(CNN) If you love your mom, consider staying away from her this Mother's Day.
Health officials are warning Americans to avoid celebrating Mother's Day in big groups, saying physical distancing is still critical to reducing the spread of coronavirus.
All it takes is one infected person at a gathering to launch a new outbreak. In Pasadena, California, officials traced a cluster of coronavirus cases back to one person at a birthday party who was coughing and not wearing a face mask.
"Guests were also not wearing face coverings or practicing social distancing," the city of Pasadena posted on Facebook. "As a result, COVID-19 spread among attendees."
"The last thing you want to give mom or anyone else is a virus," said Lisa Derderian, a spokeswoman for the city. "Stay home, stay safe. We're going to go by the science."
Louisiana health officials suggested safe alternatives, like having a virtual brunch together.
For those still planning to see their mothers in person, "Resist the temptation to hug your mom and maintain six feet of separation," the Louisiana Department of Public Health said.
Older adults have the highest risk of severe complications or death from coronavirus. And the numbers of cases and deaths keep rising.
By Sunday, more than 1,320,000 people in the US have been infected, and more than 79,000 have died, according to data from Johns Hopkins University.
"We are telling everyone, see mom virtually today," Derderian told CNN. "As much as you feel guilt on the front end for not seeing her, it's better than feeling guilt on the back end over the possibility you were carrying Covid-19 and you give it to mom or grandma, and the consequences were they got sick, or worse, it was fatal."
A projection model cited by the White House now predicts thousands more deaths, largely due to "explosive increases in mobility in a number of states."
The model, from the Institute for Health Metrics and Evaluation at the University of Washington, now forecasts 137,000 deaths in the United States by August, up from an earlier prediction of about 134,000.
IHME Director Dr. Christopher Murray said cell phone data shows Americans are moving more, suggesting more infections to come.
"We're seeing just explosive increases in mobility in a number of states that we expect will translate into more cases and deaths in 10 days from now," Murray told CBS' "Face the Nation" on Sunday.
"What's driving the change is, simply put, the rise in mobility," Murray said. "We're seeing in some states a 20 percentage point increase in just 10 days in mobility. And that will translate into more human contact, more transmission."
He said the top five states that have seen increased mobility are Montana, North Dakota, South Dakota, Minnesota and Georgia.
Other states have seen a 15-20 percentage point increase in mobility, according to an IHME press release: Alabama, Alaska, Idaho, Iowa, Kansas, Louisiana, Mississippi, Ohio, Oklahoma, South Carolina, Tennessee, Wisconsin, and Wyoming.
And public health experts have said there's still not enough testing or contact tracing to safely reopen the country.
But no one will know the health effects of each state's reopening for weeks.
"It will be at least two to three weeks before we see an increase in the number of infections because it takes time for individuals to infect others and for them to display symptoms," said data scientist Youyang Gu, whose coronavirus projection model is cited by the Centers for Disease Control and Prevention.
For those who might succumb to new infections, "around three weeks is the average time between infection to death," said Gu, citing studies from Italy and China.
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, has said if measures are lifted too early, the country could see a rebound of the virus that could land the US "right back in the same boat that we were a few weeks ago."
Fauci is one of several top government and health officials who said they came in contact with an infected person at the White House.
Fauci, a key member of the White House coronavirus task force, told CNN he will start a "modified quarantine" after making a "low risk" contact with a White House staffer who tested positive for the virus.
While Fauci was not in close proximity to the person, he said he will spend the next two weeks working from home and wearing a mask. Fauci said he might go to his office, where he will be alone.
CDC Director Dr. Robert Redfield will self-quarantine for two weeks after he was also exposed to a person at the White House who tested positive for the virus, a CDC spokesperson told CNN.
And Dr. Stephen Hahn, commissioner of the Food and Drug Administration, will also go into quarantine after coming into contact with a person who tested positive for the virus, an FDA spokesman confirmed to CNN on Friday.
Officials didn't identify the infected person with whom Hahn or Redfield came into contact. But at least two people close to the president or vice president have tested positive for coronavirus.
The White House confirmed Vice President Mike Pence's press secretary Katie Miller tested positive on Friday. She was often in White House coronavirus task force meetings.
And last week, President Donald Trump learned one of his Oval Office valets tested positive for the virus.
Federal officials and New York state officials are partnering to give other states information after the deaths of three youth that could be linked to the virus.
A teenager and two children under 8 years old died from an inflammatory illness observed in dozens of children in New York, state officials said.
That illness could be linked to the virus, they said.
"We were laboring under the impression young people were not affected by Covid-19," Gov. Andrew Cuomo said. "We're not so sure that that is the fact anymore."
Researchers still don't know whether coronavirus caused the syndrome. But this is under investigation, Cuomo said.
Many of the children tested positive for the virus or had its antibodies, Cuomo said. But they didn't always show symptoms common with Covid-19, such as respiratory distress.
"It's possible that these cases were coming in and were not diagnosed as related to Covid because they don't appear as Covid," Cuomo said.
State officials had previously warned that dozens of children in the state had been hospitalized with a condition doctors described as "pediatric multisystem inflammatory syndrome," and that it could be linked to coronavirus.
On Sunday, Cuomo said 85 cases were under investigation. The cases mainly involved toddlers to elementary-school-age children.
Many of the children had fever and symptoms similar to toxic shock syndrome and Kawasaki disease, the state said.
Kawasaki disease causes inflammation in the walls of blood vessels, including those that supply blood to the heart, which in rare cases can lead to deadly limitations in blood flow.
Also in New York, the state with the highest numbers of coronavirus cases and deaths, Gov. Cuomo unveiled new rules for nursing homes -- which he called "ground zero" for Covid-19.
All nursing home staff must be tested diagnostically twice a week, Cuomo said. He also said hospitals cannot discharge a patient to a nursing home unless the patient tests negative for Covid-19.
And nursing homes can only take in residents if they have all the necessary resources to fully serve them, Cuomo said. If a nursing home cannot provide the appropriate level of care, they must transfer to another facility or contact the state health department.
Any nursing home that doesn't follow these new rules could lose its license.
"We have alternative facilities for nursing home patients, Covid or non-Covid," Cuomo said. "We created 40,000 hospital beds because we had to."