For those who didn’t read the last post on my old blog, I have been given the opportunity to accompany researchers in Kenya and Zanzibar as they work towards the control and elimination of schistosomiasis.
Schisto-huh?
Most people have never heard of it, so here’s a very brief breakdown:
Schistosomiasis, or bilharzia, is classified by the World Health Organization as one of several neglected tropical diseases (NTDs), along with conditions like leishmaniasis, Chagas disease and dengue fever. It’s victims are disproportionately found in Africa, but cases are also common in tropical areas of the Middle East, Asia and South America. The disease is often overshadowed by more press-worthy problems like malaria and AIDS because infection primarily manifests as chronic disease rather than serious acute illness. In fact, of over 200 million people infected worldwide, only around 10 percent have a severe form of the disease.
Schistosomiasis is caused by trematodes, or flatworms, that reside in fresh water. Certain species of freshwater snails serve as the intermediate host for the worms, which are released in a larval stage (cercariae) into the water.
The disease is unique in that it is requires general contact with water rather than ingestion. The parasite only has to find your foot standing in the water to burrow in. This is particularly worrisome due to the ease of transmission in areas with poor sanitation and water supply. Car washers, children and people performing daily tasks like washing clothes are most at risk.
There are five species of the worm, but only two are of great concern in Africa: S. mansoni and S. haematobium. The parasites then develop into adult worms in the blood stream of humans and mate, and the eggs migrate through the body. S. haematobium tends to migrate to the bladder and may be released through urine, while S. mansoni often ends up in the intestines and can be released in fecal matter.
Although infection doesn’t often kill people, long-term presence of the parasites can cause abdominal problems and bladder symptoms and has been linked to developmental deficiencies in children.
The project
I’m traveling to specifically cover the activities of SCORE (Schistosomiasis Consortium for Operational Research and Evaluation) in Kisumu, Kenya and Zanzibar. SCORE, funded by the Bill and Melinda Gates Foundation, is a partnership of several institutions, government agencies and other organizations, from the Centers for Disease Control and Prevention (CDC) to the Natural History Museum in London.
SCORE’s purpose it to determine the best ways to control (and in some cases eliminate) schistosomiasis through mass drug administration and additional means. Praziquantel is a cheap, effective and available drug that is administered to treat schistosomiasis infections. Right now, SCORE is conducting studies to determine the most effective timeline to treat school-children and high-prevalence communities with Praziquantel. In addition, SCORE conducts research on diagnostic tools to better find infection.
In Zanzibar, the program is a bit different – the goal is elimination. This doesn’t necessarily mean absolutely no schisto, but it does mean an insignificant number of cases. The plan there also includes behavioral research, which I am excited about. How do they plan to keep little boys from peeing in the water, or car washers from using rivers to make their money? Furthermore, how can you keep people from discontinuing the drug over the years? Snail populations and control are added in there as well, although molluscicides can be detrimental to the environment.
So while I’m here my questions are about community reactions to these interventions and ways to integrate other methods along with the drugs to have the best possible effect on the prevalence of this disease.
That’s all the dry stuff for now, we’ll see where it goes from here when I get out into the field.
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