Banner by Nicole Rodriguez
Parasites, Poverty, and Policy: The Global Burden of Neglected Tropical Diseases
by Julia Feibusch
“I am proud of my growing reputation as the world’s most preeminent sponsor of latrines.”
The man who holds the title of “No. 1 Latrine Builder” may surprise you. Former U.S. President Jimmy Carter proudly earned this honor through his post-presidential work. His humanitarian organization, The Carter Center, is dedicated to fighting disease worldwide and promoting peace and human rights abroad. The Center has built over 3.6 million latrines since 2002, significantly reducing the rate of the bacterial eye infection trachoma, the leading cause of preventable blindness globally. Trachoma, caused by the same bacteria that causes chlamydia, is spread by flies seeking the moist tissue of human eyes. Scarring from the infection causes the eyelids and lashes to curl inward, resulting in painful abrasion of the cornea and eventually, blindness. “When you go to a village, quite often from a distance you see children and think they're wearing eyeglasses,” Carter described, “and you get close to them and you see instead of eye frames, it's a circle of flies around their eyeballs sucking out moisture.”
Household latrines reduce disease transmission by improving sanitation and reducing breeding sites for flies. The Carter Center has made it their mission to eradicate diseases like trachoma, which falls under a category many may not be familiar with—Neglected Tropical Diseases.
Neglected Tropical Diseases (NTDs) refer to a group of 20 different conditions caused by a range of pathogens, including bacteria, viruses, parasites, fungi, and toxins that primarily impact people in tropical regions. The term “neglected” highlights the lack of resources and priority these diseases receive. Dr. Mari Webel, an Associate Professor in the Department of History at the University of Pittsburgh, is an expert in modern Africa and the history of health. Dr. Webel describes that historically, there has been a “decades-long impoverishment of funding streams because of research priorities globally” resulting in these diseases being understudied. Moreover, the term “neglected” reflects the people most affected by these infections. These diseases are most prevalent in rural and impoverished communities. Dr Webel explains, “there's no good market for the drugs that would cure them” because the diseases affect “people who are who are not in positions of economic or political power, because they're...poor, or they live in rural areas or they're isolated in other ways from centers of power globally or locally.” The World Health Organization (WHO) estimates that NTDs impact more than one billion people, mostly in low-and middle-income countries, and more than 1.5 billion people need preventative and curative NTD interventions.
Despite these numbers, NTDs often receive less attention than other significant diseases globally, such as HIV/AIDs and malaria. This is, in part, because NTDs typically do not have high mortality rates. Dr. Webel comments, “They are not diseases that kill people in sort of immediate and dramatic fashion.” Nonetheless, these diseases have high morbidity rates and cause tremendous suffering. For example, lymphatic filariasis, also known as elephantiasis, is a parasitic infection that can lead to tissue enlargement and lymphedema (swelling). This can be disfiguring and debilitating, leading to disability and severe societal stigma.
Beyond the physiological and psychological impact, NTDs are diseases that keep people and communities trapped in a cycle of poverty. Those with NTDs experience chronic disability and have difficulty finding gainful employment. This exacts an enormous economic burden. Dr. Webel adds, “They’re diseases that sicken children. They’re diseases that take away from long-term livelihood…educational attainment, economic productivity. They immiserate rather than killing people quickly.” Globally, affected households lose over $33 billion of income annually in out-of-pocket health care costs and missed wages.
Dr. Webel argues that health issues must be viewed through a lens that connects disease with the “understanding that vulnerabilities and exposures are about socioeconomic conditions. They're about housing conditions, they're about education, they're about marginalization.” Despite this broad-reaching hardship that disproportionately affects impoverished communities, these diseases are frequently ignored.
Too often, these infections are dismissed as a faraway problem that only affects “developing nations”—the other. However, these diseases impact the entire world, including the United States. The newly confirmed U.S. Secretary of Health and Human Services Robert F. Kennedy Jr., commonly referred to as RFK Jr., revealed that doctors diagnosed him with a parasitic brain-eating worm. The tapeworm that infected RFK Jr.’s brain is just one example of the parasitic infections that may affect people in this country. Other types of infections, such as giardia and intestinal worms contracted from eating the eggs of roundworms and hookworms, are more common in the U.S. Similar to trends globally, these infections most often affect those in rural, low-income areas.
