In a follow-up to the initial report on the Carnival Cruise Line’s Carnival Sunshine norovirus outbreak earlier this week, CDC Vessel Sanitation Program officials put the case count up to 178 as the cruise ship docks in Port Canaveral, FL today.
Of the 3001 passengers on board, 173 have been taken ill by the contagious gastrointestinal virus (5.76%). The number of crew affected remains at five.
In 2016, five cruise ship voyages have been investigated by the CDC VSP, three with confirmed norovirus and two with a still unknown etiology.
Although cruise ship outbreaks, particularly with norovirus, the so-called “cruise ship virus”, receive much media attention, the fact is, it accounts for a small number of total cases.
In January, a study was published by the CDC and they found from 2008 to 2014, among 73,599,005 passengers on cruise ships during 2008–2014, a total of 129,678 (0.18%) cases of acute gastroenteritis were reported during outbreak and nonoutbreak voyages; among 28,281,361 crew members, 43,132 (0.15%) cases were reported. Only a small proportion of those cases were part of a norovirus outbreak.
Norovirus, the most common causative agent of outbreaks, accounted for 14,911 cases among passengers and crew members during 2008–2014, 0.01% of the estimated number of norovirus cases in the United States during the study period.