Professors from Brown University presented the latest research activities towards the elimination of schistosomiasis through a symposium organized by the Research Institute for Tropical Medicine (RITM) Schistosomiasis Study Group and the Research Innovation Office last March 12 at the RITM Auditorium.
Schistosomiasis is a disease caused by parasitic worms that live in the veins of the large intestines and release eggs in the bloodstream. The eggs either cross to the intestinal lumen and get released in the stool, or are trapped in the liver causing fibrosis.
“It’s important to remember that this is a worm that lives in the bloodstream shedding very immunogenic antigens,” said Brown University Epidemiology Professor Dr. Jennifer Friedman.
Affecting almost 240 million people worldwide with chronic ill-health, the disease poses a significant burden to global health.
Praziquantel safety to human pregnancy
Dr. Friedman and the RITM Schistosomiasis Study Group has long been working on how schistosomiasis causes morbidity. She discussed that mass drug administration is the main approach for schistosomiasis treatment across the globe.
However, pregnant women had been excluded in the mass drug administration until the group conducted a study on the safety and efficacy of the praziquantel drug in human pregnancy.
The researchers hypothesized that pregnant women diagnosed with schistosomiasis might have better pregnancy outcomes if treated with praziquantel.
Overall, praziquantel did not have a significant effect on key safety outcomes including abortion, fetal death in utero, and congenital anomalies. “The safety results were all very reassuring with no major difference at all,” she mused.
Results from the study provide important data in support of the expansion of treatment policies to include pregnant women.
Reducing schistosomiasis through water buffalo vaccination
On the other hand, Brown University Pathology and Laboratory Medicine Chair Prof. Jonathan Kurtis discussed another method in eliminating schistosomiasis – the One Health approach. The idea behind One Health is to approach a disease from both the medical and the veterinary side.
“If we could vaccinate water buffalos, we might have a significant salutary impact on the transmission of schistosomiasis to humans,” explained Dr. Kurtis.
He cited a mathematical model suggesting that a marginally effective schistosomiasis vaccine in buffalos might decrease the transmission of the parasite to humans by more than 70%.
A number of antigens are currently being developed, one of which is the complicated protein, paramyosin. According to Dr. Kurtis, the protein’s structure made it “almost impossible” to develop paramyosin using recombinant DNA technology.
This changed when RITM Immunology Department and Research and Innovation Office Head Dr. Mario Antonio Jiz II led a patented pilot scale process that enabled the production of recombinant paramyosin during his graduate studies under Prof. Kurtis.
The group then proceeded with the study and evaluated the safety and immunogenicity of paramyosin vaccine in water buffalos. They found that there was no difference in the body composition score and reactogenicity of the water buffalos between the vaccinated and placebo groups.
More importantly, the water buffalos that had been administered with paramyosin developed antibodies against parasitic worms. In similar studies in China, water buffalos vaccinated with paramyosin had 50-60% lower parasite burdens compared to placebo animals.
The next step for the group will involve challenge-based trials with water buffalos and additional vaccine candidates in Los Baños, Laguna.
Many strategies hinged on the eradication of schistosomiasis are already in the pipeline. Dr. Friedman and Dr. Kurtis are among the notable scientists who relentlessly contributed in studying schistosomiasis with RITM.
“This institution is a world leader,” said Dr. Kurtis as he expressed his gratitude to RITM. “[RITM] is recognized internationally as the epicenter for Schistosomiasis japonica research specifically and schistosomiasis research in general.”
by Allenor Enciso, Communication and Engagement Office [RITM Web Team]