The Burden of Norovirus in Schools

Charles P. Gerba, PhD

Departments of Soil, Water and Environmental Science & Epidemiology and Environmental Health

University of ArizonaTucson, AZ

We’ll Cover

Norovirus When and where it occurs Case histories Data you can use with your

administrators/school boards Help reduce disease incidence, absenteeism

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Common Infections 80% spread via air, water, food, fomites @800 million cases of respiratory and

enteric infections annually (U.S.) Being around kids means more illness

Unmarried males = one cold per year Unmarried women = 1.3 colds per year Couples with school aged kids = 2.3 colds

each School children =3.5 colds per year.

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Norovirus in the U.S.

21 million people 1.9 million outpatient visits 400,000 ER visits, esp. in young children 71,000 hospitalizations 800 deaths mostly young children and the

elderly

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Norovirus Is One Of The Worst Viruses

Highly contagious Spreads in schools via high touch surfaces Persists on hard surfaces up to 30 days Schools quickly get contaminated Occurs October-May Most school cases go unreported/

unconfirmed

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Role Of Fomites In TransmissionOf A Disease

Sick person sneezes, coughs and pathogens falls on fomite or get aerosolized.

Pathogen falls on fomites e.g. phone, computer

Person picks up pathogen through contaminated fomite. Person touches nose or eyes

with contaminated fingers, becomes infected with pathogen.

Schools –The Perfect Storm Lots of individuals, confined spaces Winter incidence—closed windows High touch areas often not effectively

disinfected Busy hands touch EVERYTHING

Kids touch faces, eyes, mouth 5+ times a minute

Hand washing is not thorough Viral transfer–up to 50% of viruses on a

surface are picked up by the hand when the surface is touched 7

The Perfect Storm, cont’d Most school cases are NOT food-borne Hugh amounts of virus are shed before

symptoms occur Virus on dust particles in the air, settles on

surfaces Disease transmission via 1-10 virus particles.

1 trillion per gram of feces (size of peanut)

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The Hand is Quicker Than The Sneeze

Hand Contact

Adults touch their faces 15.5 times per hour 2.5 eyes 5 nose 8 lip

Children touch their faces 5 times per minute

Teaching: The “Germiest” Profession

Germs per square inch by occupation

5002500450065008500

105001250014500165001850020500

Average All Sites

Highest bacteria per square inch on surfaces commonly touched

Phone, Desk, Computer, Mouse11

Frequently Contaminated SitesIn Schools

Door knobs, handles, push plates Athletic equipment Teaching manipulatives Textbooks/other shared classroom

items Locker handles

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Reported Norovirus Outbreaks

SettingFoodborne Nonfoodborne†

No. % No. %Long-term care facility 12 1 2,060 80School 13 1 148 6Other/Multiple settings 114 13 137 5Hospital 2 0.2 115 4Day care 1 0.1 52 2Restaurant 574 64 38 1

Catering or banquet facility 151 17 8 0.3

Private residence 37 4 32 0.1All settings 904 100 2,590 100

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Site % sites positive for

fecal bacteriaDesks 59Computer mouse 57Cafeteria table 55Library table 53Bathroom sink faucets 36Water fountain 33Keyboards 33Bathroom paper towel dispensers 29

The Most-Frequently Contaminated Sites in Schools

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Average Toilet Seat

Figure 1Top Three Contaminated Sites in All Schools

1.70E+068.60E+05

4.77E+06

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

Cafeteria Table Computer Mouse Desk

To

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Bacte

ria/a

pp

roxim

ate

100 c

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School Study (Grade K thru 12)- 2009

Impact of Disinfectant Wipes on Absenteeism -Seattle

Study Two school semesters 3rd and 4th graders

Intervention Children’s desk wiped with a disinfectant wipe

at the end of each school day Results

50% reduction in absenteeism

From Bright et al, 2010; J. School Nursing

Our Ohio School Study

Compared classrooms using disinfecting wipes at end of day on each desk

Could we lower incidence of gastroenteritis by treatinghard surfaces?

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The Study Details

Two school semesters 3rd and 4th graders

Classroom surfaces Influenza A virus on up to 50% contaminated Norovirus on up to 22% contaminated

Intervention Quaternary ammonium-based disinfectant

wipes registered for norovirus by EPA Used by teachers on desks at the end of each

school day 18

Results Use of disinfecting wipes reduced

detection of norovirus on hard classroom surfaces

Classrooms that did not use disinfecting wipes had a higher incidence of gastroenteritis

Absenteeism reduced by 50% in classrooms using disinfecting wipes

with EPA registration for norovirus efficacy

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What Do Outbreaks Cost?

