Respiratory Syncytial Virus (RSV)

Overview

Respiratory syncytial virus, commonly known as RSV, is a very common and highly contagious virus that infects the airways and lungs. Almost all children are infected with RSV at least once by the age of two, and people can be reinfected throughout life. For most healthy children and adults, RSV causes a mild illness similar to a common cold that resolves on its own within a week or two.

However, RSV can be much more serious in certain groups. In young infants it is a leading cause of bronchiolitis (inflammation of the small airways) and pneumonia, and in older adults and people with heart or lung disease it can cause severe respiratory illness. RSV infections follow a seasonal pattern, typically peaking in fall and winter. Knowing who is at higher risk, recognizing warning signs, and taking steps to limit spread are the keys to managing RSV safely.

Symptoms

RSV symptoms usually appear a few days after exposure and often resemble a cold. They tend to come on in stages:

• Common symptoms: Runny nose, congestion, cough, sneezing, sore throat, mild fever, and a reduced appetite.
• In infants: Sometimes the only signs are irritability, decreased activity, poor feeding, and breathing difficulties.
• More severe illness: Wheezing, fast or labored breathing, and signs of a lower respiratory infection such as bronchiolitis or pneumonia.

Warning signs of serious illness include fast or difficult breathing, pulling in of the skin around the ribs, bluish lips or skin, pauses in breathing (especially in young infants), poor feeding or signs of dehydration, and unusual drowsiness. These require urgent medical attention.

Causes

RSV infection is caused by the respiratory syncytial virus, which spreads easily from person to person. Transmission occurs through:

• Respiratory droplets: Released when an infected person coughs or sneezes and breathed in by others.
• Direct contact: Such as kissing the face of a child with RSV.
• Contaminated surfaces: The virus can survive for hours on hard surfaces like doorknobs and toys, and people become infected by touching these and then their eyes, nose, or mouth.

RSV is highly contagious, and people are usually contagious for several days, sometimes longer in infants and those with weakened immune systems. Crowded settings such as childcare centers help the virus spread, especially during the fall and winter season.

Risk Factors

• Premature infants and babies under 6 months
• Young children with heart or lung conditions
• Adults aged 60 and older, especially with chronic health problems
• People with chronic heart or lung disease
• People with weakened immune systems
• Crowded living conditions and attending or working in childcare
• Exposure to tobacco smoke

Diagnosis

RSV is often diagnosed based on symptoms and the time of year, especially during RSV season. Testing may be used in certain situations:

• Clinical assessment: Recognizing the typical symptoms and examining the chest and breathing.
• Oxygen monitoring: A sensor on the finger or toe to check oxygen levels.
• Viral testing: A nasal swab to confirm RSV, used particularly in hospitalized patients, infants, or high-risk individuals.
• Chest X-ray: Reserved for more severe cases or when pneumonia is suspected.

Treatment

Most RSV infections are mild and improve with supportive home care. Because RSV is a virus, antibiotics do not treat it. Management includes:

• Home care: Rest, plenty of fluids, and saline nose drops with gentle suction to clear a blocked nose in babies.
• Fever and comfort: Appropriate fever-reducing medicine for age; avoid over-the-counter cough and cold medicines in young children.
• Monitoring: Watching breathing, feeding, and hydration, especially in infants and older adults.
• Hospital care: For severe cases, treatment may include extra oxygen, fluids through a vein, help clearing secretions, and breathing support.

Most people recover within one to two weeks, though the cough can linger. Preventive antibody injections are available for some high-risk infants and during pregnancy, and vaccines are available for older adults and during pregnancy; ask a doctor about eligibility.

Prevention

• Wash hands often and avoid close contact with people who are sick
• Cover coughs and sneezes, and avoid touching the face with unwashed hands
• Clean and disinfect frequently touched surfaces and toys
• Keep infants and high-risk people away from crowds during RSV season when possible
• Avoid exposing babies to tobacco smoke
• Ask your doctor about RSV vaccines for older adults and during pregnancy, and antibody injections for eligible infants

When to See a Doctor

Contact a doctor if an infant, older adult, or person with heart or lung disease develops RSV symptoms and seems to be worsening. Seek emergency care immediately for:

• Fast, labored, or difficult breathing, or pulling in of the skin around the ribs
• Bluish lips or skin, or pauses in breathing in a young infant
• Signs of dehydration, such as very few wet diapers, or refusal to feed
• Unusual drowsiness, difficulty waking, or a child who is much sicker than with a typical cold

Infants and older adults can deteriorate quickly, so it is safest to seek advice early.

Related Topics

Frequently Asked Questions

References

1. Centers for Disease Control and Prevention (CDC). Respiratory Syncytial Virus (RSV).
2. American Academy of Pediatrics. RSV: When It's More Than Just a Cold.
3. Mayo Clinic. Respiratory syncytial virus (RSV) — Symptoms and causes.
4. MedlinePlus, U.S. National Library of Medicine. Respiratory syncytial virus infections.