"There are world leaders in many other countries that are able to manage their senior executive staff and not get exposed to COVID," said Dr. Mike Reid, an infectious disease specialist at UCSF.
"Everybody, the president included, needs to wear a mask."
RELATED: Trump tests positive for COVID-19, taken to Walter Reed military hospital and given remdesivir
Reid also leads San Francisco and California's contact tracing programs.
"Probably it spread to him via somebody who didn't think they were that unwell," Reid said. "If I was trying to understand the outbreak better there, I would want to understand who he spent time with, were they wearing a mask, did they spend more than 15 minutes in close proximity less than six feet away from him? And in particular, was there anybody with symptoms?"
Over the past week, Trump has attended at least 11 events, rallies and news conferences in seven different cities, including Saturday's Supreme Court announcement in the Rose Garden and Tuesday's Presidential Debate with Joe Biden in Ohio.
"It is our goal to try and reach all close contacts of confirmed cases within 24 hours," said Reid about the contact tracing program in San Francisco. "So one would hope that somebody has sat down with Mr. Trump and found out who all he has spent time."
RELATED: Contact tracing Trump: Timeline tracks president's activities leading up to his positive COVID-19 diagnosis
After White House Aide Hope Hicks tested positive for COVID-19 on Thursday, the president and first lady tested positive, and on Friday, they reported symptoms. Trump then flew to Walter Reed Medical Center on the advice of his physicians.
"The president has multiple risk factors for severe COVID disease and that includes that he's over 65, that he is obese, that he has high cholesterol and that he is male," said Dr. Yvonne Maldonado, a Stanford epidemiologist.
RELATED: 'He has not taken normal precautions': Trump's COVID-19 diagnosis not a surprise to some Bay Area lawmakers
Dr. Maldonado is involved in a clinical trial of Regeneron's antibody cocktail, which the president received a single dose of, through a compassionate use agreement with the company and FDA.
"The trials are ongoing to compare to placebo to see if it actually prevents people from getting progression of disease," explained Maldonado. "We need to protect this world leader and at this point I would use anything that I think is reasonably safe and has been reasonably tested even though they're not approved yet."
VIDEO: What does COVID-19 do to your body and why does it spread so easily?
If you have a question or comment about the coronavirus pandemic, submit yours via the form below or here.
Get the latest news, information and videos about the novel coronavirus pandemic here
RELATED STORIES & VIDEOS:
- Map: CA counties that can, can't reopen under new rules
- Updated number of COVID-19 deaths, cases in Bay Area
- COVID-19 Help: Comprehensive list of resources, information
- California EDD: The most commonly asked questions we get about unemployment and PUA
- How to tell the difference between seasonal allergies and coronavirus symptoms
- Here's which mask is better to protect from COVID-19
- First COVID-19 vaccine volunteers in US describe experience as Bay Area launches vaccine trials
- From salons to dinner parties: Experts rate the risk of 12 activities
- Coronavirus origin: Where did COVID-19 come from?
- What is a COVID-19 genetic, antigen and antibody test?
- What will it take to get a COVID-19 vaccine and how will it be made?
- What does COVID-19 do to your body and why does it spread so easily?
- Here's how shelter in place, stay at home orders can slow spread of COVID-19
- Coronavirus Timeline: Tracking major moments of COVID-19 pandemic in San Francisco Bay Area
- COVID-19 Diaries: Personal stories of Bay Area residents during novel coronavirus pandemic
- Coronavirus Doctor's Note: Dr. Alok Patel gives his insight into COVID-19 pandemic