Coronavirus updates: State declares public health emergency over case 'surge'

An internal memo from the Federal Emergency Management Agency obtained by ABC News on Monday night shows that the number of new cases and the number of new deaths recorded in the United States are both increasing in week-over-week comparisons.

Twenty-three U.S. states and territories are in an upward trajectory of COVID-19 infections, while 14 jurisdictions are at plateau and 19 others are in a downward trend, the memo said.

There were 283,332 new cases confirmed across the nation during the period of Sept 14-20, a 17.2% jump from the previous week. Meanwhile, 5,319 coronavirus-related deaths were recorded during that same period, a 2.4% increase compared with the seven days prior, according to the memo.

The national positivity rate for COVID-19 tests ticked downward slightly to 4.4%, compared with 4.6% for the previous week, the memo said.

Alabama recorded a 46.5% increase in the state's seven-day death rate during the period of Sept. 9-15, compared with the week prior. Meanwhile, the Alabama Hospital Association confirmed a statewide shortage of nurses in both hospitals and universities due to a lack of faculty, facilities and funds, according to the memo.

In Florida's Alachua County, 90% of recently reported cases are among individuals between the ages of 15 and 25, and 70% of those cases are college students, according to the memo.

Meanwhile, a recent increase in new cases in Kentucky's Hardin County is attributable to roughly 75% of students returning to school for in-person instruction, the memo said.

New Jersey's positivity rate for COVID-19 tests rose from 3% to 7% among 14-18 year-olds and from 2.7% to 7.1% among 19-24 year-olds. Nearly 20% of the state's confirmed cases are individuals below the age of 30, according to the memo.

Pennsylvania's Centre County, home to Pennsylvania State University, remains a COVID-19 hotspot, reporting a 291.3% relative increase in new cases during the period of Sept. 9-15 compared with the previous week. The county's hospitals are under strain, with inpatient beds at 88% capacity and intensive care unit beds at 81% capacity, the memo said.

South Dakota reported its highest single-day death toll of eight coronavirus-related fatalities on Sept. 16. The state saw a 21% increase in COVID-19 hospitalizations, setting a record high on Sept. 15. A major outbreak in the state's capital, Pierre, has led to at least 105 cases among inmates at a minimum-security women's prison as well as rising cases among community members, according to the memo.

ABC News' Josh Margolin contributed to this report.

An additional 356 coronavirus-related fatalities were recorded in the United States on Monday, bringing the country's death toll even closer to the 200,000 mark, according to a real-time count kept by Johns Hopkins University.

Monday's tally of COVID-19 deaths is well under the country's record set on April 17, when there were 2,666 new fatalities in a 24-hour reporting period.

There were also 52,070 new cases of COVID-19 confirmed across the nation on Sunday, down from a peak of 77,255 new cases reported on July 16.

A total of 6,857,967 people in the United States have been diagnosed with COVID-19 since the pandemic began, and at least 199,884 of them have died, according to Johns Hopkins. The cases include people from all 50 U.S. states, Washington, D.C. and other U.S. territories as well as repatriated citizens.

By May 20, all U.S. states had begun lifting stay-at-home orders and other restrictions put in place to curb the spread of the novel coronavirus. The day-to-day increase in the country's cases then hovered around 20,000 for a couple of weeks before shooting back up and crossing 70,000 for the first time in mid-July. The daily tally of new cases has gradually come down since then.