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Staff Member
Laura Ryon
303.769.4421 x112
Colorado law requires all students attending Colorado Schools and licensed child cares to be vaccinated against certain diseases unless a medical or non-medical excemption is filed. For more information about vaccine requirements, resources and exemptions, please visit the Colorado Department of Public Health and Environment's School Immunization page.
Letter from the Colorado Department of Public Health and Environment
Date: November 22, 2019
To: Colorado School Nurses
From: Colorado Department of Public Health and Environment (CDPHE) - Communicable
Disease Branch - (main phone number: 303-692-2700)
Subject: Increase in reports of gastrointestinal illness in schools
The Colorado Department of Public Health and Environment (CDPHE) and local public health
agencies (LPHAs) have noted an increase in reports of gastrointestinal illness that is consistent
with norovirus (vomiting and/or diarrhea lasting 1-2 days) in group settings around the state,
including schools and child care facilities. Norovirus is a common cause of gastrointestinal
symptoms. This letter contains information about norovirus and outbreak control and
prevention measures for schools and child care facilities.
Please work with your LPHA if any schools or child care centers in your district have increases
in student illnesses or an outbreak. All outbreaks, regardless of setting, cause, or symptoms,
are reportable to public health. Local public health agencies work with affected school
districts to recommend prevention and control measures. Find Your LPHA
General information about norovirus:
Noroviruses cause the “stomach flu,'' or “stomach bug,” which is different from influenza.
Outbreaks are common (especially in late fall and winter months in group settings), and
require immediate attention to prevent spread.
Incubation period (amount of time between being exposed and symptom onset): 12 – 48 hours
Duration of symptoms (amount of time illness lasts): 12 – 60 hours
Symptoms : Sudden onset of nausea, vomiting, diarrhea (not bloody), abdominal cramps,
low-grade fever, headache, chills, muscle aches, and/or malaise. Dehydration can occur and
can be severe.
Transmission/Communicability : Norovirus is extremely contagious and highly concentrated in
diarrhea and vomit of infected people. The virus is spread primarily person-to-person through
the fecal-oral route] (infected person does not wash hands properly after using the bathroom
and then touches items/food that will be put in someone’s mouth). It can also spread through
the air (when someone throws up) and by touching contaminated surfaces/objects and then
touching your mouth or items you put in your mouth (food, cigarettes, gum, etc.). People are
most contagious when they begin feeling ill until diarrhea stops, but can be contagious for 48+
hours after feeling better.
Treatment : There is no antiviral medication for treatment or vaccine for prevention.
Treatment consists of replacing fluids and electrolytes to prevent dehydration.
General epidemiology of norovirus outbreaks:
On average, around 200 outbreaks of suspected or confirmed norovirus are reported in
Colorado each year. There are likely many more outbreaks occurring that are not reported to
public health. Outbreak reports increase in November, with peak occurrence in December and
January. The majority of these outbreaks occur in group settings, such as health care
facilities, schools, and child care centers. Family and group gatherings during the holidays can
propagate the spread of the virus.
As of this date, we are not aware of a new strain of norovirus circulating in Colorado or the
Control measures for norovirus outbreaks :
● EXCLUDE ill students: Work with your local public health agency to determine how
long ill students should be excluded. Generally,ill students should be excluded until at
least 48 hours after diarrhea and vomiting have ceased, even if they are feeling well
● EXCLUDE ill staff : Work with your local public health agency to determine how long
ill staff should be excluded. Generally, ill staff, especially food handlers, should be
excluded from work until at least 48 hours after diarrhea and vomiting have ceased,
even if they are feeling well sooner.
● Cleaning and disinfecting: Noroviruses are very hardy and can survive relatively high
levels of chlorine. Increase the frequency of disinfection of restrooms and commonly
shared or touched items (tables, door knobs, faucets, chairs, computers, keyboards,
toys, etc). To effectively disinfect areas or items, use a solution of household chlorine
bleach (one cup of bleach per nine cups of water) or an EPA-approved disinfectant
with specific activity against norovirus. A list of EPA-registered disinfectants effective
against norovirus is available on the EPA’s website under “List G: EPA’s Registered
Antimicrobial Products Effective Against Norovirus”
ucts-effective-against-norovirus ). For help mixing disinfectants, refer to the Bleach
Dilution Calculator Tool in the online norovirus resources folder: .
This folder also contains detailed instructions on cleaning up vomiting or diarrheal
● Hand washing: Review the importance of hand washing with students and staff.
Remind children and staff to thoroughly wash their hands after using the restroom,
before eating, and before handling any food for others. Also, remind everyone that
hand washing must be done with soap and warm water, washing all surfaces of the
hands for at least 20 seconds; hand sanitizer is not an acceptable substitute for
washing hands, but can be used to supplement frequent hand washing.
● Parent/guardian notification: Consider sending a letter home to parents/guardians
about the situation. Template letters can be found in this folder:
More information/resources:
Contact your local public health agency , or CDPHE at 303-692-2700.
Additional information on norovirus:
Resources for responding to a norovirus outbreak:
Guidelines on the management of infectious diseases in schools and child care facilities: