Respiratory Syncytial Virus (RSV) is a common respiratory pathogen that infects the lungs and breathing passages. While often associated with infants, it is highly contagious in adults as well. For most healthy adults, an RSV infection presents with symptoms indistinguishable from a typical common cold. Understanding the contagious nature of RSV is important for safeguarding populations most susceptible to severe illness.
Transmission and Duration of Contagion
RSV spreads primarily through respiratory droplets released when an infected person coughs or sneezes, similar to the common cold or influenza. These droplets can travel a short distance and enter another person’s body through the eyes, nose, or mouth. Transmission also occurs through direct contact, such as kissing, or indirectly by touching a contaminated surface and then touching one’s face.
The virus is durable, surviving for several hours on hard surfaces like countertops and doorknobs, which contributes to its efficient spread during peak seasons. The incubation period—the time before symptoms appear—is typically four to six days. An infected person can become contagious and begin shedding the virus a day or two before symptoms develop, making pre-symptomatic spread a common occurrence.
For healthy adults, the contagious period usually lasts between three and eight days from the onset of symptoms. However, the duration of viral shedding can be significantly longer in certain populations. Individuals with compromised immune systems may continue to spread the virus for up to four weeks, even after their symptoms have noticeably improved. This extended period of contagiousness requires additional vigilance from immunocompromised adults to prevent further transmission.
Recognizing Adult Symptoms
In most healthy adults, an RSV infection causes mild symptoms that closely mimic a routine common cold, often leading people to underestimate the illness. Typical signs include a runny nose, sneezing, a sore throat, and a persistent cough. A low-grade fever and general fatigue may also be present, but the infection generally resolves itself within one to two weeks.
The virus can lead to more intense symptoms, especially in at-risk individuals. Symptoms that demand immediate medical attention include wheezing (a whistling sound when breathing) and a severe, worsening cough. Difficulty breathing or shortness of breath can indicate that the infection has progressed to the lower respiratory tract.
Other signs of severe infection include cyanosis (a bluish tint to the lips or skin), which reflects a lack of sufficient oxygen. Extreme exhaustion, chest tightness, or disorientation are also serious indicators that the infection is causing significant respiratory distress. Because RSV symptoms overlap with other seasonal viruses, medical testing is usually necessary to confirm a diagnosis.
High-Risk Contacts and Severe Outcomes
The primary public health concern regarding RSV in adults is the risk of transmission to those who are most vulnerable to severe disease. Adults aged 65 or older are at significantly increased risk because the immune system naturally weakens with age. RSV contributes to an estimated 110,000 to 180,000 hospitalizations each year among adults aged 50 and older in the United States.
Individuals with underlying chronic health conditions face a heightened risk of severe outcomes. This includes people with chronic obstructive pulmonary disease (COPD), asthma, or congestive heart failure, where RSV can trigger an acute exacerbation of their existing illness. The virus can also be dangerous for those with weakened immune systems, as their bodies struggle to clear the infection.
When the virus spreads to these high-risk groups, it can cause severe lower respiratory tract diseases such as pneumonia or bronchiolitis. Beyond older adults, the contagion from an infected adult poses a serious threat to infants, especially those under six months of age or those born prematurely. In these young children, RSV is the most common cause of bronchiolitis and can lead to hospitalization.
Limiting the Spread
Adults can take several steps to reduce the risk of contracting and transmitting RSV, especially during the respiratory virus season from fall through early spring. Practicing excellent hand hygiene remains one of the most effective preventive measures against the virus. Hands should be washed frequently with soap and water for at least 20 seconds, and alcohol-based hand sanitizer can be used when soap is not available.
Since the virus can survive on surfaces for hours, regularly cleaning and disinfecting frequently touched items is important for limiting indirect spread. This includes items such as doorknobs, light switches, and shared electronic devices. Adults should also avoid touching their face, nose, or mouth with unwashed hands, as this is a common route for infection.
If an adult develops cold-like symptoms, they should stay home and avoid contact with others. When it is necessary to be around others, especially vulnerable individuals like infants or older adults, wearing a well-fitting mask can help contain respiratory droplets. Covering coughs and sneezes with a tissue or the elbow significantly reduces the number of viruses released into the environment.