Over the next two weeks, McDade and his laboratory staff ran confirmatory tests. On Friday, January 14, 1977, they went to report their findings to David Sencer, the head of the CDC. As they sat in Sencer’s office, McDade and Shepard hesitated for a few moments before they spoke. They knew what they had, but could hardly believe that their lab had solved this seemingly unsolvable problem. Then they came out with it: they had isolated the organism responsible for the Legionnaires’ Disease outbreak.
Sencer, as the head of a public health organization, immediately wanted to publish the results, but the meticulous lab scientists wanted time to repeat the experiments, perhaps in a different lab, to be absolutely certain their discovery was not a fluke. Sencer told them they had until Tuesday. Then the CDC would publish their results in a special Tuesday edition of the weekly Thursday news bulletin, the Morbidity and Mortality Weekly Report, alongside a press release.
The rickettsia lab worked through the weekend to confirm and write up their findings. On Tuesday morning, with their report already at the printer, Shepard reported to Sencer that they had also tested specimens from Pontiac and from another outbreak of pneumonia in a psychiatric hospital in Washington, DC, that had never been solved. Those samples were positive too.
The presses were held, and the story was amended.
A scheduled conference call included Pennsylvania health officials, the US Surgeon General, the National Institutes of Health, and everyone at the CDC who had anything to do with the epidemic investigation, from the lowliest “backbencher,” as McDade described himself, to the heads of the laboratory and epidemiology divisions. Shepard and McDade then attended a press conference where they announced their findings. There, they distributed the special Tuesday edition of the MMWR, the only special edition of that publication ever to be published.
Larry Altman, who had so doggedly chased the nickel carbonyl theory, and also, while in the EIS had happened to be the editor of the MMWR, was on assignment in Geneva reporting on a smallpox outbreak. He did not cover the press conference.
When McDade found antibodies to the bacterium that soon became known as legionella pneumophila in samples from the Pontiac outbreak, another piece of the puzzle fell into place.