Mosquito transmitted disease was a health threat in tropical Vietnam. (They were a pain and irritiation problem also.) Each Monday we were to take an orange tablet (I doubt this is the correct spelling) Acloraquine, Primaquine Phosphate) long lasting diarrhea pill. Early in my tour a second pill given daily, Dapsone, was added and for me produced a week of diarrhea. Made by American Home Products, Pharmacology texts do not cite it for malaria. A National Cancer Institutes study show it causing cancer in male rats. This alarmed me, so I called the listed Pentagon telephone number(in the news story) and was assured that it was given only to a small group of men serving near the DMZ. We were based and operated hundreds of miles south of there.