Being a new parent is scary, but it's even scarier when your infant is running a fever, as it could be an indication of a serious bacterial infection brewing. 

Fortunately, many infants with fevers don't always have serious infections. Unfortunately, due to their age, babies currently must undergo a series of invasive and painful tests until infection is ruled out.

But a national research team has developed a method that may help emergency departments better determine which infants need more intensive care and which ones don't. 

The findings, published in JAMA Pediatrics, provide guidelines for identifying infants 60 days and younger at low risk of significant bacterial infections.

"Infections, like urinary tract infections and bacterial meningitis, can lead to dangerous complications in infants, but spinal taps, lengthy hospitalizations and antibiotics also include serious risks and high costs," says study senior author Prashant Mahajan, M.D., professor and vice-chair of emergency medicine at the University of Michigan Medical School and C.S. Mott Children's Hospital and also a member of the U-M Institute for Healthcare Policy and Innovation.

The study was led by clinicians and researchers from Michigan Medicine, UC Davis Health and the Nationwide Children's Hospital. Nathan Kuppermann, M.D., M.P.H., professor and chair of emergency medicine at UC Davis School of Medicine, was the lead author of the study. Octavio Ramilo, M.D., division chief of infectious diseases at Nationwide Children's Hospital, was the co-senior author along with Mahajan.

"Adopting a more efficient protocol helps families avoid invasive medical tests, use of antibiotics and hospital stays that are not necessary for their infant," Kuppermann says.

Low risk of infection 

The study included 1,821 febrile infants, which are infants that show symptoms of a fever. The infants had temperatures of at least 100 degrees and were evaluated at 26 emergency departments around the country. Almost all had received blood testing, urinalysis and spinal taps.

Researchers looked at variables predicting a serious bacterial infection, including the age of the infant, temperature and duration of their fever among other factors such as their clinical appearance, the clinician's own suspicion of infection, as well as blood and urine testing.

Serious bacterial infections were diagnosed in 170 infants, suggesting that approximately 10% of febrile infants get serious bacterial infections. Those who did were more likely to be 28 days old or younger, with higher temperatures and white blood cell counts.

Of all the variables investigated, only three were significantly associated with serious bacterial infections: evidence of infection in the urinalysis, the amount and type of white blood cells in the body and the body's inflammatory response to bacterial infections. 

These three variables allowed physicians to determine the presence of a serious bacterial infection with high accuracy. These tests validated a new protocol for emergency departments that could accurately identify young infants with serious bacterial infections.

Of the infants who were 29 to 60 days old, which was the majority of the study participants, more than half were considered low risk for serious bacterial infection based on the prediction rule. 

The authors say that implementing the new protocol could help to enhance decision-making for emergency room providers and bring relief to 500,000 febrile infants evaluated in U.S. emergency departments annually.

While the findings look promising, the team notes that further validation is necessary. This is especially the case among the youngest infants who have greater numbers of serious bacterial infections.

"Our data contribute important information in the decades old debate about the necessity of lumbar punctures and hospitalizations for young babies with fevers," Ramilo says. "It adds important information that we think will decrease the variability in current protocols and minimize unnecessary tests and hospital admissions, which can carry risks for young patients."

Paper Cited: Mahajan, P., Kuppermann, N., Ramilo, O., et al. "A Clinical Prediction Rule to Identify Febrile Infants 60 Days and Younger at Low Risk for Serious Bacterial Infections" JAMA Pediatrics. DOI: 10.1001/jamapediatrics.2018.5501

This study was supported in part by a grant from the Health Resources and Services Administration (HRSA) Emergency Services for Children and by the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health. It was also supported by the HRSA Maternal and Child Health Bureau and the Emergency Medical Services for Children Network Development Demonstration Program under several cooperative agreements.