Rising coronavirus cases in 39 U.S. states cast a shadow over the nation’s Fourth of July celebrations as health experts worried that holiday parties will cause a further spike in infections that could overwhelm hospitals.

The United States reported more than 55,000 new COVID-19 casesy, a new daily global record for the coronavirus pandemic, as infections rose in a majority of states.

New U.S. COVID-19 cases rose by nearly 50,000 on Wednesday, according to a Reuters tally, marking the biggest one-day spike since the start of the pandemic.

Americans’ anxieties over the spread of the coronavirus are at the highest in more than a month, a Reuters/Ipsos poll showed on Wednesday, as California recorded the state’s largest single-day spike in cases since the pandemic began.

The death toll from COVID-19 surpassed half a million people, according to a Reuters tally, a grim milestone for the global pandemic that seems to be resurgent in some countries even as other regions are still grappling with the first wave.

Global coronavirus cases exceeded 10 million on Sunday according to a Reuters tally, marking a major milestone in the spread of the respiratory disease that has so far killed almost half a million people in seven months.

Florida and four other states recorded daily highs for cases of COVID-19 on Saturday, highlighting the worsening spread of the coronavirus in parts of the U.S. South and West, prompting some officials to roll back their reopening plans.

The United States recorded 45,242 new cases of COVID-19 on Friday – the largest single-day increase of the pandemic – according to a Reuters tally, bringing the total number of Americans who have tested positive to at least 2.48 million.

The governor of Texas temporarily halted the state’s reopening as COVID-19 infections and hospitalizations surged and the country set a new record for a one-day increase in cases.

Government experts believe more than 20 million Americans could have contracted the coronavirus – 10 times more than official counts – indicating many people without symptoms have or have had the disease, senior administration officials said.