Snail fever: the threat in Suriname’s water
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The Surinamese have plenty of gods to pray to as they seek to stamp out schistosomiasis, a potentially deadly disease also known as bilharzia, or snail fever. The former Dutch colony in the Atlantic shoulder of South America is a mix of 540,000 people mainly of African, Indian or Javanese descent, and is strewn with Islamic mosques, Hindu temples and Christian churches. But the country has only one expert who has devoted his life to combating the disease.
Dayanand Panchoe is a 61-year-old descendant of immigrants from Rajasthan in India. He was born and raised in a family of celery farmers in the district of Wanica, near Suriname’s capital, Paramaribo, but trained as a medical doctor and biologist in Amsterdam and Leiden in the Netherlands. He has researched and helped treat schistosomiasis for four decades — and has been twice infected with it himself.
“I [detected] it early because I tested my own stool,” says the mild-mannered doctor, who is officially retired but continues to work on the disease. “Others were not so lucky.” When Panchoe was a young boy, his uncle died of liver failure after contracting it and so did seven of his neighbours.
“Schistosomiasis is a public health problem because it’s life-threatening: it kills people,” he says. Poor farmers are at particular risk of infection because they frequently come into contact with alkaline water in roadside gutters, ditches, irrigation canals and swamps around the marshlands and delta areas where they live and work.
There are several forms of schistosomiasis, but in the variety caused by the parasite Schistosoma mansoni (the one prevalent in the Americas), the offending agent hides in a small freshwater snail. Once the parasite has grown and multiplied in the snail host, its larvae emerge into the water and penetrate the skin of humans as they wade, swim or wash. The larvae then migrate to the liver, where they mature into adult worms that lay eggs, which leave the body in faeces. Over time, this causes irreversible damage to tissue.
Poor sanitation and the widespread habit of defaecating outdoors mean people infected with the disease then re-contaminate their freshwater sources with the parasite’s eggs. Juanita Malmberg, a Paramaribo-based consultant on infectious diseases, says that while in other countries the disease is linked to rivers and lakes, in Suriname the problem is roadside gutters and irrigation canals.
Experts say the disease was brought to South America and parts of the Caribbean by slaves taken captive in Africa, where it continues to be widespread. A 1976 paper from the World Health Assembly in Geneva said Suriname “is one of the three unfortunate countries on the American mainland suffering from schistosomiasis”. The others are Brazil, which still hosts the majority of cases in the region, and Venezuela.
Santiago Nicholls, an authority on neglected tropical diseases (NTDs) at the Pan-American Health Organisation (PAHO), estimates there are 1.6m people infected with schistosomiasis in Latin America and the Caribbean, and 25m others at risk. Worldwide, the World Health Organization estimates schistosomiasis infects more than 200m people and kills 200,000 a year. The Centers for Disease Control and Prevention in the US says it ranks second only to malaria as the most common parasitic disease, calling it “the most deadly NTD”.
Public health experts warn that the number of deaths is hard to estimate because of hidden pathologies, such as liver damage, associated with it — the disease is a silent killer. Aside from possible rashes, abdominal pain, and diarrhoea — which could indicate any number of ailments — it is asymptomatic. Schistosomiasis might not manifest itself for years, even decades, by which time the damage to a vital organ will be irreversible.
In Suriname, the disease is popularly called bilharzia, after the 19th-century German parasitologist Theodor Bilharz. It was first confirmed in the country in 1911, and was seen mainly in coastal areas. Not long before Suriname’s independence in 1975, its prevalence was as high as 45 per cent of the population in some regions, such as Saramacca in the north, where a control programme was launched that brought this figure down to 15 per cent by 1983.
On his return from the Netherlands in 1997 after two decades of studying infectious diseases, Panchoe began house-to-house surveys, gathering stool samples from 8,500 people that confirmed the disease’s presence had shrunk but was still endemic. “I did the research for free, for Suriname, because of the disease’s impact on me,” he says. “My family and neighbours died. I did not want this to happen to those who find out their condition too late.”
If detected early, mainly by testing stool as Panchoe did, treatment is a short course of a fast-acting drug called praziquantel, which kills the worms. “I had it — it’s very effective,” says Panchoe.
Between 2009 and 2010, with the backing of PAHO, the Suriname Ministry of Health’s Bureau of Public Health (BOG) carried out a narrower study, this time on 1,400 schoolchildren, to define the presence and distribution of schistosomiasis. “The survey showed schistosomiasis was still endemic, although its prevalence was very low,” Panchoe says.
That survey, which is the most recent performed in the country, also revealed a worrying fact: that transmission, albeit dwindling, was occurring in districts previously considered to be non-endemic. “Incidence is low now and the tools that you need to fight the disease are not that [complicated], such as health education and improvement of sanitary conditions,” says Dr Lesley Resida, a London-educated parasitologist who is the BOG’s director. “In Suriname we can eradicate the disease,” affirms Panchoe. “We are entering a phase of elimination.”
In the subsistence farming district of Bolletrie Hè, a man in rubber boots tends to the red peppers he is growing close to the area’s neatly arranged houses and clean ditches. This was once an endemic area, but no longer, thanks partly to better sanitation, infrastructure and greater awareness of the disease. “This gives us the belief and the conviction that we can eradicate it,” says Resida.
Although other researchers have estimated the prevalence of the disease to be almost 1 per cent of Suriname’s population, it is very hard to arrive at a definitive number because of the late manifestation of symptoms. Since 2008, the BOG has reported 53 cases revealed by positive stool tests.
