Costa Rica has a low malaria risk in Limón Province, excluding Puerto Limón, and a very low risk in the rest of the country. For most travellers, bite avoidance is the main malaria advice rather than routine malaria tablets. Tablets may still be discussed for higher-risk travellers or unusual itineraries, particularly where medical issues make malaria more dangerous. Day-biting mosquitoes are the bigger everyday issue. Dengue risk is reported in Costa Rica, and Zika is also a consideration, especially for anyone pregnant or planning pregnancy. Chikungunya can occur too. There is no simple tablet that prevents these infections, so repellent, covered skin, screened accommodation and treating daytime bites as important all matter. Hepatitis A is commonly recommended for previously unvaccinated travellers because it spreads through contaminated food and water. Tetanus should be up to date, particularly for walking, cycling or rural travel. Typhoid vaccination may be considered for longer stays, frequent travel, visits where food hygiene is uncertain, or more adventurous itineraries. Rabies is a risk in Costa Rica and has been reported in domestic animals; bats may also carry rabies-like viruses. Pre-travel rabies vaccination is worth discussing for children, long stays, animal work, running, cycling or remote travel. Yellow fever is not a risk in Costa Rica itself, but proof of vaccination may be required if you arrive from certain yellow fever risk countries.