It’s ALSO that time of year: Respiratory Syncytial Virus

Symptoms: Over 2 to 3 days development of wheezing, a so called “tight” wheezy cough, fever (usually low grade), cyanosis, tachypnea, retraction, fatigue.

Diagnosis:

Upon physical exam the above symptoms are noted, on auscultation inspiratory crackles and wheezing are usually present. Hydration status should be noted, as RSV is a diffuse small airway disease, leading to bronchiolitis.

Non-specific lab tests such as ABGs, CBC, and O2 sat., and age of child help determine candidates for admittance. Secretions can be analyzed using PCR but are expensive, a sophisticated virology lab is required in terms of antigen detection.

Imaging X-Ray is commonly ordered, revealing (nonspecific) hyperinflated lung fields, diffuse interstitial infiltrates, and in more advanced cases focal atelectasis.

DDx: Asthma, bronchitis, adenovirus, pneumonia, metapnuemovirus, influenza.

Treatment:  See part 2 coming soon!

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infection (LRTI) in children in the world1. Because it’s so common, it’s important for medical students in the hospital to be familiar with the virus, especially in how it presents in the Emergency Department, and how to determine to admit the patient or send them home to rest.

RSV belongs to the Paramyxoviridae family, Pneumovirinae subfamily. It’s a negative sense ssRNA virus (don’t forget virology!). It is spread via direct contact, inhilation, and can last up to 5 hours as a fomite on surfaces. Incidence: The virus is more common in children and most get it by 2-3 years of age, peak incidence is 2-7 months of age. However, anyone can get the virus especially the elderly. At risk are children who attend childcare, children who are not breastfed, living with smokers or being exposed to cigarette smoke, prematurity (<35weeks), and congenital immunodeficiency4 .

Epidemiology: It’s well known to be seasonal (late fall, winter, early spring) but varies by region (see chart). 4-5 million children are affected each year and ~125,000 are admitted, although admittance rates are slowly increasing. A retrospective study showed 24% of LRTI hospitalizations among children <5 years of age during the 10 study years, 1997-2006 were due to RSV5 .

rsv1

http://www.cdc.gov/Features/dsRSV/

The x-ray shows lung hyperinflation with a flattened diaphragm and opacification in the right lung apex (red circle) and left lung base (blue circle) from atelectasis. Obviously, the same changes can be seen in the x-ray of a child with acute asthma. This is one reason why children with acute asthma are often misdiagnosed as having pneumonia. http://reference.medscape.com/features/slideshow/pediatric-respiratory

click for larger view

click for larger view

References:

1. Morbidity & Mortality Weekly Report. 2007;56(48):1263-1265.

2. Corneli HM, Zorc JJ, Mahajan P, Majahan P, Shaw KN, Holubkov R. “A multicenter, randomized, controlled trial of dexamethasone for bronchiolitis.” N Engl J Med. Jul 26 2007;357(4):331-9. [Medline].

3. Seo S, Campbell AP, Xie H, Chien JW, Leisenring WM, Englund JA, Boeckh M. “Outcome of Respiratory Syncytial Virus Lower Respiratory Tract Disease in Hematopoietic Cell Transplant Recipients Receiving Aerosolized Ribavirin: Significance of Stem Cell Source and Oxygen Requirement.” Biol Blood Marrow Transplant. 2013 Jan 5. doi:pii: S1083-8791(12)01178-0. 10.1016/j.bbmt.2012.12.019. [Epub ahead of print] PMID: 23298855 (PubMed)

4. http://emedicine.medscape.com/article/971488-overview#showall

5. Stockman LJ, Curns AT, Anderson LJ, Fischer-Langley G. “Respiratory syncytial virus-associated hospitalizations among infants and young children in the United States, 1997-2006.”

Pediatr Infect Dis J. 2012 Jan;31(1):5-9. http://www.ncbi.nlm.nih.gov/pubmed/21817948

 

Compiled by: Nick Mancuso

Miss anything? Forgot to include something important? Leave a comment and help us improve our knowledge base for medical students!

Advertisements
Tagged , , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: