Ampicillin use in infant fever: a systematic review.

OBJECTIVES

To estimate the prevalence of perinatal Listeria monocytogenes and enterococcal infections in outpatient febrile infants and to evaluate the need to treat with ampicillin.

DATA SOURCES: Online bibliographies were searched for articles related to serious bacterial infection and fever in infants. Reference lists from selected and review articles were also examined.

STUDY SELECTION: Studies that reported rates and types of bacterial infection in febrile outpatients younger than 3 months were included. Those performed outside North America, lacking results by age, or those that evaluated selected patient populations were excluded.

DATA EXTRACTION: Two authors independently reviewed the selected articles for inclusion and abstracted the data.

DATA SYNTHESIS: Fourteen studies, evaluating 5247 febrile outpatients, were included. The prevalences of L monocytogenes and enterococcal infections were 7.3 (binomial exact 95% confidence interval [CI], 3.5-13.3), 1.9 (95% CI, 0.6-4.4), and 5.6 (95% CI, 0.7-2.1) per 1000 febrile infants in the first, second, and third months of life, respectively. To cover 1 infant with serious bacterial infection caused by L monocytogenes and enterococcal infections, the numbers of febrile infants who would need ampicillin were estimated as 138 (95% CI, 76-288) in the first month, 527 (95% CI, 226-1621) in the second month, and 178 (95% CI, 50-1469) in the third month. Enterococcal infections occurred in all ages studied; there were no Listeria infections after 30 days of age.

CONCLUSION

The empirical use of ampicillin to cover febrile infants for L monocytogenes and enterococcal infections is most justifiable in the first month of life.