The “vast majority” of the adult homeless shelter population in Boston who tested positive for the novel coronavirus showed no symptoms, a study released on Wednesday revealed, prompting doctors who work with the destitute in the region to sound the alarm about the asymptomatic spread of the virus and the need for more testing.

Researchers tested 408 homeless people at the Boston shelter and found that 147 (36 percent) were positive for the virus. Of the 147, only about 11 (7.5 percent) had a cough, two (1.4 percent) had shortness of breath, and one (0.7 percent) had a fever, the study revealed, adding:

Universal SARS-CoV-2 [coronavirus] PCR [polymerase chain reaction] testing of an adult homeless shelter population in Boston [during the last week of March], shortly after the identification of a COVID-19 [illness caused by the coronavirus] case cluster yielded an alarming 36% positivity rate. The vast majority of newly identified cases had no symptoms and no fever on a single point-in-time assessment.

The authors of the study maintain an affiliation with the Boston Health Care for the Homeless Program and the Massachusetts General Hospital.

Dr. Jim O’Connell, the president of the Boston Health Care for the Homeless Program, warned this week that his organization has been unable to conduct testing at the same level described in the study, adding that the shelters could be virus-Petri dishes.

“No homeless shelters that we are aware of at this point have been able to do universal testing,” he cautioned in an interview with the Common Health news outlet, citing a lack of testing across the nation.

Dr. O’Connell acknowledged that federal, state, and local governments understand the gravity of the coronavirus problems at homeless shelters and are actively working to address the issue.

“Each day that we don’t know of someone who’s asymptomatic, they are spreading that virus to two or three other people,” he pointed out. “And it becomes an exponential growth. And the sooner we stop that, the more likely we are to be able to get control.”

The authors of the study published the results on Wednesday, noting:

Our findings illustrate the rapidity with which with COVID-19 can be widely transmitted in a homeless shelter setting and suggest that the universal PCR testing, rather than symptom triggered approach, may be a better strategy for identifying and mitigating COVID-19 among people experiencing homelessness.

“This article is a preprint and has not been certified by peer review [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice,” the authors conceded about the report on the findings of their study.

The average age of the tested subjects, who were all older than 18, was about 52 years, and the majority (about 72 percent) were male. About one-third of the subjects are African-American and 19 percent are Hispanic or Latino.

Echoing former New York Times reporter Alex Berenson who has been keeping a close eye on the coronavirus outbreak, Dr. O’Connell deemed the severity of the asymptomatic spread of the coronavirus “stunning.”

His comments echoed a tweet from former New York Times reporter Alex Berenson, who has been keeping a close eye on the coronavirus outbreak.

Referring to the number of people in the study who tested positive despite showing no symptoms, Dr. O’Connell told the Common Health online news outlet:

[T]he usual screening tool we had been using in order to see who should be tested turned out to be essentially useless for us. So this was stunning to us. We were not expecting that. The shelter was certainly not expecting that … And so, asymptomatic spread of this virus, while known in the past, has always been thought to be just a small part of it.

But it may be that in certain centers like shelters — as it was in the cruise ship, as it might be in prisons … and nursing homes, for example — it can be a real problem. So we’re struggling about what the right thing to do is.

U.S. President Donald Trump’s administration is working to make fast-results testing widely available.

Early this month, Boston officials reportedly revealed that about one in three homeless people in the city has tested positive for the COVID-19 virus.