The WHO estimates that Respiratory Syncytial Virus (RSV) is the most common respiratory infection in children with approximately 34 million cases per year, worldwide. Middle- and low-income countries suffer over 90% of all RSV-related deaths. Most children are estimated by the Centers for Disease Control and Prevention (CDC) to have had the virus by the time they have reached 2 years old. Symptoms include a runny nose, wheezing, fever, sneezing, and a decrease in appetite. Like many other viruses, RSV can survive on surfaces and be spread through close contact with those with the illness. RSV is generally contagious for 3-8 days but those with a weakened immune system may shed the virus for up to 4 weeks. RSV infections can also occur in adults as well, but the symptoms are usually milder; however, severe infections can occur in older adults and those with weakened immune systems. There are indications that there may be possible interference between respiratory viruses as yearly peaks of RSV and Influenza occur at different times during the winter.
Like Influenza, RSV is also an enveloped negative sense RNA virus, but RSV belongs to the Pneumoviridae family. The virus is approximately 150-300 nm in diameter and contains F (fusion) proteins on its surface which are used to attach to the host cell. F along with G (glycoprotein) both can illicit host antibody reactions. The virus also contains M (matrix) protein and three other nonstructural proteins.