Schools closed Lost school days Make-up days might be needed

High absenteeism State reimbursements lost

Teachers and staff ill Replacement personnel needed

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Outbreak Costs, cont’d

Custodial staff often become ill Schools must be disinfected to stop the

outbreak Outside services Extra cleaning materials/supplies

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Non-School (Hidden) Costs Parents stay home from work to care

for sick students Siblings fall ill in sequence

Parents become ill, lose more work time

Virus spreads to work place, community facilities, other schools

Total hidden costs hard to estimate but very high to communities

Medical expenses22

A Real-World Outbreak Staff members and students quickly ill

25+ staff members absent multiple days Spread to other schools and the parochial

school in the community Team activities Extracurricular activities at church (choir, Boy Scouts, first

communion instruction)

Closed 11 schools for one week (school days, one holiday)

5000+ enrollment

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Real-World Outbreak Costs

DIRECT=@$93K Disinfection = $45K

Outside haz mat vendor =$25K Supplies = $10-15K Janitorial staff overtime=$5K

Personnel = $7875 Cost of substitute teachers =$105/day per sub 25 teachers x 3 days

Cancelled class trip=$40K

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Real-World Outbreak Costs

INDIRECT = $1,015,050 School operations = $335,000 per day

Three lost days of school= $1,005,000 State reimbursements = $10,050

3350 x 3+ days out (plus earlier absentees)

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Real-World Outbreak Costs

TOTALS for 2013--Direct and Indirect

$1,093,000

  TOTALS--If This Had Occurred In 2014

$2,200,000

(based on state reimbursement policy changes and increased snow days used)

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Virus active one week before closure 50% of student body and staff ill (479

people) Closure “recommended” by the Public

Health Department Closed 7 days for disinfecting

Custodial staff and outside custodial used Disinfected the school, buses

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Norovirus OutbreakReal World Case II

DIRECT COSTS=$43K+ Disinfection= $25,000 Staff costs =$18,000

Substitute teachers $100/day 36 subs/5 days

Norovirus OutbreakReal World Case II

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Indirect Costs Hospitalizations Parents lost time (minimum of six days)

from work

Norovirus OutbreakReal World Case II

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What to Use for Norovirus

Bleach works, but is hard on surfaces Requires personal protective gear (PPG)

Quat-based products are available as liquids, ready-to-use and wipes Can be used on keyboards, mice, all non-

porous surfaces Do not corrode metal PPG is generally not needed

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What Custodians Probably Don’t Know

Reduce illness sharply by disinfecting high touch areas early and often

Buy the right type of product—not all kill norovirus and flu

Read the label and use correctly Reusable cleaning cloths can spread illnesses

Bacteria grow on them, esp in human environments Cloths and other organics reduce disinfectant concentration Hard to get them clean

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Cleaning vs. Hygiene

Cleaning -- “the removal of unwanted matter”

Hygiene -- “reducing the risk of infection” Cleaning alone may increase risks by

spreading pathogens.

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Hospital Cleaning Cloth Study Results

93% of reusable cleaning cloths contained bacteria before use Average number of bacteria = 17,000

37.5 % of the disinfectant soak buckets contained bacteria Average number of bacteria = 523

Cleaning Cloth Material Makes a BIG Difference

Organism Cotton Microfiber P-value

Total bacteria

1,995 24,547 0.01

Coliforms 1 6 0.0002

Molds 1 47 0.001

Cleaning Cloths

Reuseable cleaning/towels/cloth can contain opportunistic pathogens

Washing practices affect microbial loads in reusable cleaning cloths/towels

Microfiber cloths contain more bacteria than cotton

A wide range of enteric bacterial types are present in cleaning cloths

Disease Spread in Offices(Similar to Schools)

Tracer virus on entry door push plates in 80-person office

Within 2-4 hours, 40% to 60% of fomites sampled had virus

Coffee break room is the first to be contaminated

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Hotels Tracer virus (MS-2 virus)

added to hotel room surfaces (i.e. nightstand, desk, doorknob

Sample rooms after maids clean

Sample conference room end of day

Conference attendees’ hands

Hotel Results Virus detected

Next 4 rooms cleaned by the maid On surfaces (table tops) in the conference

room On 1/3 of the conference attendees’ hands On the coffee pot handle

of the break room

Hotels -- Intervention

Intervention Give maids antimicrobial

products, disinfectant wipes for key surfaces

Hand sanitizers for attendees

Results Reduce spread between

rooms by 90% Reduce virus on hands

by 50%

Products That Kill Norovirus Also Kill Ebola In Schools

Nine Texas school districts spent $117,000 to clean schools

$36,000 for cleaning and closed school for three days

$13,000 spent by one school to purchase all new aerosol germicidal sprays

$32,000 spent on supplemental cleaning in one school

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Quat-Based Products “Quats” on the market for 60+ years

Thousands of products but not all work for all pathogens!

30+ quat-based EPA-registered formulations in 1500 products that control norovirus

Our studies in schools show disinfecting with a norovirus-specific quat-based wipe prevents illness These wipes also kill flu virus and other

pathogens 41

Which Quat-Based Products?

Products with this EPA-registration

• Labels indicate which products kill which pathogens

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http://tiny.cc/norovirus-products

Annual Costs for Quat Wipes for Norovirus/Flu

180 school days 30 desks per class

1 wipe for two desks 15 wipes per classroom per day (2700 per

year) Canister is $8.72, contains 160 wipes =

5.45 cents per wipe Cost per year is $147 per classroom

Communication Is the Key Teacher and custodial training is important

Must understand their role in school health Must know the difference between disinfecting,

sanitizing and cleaning Disinfecting is needed the moment illness

strikes The school nurse should be empowered to help

determine when and which high touch areas need to be disinfected

Your districts should see cost savings associated with illness reduction

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Take Home Messages Norovirus and flu are major causes of school

closures, absenteeism Use quat-based disinfectant formulations

registered for efficacy for norovirus and flu Labels state specific pathogens killed by the

product Norovirus is a surrogate for enterovirus, Ebola,

other emerging viral diseases Simple interventions are cost effective ,

reduce transmission of common school-based infections

Follow label directions 45

Questions?

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