‘Tis the season for respiratory virus

HOUSTON – Christmas is in the air, but not everything in it is festive. This is the time of year when respiratory syncytial virus, or RSV, can bring fun to a halt for many people.

“RSV is the most important respiratory virus of infants and young children,” Dr. Pedro A. Piedra, professor of molecular virology and microbiology and of pediatrics at Baylor College of Medicine, said. “Nearly all infants and young children will have been infected at least once by the time they reach 2 years of age, and individuals will be reinfected throughout life.”

The virus, which occurs in the fall and winter months, is the No. 1 cause of hospitalization for infants under 1 year of age and is associated with between 60,000 and 200,000 deaths annually worldwide in children under 5 years of age, Piedra said. It also can affect older adults and is probably second to influenza in causing respiratory mortality.

Respiratory distress associated with RSV is the main reason parents bring their infants to hospital emergency centers. Common symptoms include rapid breathing, coughing, not eating well, and throwing up when coughing, especially when trying to eat.

Infants who tire out from the symptoms may have to be admitted to the ICU and possibly intubated. Infants with underlying health conditions — such as those born prematurely or those who have chronic lung disease, congenital heart disease, neuromuscular disease or immunodeficiency — are at greater risk for severe disease and more likely to be admitted to the ICU.

Children who had a severe RSV infection when they were under 3 years old have a strong likelihood of recurrent wheezing during the first decade of life and potential for chronic obstructive pulmonary disease later in life, especially when the adult with that medical history is a smoker.

In adults, the virus is almost indistinguishable from the flu, Piedra said. Symptoms include significant respiratory distress and wheezing. Often the virus does not cause a fever, though that can be a symptom.

“The problem is that RSV is difficult to diagnose in adults because there is no distinguishing clinical feature other than respiratory symptoms,” Piedra said. “In infants, bronchiolitis is the major cause of hospitalization, and RSV is the main virus causing bronchiolitis.”

Adults and children can be tested for RSV, but there is no specific antiviral treatment for it. Physicians treat the symptoms in children and adults.

Piedra, who also is with Texas Children’s Hospital, said it’s important to help prevent spread of the virus. Those who have respiratory symptoms such as runny nose, coughing or sneezing should stay home, even if there’s no fever. Parents should pull their children from day care if they have respiratory illness so that they don’t spread the virus.

Ways to help prevent spreading the virus are good respiratory hygiene etiquette practices that include covering the mouth when coughing or sneezing, and washing hands with soap and water or using hand sanitizer. With children, cleaning toys and countertops with soap and water help control infections.

“RSV during the wintertime is all around us and is rampant right now,” Piedra said. “A lot of times, people confuse RSV and the flu. There are several respiratory viruses that are co-circulating right now, and many of these viruses mimic each other. Don’t assume that it’s a breakthrough infection of the flu if you have been vaccinated.”

There is a preventive therapy — monoclonal antibody — administered once a month during the RSV season for a select group of high-risk infants, and active vaccines and antivirals are in development, Baylor officials said. Currently, the only Phase III clinical trial is in maternal immunization, which is studying the effectiveness of a vaccine given to a pregnant woman to see if it is protective in newborns during their first few months of life.

Baylor is one of the sites for this worldwide trial. There are other vaccine candidates, monoclonal antibody and antiviral drugs in earlier stages of clinical development.