Leading in global health (IMAGE) University of Delaware Caption Sam Biswas (left) and Esther Biswas-Fiss, UD professors of medical and molecular sciences, have confirmed 25 different types of HPV prevalent in Nigeria. Credit Ashley Barnas/ University of Delaware Usage Restrictions Must credit Ashley Barnas/ University of Delaware 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.