Respiratory syncytial virus (RSV) is one of the most important causes of respiratory illness in infants and young children. It also causes both mild and serious respiratory diseases in older children and adults.
- In the United States, approximately 50% of infants and young children become infected with RSV each winter season, with the highest rates of RSV illness and severe complications occurring in infants 2 to 6 months old. Repeated infections may occur throughout life, but after 2-3 years of age, symptoms are generally milder.
- Approximately 125,000 children are hospitalized yearly.
- RSV infections are responsible for approximately 2,500 deaths per year.
- Infants and children younger than 2-3 years old are most at risk of developing complicated, severe, or fatal RSV infections. Premature infants or infants with underlying heart, lung, or immune problems are also at high risk.
- RSV infections occur all over the world, most often in yearly epidemics that can last up to five months, from late fall through early spring.
Infectious Agent
RSV infection is caused by the respiratory syncytial virus (RSV).
RSV is an enveloped RNA virus of the Paramyxovirus family. It is distantly related to measles virus.
RSV viral strains can be classified into two subgroups, A and B. However, much strain variation occurs, which is thought to be responsible for the virus’ ability to repeatedly infect individuals and avoid the immune system.
Transmission
RSV is a highly contagious virus.
The most common mode of transmission is by person-to-person contact with infected nasal and oral fluids.
Transmission occurs by breathing airborne droplets or by contact of eyes or nose with contaminated hands.
RSV infection is often carried home by school-age children and passed to younger children.
When RSV is introduced by an infected individual, high transmission rates, up to 100%, have been shown in day care centers and neonatal units of hospitals.
The Disease
In adults and children older than 2-3 years, RSV causes symptoms similar to a cold, with runny nose, sore throat, mild headache, mild cough, and low-grade fever.
In children younger than 2-3 years, and especially in those 2-6 months old, RSV can cause severe lower respiratory-tract illness such as bronchiolitis and/or pneumonia that can progress to respiratory failure. Symptoms may include high fever, severe cough, wheezing, abnormally rapid breathing, difficulty breathing, and a bluish color to the lips or nails caused by lowered oxygen in the blood.
Children born prematurely or those born with underlying heart, lung, or immune problems have very prolonged illness and high complication rates.
Elderly persons and adults with chronic lung disease or weakened immune systems may also develop serious illness.
Treatment
No vaccine is available for prevention of RSV infection. Antibiotics are not effective against viruses.
RSV infection in children or adults with mild disease is generally treated only with over the counter medicines (e.g. acetaminophen) for cold-like symptoms and fever.
Children or the elderly with severe disease may require hospitalization.
In patients with severe disease, the antiviral agent ribavirin may be used as an aerosol in breathing treatments to treat the virus directly in the lungs.
Immune globulin purified from individuals with high levels of immunity to RSV may be used to treat people with compromised immune systems at high risk for complications following exposure.
Our Research
We have developed a monkey model of RSV infection for our research studies. The human RSV viruses can infect and cause an identical disease in certain species of nonhuman primates. We can also grow and study this virus in the laboratory.
Experiments with RSV in monkeys are conducted to test potential medicines that may be used to treat infections and potential vaccine candidates to prevent infection.
Contact
For information about our RSV research, please contact Dr. Vicki Traina-Dorge.
