The quality of medical care the POWs received from their medical personnel for malaria, cholera, dysentery and especially tropical ulcers was important. The difference among POW cohorts depending upon the quality and number of medical doctors was substantial. Many European and American doctors had little experience with tropical diseases. As an example, one cohort of Americans suffered 100 deaths out of 450 personnel. Another American group to which Dr. Hekking, the Dutch doctor with long experience in tropical medicine, was assigned suffered only 9 deaths out of 190 personnel. A Dutch group of 400 workers which included three doctors with extensive tropical medicine experience suffered no deaths at all