horrifying human parasite has encountered a serious setback: dogs. They are being infected with Guinea worms, and no one knows how.
Scientists are desperate to solve the puzzle. If the answer isn’t found soon, or if the worms begin to spread widely into other species — a handful already have been found in cats and even baboons — then 32 years of work to end the scourge may crumble, said Mark L. Eberhard, a parasitologist at the Centers for Disease Control and Prevention.
Once a pathogen runs wild in an animal population, there is little chance it can be wiped out. “An animal reservoir is the kiss of death for eradication,” Dr. Eberhard said.
It has happened before. In the 1930s, the drive to eradicate yellow fever died when scientists realized monkeys carried the virus.
This setback has come just as the decades-long campaign edges tantalizingly close to victory.
In 1986, when the Carter Center — the global health philanthropy in Atlanta founded by President Jimmy Carter — launched the eradication drive, an estimated 3.5 million people in 21 countries had worms.
