Grant (IMAGE) Washington University School of Medicine Caption As part of the research, a finger prick is used to draw blood that is evaluated for the presence of parasitic worms. Credit Issouf Sanogo/Agence France-Presse Usage Restrictions Credit to Issouf Sanogo/Agence France-Presse License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.