America’s Hidden Diseases
Americans living in high poverty bear the burden of more than 20 common diseases that the medical establishment largely does not monitor, diagnose or treat, studies show.
Millions of poor Americans living in distressed regions of the country are chronically sick, afflicted by a host of hidden diseases that are not being monitored, diagnosed or treated, researchers say.
From Appalachia to the Mississippi Delta to the segregated inner cities of the Great Lakes and Northeast, they say, and from Navajo reservations to Latino communities along the U.S.-Mexico border, more than 20 chronic diseases are promoting the cycle of poverty in conditions of inadequate sanitation, unsafe water supplies and rundown housing.
"These are forgotten diseases among forgotten people," said Peter Hotez, a microbiologist at George Washington University, president of the Washington, D.C.-based Sabin Vaccine Institute and co-founder of the institute's Global Network for Neglected Tropical Disease Control. "If these were diseases among middle-class whites in the suburbs, we would not tolerate them. They are among America's greatest health disparities, and they are largely unknown to the U.S. medical and health communities."
Now, based on a study published by Hotez for the Public Library of Science in 2008, the U.S. House of Representatives has passed the Neglected Infections of Impoverished Americans Act. The bill would, for the first time, require the Secretary of Health and Human Services to report to Congress within the next 12 months on the country's neglected diseases of poverty and recommend funding to address them. After passing in the House in September, the bill has not advanced since it was introduced in the U.S. Senate.
"The first step is to raise awareness of these diseases," Rep. Henry Johnson, the Georgia Democrat who introduced the bill, said after the Sept. 29 vote. "Today is an important step in recognizing the threat and moving toward a solution."
Over the course of the 20th century, deaths from infectious diseases declined rapidly in the U.S., and polio, tuberculosis, typhoid fever and malaria no longer represent a serious health threat here. But diseases that are common and chronic among the poor of Africa, such as Chagas, a leading cause of heart failure and stroke among Latinos; cysticercosis, which causes convulsions; and ascariasis, which causes abdominal pain and fever, also likely afflict millions of people living in the American South, in Appalachia and along the U.S.-Mexico border, Hotez said. These illnesses are spread, respectively, by parasites in insects, tapeworms in raw pork and roundworms in soil.
Most of the diseases named in the legislation have not been surveyed in the U.S. for decades, if ever. None are tracked by the U.S. Centers for Disease Control and Prevention, though between 4 million and 10 million Americans could be infected, Hotez said. Drugs are available to treat a number of the neglected diseases, he said, but doctors are not trained to diagnose them.
"These are not even rare diseases," Hotez said. "Yet there's so little research on them, we don't know the full extent of their impact, how they are transmitted, or how they contribute to disability. We do not have good diagnostic methods. We can't even begin to think about controlling these diseases."
The website of the Centers for Disease Control and Prevention lists six "major neglected infections of poverty" in the U.S., all of them parasitic or viral diseases, and notes that they can cause birth defects, epilepsy, hearing loss, infertility, blindness and heart failure. The site says that improved tracking, testing and treatment is needed to reduce illness and death.
The CDC conducts public health surveillance only at the request of states, and the states have not asked the agency to track of any of the diseases on Hotez's list, said Susan Montgomery, an epidemiologist with the CDC's Division of Parasitic Diseases and Malaria. Based in part on blood donor data, she said, the agency estimates that 300,000 Americans are afflicted with Chagas, and that between 60 and 300 babies are born with the disease in the U.S every year. But the agency does not formally collect reports from states about cases of Chagas here.
"There's an information gap," Montgomery said. "These are diseases that are disproportionately affecting parts of our population who are living in poverty, but it's in the context of many other health challenges our country is facing, including obesity, diabetes, HIV and tuberculosis. The states have not determined that those are diseases that they want the CDC to conduct surveillance for. They are not being monitored in the public health system. They may be diseases that physicians are not aware of and don't think to test for."
If the Senate passes the new bill, the CDC will conduct a review of existing data on the neglected diseases and try to identify the information gaps, Montgomery said.
According to a report by Families USA, the National Institutes of Health in 2007 accounted for 76 percent of $376 million in U.S. government spending for research on eight globally neglected diseases, including three that afflict hundreds of thousands of Americans — Chagas disease, dengue fever, which can be fatal, and leishmaniasis, a centuries-old disease that produces skin ulcers. Tuberculosis and malaria received nearly three-quarters of the funds. (And the private market sees more opportunity in battling the scourge of baldness.) Overall, the Families USA report said, NIH funding for the eight diseases represented less than 1 percent of the agency's total research budget of $29 billion.
In 2009, the National Institute of Allergy and Infectious Diseases, which is part of the NIH, spent $367 million of its $4.7 billion budget researching most, but not all, of the 24 neglected U.S. diseases listed by Hotez, not counting stimulus funds, the institute staff said. At the same time, $1.6 billion went to biodefense and emerging infectious diseases.
Still, $367 million is "not a trivial amount of money, by any means," said Lee Hall, chief of parasitology and international programs for the institute. There is ongoing and substantial government research on most of the diseases on Hotez's list, and the research helps both the developing world and the U.S., he said. The work itself is difficult because parasites must often be grown in live animals, so the institute helps researchers by providing them with biological material for the lab, Hall said. To date, there are no licensed vaccines for any of the parasitic diseases that afflict humans.
"The NIH has had a long-standing commitment to these diseases, and we have supported research on them for a very long time," Hall said. "I've spent most of my career on parasitic diseases, many of which fall into this category. I don't think we've neglected these diseases at all."
Yet even as research goes forward, the public health problem persists.
According to a study published by Hotez in 2009, trichomoniasis, or "trich," one of the most common sexually transmitted diseases in the world, afflicts up to 29 percent of African-American women in the South and impoverished inner cities of North, approaching rates in Nigeria, where 38 percent of women are infected. People with trichomoniasis are more susceptible to HIV. About 880,000 African-American women in the U.S. are infected with the parasite that causes trichomoniasis, Hotez said.
Hotez's list includes bacterial diseases spread by rats and lice in the poor neighborhoods of Baltimore and Detroit; parasitic diseases from Africa, prevalent among the "Lost Boys and Girls of Sudan" who resettled in the U.S.; parasitic diseases among the Inuit of Alaska who eat infected seal and caribou meat; and CMV, or cytomegalovirus, a congenital virus that infects an estimated 10,000 infants in America yearly. Babies with CMV develop hearing and vision loss, sometimes years later.
Along the U.S.-Mexico borderlands and in the Gulf Coast region, Hotez said, up to 200,000 people living in poverty may be infected with dengue fever, a viral disease that is transmitted by mosquitoes. Dengue can lead to failure of the circulatory system.
In the 1970s and 1980s, Hotez said, 30 percent of rural black children in the South tested positive for toxocariasis, or roundworm, a parasitic disease that is transmitted through the feces of dogs and cats. Toxocariasis causes abdominal pain, swollen glands and vision loss and may be linked to the rise in asthma among inner-city children. Extrapolating from old data, Hotez estimates that between 1.3 million and 2.8 million poor Americans are infected with toxocariasis today.
"These are truly neglected problems," he said. "People have these diseases for years, and during this time, they promote poverty. They interfere with child growth and development and, in some cases, impair intelligence and cognition. They affect pregnancy outcomes and are co-factors in the AIDS epidemic."
"They have no advocacy," he said. "It's been very frustrating."