The Centers for Disease Control and Prevention posted a new travel health notice on Sept. 18 for a hepatitis A outbreak in Costa Rica, noting that most cases have been reported in San José province. The alert is a Level 1 notice, the lowest of CDC's four levels, which asks travelers to practice usual precautions rather than change their plans.
The numbers behind the notice are significant. Costa Rica confirmed 772 hepatitis A cases through epidemiological week 32 of 2026, more than double the 373 cases recorded in all of 2025, according to a Ministry of Health surveillance bulletin reported by Infobae. San José province accounted for 562 of those cases, roughly seven in 10 nationwide.
For U.S. households, the concern is practical rather than alarming. Costa Rica recorded 1,627,807 arrivals from the United States in 2025, according to tourism institute figures published by La Nación. The virus is vaccine-preventable, but adults who grew up before hepatitis A vaccination became routine for U.S. children in 2006 may not be protected.
Where San José Cases Are Concentrated
Surveillance data point to several neighborhood clusters rather than a single source. In the Hospital district of San José, health authorities confirmed an outbreak of 70 cases through week 31, mainly in Barrio Cuba and Cristo Rey. The Hatillo area reported 68 confirmed cases, with another 23 awaiting laboratory results.
Outside San José province, Cartago had 61 cases, and Alajuela had 60, according to preliminary ministry data summarized by Monumental. Officials said the available evidence does not point to a common water source that explains the increase across communities.
Water is still part of the picture. The ministry's bulletin describes a heavier presence of cases in the Greater Metropolitan Area and in cantons with intermittent problems in water quality or supply. In a separate cluster in the capital area, the ministry confirmed 14 cases and reported detecting contamination in a water system.
CDC Guidance for Families Booking Costa Rica Trips
CDC's notice asks travelers to make sure they are vaccinated against hepatitis A. For people who cannot receive the vaccine, a clinician may recommend immune globulin, which offers shorter-term protection. Careful handwashing before preparing or eating food, after using the bathroom, and after changing diapers also lowers risk.
On its Costa Rica destination page, CDC recommends the vaccine for unvaccinated travelers ages 1 and older. Infants 6 to 11 months old should also get a dose, although it does not count toward the routine two-dose childhood series. Unvaccinated travelers older than 40, people with weakened immune systems, and people with chronic medical conditions who leave in less than two weeks should get the first vaccine dose and may also receive immune globulin at the same appointment.
Timing matters for holiday travelers. A single dose before departure provides meaningful protection for most healthy travelers, so a last-minute appointment is still worthwhile. Parents may want to check a child's immunization record first, since many U.S. children have already been vaccinated as part of routine care.
Unvaccinated people who later learn they were exposed, for example through an infected relative, host, or food handler, should ask a clinician about post-exposure protection. CDC advises giving it as soon as possible within two weeks of exposure.
Symptoms Can Appear Weeks After the Flight Home
Hepatitis A symptoms usually appear two to seven weeks after infection, which means illness may begin after a traveler is back at work or school. Signs include dark urine or clay-colored stools, diarrhea, fatigue, fever, joint pain, loss of appetite, nausea, stomach pain, and jaundice, a yellowing of the skin or eyes.
Young children often have mild or no symptoms, yet they can still pass the virus to others in the household. Adults tend to have more noticeable illness, and older adults and people with existing liver disease face a higher risk of severe complications, according to CDC's hepatitis A guidance.
Mild symptoms warrant a call to a primary care clinician or urgent care, along with a mention of recent travel to Costa Rica. Yellowing skin or eyes, confusion, severe stomach pain, persistent vomiting, or signs of dehydration call for prompt in-person care.
What Travelers Should Watch Next
Hepatitis A vaccine is widely available at pharmacies, primary care offices, and travel clinics. Coverage for travel-related doses varies by insurance plan, so families should ask their insurer or pharmacist about out-of-pocket costs before booking. Some local health departments offer lower-cost vaccination for eligible residents.
CDC is not recommending that travelers cancel trips. A Level 1 notice signals an increase in cases, not a reason to stay home, and vaccinated travelers face low risk.
Costa Rica's ministry publishes epidemiological bulletins regularly, and future updates will show whether the outbreak is easing. CDC can raise, lower, or remove a notice as conditions change, so travelers should recheck the agency's notice page a week or two before departure. Unvaccinated adults, parents of infants, and people with liver conditions have a clear step to take before they pack, and MedicalDaily will update this story as new case counts are released.
Key Questions Answered
What did CDC announce about Costa Rica?
On Sept. 18, CDC posted a Level 1 travel health notice for a hepatitis A outbreak in Costa Rica. Most cases have been reported in San José province, and the agency recommends that travelers be vaccinated.
How many hepatitis A cases has Costa Rica reported?
Costa Rica confirmed 772 cases through epidemiological week 32 of 2026, compared with 373 cases in all of 2025. San José province accounts for 562 of them.
Should I cancel my trip to Costa Rica?
CDC is not advising travelers to cancel. A Level 1 notice asks people to practice usual precautions, with vaccination as the main protective step.
Who should get the hepatitis A vaccine before traveling?
CDC recommends it for unvaccinated travelers ages 1 and older, and infants 6 to 11 months old should also receive a travel dose. Adults unsure of their status can ask a pharmacist or clinician to check their records.
What if my trip is less than two weeks away?
Getting a dose is still worthwhile. Unvaccinated travelers older than 40, people with weakened immune systems, and those with chronic conditions should ask whether they also need immune globulin at the same visit.
What symptoms should returning travelers watch for?
Watch for dark urine, pale stools, fatigue, fever, nausea, stomach pain, and yellowing of the skin or eyes. Symptoms can appear weeks after returning, so mention the trip to a clinician.
