Importance of Fomites in the Transmission of Infectious Disease Charles P. Gerba Department of Soil, Water and Environmental Science And Epidemiology and.

Importance of Fomites in the Importance of Fomites in the Transmission of Infectious DiseaseTransmission of Infectious Disease

Charles P. GerbaCharles P. GerbaDepartment of Soil, Water and Environmental ScienceDepartment of Soil, Water and Environmental Science

AndAndEpidemiology and BiostatisticsEpidemiology and Biostatistics

University of ArizonaUniversity of ArizonaTucson, AZTucson, AZ

80% of all pathogens in the 80% of all pathogens in the hospital and home environment hospital and home environment are spread through hand contactare spread through hand contact

Most Diseases Spread Most Diseases Spread Through Hand ContactThrough Hand Contact

Every three minutes, a child brings Every three minutes, a child brings his/ her hand to nose or mouth his/ her hand to nose or mouth

Every 60 seconds, a working adult Every 60 seconds, a working adult touches as many as 30 objectstouches as many as 30 objects

Occurrence of fecal bacteria Occurrence of fecal bacteria on the hand (United States)on the hand (United States)

Preparing a mealPreparing a meal GreatestGreatest

Children after playingChildren after playing

Doing the laundryDoing the laundry LeastLeast

Person exiting a toiletPerson exiting a toilet

Detection of Pathogens on Detection of Pathogens on FomitesFomites

Hard surfacesHard surfaces Phones, tap handles, desk tops, door knobs, Phones, tap handles, desk tops, door knobs,

cutting boards, table topscutting boards, table tops E. coliE. coli, influenza, parainfluenza, norovirus, influenza, parainfluenza, norovirus

ClothingClothing Laundry, towels, bed sheetsLaundry, towels, bed sheets Salmonella, hepatitis A virus, norovirus, Salmonella, hepatitis A virus, norovirus, E. coliE. coli

Detection of Pathogens on Detection of Pathogens on FomitesFomites

Bathroom Bathroom Sinks, taps, bottom of the toilet seatSinks, taps, bottom of the toilet seat Norovirus, Giardia, Cryptosporidium, ShigellaNorovirus, Giardia, Cryptosporidium, Shigella

KitchenKitchen Sponge, sink, cutting boardSponge, sink, cutting board SalmonellaSalmonella,, Campylobacter, Campylobacter, E. coli E. coli

SchoolsSchools Norovirus, rhinovirus, Salmonella,Norovirus, rhinovirus, Salmonella, influenzainfluenza

Sites by Coliform Bacterial Densities in the Sites by Coliform Bacterial Densities in the HomeHome

-2

-1

0

1

2

3

4

5

6

7

Geo

met

ric

mea

n p

er c

m2 o

r p

er m

L

Bath Sink

Kitchen Floor

Bath Count

er

Bath Floor

Toilet Seat

KitchenSink

Sponge Cutting Board

46

36 35

29 2826

14 1411 10

0

5

10

15

20

25

30

35

40

45

50

% S

urf

ac

es

Po

sit

ive

Environments Most Environments Most Contaminated With Body Contaminated With Body

FluidsFluids

Fomite Cleaning is not enough to Fomite Cleaning is not enough to Prevent Exposure to PathogensPrevent Exposure to Pathogens

% of norovirus detected on surfaces% of norovirus detected on surfaces during outbreak at a college campus: 18%during outbreak at a college campus: 18% after cleaning with soap and water: 48%after cleaning with soap and water: 48%

% of surfaces on which % of surfaces on which E. coliE. coli detected: detected: in restroom: 8%in restroom: 8% after cleaning with soap and water: 21%after cleaning with soap and water: 21%

ConclusionsConclusions

Hand contact plays a significant role in Hand contact plays a significant role in transmission of common infectionstransmission of common infections

Fomite contamination by pathogens is a Fomite contamination by pathogens is a common event in home and work common event in home and work environmentsenvironments

Washing fomite with soap and water is not Washing fomite with soap and water is not enough to prevent the spread of enough to prevent the spread of pathogens pathogens

Overall SummaryOverall Summary

Targeted hygiene is needed for “home” infection controlTargeted hygiene is needed for “home” infection control The benefit is prophylactic but realThe benefit is prophylactic but real Topical antiseptic wash products do not contribute to Topical antiseptic wash products do not contribute to

decreased antimicrobial susceptibilitydecreased antimicrobial susceptibility Extensive data indicate environmental risks from Extensive data indicate environmental risks from

individual active ingredients are unlikelyindividual active ingredients are unlikely The data clearly support the current proposed labeling The data clearly support the current proposed labeling

indication (i.e., indication (i.e., “ to decrease bacteria on skin”“ to decrease bacteria on skin”) ) The 1994 TFM log reductions after a single wash (i.e., 2 The 1994 TFM log reductions after a single wash (i.e., 2

loglog10 10 ) are appropriate, as long as standardized ASTM ) are appropriate, as long as standardized ASTM

methods are employedmethods are employed