Prevalence of Serious Bacterial Infection in Young Infants with Hypothermia with Positive Respiratory Pathogen Testing

Compare the prevalence of serious bacterial infections (SBI; urinary tract infection (UTI), bacteremia, and/or meningitis) and invasive bacterial infections (IBI; bacteremia and/or meningitis) among hypothermic infants with positive versus negative respiratory pathogen testing. We conducted a multicenter retrospective cohort study of infants ≤90 days presenting to an emergency department or directly admitted to a hospital from September 1, 2016 to May 5, 2021 with reported or documented hypothermia (≤36oC). Positive respiratory pathogen testing included positive single or multiplex nucleic acid amplification testing. The primary outcome was prevalence of SBI, defined as positive blood, urine, and/or cerebrospinal fluid culture and antibiotic treatment course; SBI and IBI prevalence were compared between infants with positive versus negative respiratory pathogen tests using chi-square test. Respiratory pathogen testing was obtained in 40.6% (446/1098) of hypothermic infants; of those, 24.9% (111/446) had a positive respiratory pathogen result. Infants with a positive respiratory pathogen result were more often older, ill-appearing at presentation, and evaluated during fall/winter months. The prevalence of SBI in our cohort was 7.4%, and the prevalence of IBI was 4.5%. There were no associations between respiratory pathogen test result and SBI or IBI. The majority of young infants with hypothermia evaluated did not have respiratory pathogen testing performed. The diagnosis of SBI or IBI was not associated with a positive respiratory pathogen test. Further research is needed to understand the utility of respiratory pathogen testing in risk stratification for hypothermic infants.