Respiratory Syncytial Virus, commonly known as RSV, is a common respiratory virus infecting the lungs and respiratory tract. Most individuals encounter RSV by age two, with symptoms often resembling a common cold: runny nose, cough, and low-grade fever. While generally mild, this virus can lead to more significant health concerns for certain populations. Recognizing the typical course of RSV helps identify when medical attention is needed.
Overall Survival and Hospitalization Statistics
For most healthy individuals, RSV infection is not life-threatening, and recovery is common. Symptoms typically resolve within a week or two. While most cases are mild, RSV frequently causes hospitalization, particularly for young children and older adults. In the United States, RSV leads to about 58,000 hospitalizations annually in children aged five and younger, and up to 160,000 in adults aged 65 and older.
Vulnerability in High-Risk Populations
While RSV often presents as a common cold, certain populations face a higher risk of severe outcomes, including hospitalization and, in rare instances, mortality. Infants, particularly those under six months, are highly susceptible. RSV is a leading cause of lower respiratory tract disease hospitalizations in infants under 12 months. Globally, approximately half of all RSV-related deaths in children occur in infants under six months of age. Premature babies are also at elevated risk for severe RSV disease due to their underdeveloped respiratory and immune systems.
Children with certain underlying health conditions also face increased vulnerability. Those with congenital heart disease, chronic lung conditions such as bronchopulmonary dysplasia, or weakened immune systems are more prone to serious complications. Children with suppressed immunity, for instance, have a significantly higher mortality rate, around 60 percent, compared to healthy children. Older adults, especially those aged 65 and older, are also at high risk. Those 75 years or older are particularly likely to experience severe RSV disease.
Older adults with pre-existing conditions like asthma, chronic obstructive pulmonary disease (COPD), or congestive heart failure face a heightened risk of severe outcomes, hospitalization, and death. Globally, RSV causes approximately 100,000 deaths annually in children under five, with 97% occurring in low- and middle-income countries. In the United States, RSV causes an estimated 6,000 to 10,000 deaths annually among adults over 65.
Factors That Increase Complication Risk
Vulnerability to RSV complications stems from specific biological and physiological factors. Infants, especially premature babies, have smaller, less developed airways, making them prone to significant obstruction from mucus and inflammation, a condition known as bronchiolitis. Their immature immune systems are less equipped to defend against the virus, leading to prolonged viral shedding and increased disease severity.
Older adults have pre-existing health conditions that compromise their respiratory and cardiovascular systems, such as COPD, asthma, or congestive heart failure. Severe RSV can exacerbate these underlying conditions, leading to respiratory distress, pneumonia, or acute respiratory failure. The immune system naturally weakens with age, reducing the body’s ability to fight off the virus and clear the infection. This diminished immune response, combined with existing health issues, makes older adults more susceptible to severe, life-threatening outcomes.
Recognizing a Severe Infection
Recognizing signs of severe RSV infection is important for prompt medical care. In infants, symptoms include short, shallow, rapid breathing, or visible struggling to breathe (chest muscles and skin pulling inward). A bluish tint to the skin, lips, or fingernails (cyanosis) signals a lack of oxygen and requires immediate attention. Very young babies may also exhibit unusual tiredness, extreme irritability, or disinterest in feeding.
For older children and adults, severe RSV can manifest as a worsening cough, wheezing, or difficulty breathing. Signs of dehydration, such as fewer wet diapers in infants or lack of tears when crying, also indicate a need for medical evaluation. If any of these symptoms appear, contact a healthcare provider or seek emergency care immediately.