Respiratory Syncytial Virus (RSV)

Respiratory syncytial virus (RSV) is a common respiratory virus that can be dangerous for some infants and young children. It is highly contagious and most common during the winter months in the US. Emergency department visits and hospitalizations due to RSV are at record highs this season. Let's talk more about it.

What is RSV?

RSV is an RNA virus that affects the respiratory system. It was first discovered in 1956. It has since been recognized as one of the most common causes of childhood illness. It typically causes yearly outbreaks of respiratory illnesses in all age groups. It usually causes symptoms like a common cold. But in some cases, it can cause pneumonia and bronchiolitis (infection in the smallest bronchial tubes) that can be dangerous and even life threatening.

How common is RSV?

It is so common that most children have had an RSV infection by age 2. It is the single most common cause of respiratory hospitalization in infants and has been for many years. Natural immunity after an RSV infection is relatively short-lived, so reinfection rate is high. However, having the infection more than once increases your immunity and there is some protection against severe disease that remains after an infection. Due to the pandemic, with masking and social distancing, the last 2 cold weather seasons saw very low rates of RSV infections. This has contributed to both a very early start to the RSV season this year, as well as high infection rates and high rates of severe disease.

What are the symptoms of RSV?

Symptoms usually start about 4-6 days after exposure to the virus. A typical case of RSV will cause symptoms such as nasal congestion, runny nose, dry cough, low-grade fever, sneezing, sore throat, and headache. Just like any other cold. In severe cases, the virus spreads into the lower respiratory tract. Signs and symptoms of severe disease may include:

• Fever
• Severe cough
• Wheezing - a high-pitched noise heard when breathing out
• Rapid breathing - often with short and shallow breaths
• Difficulty breathing or struggling to breathe - You may see chest muscles and skin pulling inward with each breath.
• Bluish color of the skin - due to low oxygen levels
• Poor feeding - in infants
• Irritability
• Unusual tiredness or listlessness

Who is at most risk for severe disease?

Here are the children most at risk for severe RSV disease:

• Premature infants
• Infants 6 months old and younger
• Children younger than 2 years with chronic lung disease or congenital heart disease
• Children with suppressed immune systems
• Children with certain medical conditions that cause difficulty swallowing or clearing mucus secretions

What about adults?

Adults who get RSV usually have symptoms of a mild cold that lasts around 5 days. However, some adults are at high risk of severe illness from RSV. This includes:

• Older adults, particularly 65 years and older
• Adults with chronic heart or lung disease
• Adults with weakened immune systems

Next week, we will talk more about RSV, including how the diagnosis is made and how it is treated.

If you have any questions about RSV, please log into your account and send us your question. We are here to help.

Dr. Anita Bennett MD - Health Tip Content Editor