Malaria in Costa Rica

Level 1 - Practise health precautions (more details)

Original publication date: May 2, 2023

Updated: May 3, 2023

Current Situation

There is currently an outbreak of Plasmodium falciparum malaria in the province of Limón, Costa Rica, primarily affecting the cantons of Pococí and Limón. The number of cases reported is unusually high for this province. Additionally, the Plasmodium falciparum parasite is the most likely to be fatal compared to other common malaria parasites if left untreated. Cases of malaria have also been reported in Alajuela province.

If you are travelling to Limón or Alajuela provinces, antimalarial medication may be recommended depending on your itinerary. If recommended, you should start taking antimalarial drugs prior to travel. See a health care provider or visit a travel health clinic preferably six weeks before you travel to discuss your options. 


Malaria is a serious and occasionally fatal disease that is spread by the bite of an infected mosquito. It is caused by a parasite called Plasmodium. There are 5 different kinds of parasites in this group that can cause the disease.

Symptoms usually appear between 1 to 4 weeks after the mosquito bite but can take up to a year to develop. Infection with malaria can cause flu-like symptoms, including:

  • fever
  • diarrhea
  • headache
  • sweats or chills
  • nausea and vomiting
  • muscle and stomach pain

If not treated, malaria can progress to severe illness and complications may include

  • coma
  • seizures
  • respiratory failure
  • renal failure

Malaria can be fatal if not treated immediately as soon as symptoms develop. Pregnant women, young children and those with a weakened immune system are most at risk of serious illness and complications.

Malaria can be prevented and treated with antimalarial medications. There is no vaccine against malaria.


Before your trip

Consult a health care professional or visit a travel health clinic at least 6 weeks before you travel. 
Antimalarial medication can be prescribed before your trip. They may be recommended depending on your itinerary and the time of year you are travelling. They must be taken before, during and after your travels to help prevent malaria. Discuss with your health care professional which antimalarial is appropriate for you to take for prevention.

During your trip
  • Prevent mosquito bites at all times. The mosquitoes that spread malaria are often most active during the evening between sunset and sunrise, but can bite during the day and night. They are generally not found at altitudes above 2,000m. Be sure to:
    • Use an approved insect repellent and apply it properly.
    • Limit outdoor activities during peak biting periods, early in the morning and in the evening before dusk.
    • Cover up by wearing light-coloured, loose clothing, long pants and tucked-in long-sleeved shirts with closed-toe shoes or boots and a hat.
    • Sleep in indoor areas that are completely enclosed or well-screened.
    • Use insecticide-treated mosquito netting (bed net) when sleeping outdoors or staying in a building that is not completely enclosed and to cover playpens, cribs or strollers.
    • Learn more about mosquito bite prevention for travellers.
After your trip

Monitor your health 

  • If you develop symptoms similar to malaria when you are travelling or up to a year after you return home, see a health care provider immediately. Tell them where you have been travelling or living. Malaria is a medical emergency, and appropriate treatment should not be delayed.

Information for health care professionals

The Committee to Advise on Tropical Medicine and Travel (CATMAT) has developed a statement on the Canadian recommendations for the prevention and treatment of malaria to provide guidance for health care professionals who are preparing travellers to visit areas with a risk of malaria. Malaria risk and recommended preventive measures by geographical area can be found in Appendix 1.

Registration of Canadians Abroad

Sign up with the Registration of Canadians Abroad (ROCA) service to stay connected with the Government of Canada in case of an emergency abroad or an emergency at home.

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