If we assume an APM prevalence of 0.2% (1 case in the study sample), the estimated probability of obtaining our results by chance, based on binomial analysis, would be 0.37. Most of the specimens we tested were from the upper respiratory tract, whereas the only reported APM PCR-positive sample was from a lower respiratory bronchoalveolar lavage specimen (3) . Moreover, the patient populations sampled may not represent those at highest risk for APM infection. Nevertheless, our study supports the fi ndings of an Austrian study that failed to detect APM in 214 nasopharyngeal specimens from hospitalized children with respiratory symptoms (8) .