Dr. Francisco R. Velázquez: RSV makes a comeback in 2022

Respiratory syncytial virus, or RSV, is a well-known virus. Traditionally, it has a predictable seasonality of late fall and winter, usually November to April, with the highest number of cases in January or February. This predictable pattern has been altered since 2020, with many cases seen this past summer. Then, as the seasons changed to fall, there was a significant increase in clinical cases and pediatric hospitalizations across the country, including locally.

What is RSV? It is a single-stranded RNA virus identified initially in chimpanzees in 1956 and named chimpanzee coryza agent, given the cold-like symptoms associated with it. A year later, the virus was isolated from humans and renamed RSV. Humans and chimpanzees are the only known natural hosts for the virus.

RSV typically infects the nose, throat, lungs and breathing passages of the upper and lower respiratory system. Initial infection in young infants and children frequently involve the lower respiratory tract, including the bronchioles. Nearly all children get an RSV infection by the age of 2. In most cases, it causes mild, cold-like symptoms such as a runny nose, coughing, sneezing, loss of appetite, irritability and sometimes a low-grade fever. Other symptoms such as a wet-sounding cough, wheezing, difficulty breathing and difficulty eating can be associated with more severe disease. Symptoms last for four to six days and may take one or two weeks to fully resolve. People infected may be contagious for three to eight days, even if asymptomatic. Transmission usually occurs through contact with respiratory droplets expelled when sneezing or coughing.

Infants younger than 6 months, especially those less than 2 months of age and adults over 65, are at the greatest risk for more severe disease. Thousands of children and seniors are hospitalized every year, and mortality is in the hundreds for children and in the thousands for those over 65.

Since the beginning of October, we have seen a significant increase in cases requiring hospitalization – close to 1 out of every 500 babies in the United States according to some estimates.

Bronchi, the main airways in your lungs, branch into increasingly smaller branches; the smallest being the respiratory bronchioles. The bronchioles are small structures that carry air to the small air sacs known as alveoli. The alveoli perform your body’s gas exchange. When the bronchioles get inflamed and congested it can evolve into the clinical condition known as bronchiolitis. RSV is the most common cause of lower respiratory tract illness and bronchiolitis in infants and children; it’s estimated to cause between 50%-90% of bronchiolitis-associated hospitalizations. A secondary superimposed infection can occur in this environment, leading to pneumonia, with RSV causing up to 50% of pneumonia admissions in infants.

Why are we seeing so many cases? This is a critical question not only for RSV but for respiratory viruses in general. For the past three years, we have all been following various levels of precautions because of the COVID-19 pandemic. For some time now, our exposure to respiratory viruses, such as RSV, the flu and the common cold, has been less than usual. For those born during the pandemic, exposure may not have occurred at all. As we move away from these precautions and increase our activities, the potential for exposure increases accordingly. With either waning or absent immunity, due to either a decrease in the usual exposure patterns or an actual absence of exposure, viruses may move through the community with minimal resistance. The result is the high levels of clinical disease we are experiencing.

As we head into the holiday season, we will see an increase in gatherings, travel, and many other activities that bring us indoors and closer together. We have all been looking forward to a more “normal,” pre-pandemic holiday season. The good news is that there are some simple, basic precautions we can all take to decrease the potential for catching a respiratory virus like RSV:

Wash your hands with soap and water frequently.

Avoid touching your eyes, nose and mouth.

Cover your mouth if sneezing; use a tissue or the inside of your elbow to prevent the spread of droplets.

Disinfect frequently touched surfaces with the appropriate disinfectant or sanitizing solution.

Wear a mask in crowded, public settings, especially on public transportation when traveling for the holidays.

If your child or you have any symptoms, stay home and test for COVID-19; it may not be RSV.

If you or a member of your family do get sick, contact your primary care provider or your children’s pediatrician for appropriate guidance. If you think your child may need medical attention, contact your provider before going to the emergency room. Your provider will be able to guide you to the most appropriate level of care. If unable to contact your provider, a telehealth visit or an urgent care center might be an option. If advised to go to an emergency room, please do not procrastinate.

Although there is no vaccine for RSV, providers can very effectively treat RSV. Masks are still required in health care facilities and may be a good option in all public settings for those whose risk is higher. If we are all careful and mindful of those around us, we will be able to enjoy this holiday season.

Francisco R. Velázquez, M.D., S.M., FCAP, is health officer for the Spokane Regional Health District.