More biology articles in the 'Health & Medicine' category

The flu hasn't even hit hard yet this year, but it seems like everyone's getting sick. What's the deal?

Simply put, there are a lot more infectious invaders besides the flu to worry about. They don't get the big headlines, but they still knock people down for days or weeks and cause thousands of deaths each winter.

Metapneumovirus. Rhinoviruses. Coronaviruses. Parainfluenza. Respiratory syncytial virus (RSV). Pronouncing the names of the microbes can be almost as difficult as bearing the illnesses themselves. They're on doorknobs, faucets, and appliance handles all around you, and maybe in your nose and lungs too. Some of the viruses are also wafting through the air you breathe, looking to land in your eyes or nose and set up house inside your body. And those are just the respiratory germs – never mind Strep in the throat and ears, or Norwalk viral agents that attack the GI system, and so on.

While the world's attention has migrated to bird flu, not a single person in the western hemisphere has contracted the deadly form of the disease. And though "regular" flu is still a potent threat, expected to kill more than 35,000 people in the United States annually, your sick neighbor or colleague who probably doesn't have the flu is a sniffling, sneezing, wheezing, whining reminder that there are other germ threats.

Infectious disease experts at the University of Rochester Medical Center have tracked the dangers from one of the most common bugs, RSV, and they say the threat to some groups of people, such as the elderly, equals that from flu. Even though flu gets all the press, RSV is a stealth bug worthy of attention too.

Ann Falsey, M.D., and Edward Walsh, M.D., faculty members in the University's Infectious Disease Unit of the Department of Medicine, have found that RSV affects elderly and high-risk adults as much as the flu. In a paper published last year in the New England Journal of Medicine, they estimated that 14,000 elderly and high-risk adults die annually from an RSV infection, and that the bug is responsible for more than 177,500 hospitalizations of adults each year. In addition, pediatricians have long known that the bug is a danger to small children, affecting hundreds of thousands of children annually as the biggest cause of bronchiolitis and pneumonia among infants and children under 1 year of age.

For more than a decade Falsey and Walsh, who are infectious disease experts at Rochester General Hospital, have been on the hunt for a vaccine against RSV. While they've identified several proteins on the surface of RSV, an important step toward creating a vaccine, none of the vaccines they've tested has panned out.

So while people tense up about the availability of flu vaccine or wait in long lines for a flu shot, that opportunity for prevention doesn't even present itself for RSV. Falsey and Walsh have shown that over a four-year span in Rochester, about the same number of people visited the doctor and were hospitalized for RSV and flu, and that RSV infection caused more than 10 percent of hospitalizations for pneumonia during the winter.

"At least with the flu, we have something to control it – a vaccine," Falsey said. "We don't even have that for RSV. The lack of awareness is a big problem. It costs a great deal of money to develop a vaccine, but there's not much of a demand for a vaccine against an illness that a lot of people haven't even heard of.

"A lot of cases that people think are from flu aren't really the flu at all, but other respiratory viruses like RSV. RSV is responsible for a lot of the illness blamed on flu," said Falsey, whose work is funded by the National Institute of Allergy and Infectious Diseases.

It's tough to tell RSV apart from the flu. Both are primarily respiratory illnesses whose effects can range from simply giving the person a few sniffles to causing life-threatening pneumonia. Someone with the flu is more likely to have a fever and body aches, and someone with RSV is more likely to have a runny nose, a cough that produces mucus, and wheezing.

Flu is more likely to spread as an aerosol – someone coughs and the airborne virus lands on another person, or they cough and then touch the faucet or doorknob. RSV, like the common cold, spreads mainly as large droplets via surfaces – doorknobs, faucets, dishtowels, and hand-to-hand contact, for instance.

"Unlike the flu, RSV is more often spread directly by secretions," said William Hall, M.D., a geriatrician and pulmonary specialist at the University of Rochester Medical Center who has studied how respiratory viruses are spread in communities like nursing homes. "RSV lives on objects including faucets, door handles, and change from the coffee shop, for quite awhile, for at least a day. If you put your finger in your mouth, or touch your eye, or pick your nose, you're a spreader, to put it bluntly. People share cell phones, they shake hands to be social. These are effective ways to transmit disease."

While RSV may sound new, the best way to prevent it – washing your hands – is not.

"We've known for more than 100 years that hand washing prevents infection, but we still can't get people to wash their hands," said Falsey. "Hand washing is the simplest, most effective way to keep from getting sick and making others sick. But it's hard to get people to wash their hands."

In the early 1990s Falsey led an experiment involving hand washing among staff members at an adult day care center. She found that respiratory infections were less frequent among residents cared for by workers equipped with packs containing germ-killing hand gels who used the gels regularly. The team also found that RSV was spread to residents mainly through health care workers who had young children at home.

While investigators like Falsey and Walsh search for a vaccine against RSV, and a better way to check people who may have the illness, for ordinary people the effects and treatment are largely the same, whether a person gets the flu, RSV, the common cold, or another respiratory ailment. Feel crummy. Rest, drink lots of fluids, and if you suspect the flu, call a doctor immediately, because flu can be treated effectively with new medications as long as it's caught within the first 48 hours.

Source : University of Rochester Medical Center

January 14, 2006 10:02 PMHealth & Medicine




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