Another method of diagnosis is a blood test. At the main state clinic for the treatment of parasitic diseases, Panchoe shows Waldie Koerdi, a father of three who tested positive after years of swamp-fishing, an old, faded, hand-drawn placard of the infectious cycle explaining how schistosomiasis is transmitted and how it can be avoided.
“How do you prevent bilharzia?” he asks Koerdi and two others in the Sranan Tongo vernacular. “Avoid contaminated waters,” replies Koerdi, who is of Javanese origin. “I’ve heard people died after years of going into water, so I don’t let my children go into the water.” “Very good,” the doctor replies. “Education makes people aware.”
Resida explains that mortality (the death rate) has fallen “drastically” since the 1970s, partly because of people’s greater awareness. But morbidity figures (the infection rate) do not offer a clear picture, and efforts to eliminate the disease have to be continuous. “There is a possibility of it spreading into other small pockets. If we leave it, it can [come] back, because for us it is very difficult to get rid of those small pockets,” Resida says.
One of these pockets is Santo Dorp, 20 minutes’ drive from central Paramaribo. Many of the recent cases have come from the same area. The authorities have detected five new cases on one city block alone since 2014. Four are children. Residents say their toilets flush directly into the flooded ditches that run around their properties and are full of the flat snails. Unaware of the threat, parents allow their children to play barefoot nearby.
Suriname is categorised as a country aiming for “interruption of transmission”. To meet the criteria for this stage it needs to have five consecutive years of zero incidence of cases among the indigenous population — and no snails caught that are infected with Schistosoma mansoni. Local authorities and the PAHO are focusing on testing schoolchildren in several districts as a way of finding recent infections. “We are very close, so close,” says Resida.
There is international support for this view. Alan Fenwick, professor of tropical parasitology and director of the Schistosomiasis Control Initiative at Imperial College London, said at a WHO meeting in 2011 that global “control of schistosomiasis can be achieved, and now we believe that even elimination may be feasible in many areas”. Last year, the Pan-American Health Organisation included schistosomiasis among the list of neglected diseases it aimed to control or eliminate by 2022.
But Resida says schistosomiasis is not the priority in Latin America any more. “Forty years ago, we had leaflets, posters all over schools and districts. Now, it is one of the neglected diseases. Most people think, well, keep on doing what you are doing and it will go away. Funding for neglected tropical diseases is a hassle: it is hard to get and once you have it, you have to split it among diseases,” he says. “We need money, money and money.”
Well-trained technicians are scarce and poorly paid: Panchoe earns the equivalent of €650 a month from treating the disease and teaching at a university. The main clinic for infectious diseases operates in a shabby, tin-roofed building dating from 1927. But in the clinic’s grounds, there is a €4.8m laboratory built in 2012 with Dutch funding, say Panchoe and Resida. Suriname has relied on two donations of 3,000 tablets each of praziquantel since 2010. For the final push, Resida says, “we need more medicines”.
That will be a challenge. Suriname, with a GDP of $5.1bn and rich in bauxite, gold, oil as well as bananas, has enjoyed a commodity boom that has brought significant benefits to its population. Annual per capita income rocketed from some $1,800 at the turn of the century to almost $9,500 in 2015. Sanitation also improved, with 88 per cent of the urban and 61 per cent of the rural populations, respectively, having access to better sewage disposal.
Yet since 2015, the government of former military ruler Dési Bouterse, who became president following democratic elections, has been battling an economic downturn after the drop in prices for Suriname’s exports. Bouterse, who was accused of involvement in the massacre of political opponents in 1982 — and sentenced in absentia on drugs charges by a Dutch court in 1999 — has asked for help from international institutions.
The UN’s Economic Commission for Latin America and the Caribbean estimated last December that Suriname’s economy had shrunk by 10.4 per cent in 2016, deepening a 2.7 per cent contraction the previous year. While government data show steep declines in revenue and spending, depreciation of the currency makes the importation of drugs such as praziquantel much costlier.
“This is a crisis,” says Hans Breeveld, a veteran political analyst with Anton de Kom University in Paramaribo. “The government spent money as if nothing was too much; now we don’t have enough.” Health officials estimate $250,000, plus foreign donations of drugs, would be enough for a survey and a campaign to deal the final blow to schistosomiasis. But they fear that no state funds will be available.
Suriname has managed to eliminate other infectious diseases, such as lymphatic filariasis — elephantiasis but commonly known in Suriname as “big foot” — in 2015, so there is hope in some corners. Nevertheless, for Panchoe, who is a religious man, hope is not enough to finish off schistosomiasis amid the current economic woes.
“I am a Hindu believer, but I work with evidence,” he says. “In Suriname, we need surveys, to plan a campaign and then we must go for eradication and watch carefully that it doesn’t come back. But without money, there’s nothing we can do.”
 Thought to affect more than 240m people globally, schistosomiasis, known as bilharzia or snail fever, has been called the most deadly of the neglected tropical diseases by the US Centers for Disease Control and Prevention. The second most common parasitic disease, after malaria, it is caught through fresh water that contains the larvae of worms known as blood flukes or flatworms. These live in the veins, laying eggs that pass out of the body in urine or faeces and reinfect water sources. In children the disease can cause anaemia, stunting and reduced ability to learn. It can be treated with the drug praziquantel, but regular monitoring is needed to diagnose the disease as it is often asymptomatic. WHO target: Elimination in the Americas, western Pacific and selected African countries
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