New Study Shows Flu Virus Makes Itself at Home

TUCSON, Ariz. -- It only takes one child coming home with the flu for the virus to spread to phones, doorknobs and nearly 60 percent of surfaces in a household, according to a new study published by the Journal of Infection.


The study, conducted by researchers at The University of Arizona, studied

the presence of Influenza A virus, the virus most commonly associated with the

flu, in day care centers and in the homes of families with children enrolled

in the programs.  In the centers, researchers found Influenza A on 53 percent

of surfaces tested during the spring.  In homes, during March 2003, where one

child had the flu, the number was higher -- 59 percent of all surfaces tested

positive for the virus.


 "It may come as a surprise to many parents that we detected high levels of

influenza virus in March," says Stephanie Boone, study co-author and doctoral

candidate in soil, water and environmental science at the University of

Arizona.  "However, our study was conducted during a late flu season, similar

to this year's flu season.  With flu activity now increasing later than usual,

we need to be extra careful this time of year and do what we can to prevent

the spread of the flu virus even during the early spring months."


The researchers tested the most commonly touched household surfaces,

including phones, refrigerator handles, kitchen faucets and light switches.

Phone receivers were the biggest problem area -- 80 percent tested positive

for the virus.  In day care centers, kitchen dishcloths were most likely to

test positive for the virus -- 58 percent -- followed by diaper changing areas

-- 57 percent.  In both homes and centers, bathroom surfaces were among the

least contaminated surfaces, a result that did not surprise Boone.


"Most people clean their bathrooms regularly, reducing the likelihood of

germs in those areas," Boone said.  "But people rarely think to clean their

phone receivers and they are at the top of the list."


The lower presence of the virus overall in centers also could be related

to cleaning practices.  "With so many children in one place, day care centers

typically are careful to follow regular cleaning and disinfecting routines to

reduce the potential transmission of viruses and bacteria," Boone said.  "In

fact, we found infant and toddler toys -- where the highest level of germs

could be expected -- actually showed the lowest presence of Influenza A among

all surfaces tested.  Day care centers typically disinfect toys at least once

a day."


Previous studies report that the introduction of the flu virus into a

household by one family member can cause disease in about two-thirds of other

family members.  The flu is responsible for approximately 38 million missed

school days and 70 million lost workdays each year.  According to the Centers

for Disease Control and Prevention (CDC), the flu season is late hitting this

year, with high flu activity only now being reported in many areas of the



"These studies show how easy it is to spread the flu virus from place to

place," says Boone.  "Regularly disinfecting commonly used surfaces and

washing hands will help cut down on the amount of viral transmission."


 As part of a two-year study on the health of children in day care, the

study -- funded by The Clorox Company -- examined the occurrence of the

Influenza A virus on commonly touched surfaces in eight homes and 14 day care

centers in Tucson, Ariz.  Children resided in all of the homes sampled; five

of the eight homes had at least one ill child experiencing flu-like symptoms

for at least three days or more in March 2003 when the homes were tested (the

day care centers referred the homes with ill children).  The other three homes

were tested during the summer months when no ill children or adults were

present.  All of the homes and day care centers were sampled using a sterile

polyester fiber-tipped applicator swab and the virus was detected using

nucleic-acid based scientific methods.


During March 2003, researchers detected the flu virus on 59 percent of the

surfaces in the homes with ill children; however, the virus was not detected

on any surfaces during the summer months.  In the day care centers, 53 percent

of the surfaces tested positive for the flu virus during the spring months

(March through May), but only 23 percent of the surfaces tested positive for the

virus during the fall (September through November).  Below is a detailed look at the

key study findings.


The flu virus contaminated various percentages of the following sample

surfaces in homes and day care centers:


     Home Surfaces

     * Phone receivers (80%)

     * Doorknobs (60%)

     * TV remotes (60%)

     * Microwaves (60%)

     * Light switches (60%)

     * Refrigerator handles (60%)


     Day Care Surfaces

     * Kitchen dishcloths (58%)

     * Diaper changing areas (57%)

     * Bath drains (46%)

     * Kitchen drains (45%)

     * Toilet seat tops (42%)

     * Toilet floors (41%)


According to the CDC, each year in the United States the flu causes

illness in approximately 5 percent to 20 percent of the population, an estimated

200,000 hospitalizations and 36,000 deaths.  Because the flu virus is

airborne, it is easily transmitted via coughing, sneezing and talking, placing

nearly everyone at risk for exposure.  Areas where people gather, such as

homes, day care centers and offices, are likely locations for catching the



Generally, cleaning with disinfecting products can help reduce the

possibility of viral transfer, transmission and possible infection.  Simple

steps, such as disinfecting commonly touched surfaces at home, in day care

centers and in the workplace can help reduce exposure to germs that could make

you sick. 


Source: University of Arizona, Tucson