Respiratory Syncytial Virus (RSV)- An Overview


Respiratory syncytial virus (RSV) is a common and contagious virus that infects the respiratory tract of humans and animals. It belongs to the genus Orthopneumovirus within the family Pneumoviridae and order Mononegavirales. It has a single-stranded, negative-sense RNA genome that encodes 11 viral proteins.

RSV usually causes mild, cold-like symptoms in adults and older children, such as runny nose, cough, fever, sore throat, sneezing and headache . However, RSV can also cause severe infections of the lower respiratory tract, such as bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lungs), especially in infants, young children, older adults and people with weakened immune systems . RSV is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age in the United States.

RSV spreads from person to person through respiratory droplets that are produced when an infected person coughs or sneezes. The virus can also be transmitted by touching contaminated surfaces or objects, such as toys, cups or utensils, and then touching the eyes, nose or mouth. RSV can survive on hard surfaces for several hours and on soft surfaces for shorter periods . The incubation period of RSV is about 4 to 6 days, and the virus can be shed for up to 8 days after the onset of symptoms.

There is no specific treatment or vaccine for RSV infection. Most cases are mild and resolve on their own with supportive care, such as rest, fluids and fever-reducing medications. However, some people may need hospitalization for oxygen therapy, intravenous fluids or mechanical ventilation if they develop severe breathing difficulties or complications . Prevention of RSV infection mainly relies on good hygiene practices, such as washing hands frequently, avoiding close contact with sick people, covering coughs and sneezes, and disinfecting surfaces and objects. For high-risk groups, such as premature infants or children with chronic lung or heart conditions, a monthly injection of a monoclonal antibody called palivizumab may be given during the RSV season to reduce the risk of severe disease .

RSV is a major public health problem worldwide. It is estimated that RSV causes about 33 million acute lower respiratory infections (ALRI) annually in children under 5 years of age, resulting in about 3 million hospitalizations and 120,000 deaths. RSV also causes significant morbidity and mortality in older adults, especially those with chronic obstructive pulmonary disease (COPD) or cardiovascular disease. RSV infections show seasonal patterns that vary by geographic region and climate. In temperate regions, RSV outbreaks typically occur during winter months, while in tropical regions, RSV activity may be year-round or associated with rainy seasons.

RSV is a complex virus that has evolved various strategies to evade the host immune system and cause recurrent infections throughout life. Understanding the molecular mechanisms of RSV pathogenesis and immunity is essential for developing effective vaccines and antiviral therapies against this important respiratory pathogen.