Diagnosis and evaluation of febrile infants under 4 months of age in Japan by using RT-PCR for enterovirus.

OBJECTIVES AND METHODS

In order to establish an effective management for febrile infants under 4 months of age we analysed the causes of fever by using bacterial work up and a highly sensitive RT-PCR method during a 3-year-period. From February 1998 to January 2001, 263 infants under 4 months of age were admitted to our hospital because of fever (>38.0 degrees C) and enrolled in this study.

RESULTS

Eighty-nine cases (33.8%) were diagnosed as lower respiratory infections, and 62 (23.5%) as urinary tract infections. Aseptic meningitis was found in 35 cases (13.2%) and fever of unknown origin in 22 (8.3%). Sepsis and purulent meningitis were found in three and two infants, respectively. Aseptic meningitis was the most common disease in infants below 30 days. Aseptic meningitis and fever of unknown origin revealed no seasonable tendency. Twelve cases out of 20 tested infants with aseptic meningitis showed positive results for enterovirus in CSF.

CONCLUSION

Clinicians should consider age, sex and seasons when evaluating and treating infants with fever. Previously lumbar puncture, urinalysis and chest X-ray were recommended to avoid useless assays. These results also revealed that RT-PCR is a useful and significant assay to establish an exact diagnosis in very young infants.