Cleanup during a Norovirus
Outbreak in a Foodservice
Decontaminating after an
Norovirus sickens between 19 and 21 million Americans each year.1 In humans, norovirus is spread two ways—directly by person-to- person transmission, the most common route, or indirectly through contaminated
food, water, or the environment.
2 While environmental transmission is reportedly low (0.35%), emerging
evidence suggests contaminated surfaces play a more
important role in the spread of norovirus than previously believed.
3 In fact, according to the U.S. Centers
for Disease Control and Prevention (CDC), norovirus
is the number one cause of diarrhea or vomiting outbreaks spread by direct contact with an infected person
or through touching a contaminated surface. This is not
surprising, given that a single vomiting episode can release 30 million virus particles into the environment.
Fecal matter contains even higher numbers of particles—104 to 1011 per gram—with sick individuals producing 500 g/feces per day. Consequently, if contaminated
surfaces are not properly cleaned and disinfected, these
surfaces could be a source of this highly infectious virus,
possibly causing or prolonging an outbreak through residual environmental contamination.
The relationship between surfaces contaminated with
vomitus/feces and norovirus outbreaks has been documented in a number of published epidemiological investigations. For example, in 1999, more than 300 people,
over a 5-day period, became sick after
one person vomited in the auditorium
and bathroom of a concert hall.
8 In a
U.S. restaurant in 2006, 364 patrons
and employees exhibited symptoms of
a norovirus infection after an ill line
cook vomited in the kitchen.
October 2009, different groups of flight
attendants on the same airplane became
sick after a passenger vomited on the
6 In 2012, 12 employees were
infected after a toddler had a diarrheal
episode in a car dealership bathroom.
The likelihood that vomiting/diarrheal
events in food establishments could
result in a norovirus outbreak prompted
the U.S. Food and Drug Administration
(FDA) to add a regulatory provision
(2-501.11) to the 2011 Supplement of
the 2009 Model Food Code, requiring
establishments to have in place a vomit/
diarrhea cleanup program guided by 11
elements outlined in Annex 3 of the
code. It is important to note that foodservice establishments are not required
to have an outbreak response program
for any foodborne agents including
norovirus. However, CDC has published norovirus outbreak management
and disease prevention guidelines that
establishments could use to inform their
outbreak response, including cleanup.
Limitations with Current Cleanup
Before describing outbreak cleanup
protocols, it is important to first briefly
discuss three limitations to the current evidence base informing outbreak
cleanup protocols, which support the
need for additional research to inform
effective protocols. First, the lack of a
reliable cell culture system for norovirus has been a barrier to the development of environmental disinfectants as
mechanisms in which disinfectants work
are largely unknown. These mechanisms
are typically inferred through studying
norovirus surrogates, such as feline cali-
By Angela M. Fraser, Ph.D.