CDC: Norovirus outbreaks most often linked to infected food handlers

In 1929 Dr. John Zahorsky wrote about children developing sporadic cases of vomiting, supplemented by watery diarrhea each year between November and May – and over 30 years of clinical practice, he coined the term winter vomiting sickness. According to a 1950 Time Magazine article, Dr. Zahorsky was a pediatrician working extolling the virtues of good sanitation during birth and infant care – one of the fathers of disease prevention.m63e0603a1f1
In 1968, one of these winter vomiting sickness outbreaks occurred in an elementary school in Norwalk, OH. Teachers and students were both affected, with 32% of the primary cases spreading illness to others in their families and homes. After a collaborative investigation with researchers from NIH and Walter-Reed Army medical center a causative agent was found in the feces of the ill — a 27nm sized virus particle. Zahorsky’s illnesses then took on the name Norwalk. Since then, the name has morphed to Norwalk and Norwalk-like viruses, which begat noroviruses.
Often linked to cruise ships in popular culture, noro really is linked much more often to food handlers in food service. According to fellow NoroCORE collaborator Aron Hall and colleagues in this week’s MMWR, noroviruses are the leading cause of reported foodborne disease outbreaks nationally and most often linked to restaurants – with contamination occurring from infected food workers.
 
During 2009–2012, a total of 4,318 norovirus outbreaks were reported to NORS (the national outbreak reporting system -ben) , resulting in 161,253 illnesses, 2,512 hospitalizations, and 304 deaths. Foodborne transmission was the primary mode reported in 1,008 (23%) norovirus outbreaks, representing 48% of the 2,098 foodborne outbreaks reported with a single suspected or confirmed cause during the 4-year study period. Other primary transmission modes reported among the 4,318 norovirus outbreaks included person-to-person (2,976 [69%]), environmental (15 [0.35%]), waterborne (11 [0.26%]), and unknown transmission mode (308 [7%]). In 158 (16%) of foodborne norovirus outbreaks, secondary transmission through one of these other modes was reported. Norovirus outbreaks were most common in winter, with 2,394 (55%) occurring during December–February (Figure 1). Among foodborne norovirus outbreaks, 398 (39%) occurred during December–February, compared with 1,996 (60%) of nonfoodborne norovirus outbreaks.
 
Outbreak data (above, exactly as shown) demonstrates that winter vomiting virus is a fitting moniker.
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About Ben Chapman

Dr. Ben Chapman is a professor and food safety extension specialist at North Carolina State University. As a teenager, a Saturday afternoon viewing of the classic cable movie, Outbreak, sparked his interest in pathogens and public health. With the goal of less foodborne illness, his group designs, implements, and evaluates food safety strategies, messages, and media from farm-to-fork. Through reality-based research, Chapman investigates behaviors and creates interventions aimed at amateur and professional food handlers, managers, and organizational decision-makers; the gate keepers of safe food. Ben co-hosts a biweekly podcast called Food Safety Talk and tries to further engage folks online through Instagram, Twitter, Facebook, YouTube and, maybe not surprisingly, Pinterest. Follow on Twitter @benjaminchapman.