Norovirus Activity???united States, 2002

NOROVIRUS ACTIVITY—UNITED STATES, 2002 [CDC 2002 MMWR 2003;52:41] This is the CDC review of laboratory surveillance for May-December, 2002. During this time they received stool specimens from 48 outbreaks of acute gastroenteritis including restaurant/catered events (12), cruise ships (9), schools/child care centers (7), assisted living facilities (5), sporting events (2), residential camps (2), and “other” (11). Tests using RT-PCR showed 11 of 27 (41%) that were appropriate for testing showed norovirus. The characteristics of this virus include stability in the environment, spread by multiple modes and detection by RT-PCR, which is considered sensitive and specific. It is highly infectious with a minimum inoculum of only 10 viral particles necessary to achieve infection. Characteristics are summarized in table 8.TABLE 8: Norovirus-associated gastroenteritisComment: Norovirus is the former “Norwalk-like virus” which has been associated with multiple outbreaks. The Public Health Laboratory Service Communicable Disease Surveillance Center in England reported their experience with investigating 1,877 general outbreaks of gastroenteritis and this agent accounted for 79% (Emerg Infect Dis 2003;9:71). The Foodborne Viruses in Europe Network showed this agent responsible for over 85% of 3,714 nonbacterial outbreaks of gastroenteritis from 1995–2000 (Emerg Infect Dis 2003;9:90). A previous report of about 21 outbreaks of gastroenteritis on 17 cruise ships showed 9 were associated with norovirus and 3 were attributed to bacterial agents (MMWR 2002;51:1112).