Epidemiological update: Measles on a cruise ship, 21 March 2014

epidemiological update

​A measles outbreak was declared on 27 February 2014 on the Costa Pacifica ship cruising in the western Mediterranean Sea. 

On 5 March 2014, ECDC published a rapid risk assessment in response to this event [1]. On 14 March 2014, a “Rapid Communication” report detailing the descriptive epidemiology of the outbreak was published in Eurosurveillance. The report was collectively written by the outbreak response team coordinated by the Italian Ministry of Health [2].
 
Since 14 March and as of 21 March 2014, no new cases have been reported among Costa Pacifica crew members. In Italy, a case has been reported among a maintenance worker who disembarked on 1 March and six new cases. One additional Italian passenger who disembarked on 14 February developed measles. Five contacts of this passenger were reported developing the disease, including one relative, one work colleague, two health care workers and one unspecified. One of these contacts developed pneumonia and was admitted to an intensive care unit.
 
Overall, 34 cases of measles associated with this outbreak have been reported by Italy (33) and Austria (1). Of the 34 cases, 22 cases have occurred among crew members (n=21) or other workers (n=1). Seven cases occurred among passengers. The case reported by Austria was a passenger who developed symptoms on 22 February after disembarking the ship on 15 February 2014 (Figure 1).
 
The index case in the outbreak is a crew member who sought medical care off the ship for fever and rash on 22 February and was laboratory confirmed to have measles on 27 February. The disease onset among crew members was clustered in the period from 20 to 27 February 2014, while the maintenance worker developed rash on 10 March.
 
Twenty-three cases have been laboratory-confirmed in Italy and one in Austria. Measles viruses of genotype B3 have been isolated from 11 cases for which a sample was available [3].
 
In response to the outbreak, more than 800 of the 1 000 crew members have been vaccinated between 28 February and 1 March. Vaccination was also offered to passengers and information on the outbreak and recommendations was provided to embarking and disembarking passengers from 28 February 2014.
 
The Italian Health Authorities are closely monitoring the development of this outbreak in collaboration with ECDC and the cruise company.
 
Figure 1. Distribution of measles cases associated with the cruise ship outbreak, by date of rash onset and by crew/other worker, passenger and contact status (n=34), 21 March 2014