Animal bites Do not attempt to pet, handle or feed any animal. Any bite or scratch by a mammal, including bats, should be promptly and thoroughly cleansed with large amounts of soap and water, and an antiseptic such as iodine or alcohol should be applied. Contact a local health authority in the event of such an injury.
Insect bites No matter how much you safeguard yourself, getting bitten by mosquitoes is part of every traveler’s experience here. The best prevention is to stay covered up – wear long pants, long sleeves, a hat, and shoes, not sandals. Invest in a good insect repellent, preferably one containing DEET. Apply to exposed skin and clothing (but not to eyes, mouth, cuts, wounds or irritated skin). Compounds containing DEET should not be used on children under age the age of two and should be used sparingly on children under 12. Invest in a bug net to hang over beds (along with a few thumbtacks or nails with which to hang it). Many hotels in Costa Rica don’t have windows (or screens), and a cheap little net will save you plenty of nighttime aggravation. The mesh size should be less than 1.5mm. Dusk is the worst time for mosquitoes, so take extra precautions.
Sun Stay out of the midday sun, wear sunglasses and a wide-brimmed hat, and apply sunblock with SPF 15 or higher, with both UVA and UVB protection. Drink plenty of fluids and avoid strenuous exercise when the temperature is high.
Dengue fever (breakbone fever) Dengue is transmitted by Aedes aegypti mosquitoes, which often bite during the daytime and are usually found close to human habitations, often indoors. Dengue is especially common in densely populated urban environments. It usually causes flulike symptoms including fever, muscle aches, joint pains, headaches, nausea and vomiting, often followed by a rash. Most cases resolve uneventfully in a few days. There is no treatment for dengue fever except taking analgesics such as acetaminophen/paracetamol (Tylenol) and drinking plenty of fluids. Severe cases may require hospitalization for intravenous fluids and supportive care. There is no vaccine. The key to prevention is taking insect-protection measures.
Hepatitis A The second most common travel-related infection (after traveler’s diarrhea). It’s a viral infection of the liver that is usually acquired by ingestion of contaminated water, food or ice, though it may also be acquired by direct contact with infected persons. Symptoms may include fever, malaise, jaundice, nausea, vomiting and abdominal pain. Most cases resolve without complications, though hepatitis A occasionally causes severe liver damage. There is no treatment. The vaccine for hepatitis A is extremely safe and highly effective.
Leishmaniasis This is transmitted by sand flies. Most cases occur in newly cleared forest or areas of secondary growth; the highest incidence is in Talamanca. It causes slow-growing ulcers over exposed parts of the body. There is no vaccine. To protect yourself from sand flies, follow the same precautions as for mosquitoes.
Malaria Malaria is very rare in Costa Rica, occurring only occasionally in rural parts of the Limón province. It’s transmitted by mosquito bites, usually between dusk and dawn. Taking malaria pills is not necessary unless you are making a long stay in the province of Limón (not Puerto Limón). Protection against mosquito bites is most effective.
Traveler's diarrhea Tap water is safe and of high quality in Costa Rica, but when you’re far off the beaten path it’s best to avoid tap water unless it has been boiled, filtered or chemically disinfected (with iodine tablets). To prevent diarrhea, be wary of dairy products that might contain unpasteurized milk and be highly selective when eating food from street vendors. If you develop diarrhea, be sure to drink plenty of fluids, preferably with an oral rehydration solution containing lots of salt and sugar. If diarrhea is bloody or persists for more than 72 hours, or is accompanied by fever, shaking chills or severe abdominal pain, seek medical attention.
Typhoid Caused by ingestion of food or water contaminated by a species of salmonella known as Salmonella typhi. Fever occurs in virtually all cases. Other symptoms may include headache, malaise, muscle aches, dizziness, loss of appetite, nausea and abdominal pain. Possible complications include intestinal perforation, intestinal bleeding, confusion, delirium or (rarely) coma. A pretrip vaccination is recommended.