The real-time PCR assays were used to test respiratory specimens from 496 pneumonia cases representing 9 distinct patient populations, which consisted of hospitalized pneumonia patients from population-based pneumonia surveillance studies in Thailand and the United States, transplant recipients with pneumonia, and isolated pneumonia outbreaks in either retirement homes for the elderly or familial clusters ( Table 2) . Of the 496 specimens tested, no positive results were obtained for APM DNA by either assay.