News / Health

Scientists Try New Tactic Against Schistosomiasis

The re-introduction of indigenous prawns into this enclosed area in Lampsar village, in northern Senegal is reducing the rate of schistosomiasis infections.  (VOA/J. Lazuta)
The re-introduction of indigenous prawns into this enclosed area in Lampsar village, in northern Senegal is reducing the rate of schistosomiasis infections. (VOA/J. Lazuta)
Jennifer Lazuta
Every year, more than 240 million people get a potentially deadly parasitic infection known as schistosomiasis, transmitted by fresh water snails.  Infection rates have risen to as high as 80 percent in some parts of Africa, where communities often rely on rivers and lakes for bathing, cooking and other household chores. In Saint-Louis, Senegal, aid workers are using another indigenous species, the prawn, to keep parasite levels in check in local rivers.

In mid-morning, Coumba Ngiané washes a bucketful of family dishes and clothes.
 
She says the tap water is often cut off in the village, and so the women must come to the river to do laundry and bathe. She says when it gets hot, the children come here to cool off and play. People get sick, she says, and they know it is from the water but they can’t stay away.  

Freshwater snails are the host for the microscopic parasite that gives you schistosomiasis.  That parasite gets in the water and the larvae can enter your body through a cut, or even just the pores of your skin.

The larvae then lay eggs in the body, leading to diarrhea, abdominal pain and fever.  It infects the intestines and if left untreated, can lead to organ failure and even death.  In children, it can stunt growth and brain development.

There is treatment, but that won’t stop you from being re-infected the next time you enter the water.

The disease isn’t new to the Saint-Louis region of Senegal.  But it got worse after the government built a dam on the Senegal River in 1986 to stop salt water from flowing onto farmers’ fields.  The indigenous prawns that eat the snails that carry the parasite were nearly wiped out.

Amit Savaia, an Israeli prawn specialist currently working in the Saint-Louis area, said the prawns need to move from fresh water to salt water in order to breed.

“The dam that was built prevented them from migrating," said Savaia who is from Ben Gurion University. "So upstream [from] the dam, the prawns were almost sure extinct.  And if the prawns are extinct, the snails have a very comfortable habitat to bloom and grow, and spread [schistosomiasis].”

Savaia says in some villages the rate of infection rose from less than 10 percent to more than 80 percent.

Now, “Projet Crevette,” or the “Prawn Project,” is trying to change that.

Every three months, the project releases between 50 and 100 prawns into enclosures at seven test sites in the area.

Project officer Nicolas Jouanard says the idea is to restore balance to the ecosystem.

“The idea with the prawns is that when they arrive they eat the snails that are in place and that are infected," said Jouanard. "You will get new snails because the prawns are not able to eat every snail, but the snails that you will have here will be small snails, a new generation of snails.  So for them it will take time to be infected again.  When they are young and small they cannot be infected.”

Scientists say dam construction has disrupted river ecosystems and increased schistosomiasis infection rates in several parts of the world, including China, Egypt and Ivory Coast, in recent decades.

The founder of the prawn project in Senegal, Elizabeth Huttinger, says their experiment with prawns is a first and the results of the 12-month testing phase are “very promising.”
 
“On the snail info, the very exciting thing is that there are no infected snails there anymore," said Huttinger. "But what is particularly interesting, is that the intensity of the infections at the prawn site are about 15 times lower than what they are at the control site.”
 
That means 15 times fewer people are getting sick in the areas where prawns have been re-introduced.  And chronic infections are 40 times lower, as compared to the areas with no shrimp.

Because the dam is still in place, to keep the project going, researchers are teaching villagers at the test sites how to raise and breed prawns in plastic barrels full of fresh water and salt water.  The villagers can then keep transferring prawns to the river to keep infection rates down.

Huttinger said they hope to replicate the project in other villages and, ultimately, apply the model worldwide.

You May Like

IS Militants Release 49 Turkish Hostages

Turkey's state-run Anadolu news agency reports that no ransom was paid and no conditions accepted for the hostages' release; few details of the release are known More

Photogallery IS Attacks Send Thousands of Syrian Kurds Fleeing to Turkey

Syrian Observatory for Human Rights says more than 300 Kurdish fighters crossed into Syria from Turkey to defend a Kurdish area from attack by the Islamic militants More

3-day Lockdown to Fight Ebola Continues In Sierra Leone

Thousands of health workers are going door to door in the West African country of 6 million, informing people of how to avoid Ebola, handing out soap More

This forum has been closed.
Comment Sorting
Comments
     
by: Swambe Akim from: Dakar, Senegal
April 22, 2013 5:29 PM
God bless you beautiful angles of the House of Israel. in Africa we dance and cry in your honor. Thank you

