The question remains: How many of President Trump's 200 guests contracted the coronavirus after attending the announcement of his next Supreme Court nominee? The Sept. 26 gathering, since branded a super-spreader event, has resulted in at least 34 people connected to the event or to the White House testing positive for the coronavirus. An infected person could infect at least two other people.

Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, didn’t parse words Oct. 9 when he told CBS News Radio that data confirms Judge Amy Coney Barrett’s coming-out party seeded the virus’s spread.

“We had a super-spreader event in the White House,” he said. “And it was a situation where people were crowded together, were not wearing masks. So the data speaks for themselves.”

But figuring out exactly how many people at the event contracted COVID-19 will not be easy. Many attendees have scattered across the country, returning to their homes and their daily lives likely unaware that they had been exposed to the virus. And the White House has resisted much of the CDC's effort to conduct contact tracing.

“I think that it is fair to say that anybody who attended the event or worked at it could have been exposed to the virus, since it is likely that they came across others, some of whom were infected,” said Seth Welles, PhD, ScD, a professor of epidemiology and infectious disease at Drexel University’s Dornsife School of Public Health in Philadelphia. “How many have been infected is a whole other story.”

A super-spreader event is defined as when a critical number of infected individuals are in close proximity to a large group of people, allowing a virus to transfer easily. A week after the Rose Garden event, President Trump announced that he and first lady Melania Trump had tested positive for the virus. Several aides attending the ceremony, including Hope Hicks, Stephen Miller and Kayleigh McEnany, and Republican Senators Thom Tillis (R-NC) and Mike Lee (R-UT) have also tested positive.

“The Barrett Rose Garden event is a great example,” Dr. Welles said.

From there, it becomes a geometric progression. Early reports said that nine people, including two journalists, were infected at the ceremony. Epidemiologists know that one infected person is likely to infect two or three people, Dr. Welles said. Those two or three people are each likely to infect two or three people, and so on. And then there are those who have no symptoms; they are still capable of spreading the virus.

“The percentage of people with severe symptoms is 5% to 10% among those infected, and around 2% die,” Dr. Welles said. “It is concerning.”

Contact tracing is the best way to stop the super-spreading of a virus. It takes a lot of manpower and a good deal of training to do it right, Dr. Welles said. To get complete and accurate information to build a thorough chain of transmission, contact tracers have to gain the trust of each individual they interview before they ask personal questions like, When was the last time you were tested? When did you develop symptoms? Whom have you been in contact with? Where do those people live and how can they be reached?

“There are problems with the test not initially showing infection,” Dr. Welles said. “And people become detectable as they progress with their infection and the amount of virus they are harboring increases.”

But people who attended the Rose Garden event, sitting shoulder-to-shoulder without masks, were never asked those questions because contact tracing never happened, or at least it didn’t happen on a large scale. White House deputy press secretary Brian Morgenstern told the Associated Press that the White House has done limited contact tracing, looking back 48 hours to find people who may have been within six feet of an infected person for at least 15 minutes.

If the White House had just told epidemiologists that people at the event were infected, contact tracing could have been quickly ramped up. People would have been contacted, told of their exposure and tested several times for the virus.

“That is what you needed to do, and they are not doing it ,” Dr. Welles said. “They are not being upfront about this.”

Washington, D.C., and nine other area jurisdictions, however, are trying to contact trace the event locally. In an attempt to squelch an outbreak, the D.C. Department of Health published an open letter asking people who have worked at the White House in the past two weeks, attended the Rose Garden announcement, or have had close contact with people who work there, to contact their local health department.

Robert Calandra is an award-winning journalist, book author, and playwright. His work has appeared in national and regional magazines and newspapers.