Prevalence of Serious Infection Among Hypothermic Young Infants Across Medical Settings.

Abstract

Objective: We aim to determine the prevalence of urinary tract infection (UTI) and invasive bacterial infection (IBI) (bacteremia or bacterial meningitis) in hypothermic young infants presenting to outpatient clinics and emergency departments (EDs) and to identify associated risk factors.

Method: This is a retrospective cohort study of infants aged 0 to 60 days presenting with a temperature of 36 °C or below to any medical facility in a large integrated health care delivery organization from 2010 to 2022. The proportion of infants with UTI, IBI, and herpes simplex virus (HSV) were calculated. Multivariable logistic regression analysis identified risk factors for UTI or IBI.

Results: Of 3783 infants, 15 (0.40%; 95%, CI 0.22%-0.65%) had UTI, 11 (0.29%; 95% CI, 0.15%-0.52%) had IBI, and 2 (0.05%; 95% CI 0.01%-0.19%) had HSV infection. Only 0.38% of infants presenting to outpatient clinics had UTI or IBI vs 1.48% of infants presenting to EDs (P < .001). Ill appearance (adjusted odds ratio [aOR], 7.3; 95% CI, 3.1-17.4), repeated low temperature (aOR, 6.7; 95% CI 2.7-16.6), and chief concern of hypothermia (aOR, 4.2; 95% CI, 1.8-10.0) were identified as clinical risk factors for UTI or IBI. Twelve of 15 infants with UTI and all 11 infants with IBI presented with at least 1 of these 3 risk factors.

Conclusion: The prevalence of UTI and IBI among our cohort of hypothermic infants presenting to any medical setting was low. Regardless of the setting, infants with clinical symptoms of ill appearance, repeated low temperature, or chief concern of hypothermia had significantly increased risk of infection. Hypothermic infants lacking these risk factors may not require extensive infectious evaluation.