If you stay longer than 2 weeks, just bring a medicine to be able to cure the illness, in case of an infection. However, suitable medicine is available in all pharmacies of the country. Also other tropical diseases got realy seldom because of the good hygiene conditions and an excellent health system. An immunisation with Gamma-Globulin is recommended, if you decide to stay in Costa Rica for ever, since it provides protection against Hepatitis A, and realy strengthens resistance for about three months. Also the common injections against Tetanus and Polio should be up to date, because in tropical climate, viruses and bacterias grow rapidly and are more aggressive than at home.
Diarrhea is often bloody.
The mucous membrane of the colon is infected and abscesses can develop. First focus of infection is food and drink water, but also flys can transfer the amebas to the food. An amebas liver abscess is the most dangerous complication of this disease. The pathogenes can be found in the stool as well as by a blood test. A doctor should watch the treatment.