One hundred forty six homeless persons at a Boston shelter tested positive for the coronavirus without showing any symptoms, concerning experts that the pandemic may be more wide spread than originally thought.

The Pine Street Inn was following up a small cluster of cases last week and tested 397 people to discover that 146 were confirmed to have the deadly flu-like virus, also known as COVID-19.

What was equally alarming to health officials was also learning that 100 per cent of the confirmed cases at the shelter had no symptoms.

One hundred forty six homeless persons tested positive for the coronavirus with no symptoms at the Pine Street Inn shelter in Boston, health officials say

The Pine Street Inn was following up a small cluster of cases last week and tested 397 people to discover that 146 were confirmed to have the deadly flu-like virus, also known as COVID-19. Homeless people are picture on the street in Boston following the shelter's testing

The Centers for Disease Control and Prevention is now 'actively looking into the universal testing' that was conducted at the shelter, WFXT reports.

Dr. Robert Redfield, the CDC's director, earlier this month said that as many as one in four coronavirus patients in the US are asymptomatic.

Redfield says this probably explains how cases continue to spread across the country even as strict social distancing measures are enacted.

There have been 4,763 cases in Boston of the coronavirus and 122 deaths.

Meanwhile, Massachusetts has had a total of 29,918 cases and 1,108 deaths.

Across the country, there have been close to 659,000 cases and 33,524 deaths resulting from the coronavirus.

There have been close to 659,000 cases and 33,524 deaths resulting from the coronavirus

A look at how the number of new cases of the coronavirus has escalated over time

A look at how the number of new infections of the coronavirus has escalated over time

A day-to-day tally of the number of deaths in the US blamed on the coronavirus

Dr. Jim O'Connell, president of Boston Health Care for the Homeless Program, which brings medical care to the city's shelters, said the discovery of such a high number of asymptomatic cases at the Pine Street Inn caught health officials off guard.

'It was like a double knockout punch, he tells WFXT. 'The number of positives was shocking, but the fact that 100 percent of the positives had no symptoms was equally shocking.'

The 146 people confirmed to have COVID-19 were immediately moved to two different temporary isolation facilities in Boston. Only one of the homeless persons needed hospital care, and many continue to show no symptoms, O'Connell said.

Dr. Jim O'Connell, president of Boston Health Care for the Homeless Program, which brings medical care to the city's shelters, said the discovery of such a high number of asymptomatic cases at the Pine Street Inn caught health officials off guard

As the CDC follows up, testing in the shelters will have to change, he said.

'All the screening we were doing before this was based on whether you had a fever above 100.4 and whether you had symptoms,' O'Connell explains. 'How much of the COVID virus is being passed by people who don't even know they have it?'

Lyndia Downie, President and Executive Director at the Pine Street Inn questioned if doing universal testing among the general homeless population would produce similar results.

Lyndia Downie, President and Executive Director at the Pine Street Inn questioned if doing universal testing among the general homeless population would produce similar results

'I think there are so many asymptomatic people right now. We just don't know. We don't have enough data on universal testing to understand how many asymptomatic people are contagious.'

The shelters have scheduled hundreds of tests in the coming days.