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Migrants Caught in No-Man's Land Called Calaisi
X
Lisa Bryant
September 19, 2014 5:04 PM
The deaths of hundreds of migrants in the Mediterranean this week has only recast the spotlight on the perils of reaching Europe. And for those forunate enough to reach a place like Calais, France, only find that their problems aren't over. Lisa Bryant has the story.
Video

Video Migrants Caught in No-Man's Land Called Calais

The deaths of hundreds of migrants in the Mediterranean this week has only recast the spotlight on the perils of reaching Europe. And for those forunate enough to reach a place like Calais, France, only find that their problems aren't over. Lisa Bryant has the story.
Video

Video Westgate Siege Anniversary Brings Back Painful Memories

One year after it happened, the survivors of the terror attack on Nairobi's Westgate Shopping Mall still cannot shake the images of that tragic incident. For VOA, Mohammed Yusuf tells the story of victims still waiting for the answer to the question 'how could this happen?'
Video

Video Militant Assault in Syria Displaces Thousands of Kurds

A major assault by Islamic State militants on Kurds in Syria has sent a wave of new refugees to the Turkish border, where they were stopped by Turkish border security. Turkey is already hosting about 700,000 Syrian refugees who fled the civil war between the government and the opposition. But the government in Ankara has a history of strained relations with Turkey's Kurdish minority. Zlatica Hoke reports Turkey is asking for international help.
Video

Video CERN Accelerator Back in Business

The long upgrade of the Large Hadron Collider is over. The scientific instrument responsible for the discovery of the Higgs boson -- the so-called "God particle" -- is being brought up to speed in time for this month's 60th anniversary of the European Organization for Nuclear Research, known by its French acronym CERN. Physicists hope the accelerator will help them uncover more secrets about the origins of the universe. VOA’s George Putic reports.
Video

Video Whaling Summit Votes to Uphold Ban on Japan Whale Hunt

The International Whaling Commission, meeting in Slovenia, has voted to uphold a court ruling banning Japan from hunting whales in the Antarctic Ocean. Conservationists hailed the ruling as a victory, but Tokyo says it will submit revised plans for a whale hunt in 2015. Henry Ridgwell reports from London.
Video

Video Russian Economy Reeling After New Western Sanctions

A new wave of Western sanctions is hitting Russia’s economy hard. State-owned energy firms continue to bleed profits and Russia’s national currency plunged to a new low this week after the U.S. and the European Union announced new sanctions to punish Russia's aggressive stance in eastern Ukraine. But as Mil Arcega reports, the sanctions could also prove costly for European and American companies.
Video

Video Belgian Researchers Discover Way to Block Cancer Metastasis

Cancer remains one of the deadliest diseases, despite many new methods to combat it. Modern medicine has treatments to prevent the growth of primary tumor cells. But most cancer deaths are caused by metastasis, the stage when primary tumor cells change and move to other parts of the body. A team of Belgian scientists says it has found a way to prevent that process. Zlatica Hoke has more.
Video

Video Mogadishu's Flood of Foreign Workers Leaves Somalis Out of Work

Unemployment and conflict has forced many young Somalians out of the country in search of a better life. But a newfound stability in the once-lawless nation has created hope — and jobs — which, some say, are too often being filled by foreigners. Abdulaziz Billow reports from Mogadishu.
Video

Video A Dinosaur Fit for Land and Water

Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video Iraqi Kurdistan Church Helps Christian Children Cope find shelter in churches in the Kurdish capital, Irbil

In the past six weeks, tens of thousands of Iraqi Christians have been forced to flee their homes by Islamic State militants and find shelter in churches in the Kurdish capital, Irbil. Despite U.S. airstrikes in the region, the prospect of people returning home is still very low and concerns are starting to grow over the impact this is having on the displaced youth. Sebastian Meyer reports from Irbil on how one church is coping.
Video

Video NASA Picks Boeing, SpaceX to Carry Astronauts Into Space

The U.S. space agency, NASA, has chosen Boeing and SpaceX companies to build the next generation of spacecraft that will carry U.S. astronauts to the International Space Station by the year 2017. The deal with private industry enables NASA to end its dependence on Russia to send space crews into low Earth orbit and back. Zlatica Hoke has more.
Video

Video Future of Ukrainian Former President's Estate Uncertain

More than six months after Ukraine's former President Viktor Yanukovych fled revolution to Russia, authorities have yet to gain control of his palatial estate. Protesters occupy the grounds and opened it to tourists but they are also refusing to turn it over to the state. VOA's Daniel Schearf reports from Mezhigirya, just north of Kyiv.


Carnage and mayhem are part of daily life in northern Nigeria, the result of a terror campaign by the Islamist group Boko Haram. Fears are growing that Nigeria’s government may not know how to counter it, and may be making things worse. More

AppleAndroid