Definition of Respiratory syncytial virus (RSV):

Respiratory syncytial virus (RSV) is a very common virus. This virus causes mild, cold-like symptoms in adults and older healthy children. It can cause serious lung infections in young babies, especially those in certain high-risk groups.

Causes, incidence, and risk factors:

RSV is the most common respiratory germ in infants and young children. It has infected nearly all infants by the age of two years. Seasonal outbreaks typically begin in the fall and run into the spring.

RSV is spread easily by physical contact. Touching, kissing, and shaking hands with an infected person can spread RSV. You can spread the infection to others if you come in contact with contaminated secretions, which may involve tiny droplets, or objects that droplets have touched. RSV can live for half an hour or more on hands. The virus can also live up to five hours on countertops and for several hours on used tissues. RSV often spreads very rapidly in crowded households and day care centers.

In infants and young children, RSV can cause pneumonia, bronchiolitis (inflammation of the small airways of the lungs), and croup. In healthy adults and older children, RSV is usually a mild respiratory illness. The infection can occur in people of all ages.

Each year up to 125,000 infants are hospitalized due to severe RSV disease, and about 1-2% of these infants die. Infants born prematurely, those with chronic lung disease, those who are immunocompromised, and those with certain forms of heart disease are at increased risk for severe RSV disease. Those who are exposed to tobacco smoke, who attend daycare, who live in crowded conditions, or who have school-age siblings are also at higher risk.