Measles outbreak on a cruise ship- Mediterranean Sea – 2014

On 27 February 2014, Italy reported an outbreak of measles on board a cruise ship sailing in the north-western
Mediterranean with regular port calls in Italy, Spain and France.

As of 13 March 2014, 27 cases (22 laboratory confirmed and 5 probable) have been reported with onset from 20 February to 1 March.

More than 800 crew members were vaccinated in response to the outbreak. Most cases were among the crew. Two unvaccinated infants were among the affected passengers.

The outbreak has not been declared over and new cases among crew and passengers cannot be ruled-out.

Epidemiological and molecular evidence suggest that the outbreak strain may be linked to the large and still ongoing measles outbreak in the Philippines.

Measles is a highly infectious disease and frequently results in outbreaks.

Introduction of measles virus into confined groups, such as passengers and crew on a ship, can result in large and rapidly evolving outbreaks if vaccine uptake in the group is below the epidemic threshold.

The most recent case associated with the Costa Pacifica outbreak is a passenger who developed symptoms on 1 March after having returned home.

However, measles has a long incubation period, up to 21 days, and cases are contagious on average 4 days prior to onset of rash until 4 days after rash. This means that new cases may still be reported among crew and passengers.