Respiratory Syncytial Virus (RSV) infection typically begins with symptoms that resemble a common cold but can vary widely depending on age and overall health. The earliest signs often include a **runny nose**, **sneezing**, and a **decrease in appetite**. These initial symptoms may appear gradually over several days, usually within 4 to 6 days after exposure to the virus.
As the infection progresses, a person may develop a **cough**, which can be dry or produce mucus. Alongside coughing, **fever** is common, often mild but sometimes higher, especially in infants and young children. **Wheezing**—a high-pitched whistling sound during breathing—can also occur, indicating that the virus is affecting the lower airways. Sneezing and nasal congestion continue to be prominent during this phase.
In infants and very young children, symptoms can be less obvious or more subtle. Instead of typical cold signs, babies may show **irritability**, **increased fussiness**, and **decreased activity or lethargy**. They might have trouble feeding or refuse to eat, which is a critical symptom to watch for. Breathing difficulties are a serious concern in this age group and can manifest as **fast breathing**, **flaring nostrils**, **head bobbing with each breath**, or **grunting sounds** during exhalation. You might also notice **retractions**, where the skin pulls in between the ribs or under the neck during inhalation, showing the child is working hard to breathe.
In more severe cases, especially in infants under 12 months, RSV can lead to **bronchiolitis** or **pneumonia**, infections of the smaller and larger airways in the lungs. Symptoms of bronchiolitis include persistent coughing, wheezing, and difficulty breathing. The child may also show signs of **dehydration**, such as fewer wet diapers, dry mouth, or lethargy. Skin color changes like **paleness**, **grayness**, or a bluish tint around the lips, face, or nail beds are alarming signs that require immediate medical attention.
Adults infected with RSV often experience milder symptoms similar to a cold: **cough**, **nasal congestion**, and **runny nose**. However, in older adults or those with underlying health conditions, RSV can cause more serious lower respiratory tract infections such as **bronchitis** or **pneumonia**. Severe symptoms in adults include a **persistent or severe cough**, **wheezing**, **shortness of breath**, and **rapid breathing**. Fever may also be present but is not always high.
The course of RSV symptoms usually peaks around days 3 to 5 of illness and can last from one to two weeks. Most healthy individuals recover without complications, but infants, older adults, and people with weakened immune systems may experience prolonged symptoms or more severe illness.
Throughout the infection, symptoms can appear in stages:
– **Early stage:** Runny nose, sneezing, mild cough, decreased appetite, mild fever.
– **Progressive stage:** Increased coughing, wheezing, difficulty breathing, irritability (in infants), poor feeding.
– **Severe stage:** Signs of bronchiolitis or pneumonia, fast or labored breathing, chest retractions, grunting, dehydration, skin color changes.
Because RSV symptoms overlap with those of other respiratory viruses like the flu or COVID-19, it can be difficult to identify without testing. However, the hallmark of RSV in young children is the progression from mild cold symptoms to respiratory distress signs such as wheezing and difficulty breathing.
In summary, RSV infection symptoms range from mild cold-like signs to severe respiratory distress, especially in vulnerable populations. Key symptoms to monitor include runny nose, cough, fever, wheezing, feeding difficulties
