What Is the Mortality Rate of RSV in Babies?

The mortality rate of RSV in babies depends on the immunologic status of the child, which resembles the following:

• In healthy children, the reported mortality rate is about 0.5 to 1.7 percent.
• In children with suppressed immunity, the mortality rate is higher (about 60 percent).
• Presence of severe underlying comorbidities, such as neuromuscular disease, immunosuppression and malignancies, were associated with deaths among term and/or older (over one-year-old) children.
• High-risk infants remain hospitalized longer with higher rates of admission to the intensive care unit (ICU) and on mechanical ventilation. Higher fatality rates have been reported for infants receiving intensive unit care (1.1 to 8.6 percent) and extracorporeal life support (33 percent), or for those who acquired nosocomial (hospital acquired) respiratory syncytial virus (RSV) infection (0 to 12.2 percent).

Apart from a history of possible exposure at a childcare center, school and a known outbreak, these signs and symptoms are indicative of a severe respiratory syncytial virus (RSV) infection in infants that require emergency medical care (child needs to be taken to the emergency room):

• Short, shallow and rapid breathing
• Flaring (spreading out) of the nostrils with every breath
• Belly breathing (look for “caving in” of the chest in the form of an upside-down “V” starting under the neck)
• Bluish coloring of the lips, mouth and fingernails
• Wheezing (this can be a sign of pneumonia or bronchiolitis)
• Poor appetite

Complications of respiratory syncytial virus (RSV) include:

• Hospitalization: A severe RSV infection may require a hospital stay so that doctors can monitor and treat breathing problems and give intravenous (IV) fluids.
• Pneumonia: RSV is the most common cause of pneumonia (inflammation of the lungs) or bronchiolitis (inflammation of the lungs’ airways) in infants. These complications can occur when the virus spreads to the lower respiratory tract. Lung inflammation can be quite serious in babies, young children, older adults, immunocompromised individuals or people with chronic heart or lung disease.
• Middle ear infection: Germs entering the space behind the eardrum can lead to a middle ear infection (otitis media). This occurs most frequently in babies and young children.
• Asthma: There may be a link between a severe RSV episode in children and the risk of developing asthma later in life.
• Repeated infections: Reinfection from the same virus after recovery is possible, even during the same RSV season. While symptoms usually aren't as severe, typically in the form of the common cold, they can be serious in older adults or people with chronic heart or lung disease.

Diagnosis of respiratory syncytial virus (RSV) infections in babies are accomplished by several methods, including viral culture, serology, antigen detection tests and nucleic acid amplification tests (NAATs). Conventional polymerase chain reaction (PCR) and nested PCR are considered simple and economic for any laboratory setting.

Antigen detection test

• Antigen detection assays include:
  • Direct immunofluorescence assay (DFA)
  • Enzyme immunosorbent assay (EIA)
  • Chromatographic and optical immunoassay
• DFA uses fluorescein-labeled antibodies that detect RSV antigen in the epithelial cells in respiratory secretions and have the advantage that the immunofluorescence pattern of the infected cells can be directly examined by microscopy that provides additional confirmation of specificity.

Virus isolation in tissue culture

• Isolation of RSV in tissue culture was considered the gold standard for confirmation of presumed RSV infection. The advantage of this tissue culture technique is that it is more sensitive than rapid antigen detection kits, and it provides the ability for further antigenic and genetic characterization of the amplified virus.

Nucleic acid tests (NATs)

• Nucleic acid assays have revolutionized diagnostic procedures in virology and are the most sensitive and specific methods for the detection of RSV. Of the different nucleic acid amplification techniques, reverse transcription polymerase chain reaction (RT-PCR) was the first and most frequently used nucleic acid-based assay.

Treatment of respiratory syncytial virus (RSV) in infants is as follows:

• Treatment of uncomplicated RSV infection is supportive in nature. Supportive care includes adequate hydration, oxygen supplementation and additional management of symptoms or comorbid conditions such as bronchiolitis.
• Ribavirin is the only effective antiviral agent currently available for the treatment of RSV pneumonia. It acts by interfering with a viral multiplication process called transcription. This drug is delivered as a small-particle aerosol.
• RSV-specific intravenous immunoglobulin such as palivizumab is a monoclonal antibody directed against the RSV segment called the fusion (F) glycoprotein. It has also been used with aerosolized and oral ribavirin in people with a high risk of RSV infection.