Table 1 Common viral illnesses presenting as fever in young infants and association with bacterial illness. Data from references [21,46,47,, 24, 25, 45–48]

Enterovirus (EV)

CSF EV PCR; EV serum PCR if EV sepsis is suspected

Low risk for concomitant bacterial meningitis and bacteremia. Decreased risk for UTI

Human parechovirus (HPeV)

CSF HPeV PCR

Insufficient data, but likely decreased risk of bacterial meningitis, bacteremia, and UTI

Respiratory syncytial virus (RSV)

Nasopharyngeal RSV Ag detection or RSV RT‐PCR

Low risk for concomitant bacterial meningitis or bacteremia. Decreased risk for UTI

Influenza A/B

Nasopharyngeal Influenza A/B Ag detection or Influenza A/B RT‐PCR

Low risk for concomitant bacterial infection

Human rhinovirus (hRV)

Nasopharyngeal rhinovirus PCR

Unknown. Due to prolonged viral shedding, unable to solely attribute febrile illness to rhinovirus

Adenovirus (ADV)

Nasopharyngeal adenovirus RT‐PCR

Unknown. Due to prolonged viral shedding, unable to solely attribute febrile illness to adenovirus

Human parainfluenza virus (HPIV) 1,2,3,4

Nasopharyngeal HPIV 1,2,3,4 RT‐PCR

Insufficient data, but likely low risk of concomitant bacterial infection

Rotavirus (ROTA)

Stool rotavirus Ag detection, stool rotavirus enzyme immunoassay or rotavirus PCR

Insufficient data, but likely low risk of concomitant bacterial infection

Herpes simplex virus (HSV) Types 1 and 2

CSF HSV PCR, viral culture or PCR of vesicles

Surface cultures in neonates (mouth, nasopharynx, conjunctivae, perianal)

Serum HSV PCR (if available)

Insufficient data, but likely low risk of concomitant bacterial infection

Human herpes virus‐6 (HHV‐6)

Plasma HHV‐6 RT‐PCR; HHV‐6 serologic antibody titers

Insufficient data, but likely low risk of concomitant bacterial infection