Costa Rican health authorities are investigating suspected measles cases linked to an international youth camp that included foreign participants, as officials work to determine how the virus entered the country and to contain any further spread. Preliminary findings from the Ministry of Health indicate the virus may have entered Costa Rica after contact with Mexican nationals who took part in a cultural activity alongside Costa Rican teenagers.
The investigation follows two confirmed measles cases detected in recent weeks. The first involves a minor from Pococí, while the second involves a 41-year-old woman from Dulce Nombre de Coronado. Both patients were reported in stable condition and recovering without complications. Health officials said both had been vaccinated against measles, though no vaccine offers complete protection in every case.
Authorities said the suspected chain of transmission appears tied to a youth camp organized in late January or early February that brought together delegations from several countries. Health Minister Mary Munive said the strongest working hypothesis points to a Mexican delegation that may have included a participant with the disease. According to local reporting based on the ministry’s briefing, at least 196 people may have been exposed during the event.
Costa Rica’s Health Ministry said it is continuing to monitor direct contacts of the confirmed cases for 21 days as part of its epidemiological surveillance. Officials have also stressed that the country’s vaccination coverage likely limited wider transmission. Munive said that without existing immunization levels, the number of infections could have been far higher given measles’ extreme contagiousness.
The new investigation comes after Costa Rica confirmed an imported measles case in Pérez Zeledón on February 14. That case prompted the immediate activation of national surveillance protocols. A second confirmed case was later announced on March 9, before the ministry updated the public again on March 17 with the preliminary link to the cultural youth activity.
Health officials are urging parents and caregivers to verify that children have received both doses of the measles, mumps and rubella vaccine. Costa Rica has also warned travelers to review their vaccination status, especially amid rising measles activity in the Americas. The Pan American Health Organization issued an epidemiological alert in February, citing a sharp increase in measles cases across the region during 2025 and early 2026.
Costa Rica has maintained its status as a country free of endemic measles transmission since 1999, so recent infections are being treated as imported or linked to imported exposure rather than sustained local circulation. Still, the cluster has raised concern because it shows how quickly the virus can move through international gatherings, even in countries with long-standing vaccination programs.
