Coronavirus latest: Over 74K new cases in US children since early August, report says

The proportion of people testing positive for COVID-19 in Germany who were likely infected abroad has "markedly increased to 42%," according to the country's public health institute.

That figure hit 45% earlier this year, the highest so far, but then fell steadily to 0.3% in the following weeks as a result of travel restrictions. Since borders have reopened, initially in Europe, the proportion of Germany's cases with a probable place of infection abroad "has increased significantly in recent weeks," the Robert Koch Institute said in Tuesday's daily situation report.

Kosovo, Croatia, Turkey, Bosnia and Herzegovina, Bulgaria, Spain and Romania were most frequently reported as the country of exposure.

"Through consistent prevention and early case identification, transmission and subsequent cases can be greatly reduced," the institute said. "It remains essential that people follow the rules of physical distancing and hygiene and avoid crowds, and that anyone who develops symptoms compatible with COVID-19 be tested immediately. In addition, travelers who stayed in a COVID-19 risk area within 14 days of entry must maintain a 14-day quarantine unless they have a negative test result."

As of Wednesday, Germany had reported 236,429 confirmed cases of COVID-19 and 9,280 deaths. There were 1,567 new cases recorded in the past 24 hours, according to the latest data from the Robert Koch Institute.

Arizona State University said it has 161 known cases of COVID-19 among its students and staff.

"Please keep in mind this number includes students and employees across our four metropolitan campuses and includes students living on and off campus throughout the broader community," Arizona State University president Michael Crow said in a statement Tuesday night. "I know there has been and will continue to be interest in this number. What I am committing to are regular updates about our COVID management strategy."

Since Aug. 1, the public research university has collected test results from 32,729 students and employees so far, according to Crow.

Crow also released clarification on the school’s coronavirus-related policies, including a no-visitor policy in the residence halls, a face covering requirement in all of the university’s buildings and outdoors spaces at all times (except when eating), and the barring of social gatherings among students on or off campus that don’t adhere to public health protocols.

ABC News contacted the U.S. Centers for Disease Control and Prevention on Tuesday night inquiring about the updates to its COVID-19 testing guidelines, what evidence exists to justify the changes and whether the agency can address concerns from the public that this was done for political reasons to reduce case numbers.

But the answer that came back was from the U.S. Department of Health and Human Services, not the CDC.

"CDC recommends the decision to be tested should be one made in collaboration with public health officials or your health care provider based on individual circumstances and the status of community spread," an HHS spokesperson told ABC News in an email. "The Guidance fully supports public health surveillance testing, done in a proactive way through federal, state, and local public health officials."

The HHS spokesperson listed the following as bullet points on the intent of the CDC’s updated guidance: "Ensure testing is used appropriately and individuals are protecting themselves and others; Place an emphasis on testing individuals for both clinical and/or public health reasons, including the testing of asymptomatic people when directed by public health leaders or health care providers; Emphasize how negative tests should be interpreted, and how they should (and should not) be acted on."

The White House declined to comment on whether the president or any administration staff was involved with or had any communications with the CDC or HHS about the updated guidelines.

ABC News’ Anne Flaherty and Ben Gittleson contributed to this report.

There were 38,174 new cases of COVID-19 identified in the United States on Tuesday, according to a count kept by Johns Hopkins University.

Tuesday’s tally is well below the country's record set on July 16, when 77,255 new cases were identified in a 24-hour reporting period. It’s the third straight day that the country has reported less than 40,000 new cases.

An additional 1,242 coronavirus-related deaths were also recorded Tuesday, a nearly threefold increase from the previous day. The latest daily death toll is still under the record 2,666 new fatalities that were reported on April 17.

A total of 5,779,371 people in the United States have been diagnosed with COVID-19 since the pandemic began, and at least 178,524 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.

However, the numbers of new COVID-19 cases and new deaths in the United States have both decreased by substantial amounts in week-over-week comparisons, according to an internal memo from the Federal Emergency Management Agency obtained by ABC News Tuesday night.