From Plague to Leprosy: 7 Diseases We'd Forgotten About

"A lot of these neglected diseases are poverty promoting -- they not only occur in poverty but they promote poverty," he said.

Franco-Paredes notes that interventions have helped reduce cases, including vaccines and having people wear shoes.

It remains unclear how long this disease will persist, since much of its root cause lies in poverty -- well off people do not get hookworm infections.

"Any of these diseases … these are diseases that occur mostly in the setting of extreme poverty, and exposure as a result," Hotez said.


As a few prominent cases in recent years have shown, tuberculosis is still around, even if it isn't as deadly as it once was. But TB still poses a major problem for doctors, even if most cases do not occur in the United States.

"It's very difficult to eradicate and it's been with human beings … since before written history," said Dr. Douglas Hornick, a professor of internal medicine at the University of Iowa who is consulted by the Iowa Department of Public Health for tuberculosis-related matters.

"It's an insidious, slow-onset disease that patients develop a cough over time," he said. Ultimately, patients can develop a persistent fever and lose energy and weight.

While patients may not know they have the disease, they can be spreading it to other people during that time.

"Most tuberculosis is still susceptible to the standard drugs that we have available," Hornick said.

But tuberculosis has become more of a threat than it once was with the development of forms that are resistant to the drugs typically used to treat the disease.

While tuberculosis was once fatal to 40 to 50 percent of people who caught it, that number remains the same for people with resistant forms.

"We can cure tuberculosis, but it is extremely difficult to treat in drug-resistant forms," Markel said. "It's a terrible disease, and particularly with drug-resistant or multi-drug-resistant tuberculosis, a real fear. You're instantly jerked back into the 19th century, where we didn't have these wonderful antibiotics to treat these terrible diseases."

Compounding the problem is surveillance. People in the United States often receive a skin test to see if they have ever had the disease, but that is not done around the world, where such screening may prove impractical or unaffordable -- and where a great number of cases exist.

Some estimates place up to a third of the world's population as having tuberculosis.

"Eighty to 90 percent of those people don't know they're infected, because it's latent," Hornick said, referring to the phase when TB does not show symptoms. "The majority of people that are infected never have active disease; they just carry it in their system."

And tuberculosis still presents a challenge in some areas of the United States. "Even in the U.S., there are so many cases in local areas, like the major cities," Franco-Paredes said.

He said rates where he works, in Fulton County, Ga., are "as high as some of the rates of a country in Africa, like Uganda or Kenya."

"I'm not very optimistic," he said. "I think TB will remain with us forever."

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