Acute XXXX on Cruise Ships - United States, 2008-2014.

@entity697 @entity221 @entity294 @entity391 @entity1902 @entity2708 @entity10 @entity121 @entity5163
From 1990 to 2004, the reported rates of @entity5163 (three or more loose stools or a greater than normal frequency in a 24-hour period) on cruise ships decreased 2.4%, from 29.2 cases per 100,000 travel days to 28.5 cases (1,2). Increased rates of acute @entity1902 ( @entity294 or @entity391 that is associated with loose stools, bloody stools, abdominal cramps, @entity10 , @entity121 , or @entity221 ) occurred in years that novel strains of norovirus, the most common etiologic agent in cruise @entity2708 outbreaks, emerged (3). To determine recent rates of @entity697 on cruise ships, CDC analyzed combined data for the period 2008-2014 that were submitted by cruise ships sailing in U.S. jurisdiction (defined as passenger vessels carrying >= 13 passengers and within 15 days of arriving in the United States) (4). CDC also reviewed laboratory data to ascertain the causes of @entity697 outbreaks and examined trends over time. During the study period, the rates of @entity697 per 100,000 travel days decreased among passengers from 27.2 cases in 2008 to 22.3 in 2014. Rates for crew members remained essentially unchanged (21.3 cases in 2008 and 21.6 in 2014). However, the rate of @entity697 was significantly higher in 2012 than in 2011 or 2013 for both passengers and crew members, likely related to the emergence of a novel strain of norovirus, GII.4 Sydney (5). During 2008-2014, a total of 133 cruise @entity2708 @entity697 outbreaks were reported, 95 (71%) of which had specimens available for testing. Among these, 92 (97%) were caused by norovirus, and among 80 norovirus specimens for which a genotype was identified, 59 (73.8%) were GII.4 strains. Cruise @entity2708 travelers experiencing @entity294 or @entity391 should report to the @entity2708 medical center promptly so that symptoms can be assessed, proper treatment provided, and control measures implemented.