Dr. Peter Hotez, Dean of Baylor College of Medicine’s National School of Tropical Medicine and national vaccine expert, describes the “hidden burden” of these diseases in the U.S. For example, toxocariasis is an intestinal roundworm spread to humans from infected dogs and cats, often through contaminated yards, playgrounds, and sandboxes. It disproportionately impacts minorities and underprivileged communities, mainly in the South, especially African Americans and people living in poverty. Dr. Hotez has estimated that as many as 2.8 million African Americans living in poverty have toxocariasis. Toxocariasis also exists in urban centers. A study in New York City found that contamination of city parks and playgrounds with toxocariasis from animal feces was linked to socioeconomic status throughout the city. The Bronx, the borough with the poorest neighborhoods in the study, had the highest rates of playground contamination with infectious Toxocara eggs, while the wealthiest areas in the borough of Manhattan had the lowest rates. Moreover, toxocariasis has been linked to cognitive and developmental delays, and Dr. Hotez suggests that “these chronic infections may partially account for the achievement gap noted among socioeconomically disadvantaged students.” Much remains to be understood about the health disparities of toxocariasis and other parasitic infections in this country, but it is clear that these neglected diseases are not just a problem of the “developing world.”
Instead, NTDs are a global problem that casts a wide net, with about 24% of the world’s population estimated to have soil-transmitted helminth (STH) infections like toxocariasis. Because STHs are spread through contaminated feces in soil, these parasitic worms are most prevalent in areas with poor sanitation that lack educational resources about the importance of wearing shoes to protect skin from the contaminated soil. These infections cause malnutrition, making children and pregnant women most vulnerable. However, STH infections can be effectively addressed through deworming programs, education, and improved sanitation.
While RFK Jr. has been fortunate enough to receive treatment, the U.S. government is cutting funding from programs that facilitate access to the same treatment for people around the world. The United States Agency for International Development (USAID) and the WHO have global initiatives focused on reducing rates of NTDs and providing critical care to people worldwide. President Trump signed an executive order to withdraw the U.S. from the WHO on the first day of his second term. This has tremendous repercussions for health both abroad and domestically. The U.S. is the top contributor to the WHO, having provided about 1.3 billion dollars in 2022–2023. It’s not clear if other countries or non-governmental organizations will close this gap. In addition to the WHO withdrawal, the Trump administration has issued a stop-work order for USAID. Through USAID, the U.S. has contributed significant funding towards treating NTDs and meeting WHO goals. In 2024, USAID allocated about $115 million to treat the most common NTDs. Interventions offer significant economic and social returns, with school-based deworming programs costing less than $1 per child annually—a worthwhile investment for a healthier future. Although some “lifesaving” waivers for USAID programs have been approved, these have not included the NTDs, putting in jeopardy the control of diseases such as the parasitic infection river blindness, or onchocerciasis, that have nearly been eradicated. Interventions like mass drug administration of the antiparasitic drug ivermectin in endemic regions have successfully reduced and eliminated river blindness in several countries. The WHO goals have placed the world on track to meet elimination targets for the disease by 2030, but the future is now uncertain with the recent funding cuts and the decision for the U.S. to withdraw from the WHO.
The U.S. government has the ability to effectively treat people in our country and to dramatically reduce suffering around the globe. Past successes have shown that goals can be met when these neglected diseases receive proper attention and funding. In addition to Jimmy Carter’s coveted reputation as the number one latrine builder, one of the Carter Center’s earliest and well-known campaigns was to eradicate Guinea Worm, or dracunculiasis, a parasitic roundworm infection spread by contaminated water. The worm can grow up to three feet long, and in a very slow and painful process, it emerges from an erupted blister on one’s foot about a year after the initial infection. The worm takes several weeks to fully emerge from the open sore, causing significant disability and pain during this time. The Carter Center set out on the daunting task to eradicate the disease in 1986 when approximately 3.5 million people in Asia and Africa were impacted by the disease. Through non-pharmaceutical interventions like improving health education and access to clean water, the incidence rate was reduced by over 99.99%. Former President Carter's goal of Guinea Worm eradication was nearly realized at the time of his death in December 2024, with only 14 cases remaining. This level of success is possible when these diseases receive proper funding and attention. Knowing the possibilities, the U.S. has a duty to bolster resources to eradicate NTDs. Treating these neglected diseases benefits everyone all over the world, from people in the Amhara region of Ethiopia to those living in rural communities of Texas.