Concurrent Detection of Bacterial Pathogens in Hospital Roommates.

Most cultures were ordered because clinicians suspected infection, not because all patients were screened, so patients colonized without symptoms may not be counted. The study did not use molecular typing, so it cannot confirm that roommates carried genetically identical strains. Concurrent detection cannot show how the organism was acquired. Room contamination, a previously colonized roommate, healthcare personnel, or unrelated sources remain possible. The data were retrospective and came from existing administrative and laboratory records, not direct observation of cleaning, hand hygiene, or patient contact. Only six organisms were analyzed, and six roommate pairs were excluded because of prior hospitalization with the same organism.

The paper lists NIH extramural research support. The authors declared no conflicts of interest.

Do not read the 379 concurrent detection events as proof that one roommate infected the other. The study did not type strains, and it cannot separate room contamination, staff transmission, or unrelated acquisition.