Does COVID-19 increase the risk of bacterial infections in infants?

In a recent study published in JAMA Network Open, researchers assess the prevalence of bacterial meningitis, bacteremia, and urinary tract infections (UTIs) among infants tested for non-Severe Acute Respiratory Syndrome Coronavirus 2 viral (SARS-CoV-2) and SARS-CoV-2 infections.

Study: Urinary Tract Infection, Bacteremia, and Meningitis Among Febrile Young Infants With SARS-CoV-2 and Non–SARS-CoV-2 Viral Infections. Image Credit: Alexander Ishchenko / Shutterstock

Discerning between viral and bacterial infections in young infants

About 200,000 febrile infants 60 days or younger are evaluated annually in emergency departments throughout the United States. Between 7-10% of these infants have a UTI, 2-3% have bacteremia, and 0.5-1% have bacterial meningitis.

The American Academy of Pediatrics has provided guidelines to assess febrile infants between six and 60 days of age for bacterial meningitis, UTIs, and bacteremia. Evidence suggests that the presence of a respiratory viral infection can alleviate the risk of these infections.

Nevertheless, it remains unclear how testing for viruses should inform evaluation and clinical management in young infants. Furthermore, the emergence of SARS-CoV-2, the virus responsible for the coronavirus disease 2019 (COVID-19), and its dynamic epidemiology have posed additional challenges.

About the study

To this end, data on febrile infants 60 days or younger between March 2020 to December 2022 were obtained, in addition to standardized laboratory and clinical data at follow-up.

Healthy infants with a rectal temperature of 38 °C or greater were also included in the current study. Multiplex respiratory testing, including SARS-CoV-2, was performed for all infants.

Cerebrospinal fluid was tested at the physician’s discretion. The final infection status was determined through urine or blood culture tests. Telephonic follow-up interviews were conducted between 14 and 28 days following discharge.

Infants infected with SARS-CoV-2 and other viruses were evaluated in the SARS-CoV-2 group. The researchers compared the prevalence of bacterial meningitis, bacteremia, or UTI, as well as other invasive bacterial infections (IBIs), between infants with and without a viral infection using the chi-squared test.

Lower risk of UTIs and IBIs in SARS-CoV-2-infected infants

The study included 931 infants, 384 female, with a median age of 38 days. Within the study cohort, 428 infants were hospitalized.

Culture results for urine and blood samples were available for about 94% of the cohort, whereas cerebrospinal fluid cultures were available for 35.3% of infants. Twenty infants were diagnosed with IBIs, whereas 107 were diagnosed with bacteremia, meningitis, or UTI.

Viral infections were documented in 611 infants, 163 of whom were diagnosed with SARS-CoV-2 infection. The prevalence of bacterial meningitis, UTIs, or bacteremia was lower at 7.8% among infants with non-SARS-CoV-2 viral infection than those without detectable viral titers at 20.9%.

Five SARS-CoV-2-infected infants who were between 41 and 59 days of age had culture-confirmed UTIs and a positive urinalysis at the initial evaluation.

IBIs were significantly less prevalent among virus-infected infants than those negative for viral infections. Furthermore, IBIs occurred among five infants with non-SARS-CoV-2 viral infections, with no IBIs documented in SARS-CoV-2-infected infants. Bacteremia was reported among five infants between 11 and 56 days of age with concomitant non-SARS-CoV-2 viral infections.


The current study evaluated the prevalence of bacterial meningitis, UTIs, and bacteremia among febrile infants tested for viral infections. The study findings indicate a significantly lower and non-negligible risk of IBIs and UTIs among infants with non-SARS-CoV-2 viral infections, consistent with previous studies. The risk of IBIs among SARS-CoV-2-infected infants was also considerably low.

These findings are similar to those of a previous large cohort study on over 14,000 full-term infants, in which the risk of UTIs, bacteremia, and bacterial meningitis was 0.8%, 0.2%, and less than 0.1%, respectively, in SARS-CoV-2-positive infants. Likewise, the risk of concomitant bacterial infections in non-SARS-CoV-2-infected infants was higher than in those infected with SARS-CoV-2.

Taken together, these observations emphasize recommendations provided by the American Academy of Pediatrics that the initial evaluation of febrile infants should not be influenced due to the confirmation of a non-SARS-CoV-2 viral infection. Furthermore, the substantially lower IBI risk among SARS-CoV-2-infected infants might help clinicians personalize patient care to ultimately make more informed and shared decisions with parents.

Some of the limitations of the current study include the fact that it was a single-center investigation and the lack of testing for SARS-CoV-2 variants. Moreover, multiplex respiratory testing cannot differentiate between enterovirus and rhinovirus, thereby underestimating any potential differences between non-SARS-CoV-2 viral infection and virus-negative groups.

Journal reference:
  • Burstein, B., Yannopoulos, A., & Dionne, K. A. (2023). Urinary Tract Infection, Bacteremia, and Meningitis Among Febrile Young Infants With SARS-CoV-2 and Non–SARS-CoV-2 Viral Infections. JAMA Network Open. doi:10.1001/jamanetworkopen.2023.21459