There are many different viruses that cause cold and flu-like symptoms. These viruses tend to target the respiratory tract (nose, throat, larynx, trachea, bronchi), with some infections focused on the upper respiratory tract while others affect the lower respiratory tract. The respiratory syncytial virus (RSV) is one of the most common viruses that causes such an infection in infants and children.
What is RSV?
RSV stands for respiratory syncytial virus. It causes infections of the lower respiratory tract (trachea and bronchi) as well as the lungs. In fact, RSV infections are the most common cause of lower respiratory tract and lung infections in children with most children having contracted an RSV infection within the first two years of life. Sometimes these infections can become very severe in children and even lead to hospitalization.
RSV infections affect around 5 million children under the age of 4 every year in the United States. It also leads to as many as 125,000 hospitalizations among this age group annually. Older children and adults can also be infected by the respiratory syncytial virus (RSV) but the infection usually only affects the upper respiratory tract. It tends to be milder in older children and adults and typically appears similar to the flu.
Read more on common cold vs flu.
Causes and Spread of RSV
The respiratory syncytial virus (RSV) is prevalent throughout the world and reinfection occurs many times throughout life. The virus enters the body through the mouth, nose or eyes. It initially infects the epithelial cells of the upper respiratory tract (nose and throat) and then travels down the tract through cell-to-cell transfer.
The secretions of an infected person contain the virus. It may then be airborne by coughing or sneezing, or be spread through skin-to-skin contact. Objects contaminated with the secretions can also spread the virus. The infection is highly contagious and rapidly spreads among children in close contact like in day care centres, schools and among siblings.
The incubation period is about 5 days which means that a child may have little to no symptoms during this time after being infected. RSV can infect any person of any age but certain children and adults are at greater risk of contracting an RSV infection. This risk depends on a host of different factors.
Risk Factors in Children
- Younger than 2 years with infants under 6 months having the highest risk.
- Premature infants.
- Congenital (present from birth) heart and lung conditions.
- Triplets and greater.
- Little to no breastfeeding.
- Weakened immune system like chemotherapy.
- Exposure to environmental toxins like cigarette smoke.
Risk Factors in Adults
- Older adults.
- Weakened immune system like HIV/AIDS.
- History of chronic lung diseases (like COPD or asthma) and congestive heart failure.
Signs and Symptoms
The initial signs and symptoms of RSV can be difficult to differentiate from other similar respiratory tract infections, like the flu in children and common cold in adults. For most older children and adults these symptoms are mild and self-limiting. However, in young children and particularly in infants the infection can be severe and even require hospitalization.
Infants and Young Children
Young children and infants may experience a relatively mild illness in most cases of RSV infection but it can be very severe in some cases, particularly in within the first one to two years of life. These severe symptoms include:
- Fever (usually low-grade)
- Persistent coughing
- Wheezing and rales (abnormal breathing sounds)
- Rapid breathing (tachypnea)
- Cyanosis (bluish discoloration of the skin)
As many as 4 out of 10 children with these symptoms may also have a middle ear infection (otitis media) due to viruses or bacteria.
Older Children and Adults
In older children and adults the symptoms are largely the same as the common cold since the infections is limited to the upper respiratory tract. These symptoms include:
- Runny nose
- Nasal congestion
- Cough (usually dry)
- Fever (usually low-grade)
- Sore throat
Treatment of Respiratory Syncytial Virus Infection
There is no cure for an RSV infection. Treatment is mainly supportive to ease symptoms and prevent complications. However, antivirals may be prescribed for high risk patients but it is only effective if it is commenced once the infection arises. Supportive measures include:
- Acetaminophen to control fever. Do not use aspirin on children.
- Oral rehydrating solutions (ORS) to prevent and treat dehydration. Intravenous (IV) fluids may be necessary for infants and children who are severely dehydrated.
- Antibiotics may be prescribed if there is a secondary bacterial infection like bacterial pneumonia. Antibiotics cannot treat a viral infection.
- Nebulization with a bronchodilator may be advised by a doctor or conducted in a hospital.
In severe cases, a child may have to be mechanically ventilated within the hospital setting. Always consult with a medical professional, especially when the symptoms are severe and there is no sign of improvement.
Read more on how to treat a common cold in children.
Prevention of RSV Infection
Respiratory syncytial virus infections are preventable to a certain degree. However, these preventative measures are not simple for young children to follow. There is no vaccine against RSV and infection does not provide lifelong immunity. Monoclonal antibodies (palivizumab) may assist with preventing the infection but is only given to high risk children (like those with congenital heart or lung defects) who are under the age of 2 years. However, for all other children and adults the following preventative measures should be considered.
- Do not smoke and do not let infants and children be exposed to tobacco smoke. Smoking in a car with the windows open or in another room within the same house is unacceptable.
- Wash hands frequently, preferably with an antiseptic soap or hand wash. Teach children the habit of washing before eating, after using the toilet and so on.
- Clean surfaces and toys regularly especially in places and with objects shared among children. Preferably use an antiseptic detergent or cleaner.
- Do not share utensils and glasses. Children should be taught this habit irrespective of whether another child appears ill or not.
- Stay away from people who have respiratory tract infections or with any infection that appears like a cold or the flu.
- Ensure a healthy and balanced diet for maximum immune defences. While this will not necessarily prevent the infection, it will help to avoid more serious complications.