What is the first manifestation of SARS-CoV-2 infection in infants?

Contemporary PEDS Journal, September 2021, Volume 38, Issue 9

With the delta variant leading to more pediatric infections, awareness of initial symptoms in infants is very important.

Fever without source (FWS) was the first sign of SARS-CoV-2 infection in 40% of infants younger than 90 days old who were included in a study conducted in Spain. Sixty-seven infants were included, and of the 27 who had FWS and SARS-CoV-2 (the cause of COVID-19), 59% had household contact with a confirmed COVID-19 case. Five of the 27 children (15%) had co-morbidities: Two were born preterm and the other 3 had congenital heart disease, phenylketonuria, and Shwachman-Diamond syndrome, respectively. Blood culture, urine culture, and lumbar puncture were performed in some of the infants, revealing that 2 of the 27 whose FWS was the first manifestation SARS-CoV-2 infection had bacterial infections—1 with urinary tract infection (UTI) and bacteremia and 1 with UTI. C-reactive protein was more than 20 mg/L in 2 children (1 with bacterial coinfection), and procalcitonin was normal in all. Outcomes were good overall, although 1 child was admitted to the pediatric intensive care unit because of apnea episodes. Investigators concluded that standardized markers to rule out serious bacterial infection seem to remain useful in this population and recommended that practitioners rule out COVID-19 in infants with FWS in areas with community transmission of SARS-CoV-2.

Thoughts from Dr. Farber

How much of a work-up to do in very young febrile infants is an ongoing concern. In the child without an obvious need for an aggressive work-up (eg, extreme irritability), testing for and finding SARS-CoV-2 can spare the child unnecessary testing and antibiotic treatment.


1. Blazquez-Gamero D, Epalza C, Cadenas JAA, et al. Fever without source as the first manifestation of SARS-CoV-2 infection in infants less than 90 days old. Eur J Pediatr. 2021;180:2099-2106. doi:10.1007/s00431-021-03973-9