What Children Should Know About Bilharzia; Educational Comic. ACKNOWLEDGEMENT: This document was made possible through a financial grant from Merck, Germany. In 2007, Merck entered into a partnership with the World Health Organization (WHO) to combat schistosomiasis in school children on the African continent. In the medium term, Merck will donate 250 million tablets of Cesol 600 containing the active ingredient praziquantel. Merck will maintain its efforts until the disease has been eliminated in Africa.