Six samples, he said, tested positive for amosite, a very hazardous type of asbestos.
Barnes said there was no way of telling whose samples actually tested positive.
No other samples, swabs, or tests taken at the facility have tested positive for Salmonella.
He said his office was developing a plan for a sample of up to 840 of the 4,200 apartments already cleaned or tested.
But city officials said that samples taken from that hospital area had thus far tested negative, suggesting she caught the disease somewhere else.
But a company executive, speaking on condition of anonymity, said that the city knew within hours that some samples had tested positive.
One sample tested positive for anthrax and seven tested negative, officials said.
Dr. Davis said pipes in the city water supply were flushed and samples tested.
If needed, the clinician will take samples to test for sexually transmitted infections.