22 Guinea worm cases reported in 2015, Carter Center says

Just 22 cases of Guinea worm disease were reported worldwide in 2015, down from 126 cases during the previous year, officials with The Carter Center said this week.

The human rights organization founded by former President Jimmy Carter began targeting the painful parasitic disease in 1986 for eradication. At that time, an estimated 3.5 million cases occurred annually worldwide.

The 2015 figures include cases in four African countries: Chad, Ethiopia, Mali and South Sudan.

The disease is a top priority for the former president, who playfully told reporters that he hoped to outlive the last Guinea worm after revealing a cancer diagnosis in August. Carter has since said that doctors found no signs of cancer in a December brain scan.

Dr. Don Hopkins, the center's special adviser for Guinea worm eradication, said its goal of eradicating the disease "feels very close." South Sudan and Mali reported cases in the single digits despite political turbulence, war and poor infrastructure, he said.

But those working on the issue remain cautious. Guinea worm is a disease that doesn't appear until a year after people become infected by drinking water containing the larvae.

A worm grows inside the human body, emerging later through painful blisters on the skin, and there is no vaccine or medical treatment to prevent it. Instead, public health organizations teach people to filter their water—and in some countries, cook fish properly and prevent dogs from eating raw fish that may also contain the larvae.

Small mistakes can lead to outbreaks of dozens of cases, Hopkins said.

"We know it's not over until we have zero cases," he said.

Smallpox is the only human disease to be declared eradicated by the World Health Organization.