Schistosomiasis: Preventable and Treatable

By Edward Kim, GRC 2024 Global Essay Competition Top 30

Schistosomiasis is a parasitic infection that is extremely prevalent across the developing world, with roughly 200 million cases around Sub Saharan Africa and the Middle East. The CDC classifies it as the second most dangerous parasitic disease after malaria, yet also classifies it as a neglected tropical disease, meaning that it does not get enough attention (CDC, 2024). However, even though it is highly contagious, it is both easy to

prevent and treat, given the right precautions and medication. Therefore, taking inspiration from the near-eradication of the Guinea worm, the global community should take measures to protect vulnerable populations and ensure that they perform sanitary practices to help ward off schistosomiasis.

Schistosomiasis is typically caused by contact with contaminated water. Immature Schistosoma parasites in the water latch onto human skin and start burrowing into the blood vessels, where they mature and produce eggs, which are transported to the bladder or intestine and expelled with feces or urine. If infected human waste enters rivers or lakes, the parasite will find an intermediate host, normally a freshwater snail, which it grows inside until it is large enough to leave. At this point, it has roughly 48 hours to find a new human host and restart the cycle of infection (WHO, 2023).

Once a patient is infected, Schistosomiasis causes adverse symptoms, including fevers, chills, stomach aches, and swelling, depending on the specific strain of Schistosoma. In a healthy person, the immune system can typically deal with the infestation in one or two weeks. However, in areas without sufficient sanitation and medical infrastructure, infections may persist, leading to the enlargement of the liver or spleen, anemia, and even death. Schistosomiasis has also been linked to stunted growth and increased susceptibility to future urogenitary problems, pulmonary hypotension, neurological complications, cancer, immunosuppression, and increased risk of HIV/AIDS (NHS, 2021). Even if the patient ultimately recovers, the long-term effects of Schistosomiasis can cripple them so that they cannot work, leading to harm on individual, familial, and societal levels (Rinaldo, 2021).

Despite the destructive symptoms, Schistosomiasis is remarkably easy to prevent and cure. The disease can be diagnosed through a simple stool or urine test and the subsequent treatment usually consists of a short course of medication, such as praziquantel, which is widely available in developed nations (CDC, 2024). Prevention involves simple hygiene principles, such as avoiding contaminated water and maintaining proper sanitation (NHS, 2021). Consequently, Schistosomiasis is not a major problem in developed nations, and is most prevalent in less developed regions, which lack proper sanitation standards (CDC, 2024). Its lifecycle also means that reinfections are common, requiring repeated treatments, which can become financially or logistically prohibitive, especially in rural areas (Tchuenté, 2017).

Although Schistosomiasis is currently regarded as a neglected tropical disease, the near-eradication of the Guinea worm, a similar parasite, could serve as a roadmap for tackling Schistosomiasis. While not quite as widespread as Schistosomiasis, the Guinea worm was nonetheless a similarly devastating parasite that caused crippling damage in at least 20 countries, according to the WHO (WHO, 2023). Similar to Schistosoma, the Guinea worm spread through people drinking or coming into physical contact with contaminated water. In response, institutions such as the Carter Center supported community education in areas where the disease was most prevalent to prevent disease spread (The Carter Center, 2024). Simultaneously, the UN declared the International Drinking Water Decade to promote clean drinking water

across the world, These initiatives proved to be highly successful, with the UN health agency reporting that the disease is on track for eradication (WHO, undated).

A similar approach should therefore be applied to treat Schistosomiasis. Given the logistical challenges associated with distributing tests and praziquantel, especially in isolated regions or conflict zones, prevention through avoidance and education should be the primary goal.

Most important is having access to safe drinking water through techniques such as cloth filtering and harvesting rainwater. For example, cloth filters with small pore sizes, often made from layers of worn cotton materials, have done wonders in preventing the spread of cholera in Bangladesh after villagers were given education (Kristiansen, 2015). Given that Schistosoma is much larger than cholera, similar filters should work just as well, drastically decreasing the spread of the parasite via consumption of contaminated water. A similar approach was also undertaken with the Guinea worm, with the Carter Center partnering with organizations such as LifeStraw to donate basic filter straws to rural communities. (LifeStraw, undated).

Proper sanitation systems are another important and relatively easy measure to prevent human waste entering local water sources. Because Schistosoma eggs primarily exit the human body through urine or feces, even simple pit toilets will ensure that the eggs cannot find new hosts, thus breaking the cycle of infection.

A key factor in the near eradication of Guinea worm was the visits made to communities to educate them about what the disease is, how it spreads, and how to prevent it. A similar approach should be applied for Schistosomiasis, especially as prevention measures such as filtration and pit toilets can be implemented by residents with minimal external support. The Guinea worm affected around a million people annually at its height in the 1990s, but the current number of cases is down to the low to mid teens annually. This shows the effectiveness of simple educational and prevention measures when organizations and nations step up and take action.

There is no doubt that Schistosomiasis is a highly dangerous disease, which can result in the crippling of one’s ability to work, damaging not only the individual, but their family, community, and national economy. However, by applying lessons from the Guinea worm, we can prevent many cases and begin to ease the situation. The solution to this does not need to be fancy, elaborate, or expensive; rather, providing education about sanitary practices and helping communities to improve their hygiene will go a long way towards tackling another neglected tropical disease.

Sources Used

CDC. 2024. “About Schistosomiasis.” https://www.cdc.gov/schistosomiasis/about/index.html

Kristiansen, Cathy. 2015. “Sari Cloth Can Filter Cholera From Water, Research Shows,” NIH. https://www.fic.nih.gov/News/GlobalHealthMatters/january-february-2015/Pages/nursing -cholera-sari-water-filter.aspx

LifeStraw. n.d. “Guinea Worm Eradication.” https://lifestraw.com/pages/guinea-worm-eradication

NHS. 2022. “Schistosomiasis (Bilharzia).” https://www.nhs.uk/conditions/schistosomiasis

Rinaldo, Daniele, Javier Perez-Saez, Penelope Vounatsou, Jürg Utzinger, and Jean-Louis Arcand. 2021. “The Economic Impact of Schistosomiasis.” Infectious Diseases of Poverty 10, no. 1. https://doi.org/10.1186/s40249-021-00919-z

Rogers, Kara. 2011. “Guinea Worm Disease | Definition, Infection, Treatment, & Eradication.” Encyclopedia Britannica. https://www.britannica.com/science/guinea-worm-disease

Tchuenté, Louis-Albert Tchuem, David Rollinson, J. Russell Stothard, and David Molyneux. 2017. “Moving From Control to Elimination of Schistosomiasis in sub-Saharan Africa: Time to Change and Adapt Strategies.” Infectious Diseases of Poverty 6, no. 1. https://doi.org/10.1186/s40249-017-0256-8

The Carter Center. n.d. “Guinea Worm Eradication Program.” https://www.cartercenter.org/health/guinea_worm/index.html.

WHO. 2023. “Schistosomiasis.” https://www.who.int/news-room/fact-sheets/detail/schistosomiasis