Prevalence of Serious Bacterial Infections Among Febrile Infants Spikes During Pandemic

The prevalence of serious bacterial infections among febrile infants who visited an emergency department in Canada doubled during the pandemic, while ED visits fell by two-thirds, a new study found.

The retrospective cross-sectional study, detailed in a research letter published in JAMA Network Open, included data from young infants up to age 3 months evaluated for fever between March 2018 and March 2021 at Montreal Children’s Hospital of the McGill University Health Centre. Primary outcomes were the proportions of serious bacterial infections (SBIs) and invasive bacterial infections (IBI).

“The spike in serious bacterial infections that we observed during the pandemic is concerning,” said corresponding author Brett Burstein, MD, CM, PhD, MPH, a pediatric emergency medicine physician and a junior investigator in the Child Health and Human Development Program at the Research Institute of the McGill University Health Center. “With fewer viruses circulating because of public health measures, fever is now more often a sign of a serious bacterial infection.”

Between March 2020 and March 2021, 324 infants were evaluated for fever, down dramatically from 951 between March 2018 and March 2019 and 973 between March 2019 and March 2020.

Before the pandemic, 63.3% of infants received multiplex virus testing. During the pandemic, SARS-CoV-2 testing replaced the 13-virus panel, and 96% of infants were tested for SARS-CoV-2.

“About 2% of all full-term babies are evaluated for fever in the first few months of life, and there exists significant ongoing variation in their management,” Burstein said. “These babies often have few other symptoms and doctors want to avoid unnecessary invasive tests, antibiotics and hospitalization.”

While the number of febrile infants who came to the emergency department decreased dramatically (66.3%) during the pandemic, the proportion of those with serious bacterial infections doubled from 10% before the pandemic to 20.4% during the pandemic. Serious bacterial infections include urinary tract infections, bacteremia and bacterial meningitis.

The proportion with life-threatening invasive bacterial infections tripled from 1.1% before the pandemic to 3.4% during the pandemic.

Among the infants who came to the emergency department during the pandemic, 20 tested positive for SARS-CoV-2. The study also found that the proportion of concomitant SBIs among those infected with SARS-CoV-2 (5%) was similar to that of other respiratory viruses before the pandemic.

“It is critical that physicians exercise caution and investigate appropriately, and that parents seek care for infants with fever, during the pandemic even more than before,” Burstein said.

Limitations of the study include a shortage of reagents leading to infrequent testing for respiratory viruses other than SARS-CoV-2 during the pandemic and that data was limited to a single hospital.

Diagnosing serious bacterial infections in young infants can be difficult and risky, and work is ongoing to improve diagnosis and treatment.

Investigators from the Pediatric Emergency Care Applied Research Network (PECARN) sought to avoid spinal taps and unnecessary antibiotic treatments with a new protocol to rule out serious bacterial infection by evaluating levels of bacteria in the urine, as well as procalcitonin in serum, and neutrophils.

A study published in January 2020 found that taking 2 blood cultures before administering antibiotics for children admitted to the hospital with suspected sepsis or serious bacterial infection increased pathogen isolation and improved anti-microbial decision-making.

A study published last year found that children prescribed at least 1 course of antibiotics before age 2 were more likely to develop asthma, allergic rhinitis, overweight, and ADHD.