Respiratory Syncytial VIrus

Respiratory syncytial virus (RSV), which causes infection of the lungs and breathing passages, is a major cause of respiratory illness, especially in young children.

Background
​Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections among young children worldwide. RSV infections occur mostly in yearly epidemic outbreaks. It is highly contagious and spreads through droplets upon coughing or sneezing. Approximately 33.8 million episodes of RSVassociated acute lower respiratory infections occur in children worldwide every year. RSV infection causes a worldwide burden of morbidity and mortality and has been presented as the second main cause of death during infancy. It is estimated that 53.000 to 199.000 RSV-related deaths happen per year, of which 99% occur in developing countries. In Europe and the US, on average 1% of children in their 1st year of life are hospitalised with a severe infection. In Europe, RSV accounts for 42-45% of hospital admissions for lower respiratory tract infections in children under 2. In addition to being a severe acute disease, RSV infection has been linked to an increased risk of the development of asthma in later life.

​Existing problems
RSV is a complex public health problem. The level of clinical, industrial and public interest is only becoming proportionate to the magnitude of the problem. There are currently no vaccine
approaches and prophylaxis is limited to passive immunisation with palivizumab.
An unmet need exists for both (i) long-term development strategies for vaccine and immunoprophylaxis candidates against RSV and (ii) biosimilars that can replace off-patent palivizumab on the short-term. Although the recent increase in industrial activity in development of RSV therapeutics is apparent, concerted and timely solutions to the medical needs are not yet in sight. Key research questions can only be answered through multidisciplinary and networking approaches. ReSViNET is the first and the only international, integrated, multidisciplinary and translational research approach focused on RSV infections.

​Highly contagious
RSV is spread through direct contact. It can live on surfaces (such as counter tops or doorknobs) and on hands and clothing, so it can be easily spread when a person touches something contaminated.

RSV can spread rapidly through schools and childcare centers. Babies often get it when older siblings  carry the virus home from school and pass it on to them. Almost all kids have been infected with RSV at least once by the time they are 2 years old.

Epidemics
RSV is spread through direct contact. It can live on surfaces (such as counter tops or doorknobs) and on hands and clothing, so it can be easily spread when a person touches something contaminated.

RSV can spread rapidly through schools and childcare centers. Babies often get it when older siblings  carry the virus home from school and pass it on to them. Almost all kids have been infected with RSV at least once by the time they are 2 years old.

Risk factors
Birth around the start of the RSV season is an important risk factor for severe course of disease in case of RSV infection.
By age 2, most children will have been infected with respiratory syncytial virus. Children who attend child care centers or who have siblings who attend day care are at a higher risk of exposure.

People at increased risk of severe — sometimes life-threatening — infections include:
Infants younger than 6 months of age
Younger children, especially under 1 year of age, who were born prematurely or who have an underlying condition, such as congenital heart or lung disease
Children with weakened immune systems, such as those undergoing chemotherapy or transplantation
Children with neuromuscular diseases
Older adults
Adults with asthma, congestive heart failure or chronic obstructive pulmonary disease
People with immunodeficiency, including those with certain transplanted organs, leukemia or HIV/AIDS
​
RSV can spread rapidly through schools and childcare centers. Babies often get it when older siblings  carry the virus home from school and pass it on to them. Almost all kids have been infected with RSV at least once by the time they are 2 years old.

Risk factors
Birth around the start of the RSV season is an important risk factor for severe course of disease in case of RSV infection.
By age 2, most children will have been infected with respiratory syncytial virus. Children who attend child care centers or who have siblings who attend day care are at a higher risk of exposure.

People at increased risk of severe — sometimes life-threatening — infections include:

• Infants younger than 6 months of age
• Younger children, especially under 1 year of age, who were born prematurely or who have an underlying condition, such as congenital heart or lung disease
• Children with weakened immune systems, such as those undergoing chemotherapy or transplantation
• Children with neuromuscular diseases
• Older adults
• Adults with asthma, congestive heart failure or chronic obstructive pulmonary disease
• People with immunodeficiency, including those with certain transplanted organs, leukemia or HIV/AIDS

​

Diagnosis
​Physicians typically diagnose bronchiolitis by taking a medical history and doing a physical exam.
​Generally, in healthy kids it's not deemed necessary to distinguish RSV from other respiratory viruses.
​
​​Physicians typically diagnose bronchiolitis by taking a medical history and doing a physical exam.
​Generally, in healthy kids it's not deemed necessary to distinguish RSV from other respiratory viruses.

But if a child requires hospital admissions or has severe co-morbidity, a doctor might want to make a specific diagnosis of viral etiology; in that case, RSV is identified in nasal secretions.

Polymerase Chain Reaction (PCR) on nasal aspirations is most sensitive. During infancy, PCR on mucus obtained by a swab also has high sensitivity. Direct immuno fluorescence only has sufficient sensitivity (>90%) in infants hospitalized for RSV infection.
​
​Treatment
There is no specific treatment for children with RSV infection. A monthly injection with palivizumab, a monoclonal against the RSV F glycoprotein, during the RSV season prevents RSV-related hopital admission in children with congenital heart disease and preterm children with gestational age <= 35 weeks.

Supportive care consists of:

• Oxygen supplementation​
• Fluids through a gastric tube or by a vein (by IV)
• Airway support may be provided by non-invasive ventilation (high flow nasal cannula oxygen), noninvasive ventilation (nCPAP or BiPAP) or by invasive mechanical ventilation.