SPECIMEN TYPE AS A SOURCE OF VARIABILITY IN THE REPRODUCIBILITY AND TIMING OF CYTOMEGALOVIRUS IDENTIFICATION BY CULTURE

Cytomegalovirus (CMV) is a significant contributor to morbidity and mo rtality among immunocompromised individuals; therefore, rapid and accu rate diagnosis is essential. We compared positive cultures In = 147) f rom different specimen types as to (a) the incubation time to a positi ve result and (b) the reproducibility of positive findings in replicat e cultures. Five replicate shell vials were inoculated from each speci men: Two vials were stained at 24 h, two at 48 h, and one held and obs erved for a maximum of 30 days. Positive cultures from tissue biopsy s pecimens required the shortest incubation (mean = 1.9 days) and urine specimens the longest (mean = 3.9 days) (P <.005). Tissue biopsy speci mens were the most reproducible (48.4% of specimens were positive in f ive of five replicates) and urine specimens the least (no specimens we re positive in five of five replicate vials) (P <.0002). The observed interspecimen variability is important because failure to understand a nd adjust for these differences could negatively influence the ability to identify CMV in culture.