Tropical disease

I guess you learn these things by experience. A minor graze on the back of your leg, and you ignore it - in the UK, it'd be fine. But we're in the Tropics, and a few days later, you suddenly notice it's gone very wrong. I won't go into the grizzly details; let's just say that luckily there was a first aid station nearby. That was 2 weeks ago, and after some careful nursing, it's just about healed up.