The Syrian crisis that has brought devastation to millions has left a tropical pathogen thriving in the rubble.
Hundreds of thousands of people living in refugee camps or trapped in conflict zones are now affected by a disfiguring disease called cutaneous leishmaniasis, the journal PLOS reports, with the outbreak sweeping through the Middle East.
Cutaneous leishmaniasis, or “CL” for short, is caused by a parasite which is transmitted between people or animals through sandflies, which are common in the Middle East. The infection causes large, open skin ulcers which, while generally not fatal, leave disfiguring scars that can cause social and psychological problems.
The disease is not new to Syria – the first case was reported in 1765, then known as the “Aleppo boil” – but its incidence has risen since the early 1990s, when urbanisation saw Syria’s city suburbs expand, populations becoming denser and hygiene diminishing.
Now, with the Syrian conflict approaching its fifth year, half of the Syrian population has been forced to leave their homes, while half of the country’s public hospitals have been destroyed and a healthcare infrastructure barely exists.
“Prior to the outbreak of war there was good control of diseases, parasites and sandflies but when the conflict started no one cared, conditions worsened and the health system broke down, which has created an ideal environment for disease outbreaks,” author Waleed Al-Salem told The Independent.
A Ministry of Health study found the incidence of CL in Syria jumped from 23,000 cases per year before the civil war to 41,000 cases in the first half of 2013 alone. The PLOS paper estimates that because the disease is underreported, the annual incidence could exceed 100,000.
And the disease is hitching a ride with refugees fleeing the country.
Higher incidence of the disease has been reported in neighbouring Turkey, and in Lebanon 1,033 cases were reported in 2013 – that’s up from just six between 2000 and 2012.
“It’s quite a slow-growing disease – it probably won’t suddenly explode,” said Grant Hill-Cawthorne, an epidemiologist at the University of Sydney. But “what we are getting is a gradual increase and people not being treated so we’re not getting on top of the infection”.
What can be done to curb the outbreak?
The paper authors are calling for policies which improve refugee living conditions, as well as development of better diagnostic tests and a commercially available vaccine.
The drug currently used to treat CL, sodium stibogluconate, has nasty side effects such as vein damage and pancreatitis, and needs to be given intravenously which isn’t practical for large refugee camps, Hill-Cawthorne said.
Also, a 2014 study found 85% of CL cases in Lebanon refugee camps were caused by Leishmania tropica, a species of the pathogen which is has been reported to be more resistant to sodium stibogluconate than other species.
In 2014, the US FDA approved an oral drug to treat leishmaniasis, a broad-spectrum antimicrobial called miltefosine. The rights to this drug’s distribution and sale in all countries other than the US, as of March this year, belongs to Canada-based company Knight Therapeutics.
Problem is, “there are lots of different species of leishmaniasis, all of them cause slightly different symptoms and respond differently to drugs”, Hill-Cawthorne explained.
“Unless the company that makes miltefosine makes it widely available and actually starts to try and do a trial – and this [outbreak] might be a good opportunity to do that – we’re not really going to have an effective drug.”
Hill-Cawthorne is hopeful that as one of 17 so-called “neglected tropical diseases” classified by the World Health Organisation, CL will receive more attention.
The paper authors stressed that countries such as Germany or Britain, which have a working medical system and where sandflies are not common, are not at risk of an outbreak.
But “eventually, in these interconnected worlds these infections will end up being a bigger problem for developed countries”, Hill-Cawthorne said. “So it’s always worth doing the research now before it becomes a problem.”
Viviane Richter is a freelance science writer based in Melbourne.
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