A polymerase chain reaction-based epidemiologic investigation of the incidence of nonpolio enteroviral infections in febrile and afebrile infants 90 days and younger

Objective. Enteroviruses are important pathogens in infants, but their true contribution to febrile illness in infants less than or equal to 90 days o ld is unknown. The purpose of this study was to use the polymerase chain re action (PCR) for diagnosis of enteroviral (EV) infection in febrile and afe brile infants less than or equal to 90 days of age to improve the understan ding of the epidemiology of EV infection in this population. Methods. Patients included all unimmunized, febrile infants less than or eq ual to 90 days of age admitted to Primary Children's Medical Center (Salt L ake City, UT) for sepsis evaluation from December 1996 to December 1997. Bl ood, urine, cerebrospinal fluid, and throat swabs were tested for enterovir uses using a PCR assay (Roche Molecular Systems, Branchburg, NJ). Alternate PCR assays separated polio and nonpolio enteroviruses. Results of bacteria l cultures, outcome, and hospital charges were obtained. Blood from afebril e, control infants less than or equal to 90 days old was tested for enterov iruses. Results. A total of 345 febrile infants were enrolled; 89 (25.8%) were posi tive for enterovirus. The incidence of EV infection ranged from 3.2% in Jan uary to 50% in August and October. Five EV-positive, febrile infants (5.6%) had concomitant urinary tract infections, and 1 (1.1%) had concomitant bac teremia. Infants with confirmed EV infection were significantly less likely to have bacterial infection than those who were EV-negative. All infants i nfected with an enterovirus recovered. Average length of stay was 3 days, a verage charges were nearly $4500. Eighty-six afebrile, control infants were enrolled; 6 (6.9%) were positive for enterovirus; 3 had received oral poli o vaccine. Conclusions. Nonpolio EV infections commonly cause fever in infants less th an or equal to 90 days of age. Rates of EV positivity are low in afebrile, unimmunized infants. The use of PCR to identify febrile infants with nonpol io EV infections may decrease length of hospital stay, unnecessary antibiot ic administration, and charges.