RT Journal Article SR Electronic T1 The prevalence of serious bacterial infections in infants 90 days and younger with viral respiratory tract infections JF Saudi Medical Journal JO Saudi Med J FD Prince Sultan Military Medical City SP 1007 OP 1012 DO 10.15537/smj.2022.43.9.20220400 VO 43 IS 9 A1 Abdullah I. Almojali A1 Musab S. Alshareef A1 Othman F. Aljadoa A1 Fahad F. Alotaibi A1 Emad M. Masuadi A1 Tahir K. Hameed YR 2022 UL http://smj.org.sa/content/43/9/1007.abstract AB Objectives: To determine the prevalence and risk factors of serious bacterial infections (SBIs) in infants 90 days and younger with a confirmed respiratory tract infection (RTI).Methods: A retrospective cross-sectional study was carried out of infants 90 days and younger who were admitted to King Abdullah Specialized Children’s Hospital, Riyadh, Saudi Arabia, from January 2019 to December 2020, with polymerase chain reaction (PCR)-proven RTI. Cultures from the urine, blood, and cerebrospinal fluid were reviewed with the patients’ demographic information and clinical presentation.Results: Of 322 patients with a viral RTI, 21 (6.5%) had a concurrent urinary tract infection (UTI), and no patients had bacteremia or bacterial meningitis. The risk of a concurrent SBI was 4 times higher in neonates (odds ratio [OR]=4.66, 95% confidence interval [CI]: [1.32-16.47]). Previously healthy infants were at lower risk to have a SBI in comparison to those with chronic diseases or renal abnormalities (OR=0.23, 95% CI: [0.09-0.61]). In addition, male gender (OR=3.49, 95% CI: [1.07-11.38]) and abnormal urinalysis (OR=4.12, 95% CI: [1.48-11.42]) were predictors of SBIs. There was no statistically significant association between the number or type of detected viruses and SBIs.Conclusion: No cases of invasive bacterial infections were found in infants with PCR-proven viral RTIs. There is a risk of having a concurrent UTI in this cohort of patients. Neonates had a higher risk of UTIs as compared to older infants.