ST. LOUIS, Missouri — Neglected tropical diseases (NTDs) affect more than 1 billion people globally, bringing with them pressing “health, social and economic consequences.” NTDs cost nations the “equivalent of billions of United States dollars each year” as a result of “direct health costs, loss of productivity and reduced socioeconomic and educational attainment.” However, NTDs have historically been under the radar and absent from any global health policies. In fact, the world only officially prioritized the eradication of NTDs in 2015 with the implementation of the U.N. Sustainable Development Goals (SDGs). One neglected tropical disease that is especially important to acknowledge is soil-transmitted helminths (STHs), or intestinal worms, as the NTD impacts approximately 1.5 billion people globally. Causing short and long-term negative health outcomes, STHs are not only “among the most common infections worldwide” but also mostly affect the most impoverished nations. While initiatives from philanthropic organizations and global governmental administration have helped control infection, increased efforts to control STHs are still crucial.
What are Soil-Transmitted Helminths?
Soil-transmitted helminths are intestinal worms “transmitted by eggs present in human feces, which in turn, contaminate soil in areas where sanitation is poor,” according to the World Health Organization (WHO). The three main species that infect humans are roundworms, whipworms and hookworms. While the same medicine can treat this group of STHs, Strongyloides stercoralis is another kind of helminth that does not respond to typical intestinal worm treatment and is not as easily diagnosable. According to the WHO, Strongyloides stercoralis infects more than 600 million people worldwide.
How are STHs Transmitted?
Intestinal worms transmit through the feces of infected people, and when the area has inadequate sanitation, these eggs can contaminate the soil. However, the eggs can infect through other means of transmission, such as the consumption of worm-riddled vegetables or contaminated water sources. It can also transmit “by children who play in the contaminated soil and then put their hands in their mouths without washing them.” For hookworms, the eggs hatch in the soil, and when fully grown, the worm can penetrate the skin if the subject is walking barefoot.
While transmission is unnervingly simple, roundworms, whipworms and hookworms “do not multiply in the human host.” Re-infection is only possible if a human comes in contact with the contaminated environment once more. Unfortunately, “S. stercoralis can reproduce in the host, and in immunocompromised individuals, its uncontrolled multiplication can be fatal.” Without treatment, heavy loads of any of these intestinal worms can lead to death and many LMICs bear the brunt of the negative consequences.
Why are STHs a Problem for LMICs?
People with heavier loads of worms often endure symptoms such as diarrhea, abdominal pain, malnutrition, general malaise and weakness. In children, intestinal worms can impair growth and compromise physical development. These symptoms and impacts are sometimes far-reaching, leading to negative outcomes in the economic, social and educational spheres of life.
The Borgen Project spoke to Dr. Theresa Gildner, an associate professor of Anthropology at Washington University about the issue. Gildner states that especially for “children [with]moderate or heavy parasite infections that aren’t being treated,” over time, these children “might have a range of negative outcomes.”
Gildner also points out that the worms often absorb essential nutrients and vitamins that children might need and when these children do not have access to treatment, it can lead to “poor performance in school, trouble with memory or trouble focusing.” Gildner also explains the long-term outcomes linked with development, such as the ability to go to work and school. If people are unable to do so, there are substantial economic consequences.
STHs are also more likely to exist alongside other global health concerns. For example, areas that have intestinal worm cases may simultaneously face other infectious diseases that can further worsen the issue, such as malaria. If people do not have access to nutritious food, this can further compound the symptoms of these illnesses and can impair cognitive and physical development. Gildner adds that “It’s just as important to think about how these types of infections intersect with other global health issues. And they’re not usually occurring in isolation”.
When LMICs are unable to create the infrastructure necessary, such as sanitation facilities, to promptly address the transmission of intestinal worms due to limited resources and money, then nations cannot effectively resolve the issue.
Solutions to Intestinal Worms
According to the Pan American Health Organization (PAHO), control of the infection is based on periodic deworming, health education and improved sanitation. For all endemic nations, the PAHO/WHO ensure that “safe and effective medicines” are available for “all children of school-age and pre-school age.”
Evidence Action is an organization that uses “evidence-based and cost-effective programs to reduce the burden of poverty for hundreds of millions of people” in seven countries across the world. According to the organization, “more than 835 million children” risk contracting parasitic worm infections globally.
Evidence Action’s Deworm the World Initiative specifically fights against worm infections among children by working alongside governments “to deliver mass school-based deworming programs.” The organization has “supported delivery of [more than]1.3 million deworming treatments since 2014 at an average cost of less than USD $0.50 per treatment.”
And while the world notes great successes in deworming and providing essential equipment and strategies, foreign aid is not a sustainable measure. While treatment is helpful in many cases for the short-term, many people argue that structural changes are necessary to implement real change for LMICs.
Professor Gildner weighed in on the subject, speaking about her own studies on parasitic worms with the Indigenous Shuar of Amazonian Ecuador. Gildner says that she and her research team try to “produce information that communities can use to advocate for more funding and more care because if people don’t notice this is even an issue, how [will the community]get funding and the resources [necessary]?” In their research work, Gildner’s team worked with community partners and wrote up data for the community to present to the Ecuadorian government. The Indigenous Shuar requested funds to support school treatment programs and improve infrastructure to help reduce transmission.
In order for effective management and treatment of intestinal worms to occur, it is vital that foreign aid works side-by-side with communities to identify sources of infection and advocate for governments to prioritize the issue. Overall, this will safeguard the health and well-being of citizens, allowing for people to stand as productive citizens who can contribute to the economy.
– Gaby Mendoza