Respiratory syncytial virus

Overview

Respiratory Syncytial Virus (RSV) infection is a common respiratory illness that affects individuals of all ages, causing upper and lower respiratory tract infections. While RSV infection is often mild and self-limiting, it can lead to severe disease, particularly in infants, older adults, and individuals with underlying medical conditions.

Disease epidemiology

RSV is a globally prevalent cause of upper and lower respiratory tract infections across all age groups. RSV infections occur year-round in Singapore.

Pathogen(s)

Respiratory syncytial virus

Transmission

RSV primarily transmits through inhalation or direct deposition of infectious respiratory particles (IRPs) such as when an infected person coughs or sneezes. It can also spread via contact with contaminated surfaces such as when IRPs settle on surfaces or transfer through contact (e.g. handshake) before reaching the mouth, nose or eyes.

Incubation period: Typically 5 days, ranging from 2 to 8 days.

Infectious Period: From 1 or 2 days before the onset of symptoms until 3 to 8 days after onset.

Clinical features

The signs and symptoms of an RSV infection range from mild respiratory symptoms to severe illnesses such as pneumonia and bronchiolitis.

Common symptoms include:

• Runny nose

• Fever

• Cough

• Sneezing

• Decrease in appetite

• Wheezing

Pneumonia or bronchiolitis may develop in severe infection, especially among infants and older adults.

In infants, symptoms of severe infection include:

• Short, shallow and rapid breathing

• Struggling to breathe

• Cough

• Poor feeding

• Unusual tiredness

• Irritability

• Bluish colour of the skin due to lack of oxygen (cyanosis)

Risk factors

People at greater risk of severe diseases or complications when infected include:

• Premature infants or infants aged 6 months and below

• Children with heart disease present from birth (congenital heart disease) or chronic lung disease

• Children or adults with weakened immune systems from diseases such as cancer or treatment such as chemotherapy

• Children or adults with neuromuscular disorders, such as muscular dystrophy

• Adults with diabetes mellitus

• Adults with chronic medical problems such as heart disease, lung disease, liver disease, or end-stage renal disease

• Seniors aged 60 and above

Diagnosis

Detection of RSV through rapid RSV diagnostic tests (antigen-based) or polymerase chain reaction (PCR).

Treatment and management

RSV infection is usually mild and self-limiting. Supportive care and symptomatic treatment, such as treatment with antipyretics, plenty of fluids, and adequate bed rest, are usually sufficient in the management of acute symptoms of RSV.

For cases with severe symptoms, hospitalisation may be required to monitor and treat breathing problems.

Precaution, prevention and control

Isolation measures

Standard and droplet precautions should be implemented. Patients should wear a surgical mask and be isolated when possible. Good hand hygiene and respiratory etiquette should be reinforced for both healthcare workers and the general public.

Contact management

No specific management of contacts is required.

Vaccination

In Singapore, two vaccines have been approved to protect against RSV-related complications:

• Arexvy (GSK): Approved by the Health Sciences Authority (HSA) in May 2024, Arexvy is designed for individuals aged 60 and above. It offers protection against lower respiratory tract diseases (LRTD) caused by RSV, which can lead to severe complications such as pneumonia and bronchiolitis in older adults. The vaccine is administered as a single intramuscular injection.

• Abrysvo (Pfizer): In July 2024, HSA approved Abrysvo for individuals aged 60 and above to prevent RSV-related LRTD, as well as pregnant individuals at 32 through 36 weeks gestational age for the prevention of LRTD and severe LRTD caused by RSV in infants from birth through 6 months of age.

Notification

RSV is not a legally notifiable disease in Singapore.

Note: While single cases are not notifiable, medical practitioners should report events of public health significance (e.g. cluster of infectious diseases in the community). Please refer to the Infectious Disease Notification for more information.

Resources

For more information on RSV, please refer to the World Health Organization website.

For general travel advisory, please refer to Health Advice for Travellers.