Schistosomiasis Documentary — River of Hope by Clifford Bestall — Addresses the Burden of Snail Fever/Bilharzia — as Caused by Dam Building in this Instance — in a Problem-Solving Way that Will Interest Medical Professionals and Ecologically Oriented Biologists — a Tribute to Elizabeth Huttinger and Her Colleagues

06 May 2014

Citation

Clifford Bestall, River of Hope, Aljazeera English (02 May 2014) (a video documentary)

What is schistosomiasis?

From the US Centers for Disease Control and Prevention:

Schistosomiasis, also known as bilharzia, is a disease caused by parasitic worms. Although the worms that cause schistosomiasis are not found in the United States, more than 200 million people are infected worldwide.

In terms of impact this disease is second only to malaria as the most devastating parasitic disease. Schistosomiasis is considered one of the Neglected Tropical Diseases (NTDs).

The parasites that cause schistosomiasis live in certain types of freshwater snails. The infectious form of the parasite, known as cercariae, emerge from the snail, hence contaminating water. You can become infected when your skin comes in contact with contaminated freshwater.

Most human infections are caused by Schistosoma mansoni, S. haematobium, or S. japonicum.

Disease

Infection occurs when skin comes in contact with contaminated freshwater in which certain types of snails that carry the parasite are living. Freshwater becomes contaminated by Schistosoma eggs when infected people urinate or defecate in the water. The eggs hatch, and if the appropriate species of snails are present in the water, the parasites infect, develop and multiply inside the snails. The parasite leaves the snail and enters the water where it can survive for about 48 hours. Schistosoma parasites can penetrate the skin of persons who come in contact with contaminated freshwater, typically when wading, swimming, bathing, or washing. Over several weeks, the parasites migrate through host tissue and develop into adult worms inside the blood vessels of the body. Once mature, the worms mate and females produce eggs. Some of these eggs travel to the bladder or intestine and are passed into the urine or stool.

Symptoms of schistosomiasis are caused not by the worms themselves but by the body’s reaction to the eggs. Eggs shed by the adult worms that do not pass out of the body can become lodged in the intestine or bladder, causing inflammation or scarring. Children who are repeatedly infected can develop anemia, malnutrition, and learning difficulties. After years of infection, the parasite can also damage the liver, intestine, spleen, lungs, and bladder.

Common Symptoms

Most people have no symptoms when they are first infected. However, within days after becoming infected, they may develop a rash or itchy skin. Within 1-2 months of infection, symptoms may develop including fever, chills, cough, and muscle aches.

Chronic schistosomiasis

Without treatment, schistosomiasis can persist for years. Signs and symptoms of chronic schistosomiasis include: abdominal pain, enlarged liver, blood in the stool or blood in the urine, and problems passing urine. Chronic infection can also lead to increased risk of bladder cancer.

Rarely, eggs are found in the brain or spinal cord and can cause seizures, paralysis, or spinal cord inflammation.

River of Hope documentary

This outstanding film focuses on the Lampsar River in Senegal.

Roughly five years after the Senegal River (into which the Lampsar feeds) was dammed 30 years ago, residents noticed a remarkable increase in a virulent strain of intestinal schistosomiasis among people who regularly entered the Lampsar’s water. The cancer rate escalated at the same time.

The documentary follows Elizabeth Huttinger’s effort to uncover the origins of the epidemic and a possible solution to it. With the assistance of the people affected, she discovered that the dam had dramatically boosted the Lampsar River’s population of the snails that carry the worms:

In 2010, Elizabeth Huttinger was awarded a Global Health GCE grant from the Bill and Melinda Gates Foundation that enabled 20|20 [meaning The 2020 Initiative: PROJET-CREVETTE] to implement a pilot program to test whether or not we can eliminate human schistosomiasis through the development of "free range" freshwater prawn farming in West Africa.

20|20 works closely together with Sanna Sokolow DVM/PhD at the Kuris Lab, UC Santa Barbara's Marine Sciences Institute and is developing new partnership agreements to expand the number of sites currently being tested.

20|20 partners with the Senegalese government's national Aquaculture Agency and Kentucky State University in developing protocols for prawn reproduction near the village sites where they will be grown.

20|20 is also supported by The Seaver Institute, Gulf Aquatics, Cameroon and the Senegal Ministry of Health and Disease Prevention.

The dam prevented migratory prawns — which formerly fed on the snails — from completing their reproductive migration from fresh to salt water and back. As the prawns died out above the dam, the snail population exploded and with it, the number of people who fell grievously ill with intestinal schistosomiasis.

Huttinger recognized that reestablishing the prawn population might diminish the snail population and thereby ameliorate the (now grossly endemic) bilharzia epidemic. She experimented by fencing off a Lampar River watering site and populating it with prawns transported from Cameroon’s Lobe River, more than 3,500 kilometers away.

Six months after the transplant experiment began, schistosomiasis had dropped to only 6 percent of the children who were using the fenced off part of the river. By the end of Huttinger’s experiment, no infected snails were left in the fenced off part of the prawn-repopulated river.

With her proof of concept in hand, Huttinger began working on getting permission to alter the dam by adding a fish ladder to it. The ladder would (theoretically) permit a restored prawn population to complete its life cycle in much the same manner that they had before the dam was constructed.

The film ends with Huttinger waiting for permission from the four countries through which the Senegal River flows to approve construction of the proposed fish ladder.

The moral? — Perhaps one person can make a difference, if other people don’t get in her way

Clifford Bestall's documentary is a reminder that dams are a mixed blessing. The often influential people they help are often not the less powerful people they harm.

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