Norovirus Called "The Most Common Cause" Of Food-Borne Illness Outbreaks By CDC
Norovirus is on the upswing in the United States, a new report by the Centers for Disease Control & Prevention (CDC) suggests.
No national surveillance system exists for Norovirus except where food-borne transmission is suspected. In last half of 2006, state public health departments began reporting more outbreaks involving acute gastroenteritis (AGE). Many of these involved residents of long-term care facilities.
Two years ago, in the (Aug. 24, 2007) Morbidity & Mortality Weekly Report (MMWR), CDC confirmed that “ a national increase has occurred in the frequency of AGE outbreaks caused by norovirus (including fatal cases in long-term--care facilities). Two new co-circulating GII.4 norovirus strains emerged nationwide in 2006 and likely accounted for this increase in activity.”
In today’s MMWR, CDC takes a more robust look at food-borne outbreaks in 2006 and finds Norovirus is “the most common cause.” In an analysis titled: “Surveillance for Foodborne Disease Outbreaks --- United States, 2006,” CDC breaks down the outbreaks for 2006 on which it has data.
“A total of 1,270 Food-Borne Disease Outbreaks (FBDOs) were reported, resulting in 27,634 (illness) cases and 11 deaths.
“Among the 624 FBDOs with a confirmed etiology, norovirus was the most common cause, accounting for 54 percent of outbreaks and 11,879 cases…” CDC reports.
In 621 outbreaks involving 18,111 cases, there was a single confirmed etiologic agent responsible. In 55 percent of those outbreaks (343) involving 66 percent of the cases (11,981), the cause was a virus. (Bacteria, parasites, and chemical agents caused the remainder.)
Calicivirus caused 337 (98 percent) of the confirmed FBDOs attributed to viruses; and all calicivirus outbreaks reported in 2006 were attributed to norovirus.
