Objective Neonates are frequently treated with antibiotics direct postnatally. Given the low rate of early onset sepsis (EOS) and the side effects of antibiotics, a restrictive approach is necessary. Negative blood cultures are considered helpful to evaluate discontinuation of antibiotic treatment. When results of blood cultures are not available, other cultures may be helpful. We determined the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of an ear culture taken for the diagnosis of EOS.

Methods Data of simultaneously taken blood cultures and ear cultures were retrospectively analyzed in neonates admitted between 1998 and 2004 to a tertiary neonatal intensive care unit on the first postnatal day.

Results In 156 of 369 neonates a positive ear culture was found and 13 of 369 neonates had a blood culture-proven EOS. 12 positive ear cultures were found in 13 neonates with a blood-culture proven EOS. One blood culture was positive for a coagulase negative staphylococcus after 3 days, but the ear culture was negative. The sensitivity, specificity, PPV and NPV were 93%, 60%, 7.7% and 99.5%, respectively.

Conclusions A negative ear culture almost completely rules out the presence of an EOS. When no blood culture is taken or when there is doubt about the reliability of the blood culture, a negative ear culture can help in the evaluation to discontinue antibiotic treatment.