Coronavirus infections can be controlled at universities this fall if students are tested for the virus every two days, according to a study published Friday. 

The study was done by researchers from the Yale School of Public Health, Harvard Medical School and Massachusetts General Hospital and published in the Journal of the American Medical Association Network Open. The study used computer simulations to show how the virus might spread among a hypothetical cohort of 5,000 students.

In the simulations, 4,990 students were assumed to be coronavirus-free, while 10 were assumed to be infected. Researchers found screening every two days using a rapid, inexpensive test - even one that was not always accurate - would "maintain a controllable number of COVID-19 infections" if coupled with "strict behavioral interventions" such as quarantining positive students in isolation dormitories.

The study estimated screening would cost $470 per student per semester and did not consider the effects of reopening schools on staff and communities where colleges are located. It also said that monitoring students for symptoms was not sufficient and that logistical challenges such as the availability of tests or isolation dormitories "may be beyond the reach of many university administrators and the students in their care."

But the pace and extent of viral testing that the study envisions could be difficult to carry out.

Brett Giroir, a top federal health official overseeing coronavirus testing, acknowledged to lawmakers Friday that getting results back to all patients within two to three days is not possible now. Giroir told a House panel that 75% of test results are coming back within five days.

Still, the study suggested that with sufficient resources, universities could reopen.

"We believe there is a safe way for students to return to college in fall 2020," the study said.

A. David Paltiel, a professor at the Yale School of Public Health and the study's lead author, said the study was undertaken as a consortium of university presidents in the Boston area looked for a way to safely reopen.

Paltiel said the frequency of testing is more important than its accuracy. Repeated tests would eventually find the positive cases, he said.

While there are risks in any plan to reopen campuses in a pandemic, according to Paltiel, there are also risks to letting students stay at home.

"The problem doesn't go away simply because you don't reopen campus," he said. "We can't let the perfect be the enemy of the good."

The study comes as many universities, including some in the Washington region, announced plans to move online for the fall semester. Georgetown University and George Washington University will remain remote for the rest of the year. Other schools, including Yale and Harvard, plan to welcome some students back to campus. Yale will require undergraduates living in dorms to be tested twice weekly, while Harvard plans to test students on campus every three days.

Other schools, such as those in the University of Maryland system, will require students to test negatively for the novel coronavirus before enrolling.

Colby College in Maine, which has about 2,000 students, has set an ambitious viral testing goal. It has pledged to test everyone on campus - students, faculty and staff - three times a week at the start of the semester and twice weekly for the rest of the term. The cost for testing will be as much as $2.5 million.

But Colby, like several schools in the Northeast, has access to relatively inexpensive testing through a nonprofit biomedical research center in Cambridge, Mass., that is charging about $25 to $30 per test. Elsewhere in the country, prices can surpass $100 per test. For colleges facing fiscal challenges, that could be a steep cost.

"All college presidents want tests that are fast, cheap and reliable," said Terry Hartle, senior vice president of the American Council on Education, a higher education advocacy group. "Unfortunately those don't exist."

Michael Mina, an epidemiology professor at Harvard who was not involved in the study, said high-volume testing by universities is "a little bit niche," but may be the key to safely reopening for the fall semester.

While the public, many drug companies and the Food and Drug Administration are focused on tests' accuracy, Mina said, battling the coronavirus successfully may simply demand testing more often, even if tests aren't always reliable.

The problem is not all schools - let alone the general public - have private labs or relationships with the pharmaceutical industry that give them access to a large number of tests. Simple at-home tests that provide rapid results are necessary everywhere, Mina said.

"This is a very powerful approach to get society running again," he said. "It's a way we should all be thinking."

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The Washington Post's Rachel Weiner and Nick Anderson contributed to this report.