Respiratory syncytial virus: Difference between revisions

Revision as of 11:31, 7 November 2019

Background

Microbiology

Single-stranded, enveloped RNA virus in the Pneumoviridae subfamily of the Paramyxoviridae family
Two antigenic groups, A and B

Epidemiology

Worldwide distribution
In Canada and US, more common in late fall to early spring, but can occur at any time
Most common cause of bronchiolitis in children
Spread via droplets, either person-to-person or via fomites
- Typically inoculated into respiratory or ocular mucosa rather than inhaled
Infection does not generate persistent immunity

Clinical Presentation

Incubation period of 3 to 5 days (up to 8)

Children

Generally starts with an upper respiratory tract infection ± fevers and otitis media
Then can progress to bronchiolitis, pneumonia, tracheobronchitis, and, rarely, croup
- Highest risk for lower respiratory infections are with the first infection, age less than 6 months, and underlying cardiac or lung disease
- Highest risk for requiring hospitalization is premature infants and those with chronic lung disease, congenital heart disease, immunosuppression, and neuromuscular disease
Wheezing and increased work of breathing are common and cough becomes prominent
Bronchiolitis may involve inspiratory and expiratory obstruction
Hypoxia necessitates hospitalization, and may fluctuate, and can also have apnea

= Outcomes and sequelae

Cough may last for 4 or more weeks, despite resolution of the infection
Recurrent infections are common
May have persistent wheezing into adolescence

Adults

More common in people who work with children and military recruits living in barracks
Highest risk for severe disease includes the elderly, patients with COPD, and immunocompromised patients
Immunocompromised patients include solid-organ and hematologic transplant patients and those on chemotherapy
- Much higher mortality

88 Bronchiolitis obliterans syndrome can be a complication in lung transplant patients with RSV pneumonia

Diagnosis

Most often with PCR
Serology not generally helpful

Management

Supportive care
- Can use puffers and steroids for bronchiolitis with wheezing, but not clear that they are helpful in children
- Monitor for development of bacterial superinfection
Hospitalized children may benefit from inhaled ribavirin, though the benefit is unclear
In high-risk patients with hematologic malignancies, hematologic transplants, or solid-organ transplants, treat with ribavirin
In the highest-risk group of patients, those with allogeneic stem cell transplantation who present with pneumonia, add IVIg

Prevention

Palivizumab is indicated for some high risk groups of infants in order to prevent severe disease1
- Children with hemodynamically significant CHD or CLD if they are <12 months of age at the start of RSV season
- Preterm infants born before 30+0 weeks’ GA who are <6 months of age at the start of RSV season, it is reasonable (but not essential) to offer palivizumab
- Infants in remote communities who would require air transportation for hospitalization born before 36+0 weeks’ GA and <6 months of age at the start of RSV season should be offered palivizumab

References

^ Joan L Robinson, Nicole Le Saux. Preventing hospitalizations for respiratory syncytial virus infection. Paediatrics & Child Health. 2015;20(6):321-326. doi:10.1093/pch/20.6.321.

@@ Line 1: / Line 1: @@
+== Background ==
+=== Microbiology ===
+* Single-stranded, enveloped RNA virus in the Pneumoviridae subfamily of the Paramyxoviridae family
+* Two antigenic groups, A and B
+=== Epidemiology ===
+* Worldwide distribution
+* In Canada and US, more common in late fall to early spring, but can occur at any time
+* Most common cause of bronchiolitis in children
+* Spread via droplets, either person-to-person or via fomites
+** Typically inoculated into respiratory or ocular mucosa rather than inhaled
+* Infection does not generate persistent immunity
+== Clinical Presentation ==
+* Incubation period of 3 to 5 days (up to 8)
+=== Children ===
+* Generally starts with an upper respiratory tract infection ± fevers and [[otitis media]]
+* Then can progress to [[bronchiolitis]], [[pneumonia]], [[tracheobronchitis]], and, rarely, [[croup]]
+** Highest risk for lower respiratory infections are with the first infection, age less than 6 months, and underlying cardiac or lung disease
+** Highest risk for requiring hospitalization is premature infants and those with chronic lung disease, congenital heart disease, immunosuppression, and neuromuscular disease
+* Wheezing and increased work of breathing are common and cough becomes prominent
+* Bronchiolitis may involve inspiratory and expiratory obstruction
+* Hypoxia necessitates hospitalization, and may fluctuate, and can also have apnea
+==== Outcomes and sequelae ===
+* Cough may last for 4 or more weeks, despite resolution of the infection
+* Recurrent infections are common
+* May have persistent wheezing into adolescence
+=== Adults ===
+* More common in people who work with children and military recruits living in barracks
+* Highest risk for severe disease includes the elderly, patients with COPD, and immunocompromised patients
+* Immunocompromised patients include solid-organ and hematologic transplant patients and those on chemotherapy
+** Much higher mortality
+'''[[Bronchiolitis obliterans syndrome]]''' can be a complication in lung transplant patients with RSV pneumonia
+== Diagnosis ==
+* Most often with PCR
+* Serology not generally helpful
 == Management ==
+* Supportive care
-* In high-risk patients, can treat with [[Is treated by::ribavirin]] ± [[Is treated by::IVIg]]
+** Can use puffers and steroids for bronchiolitis with wheezing, but not clear that they are helpful in children
+** Monitor for development of bacterial superinfection
+* Hospitalized children may benefit from inhaled [[Is treated by::ribavirin]], though the benefit is unclear
+* In high-risk patients with hematologic malignancies, hematologic transplants, or solid-organ transplants, treat with [[Is treated by::ribavirin]]
+* In the highest-risk group of patients, those with allogeneic stem cell transplantation who present with pneumonia, add [[Is treated by::IVIg]]
+=== Prevention ===
+* [[Palivizumab]] is indicated for some high risk groups of infants in order to prevent severe disease[[CiteRef::robinson2015pr]]
+** Children with hemodynamically significant CHD or CLD if they are <12 months of age at the start of RSV season
+** Preterm infants born before 30+0 weeks’ GA who are <6 months of age at the start of RSV season, it is reasonable (but not essential) to offer palivizumab
+** Infants in remote communities who would require air transportation for hospitalization born before 36+0 weeks’ GA and <6 months of age at the start of RSV season should be offered palivizumab
 [[Category:RNA viruses]]