You are unlikely to encounter any serious diseases in Costa Rica.
Sanitary standards are high and the health system is excellent.
During the past two wet seasons there have been several outbreaks of the mosquito-borne disease dengue but so far there have been no reported cases of the more serious hemorrhaging dengue. No vaccinations are required to enter Costa Rica as epidemic diseases have been all but eradicated throughout the country. Infectious hepatitis, a serious problem throughout Central America, is reported only rarely in Costa Rica. The coverage can be bought at travel agencies, language schools or through tour companies.