As Los Angeles County grapples with a spike in coronavirus infections and hospitalizations, health officials said Wednesday they traced several COVID-19 outbreaks to recent parties and family gatherings.

“Unfortunately, many of these celebrations resulted in the spread of COVID-19, and for some, serious illness that required hospitalization,” county Public Health Director Barbara Ferrer said in a media briefing.

Ferrer said this underscores the “very real risk” of celebrating with members of different households during the upcoming Fourth of July weekend.

There were 1,889 people hospitalized for COVID-19 across the county’s hospitals on Wednesday — the highest number reported since early May. About 27% of them were in intensive care units and 18% on ventilators.

And while older people and those with underlying health conditions continue to experience worse illness from COVID-19, officials are beginning to see “a slight shift toward a younger demographic” among those hospitalized for the respiratory illness, county Health Services Director Dr. Christina Ghaly said.

The county recorded 2,002 new coronavirus cases and another 35 deaths Wednesday, bringing the countywide case total to 105,507 with 3,402 deaths.

Though Wednesday marked the fourth consecutive day the county has reported more than 2,000 infections in just one 24-hour period, Ferrer said the number could be even higher since a major lab had not yet reported test results to the health department.

The troubling upward trend in cases and hospitalizations prompted Gov. Gavin Newsom to order L.A. County and 18 other counties to roll back reopenings and close indoor operations for at least three weeks.

Ferrer said the county will modify its health order to require the closure of indoor in-person dining at restaurants, as well as the closure of indoor museums, zoos, aquariums, cardrooms and satellite wagering facilities.

And at fitness facilities, all people working out and staff are now required to wear cloth face coverings and gloves the entire time, the health director said.

The county has also shut down all bars, temporarily closed beaches and banned large firework displays in an attempt to mitigate a surge in transmissions that could result from crowding during the holiday weekend.

“I know these closures are frustrating, and it is heartbreaking to think we are losing ground,” Ferrer said. “These immediate actions give us a chance to regain control over the increased spread. With steep increases in cases and hospitalizations, it is important to act now to prevent as many future cases, hospitalizations and deaths as we can.”

Ghaly reminded residents that estimates show one in 140 Angelenos could be infectious and are not isolating themselves — a number three times higher than last week’s estimates.

“That is a very much a change for the worse and should be cause for concern,” she said. “And it serves as a reminder of the importance of taking those protective health measures, the public health measures that we talked so much about, seriously.”

The county continues to see an increase in the rate of people testing positive for the virus, with the overall positivity rate standing at 9% as of Wednesday.

“There’s so much more infection in our county circulating right now than there was even a week ago. So, this would be the time I’d really urge people not to get out of your household,” Ferrer said.

The health director said the county is now “at a critical juncture” amid the pandemic and urged residents to remain steadfast in following public safety guidelines.

Asked about coronavirus spread at massive protests that took place in the county in recent weeks, Ferrer again explained that it’s too difficult to trace exposures at protests, and added that risk of transmission at the demonstrations is the same as it is on a crowded boardwalk or at a party.

“These crowded situations where people don’t have their face coverings, unfortunately, happen in lots of different places,” Ferrer said. “And it’s not about blaming anybody or trying to figure out if they get it here or did they get it there. The real issue for all of us is to reduce our risk of either giving it to somebody else or getting it.”

Though officials have been urging residents who believe they’ve been exposed to the virus to get tested, the county and city coronavirus testing sites are not taking any more appointments for the rest of the week.

Ghaly said this in part due to thousands of appointment slots being taken offline because of the holiday, and also because there has been an increase in demand for testing. The doctor added that in contrast to the early stages of the pandemic, testing is now more widely available through the healthcare system, and residents can get tested for the virus through their provider.

Ferrer asked those who believe they’ve been exposed and can’t get tested to stay home and avoid contact with others.