Measles outbreak on a cruise ship in the Western Mediterranean, February 2014, preliminary report

ECDC comment

​The central task force for the measles outbreak on a cruise ship in the western Mediterranean Sea has published a preliminary report as a rapid communication in Eurosurveillance.

​MEASLES OUTBREAK ON A CRUISE SHIP IN THE WESTERN MEDITERRANEAN, FEBRUARY 2014, PRELIMINARY REPORT

By S Lanini, M R Capobianchi, V Puro, A Filia, M Del Manso, T Kärki, L Nicoletti, F Magurano, T Derrough, E Severi, S Bonfigli, F N Lauria, G Ippolito, L Vellucci, M G Pompa, the Central task force for the measles outbreak

The central task force for the measles outbreak on a cruise ship in the western Mediterranean Sea has published a preliminary report as a rapid communication in Eurosurveillance. Since 26 February, when the outbreak was first reported, 27 cases have been reported: 21 crew members, four passengers and for two cases the status was unknown. The ship can accommodate around 3,750 passengers and 1,000 crew members.
 
A measles outbreak on board a cruise ship is a significant public health event for several reasons: the large number of people with unknown vaccination status in a closed environment; the constant flow of passengers on and off the ship; and, limited medical facilities on the ship.
 
The article provides an epidemic description of the cases reported so far and describes the control measures taken to reduce the spread of the infection, including informing those embarking and disembarking the ship of the outbreak and the vaccination campaign with the MMR vaccine on board. Information on the outbreak and passenger lists have been shared with countries where exposed passengers originated from, in order to inform individuals of the potential risk. Of note, Austria set up a telephone hotline which identified one individual, after returning home from the ship, with measles.
 
The preliminary report concludes that the “[isolation and control] measures seem to have been successful in controlling the circulation of the virus among the crew and this is indicated by the fact that since 27 February 2014 there have been no cases identified.” However, “[t]he limited number of cases [four] reported for passengers to date […] is likely to be due to underestimation. The average passenger time on board is about seven days which is usually not sufficient for a susceptible exposed patient infected to develop symptoms while still on board (range of 7 to 18 days from exposure to rash onset)”, highlighting the importance of active contact tracing of passengers.
 
ECDC comment

ECDC is part of the central task force for the outbreak which is lead by the Ministry of Health in Italy and two of ECDC’s experts took part in a mission to support the central task force between 10 and 14 March.ECDC welcomes the rapid publication on the work of the task force and the insight it provides of response measures taken thus far.