WEDNESDAY, April 27, 2005 (HealthDay News) -- A common childhood respiratory infection, long overlooked in the elderly, is emerging as a significant health problem in that group as well.
Awareness of the broader scope of respiratory syncytial virus (RSV) may spur development of a vaccine, argue the authors of a study in the April 28 issue of the New England Journal of Medicine.
"It's a bad problem. I don't think it's quite as bad as the flu, but it's a close second," said study author Dr. Ann Falsey, an attending physician at Rochester General Hospital in Rochester, N.Y., where the study was conducted.
RSV was first recognized in 1957. "It is perhaps one of the most common causes of more serious respiratory type infections in infants and children," said Dr. Timothy Murphy, co-author of an accompanying editorial and a professor of medicine at the University at Buffalo, State University of New York. "No one would question its importance there."
Experts have been slow to understand its prevalence in adults, however.
"Shortly after its discovery in the 1950s, it was understood that RSV could infect young adults and produce colds," Falsey explained. "It wasn't until the 1970s and '80s, where reports started to surface of severe outbreaks of respiratory disease in nursing homes, that it was understood that it could produce a fairly severe syndrome in these fragile adults who could get pneumonia and be hospitalized."
Since then, there have been studies among hospitalized adults, but the scope of the problem among older people is not well-defined. One estimate attributes 10,000 deaths each year among adults in the United States aged 65 and over to RSV.
"We were trying to see if the problem was of sufficient magnitude for developing a vaccine," Falsey said of the latest study.
To assess the overall scope of the problem, the researchers evaluated all respiratory illnesses in 608 healthy elderly people, 540 high-risk adults and 1,388 people who were hospitalized during four consecutive winters.
RSV infection developed annually in 3 percent to 7 percent of the healthy people and 4 percent to 10 percent of the high-risk individuals.
RSV generated fewer visits to doctors among healthy people than did the flu. Among high-risk adults, however, both RSV and influenza resulted in similar levels of health-care services. Among the hospitalized group, RSV infection and influenza A resulted in similar lengths of stay, rates of intensive care (15 percent for RSV and 12 percent for the flu) and mortality (8 percent and 7 percent, respectively). Hospitalizations from the flu may have been cut by as much as half because of widespread vaccination, the researchers said.
RSV infection was responsible for 10.6 percent of hospitalizations for pneumonia, 11.4 percent for chronic obstructive pulmonary diseases, 5.4 percent for congestive heart failure, and 7.2 percent for asthma, the study found.
The authors estimated that RSV infection would account for about 177,525 hospital admissions each year and 14,000 deaths, a number that is similar to previous estimates.
Because this is a prospective study, Murphy said, "it really allows us to make a more accurate statement about the frequency and importance of RSV in the adult population."
"We hope there's enough information for companies to move forward with vaccine trials with older people," Falsey added.
Interestingly, a vaccine against RSV in children was developed in the 1960s. "Tragically, it made the disease worse to the point where there were a couple of fatalities," Murphy said. Although it's not clear why the vaccine had that effect, it does seem clear that it caused the children to have an "overexuberant immune response," he noted.
Needless to say, the experience put a damper on vaccine development efforts.
The children's vaccine used a killed whole virus, Murphy explained, adding it was unlikely that approach would be duplicated. Companies now are looking into possibilities with attenuated live virus and vaccines that use purified protein molecules from the surface of the virus, he said.
More information
The U.S. Centers for Disease Control and Prevention offer information on RSV.
