Norovirus can live on surfaces for several days, experts say

From HealthDay

The highly contagious norovirus, often called the stomach flu, can be passed from one person to another through contact with commonly shared items such as computer keyboards and computer mice, U.S. health officials report.

The virus, which is common in winter and is the most frequent cause of outbreaks of vomiting and diarrhea in the United States, is often contracted in schools, at work and on cruise ships.

On Thursday, the U.S. Centers for Disease Control and Prevention reported on a norovirus outbreak at a Washington, D.C., elementary school last February in which some of the victims picked up the virus from contaminated computer equipment.

“There is evidence that shared objects and surfaces help transmit disease,” said Dr. Shua Chai, a CDC epidemiologist and co-author of the report, published in the Jan. 4 issue of the CDC’s Morbidity and Mortality Weekly Report.

“This is the first time that we have demonstrated that keyboards and computer mice can be a source of transmission of norovirus,” he added.

Of the 314 students and 66 staffers at the D.C. school, 103 came down with the illness — 79 students and 24 staff members. To find the sources of contamination, samples were taken from various surfaces around the school. In one first-grade classroom, a computer mouse and keyboard tested positive for norovirus, according to the report.

The virus can live on surfaces for several days, Chai said. To prevent infection with the virus, people should wash their hands after using shared objects, and computer keyboards and mice should be disinfected regularly with diluted bleach, he said.

“In addition, people who are ill should stay home for one to three days after they have had their last symptom, because they continue to shed the virus and can still contaminate objects,” Chai added.

One infectious disease expert said norovirus is a common infection, second only to the common cold.

“These outbreaks are extremely common, and they occur in a variety of settings,” said Dr. Pascal James Imperato, distinguished service professor, chairman of the department of preventive medicine and community health, and director of the master of public health program at the State University of New York Downstate Medical Center, in New York City.

Most outbreaks are food-borne, Imperato said. “A smaller percentage are due to person-to-person contact, and an even smaller proportion are water-borne,” he said. “Outbreaks in schools account for about 12 percent of all the outbreaks.”

Contamination of surfaces such as computer keyboards is fairly common, Imperato added.

Norovirus causes severe vomiting and diarrhea that can last for several days. The virus is usually not serious, and most people get better without treatment. However, it can be life-threatening to infants, older people and those with weakened immune systems.

In New York City, an outbreak of norovirus has been ongoing since November. Some 500 infected people have been showing up each day at emergency rooms around the city, health department officials said.

“The best way to stop the spread of norovirus is to wash your hands regularly with soap and stay home from work or school if you are sick,” Dr. Sharon Balter, director of enteric disease for the New York City Health Department’s Bureau of Communicable Disease, said in a prepared statement. “Norovirus is common at this time of year and is not serious for most people, but it is important to take these steps to keep others from getting sick.”

Imperato agreed. “Hand-washing remains the foundation of preventing the spread of norovirus,” he said.

From Sciencedaily.com

We’ve all heard people say ‘I won’t kiss you, I’ve got a cold’. But a report just published warns that we may be far more at risk of passing on an infection by shaking someone’s hand than in sharing a kiss.

A group of hygiene experts from the United States and the UK have published the first detailed report on hand hygiene in the home and community, rather than in hospital and healthcare settings. Their findings are published in the American Journal of Infection Control. They say that, if we want to avoid catching flu or tummy bugs, or protect ourselves and others from organisms such as MRSA, salmonella or C. difficile, then we have to start in our own homes, by paying greater attention to good hand hygiene.

They also warn that, in the event of a flu pandemic, good hand hygiene will be the first line of defence during the early critical period before mass vaccination becomes available. This new report follows on from a study published last month in the British Medical Journal which indicated that physical barriers, such as regular handwashing and wearing masks, gloves and gowns may be more effective than drugs in preventing the spread of respiratory viruses such as influenza and SARS.

Good hygiene at home prevents organisms spreading from one family member to another. By reducing the number of carriers in the community, the likelihood of infections being carried into health care facilities by new patients and visitors is reduced. Good hygiene at home also means fewer infections, which means fewer patients demanding antibiotics from the GP, and fewer resistant strains developing and circulating in the community.

Cold and flu viruses can be spread via the hands so that family members become infected when they rub their nose or eyes. The report details how germs that cause stomach infections such as salmonella, campylobacter and norovirus can also circulate directly from person to person via our hands. If we put our fingers in our mouths, which we do quite frequently without being aware of it, or forget to wash our hands before preparing food, then stomach germs can also be passed on via this route. Some of us also carry MRSA or C.difficile without even knowing, which can be passed around via hand and other surfaces to family members or, if they are vulnerable to infection, go on to become ill.

Professor Sally Bloomfield, one of the report’s authors, is the Chairman of the International Scientific Forum for Home Hygiene, the international organisation which produced report. She is also a member of the London School of Hygiene & Tropical Medicine’s Hygiene Centre. She comments: ‘With the colds and flu season approaching, it’s important to know that good hand hygiene can really reduce the risks. What is important is not just knowing that we need to wash our hands but knowing when to wash them. Preventing the spread of colds and flu means good respiratory hygiene, which is quite different from good food hygiene. That’s why the new respiratory hygiene campaign from the Department of Health in the UK, which advises people to “catch it, bin it, kill it”, is spot on’.

The authors say that breaking the chain of infection from one person to another all depends on how well we wash our hands. If we don’t do it properly, washing with soap and rinsing under running water, then we might as well not do it at all. They recommend also using an alcohol handrub in situations where there is high risk, such as after handling raw meat or poultry, or when there is an outbreak of colds or stomach bugs in the family home or workplace, or if someone in the family is more vulnerable to infection. They suggest carrying an alcohol rub or sanitiser at all times so that good hand hygiene can still be observed away from home in situations where there is no soap and water available.

Carol O’Boyle, of the School of Nursing, University of Minnesota, and a co-author of the report, says: ‘Hand hygiene is just as important when we are outside the home - on public transport, in the office, in the supermarket, or in a restaurant. Quite often it’s not possible to wash our hands in these situations, but carrying an alcohol-based hand sanitizer means we can make our hands hygienic whenever the need arises’.

The report warns that good hygiene is about more than just washing our hands. Although the hands are the main superhighway for the spread of germs — because they are the ‘last line of defence’, surfaces from which the hands become contaminated, such as food contact surfaces, door handles, tap handles, toilet seats and cleaning cloths also need regular hygienic cleaning. Clothing and linens, baths, basin and toilet surfaces can also play a part in spreading germs between family members in the home.

Professor Elaine Larson, of the Mailman School of Public Health in New York and another co-author, says: ‘Because so much attention has been paid to getting people to wash their hands, there is a danger that people can come to believe this is all they need to do to avoid getting sick’.

Professor Bloomfield concurs. ‘We hear a lot of discussion about whether being “too clean” is harming our immune systems, but we believe that this targeted approach to home hygiene, which focuses on the key routes for the spread of harmful organisms, is the best way to protect the family from becoming ill whilst leaving the other microbes which make up our environment unharmed’.

Dr. Val Curtis, Head of the London School of Hygiene & Tropical Medicine’s Hygiene Centre concludes: ‘Handwashing with soap is probably the single most important thing you can do to protect yourselves and your loved ones from infection this Christmas’.

Antibacterial soaps show no health benefits over plain soaps and, in fact, may render some common antibiotics less effective, says a University of Michigan public health professorFrom PhysOrg.com