The number of confirmed coronavirus cases per day in the US has climbed to a record high of more than 50,000, with the infection curve rising in 40 of the 50 states in a reversal that has largely spared only the northeast.

An alarming 36 states are seeing an increase in the percentage of tests coming back positive for the virus.

“What we’ve seen is a very disturbing week,” Dr Anthony Fauci, the government’s top infectious-disease expert, said in a live-stream with the American Medical Association.

Dr Anthony Fauci is urging Americans to wear face masks to slow the spread of the virus.

In a major retreat, Republican Governor Greg Abbott ordered the wearing of masks across most of the state after refusing until recently to let even local governments impose such rules.

The surge has been blamed in part on Americans not covering their faces or following other social distancing rules as states lifted their lockdowns in the past few weeks. Fauci warned if people did not start complying, “we’re going to be in some serious difficulty”.

The US has recorded 50,700 new confirmed cases, according to Johns Hopkins University. That represents a doubling of the daily total in the past month and is higher even than what the country witnessed during the most lethal phase of the crisis in April and May.

• Related: Global infections surge to grim milestone, as US hits new daily record

All but 10 states are showing an upswing in newly reported cases in the past 14 days, according to COVID Tracking Project data. The outbreaks are most severe in Arizona, Texas and Florida, which together with California have closed again or clamped back down on bars, restaurants and cinemas.

Nebraska and South Dakota were the only states outside the northeast with a downward trend in cases.

In the past two weeks, the percentage of positive tests has doubled in Georgia, Kansas, Montana, Michigan, Missouri, Tennessee, Mississippi, South Carolina and Ohio. In Nevada, it has tripled. In Idaho, it is five times higher.

In Texas, where new cases in the past two weeks swelled from about 2400 a day to almost 8100 by midweek, the positive rate ballooned from eight per cent to 14.5 per cent. In Arizona, it has gone from 5.7 per cent to 10.3 per cent.

The surge comes as Americans head into a Fourth of July holiday that officials warn could fuel the outbreak by drawing big crowds. Fireworks displays have been cancelled and California and Florida beaches are closed.

Florida reported more than 10,000 new confirmed cases for the first time on Thursday. The state also reported 67 deaths for the second time in a week and 325 new hospitalisations – one of the biggest 24-hour jumps in Florida yet. Georgia also saw its biggest single-day increase, nearly 3500 cases.

Meanwhile, the government reported that US unemployment fell to 11.1 per cent in June as the economy added a solid 4.8 million jobs.

Several northeastern states have seen new infections slow down significantly, including New York, Massachusetts, Connecticut, Rhode Island and New Jersey.

Pennsylvania, an outlier among northeastern states, reported its highest one-day total of new cases since May, with more than 830.

President Donald Trump on Wednesday seemed confident the virus would soon subside, telling Fox Business: “I think that, at some point, that’s going to sort of just disappear, I hope.”

The US has reported at least 2.7 million cases and more than 128,000 dead, the highest toll in the world.