FRIDAY, SEPTEMBER 30, 2016

Researchers seek vaccine to fight schistosomiasis

Scientists with Cairo University in Egypt are testing combinations of immunizations in mice to determine the most effective vaccine antigen against schistosomiasis, a widespread parasitic disease, according to a recent study.

Rashika El Ridi and Hatem Tallima, faculty members from the university's zoology department, hypothesized that the immune responses elicited by the excretory-secretory products of the Schistosoma mansoni parasite could almost completely eliminate the parasite. The researchers immunized mice and exposed the mice to the parasite two weeks later.

The six experiments demonstrated 62 percent to 78 percent reduction in challenge worm burden when compared to untreated controls. The researchers plan to follow the schistosomiasis vaccine studies by clarifying the molecular basis of protection, moving toward production of the antigen and conducting trials and studies.

The researchers published their results in the The Journal of Parasitology.

Snails carry the Schistosoma mansoni parasite to humans, typically in areas that lack water sanitation facilities. Schistosomiasis can lead to progressive liver or urinary bladder tissue damage and subsequent infections can be more severe after multiple exposures.

While the drug praziquantel is effective at killing the parasite, it does not prevent infection and there are concerns the parasite could develop resistance to the drug.

Approximately 800 million people are at risk for the parasitic disease.