If your travel plans in and out of Costa Rica include any of these South American countries, be advised that to get back into Costa Rica you will need to have an official document attesting to having received a yellow fever vaccine.

Bolivia, Brazil, Colombia, Ecuador, Peru, Venezuela have yellow fever risk areas in many parts of their territories, and you will be required to present proof of your vaccine upon your return to Costa Rica if traveling from one of these countries.

The vaccine – which used to be considered valid for 10 years – now has a lifetime validity, said Roberto Arroba Tijerino, coordinator of immunizations at the Costa Rican Health Ministry.

If you were previously vaccinated for yellow fever in the U.S., Canada, or another country, you will need to make sure the vaccine is accurately validated on your vaccine card. So for example, if you received it more than 10 years ago, and the stamp on your card now says it is expired, you would need to return to the clinic where you were vaccinated to have them update the card to reflect the new World Health Organization guidelines that have established lifetime immunity from the vaccine.

Otherwise, you will need a new vaccine in Costa Rica to travel to the countries in South America listed above – if you are planning to return here.

The vaccine is not provided through the public health system, so must be obtained at a pharmacy that does injections, or your private health provider. The cost is roughly 50,000 – 60,000 colones.

The World Health Organization provides complete information on all of the vaccines recommended for travel to different countries. And, while others may be recommended for travel to South America, the yellow fever vaccine is the only one required for you to re-enter into Costa Rica.

If you don’t already have a valid vaccine stamp for yellow fever, make sure you get the vaccine done at least 10 days prior to your trip, added Arroba Tijerino.

Yellow fever is a viral disease spread by mosquitos, typically of short duration. In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains particularly in the back, and headaches, according to information on Wikipedia. The disease infects only humans, other primates, and several species of mosquitoes.