Norovirus and its Importance in School Cafeterias

Dr. Ben Chapman and Katie Overbey

North Carolina State University

March 26, 2015

What is Norovirus?

• Virus that causes gastrointestinal (GI) illness around the world

• Leading cause of GI illness

• You may also know it as:o Norowalk viruso Winter vomiting diseaseo Cruise ship viruso Stomach flu*

http://www.dailymail.co.uk/news/article-2253996/Around-150-passengers-hit-norovirus-Queen-Mary-2-

luxury-Christmas-cruise.html

Symptoms

• Symptoms usually resolve on their own after 2-3 days, but may be more severe in young children, the elderly and immunocompromised people

• After becoming infected with the virus, it takes 24-48 hours to show symptoms

Norovirus Shedding

Atmar et al. 2008. Emerg Infect Dis. 14(10):1553-7.

Asymptomatic Vomiting/diarhea

Virus particles shed even up to two weeks

About Norovirus Infection

• Can infect persons of all ages

• Takes a very small amount of virus to cause infection

(Patel, Hall, Vinjé, & Parashar, 2009)

Treatment

• No vaccine or drug for treatment is available, symptoms usually go away on their own

• Antibiotics will not work• Hydration is recommended,

and in some severe cases an IV may be necessary

http://www.rgvfit.net/proper-hydration-tips-training-physical-events/Source: CDC

Recent outbreaks

• March 2014: Elementary and High School in Asheville, NCo More than 160 students illo Appeared to have spread from

the Elementary to the High School

• February 2015: Longwood University in Farmville, VAo Three dozen confirmed caseso Thought to have spread from

Hampden-Sydney College where there were about 300 cases

How common is Norovirus?

• About 1 in 15 Americans will get it each year

• 5.5 million food related cases in the US each year

• Second leading cause of food related hospitalizations

(Scallan et al., 2011; CDC, 2013)

Transmission of Norovirus

• Can spread easily from person to persono Fecal- oral route

• Contaminated water or foodo Contamination originates

from human source

(Anderson et al., 2001; Maunula et al., 2005; Shieh et al., 2003)

Transmission of Norovirus

• Touching infected surfaceso Can survive on surfaces

for up to 2 weeks and in water for up to 2 months

• From aerosolized particles

http://www.cidd.psu.edu/research/synopses/social-contact-network-disease-transmission

(Lopman et al., 2004)

Norovirus on Surfaces

• Norovirus is extremely hardy and can survive on surfaces for up to 2 weeks

• Surface disinfection is crucial

https://followtheoutbreak.files.wordpress.com/2014/09/door-knob.jpg?w=2560&h=1200&crop=1

http://onmilwaukee.com/images/articles/sc/schoolcafeteria/schoolcafeteria_story1.jpg(Lopman et al., 2004)

Relevance of Norovirus in School Settings

• Highly infectious• Common food lines and

eating areas can lead to increased transmission

• Lives on surfaces for long periods of time

(Lee & Greig, 2010)

Prevention Strategies

• Exclusion of sick food handlerso People may be infectious even if they don’t show

symptomso If an employee is showing symptoms, they are

infectious and can remain infectious for up to 72 hours after symptoms subside

• It is important that employees who have been sick are excluded from food preparation while they are ill and 72 hours after getting better

(Barrabeig et al., 2010)

Food Handling Precautions

• If you’re sick- do not prepare food!

• If you think food has come in contact with norovoris- throw it out!

Cleaning To Prevent Norovirus

• Proper hand washing is crucial

• Hand sanitizer does not work

• On surfaces, only a bleach solution will worko Products like Lysol or Clorox

wipes are not effectiveo Other sanitizer, like quaternary

ammonium compounds, are not recommended either

http://www.naturescornernaturalmarket.com/wp-content/uploads/2013/07/hand-sanitizer.jpg

(Hall et al., 2011; Liu, Yuen, Hsiao, Jaykus, & Moe, 2010)

Cleaning To Prevent Norovirus

• Use appropriate personal protectiono Disposable masko Disposable gloves

• If there is a vomit incident, it must be properly cleaned firsto Use of absorbent powder

(Hall et al., 2011)

Preparing a Bleach Solution

• Need to prepare a fresh bleach solutiono No more than 24 hours old

• Need between a 1:10 and 1:50 dilutiono Correct concentration is criticalo Because of the way bleach is

formulated if there is too little or too much it will not work

(Hall et al., 2011)

Cleaning to Prevent Norovirus

• Bleach needs to have appropriate contact time with surface to disinfect properlyo Current recommendation is about 4

minutes

• Radiuso When a vomiting incident occurs,

particles can spread between 3 and 15 feet around the original site

o Important to clean around the area (Tung, 2013)

Summary

• Only takes 1-10 virus particles to cause illness

• Billions in each poop or vomit event• Shedding lasts for 10+ days

Dr. Ben Chapmanbenjamin_chapman@ncsu.eduFollow me on twitter @benjaminchapman919 809 3205foodsafetyinfosheets.orgfoodsafetytalk.combarfblog.com