Impact of PCR for respiratory viruses on antibiotic use: theory and practice.

rationale for the studyReal-time polymerase chain reaction (PCR) for respiratory viruses is more sensitive, yet more expensive, than conventionally used direct immunofluorescence (DIF). We determined the impact of real-time PCR, additional to DIF, on antibiotic prescription in ventilated children with lower respiratory tract infection (LRTI) at admission to the pediatric intensive care unit (PICU).

methodsFirst, a multicenter survey study was performed. Subsequently, in a prospective study, children (≤ 5 years) with LRTI were tested at admission by DIF and PCR. Positive DIF results were reported at the end of the first working day. PICU physicians reported antibiotic treatment on the second working day. After informing them of the PCR result antibiotic treatment was reevaluated.

resultsThe multicenter survey study (94 respondents) showed that PCR decreased antibiotic use (P < 0.001). In the prospective study 38 children were included, of which 19 (50%) were DIF positive. Of the 19 DIF negative patients 12 (63%) were treated with antibiotics before revealing the PCR result; the PCR test was positive in 9 out of 12. Revealing PCR results did not alter antibiotic treatment. In 7 DIF negative patients antibiotics not given, the PCR test was positive.

conclusionIn contrast to their responses to the survey study, in real-life PICU physicians did not let their antibiotic prescription be influenced by respiratory real-time PCR in children ventilated for LRTI.