A new study, set to appear in the May 15 issue of Cancer, found that people being treated for cancer were more likely to be seriously affected by common respiratory viruses. In fact, the researchers found death rates in cancer patients contracting such common illnesses as flu and respiratory syncytial virus (RSV) were as high as 75 percent.
"Whatever we see in the general population will be magnified a hundredfold in people with disease," says study author Krystal Hicks, a clinical practice specialist in the department of blood and marrow transplantation at the University of Texas M.D. Anderson Cancer Center in Houston.
For cancer, transplant and other immune-compromised patients, Hicks explains, "symptoms that start out innocently can progress very quickly into something life-threatening." She says that for most people, a cold stays in their upper respiratory airways, but in people whose immune systems are compromised simple colds can quickly settle in the lower respiratory tract. "Within 24 to 48 hours, you can have someone with a life-threatening pneumonia," she adds.
Other groups at high risk from these viruses include people with AIDS, people who have had an organ transplant, people in nursing homes and older people with two or more risk factors, such as emphysema or heart disease.
Hicks and her colleagues gathered information on the incidence of three common respiratory infections at three large bone marrow transplant centers in the United States and in Europe. The viruses studied were influenza (flu) and two common childhood viruses, parainfluenza and RSV.
Flu still claims 20,000 lives in the United States every year. RSV causes 4,500 deaths and 90,000 hospitalizations annually, mainly in children, and parainfluenza is responsible for 70,000 hospitalizations every year, according to the study.
The viruses are transmitted through direct contact with body secretions, such as saliva, or by inhaling contaminated droplets in the air.
In most healthy adults, these viruses are rarely serious, but in those with compromised immune systems they can be deadly. This study found that between 30 percent and 50 percent of those undergoing treatment at these centers had one of these respiratory infections, and the mortality rate was between 28 percent and 75 percent.
There are treatments for these infections, but Hicks says they're often ineffective, expensive and difficult to administer. That's why the authors emphasize prevention.
Prevention is also important because of new, emerging viruses, such as SARS and West Nile, Hicks says.
First, she says, get a flu vaccine. Next, she recommends thorough and frequent hand washing. During months when these viruses are particularly active, she says it's best for people with cancer to avoid places with large crowds, such as movie theaters and malls. She adds you should also let family members know that, if they have a cold, they need to stay away until they're better. And at the first sign of illness, let your provider know because these illnesses can quickly progress.
Dr. Jay Brooks, chair of hematology and oncology at the Ochsner Clinic Foundation in New Orleans, says people definitely underestimate the risk of infection when they're undergoing cancer treatment.
"The flu vaccine is very important and is grossly underused," Brooks adds. The study says that only 20 percent of those at high risk get vaccinated for influenza every year. Brooks also says that if possible, immune-compromised patients should get the pneumoccocal vaccine as well.