US Pediatric Deaths due to Novel H1N1...So Far

Children with underlying medical conditions are particularly vulnerable to complications, including death, due to infection with the novel (2009) H1N1 virus. This conclusion is based on a recent analysis of 36 pediatric deaths that have occurred in the United States due to the virus.* Features of these cases are provided in the latest issue of the CDC's MMWR.

Among the 477 deaths associated with laboratory-confirmed novel H1N1 virus in the United States (as of August 8), 36 (7.5%) have occurred in persons younger than 18 years of age. The age breakdown of the pediatric victims is as follows:

Most of the children (67%) had at least 1 "high-risk" medical condition (eg, respiratory, cardiac, or neurologic condition), and 92% of these children had neurodevelopmental conditions (eg, developmental delay, cerebral palsy).

A substantial percentage (43%) with culture or pathologic data (n = 23) had bacterial coinfections; among these 10 children, 6 were 5 years of age or older and had no high-risk comorbidities. Confirmed bacterial pathogens were Staphylococcus aureus (3/5 of which were methicillin resistant), Streptococcus pneumoniae, Streptococcus pyogenes, and Streptococcus constellatus. All pathogens were community acquired, according to the CDC's Thomas Frieden (at today's broadcasted press conference; see today's follow-up post).

The median duration of illness, from symptom onset to death, was 6 days (range, 1-28 days). One half of pediatric victims were male; one third were Hispanic.

Among 31 children for whom data were available, 19 (61%) received antiviral treatment; but only 4 received treatment within 2 days of symptom onset. Just over half (13/25) of the children had received at least 1 inoculation against the 2008-2009 seasonal H1N1 virus.

The MMWR article also provides pediatric-death data from previous influenza seasons; however, the editors advise caution when comparing seasonal death data because of possible differences in case ascertainment and differing sensitivities of laboratory tests (particularly rapid H1N1 tests). In addition, comparisons of seasonal data are highly limited during an ongoing epidemic/pandemic. 

The CDC editors stress the importance of pneumococcal vaccination in children, particularly in very young children with high-risk medical conditions, and the benefit of antiviral treatment in persons who are hospitalized for novel H1N1 infection, even when treatment is started 48 hours after symptom onset. Empiric antibacterial therapy should be directed at S. aureus, S. pneumoniae, and S. pyogenes. 

* The conclusion is not unexpected, given that complications due to seasonal influenza are increased in very young children (<5 years of age) with certain chronic medical conditions.