Sex: U
Vaccine: FLUX
Symptoms: Death, Influenza, Influenza virus test positive
Clinical narrative: This literature report concerns a retrospective, descriptive study of all reported influenza-associated pediatric deaths in 2007-2008 influenza season. A case was defined as the death of a resident aged <18 from October 1, 2007 to September 30, 2008 with laboratory evidence of an influenza virus type A or B infection. A positive laboratory test for influenza type A or B could occur before or after death and may be determined by any of the following methods: rapid influenza diagnostic test, viral isolation, enzyme immunoassay, fluorescent antibody staining, immunohistochemical staining of tissue samples, or reverse transcription polymerase chain reaction. Specimens for bacterial and viral culture were collected as part of routine clinical care and the postmortem examination, when applicable. CDC requested that respiratory specimens and postmortem lung specimens were sent to CDC laboratories if available. Influenza virus isolates, other viral isolates, and bacterial isolates were characterized at local, hospital, state, or CDC laboratories. Genotyping of available S. aureus isolates was performed at CDC by pulsed field gel electrophoresis (PFGE) using SmaI-digested DNA. Gel patterns were analyzed as previously described. State or local health departments completed a standardized reporting form for each case of influenza-associated pediatric mortality and transmitted the information to CDC via a web-based interface hosted on CDC's Secure Data Network. Through the standardized reporting form, information was collected on patient demographics, influenza laboratory test results, date and location of death, preexisting conditions, complications during the acute illness (including radiologically confirmed pneumonia), influenza vaccination history, and results of bacterial cultures obtained from normally sterile (blood, pleural fluid, chest tube fluid, or cerebral spinal fluid) and specified non-sterile (endotracheal tube aspirates, tracheal aspirates, and bronchial washes) sites. Information was not collected on bacterial cultures obtained from nares or sputum, as positive cultures from these sites are more likely to represent colonization rather than infection. The reporting form includes a notes section for reporting additional information and for clarification. Information regarding bacterial isolation from postmortem lung biopsies and fungal co-infections was not directly solicited; however, this information could be reported in a notes section of the reporting form. For our analysis, bacterial isolation from postmortem lung biopsies were included only if the specimen was collected on the calendar day of death or the calendar day following death. Dates of hospital admission and specimen collection were obtained from all patients from whom S. aureus was isolated from one of the designated sites. We focused our analyses on those patients from whom S. aureus was isolated from a specimen collected within three days of hospital admission, as we were attempting to identify patients in whom a bacterial co-infection may have contributed to their severe presentation (as opposed to having been acquired during hospitalization). During the 2007-2008 influenza season, a total of 88 influenza-associated pediatric deaths were reported to CDC. Of the 88 children, 47 (53%) were boys and the median age at death was 5. Forty-two (47%) of the children were <5 years of age, and 14 (16%) were <1 year of age. Most were white. Fifty-six (66%) of 85 children were recommended for vaccination by 2007-2008 ACIP criteria, and of these 48 had a known vaccination status for the 2007-2008 influenza season. Eleven (23%) of 48 recommended children received at least one dose of influenza vaccine in the 2007-2008 season at least 14 days prior to illness onset. Of these 11 children, six were completely vaccinated, one was partially vaccinated, and complete vaccination status could not be determined in four. One child who received the vaccine in the 2007-2008 season did not meet an age-related or ACIP-defined high-risk criteria for vaccination. This case (case 3 of 4) relates to 4 of 11 children whose vaccination status could not be determined, but they received at least one dose of vaccine. Authors comment: S. aureus continues to be the most common bacteria isolated from children with influenza-associated mortality. S. aureus isolates were associated with older age and lack of high-risk medical conditions. Healthcare providers should consider influenza co-infections with S. aureus when empirically treating children with influenza and severe respiratory illness.