VANCOUVER -- Health officials in British Columbia have announced another 55 test-positive cases of COVID-19, bringing the national total to more than 50,000 infections.

Provincial health officer Dr. Bonnie Henry said the majority of the cases announced during Tuesday's virus briefing are connected to the two poultry plant outbreaks that B.C. is still working to contain in the Lower Mainland.

There are now 46 cases of COVID-19 associated with Superior Poultry Processing Ltd. in Coquitlam and 34 associated with United Poultry Ltd. in East Vancouver.

In addition, the massive outbreak at Mission Institution, the federal prison in B.C.'s Fraser Valley, has grown to 132 cases. That includes 120 inmates, or about 40 per cent of the prisoner population at the facility.

Though the ongoing community outbreaks are concerning, and highlight how easily the province's progress in flattening its pandemic curve can be reversed, Henry said they have not yet forced officials to rethink their plans to lift some of B.C.'s COVID-19 restrictions in May.

"I still think we're looking at mid-to-end May," she said. "I still want to see things going down, but these outbreaks are known outbreaks."

More concerning for health officials are what's known as unlinked cases, where people fall ill without any obvious clues leading investigators to the source of the infection. Dr. Henry said there are still some of those cases emerging in B.C., but that the majority of patients are connected to known sources.

"They may be a household contact of somebody who worked in the poultry plant, for example," she said.

Officials did not announce any new outbreaks at seniors' homes or acute care units, which account for 391 of the 2,053 cases that have been identified in the province since the first confirmed infection in late-January.

Dr. Henry did reveal two more people have died from the virus, however, leaving the provincial death toll at 105.

She noted that the announcement of the latest fatalities coincided with the National Day of Mourning, "a time to honour those who were killed, injured or made ill as a result of workplace injuries."

A number of the people who have suffered from COVID-19 in the province should be included in that group, she said.

Meanwhile, another 41 patients have fully recovered from the virus, bringing the total to 1,231 and the number of remaining active cases to 717.

Of those, there are 94 people battling COVID-19 in hospital, including 37 patients who are in critical care or intensive care. Officials have called the number of hospitalizations, which represents the most severe infections, as one of the more accurate measures of the seriousness of B.C.'s epidemic.

Dr. Henry said some of the people who have beaten COVID-19 are helping the province determine the accuracy of a number of available serology tests, which detect antibodies that indicate whether a person has already recovered from the virus and is potentially immune.

"People who have recovered from COVID-19 are in line to help us validate, as we call it, the test. And that's happening even this week," she said.

She said the B.C. Centre for Disease Control is assessing 17 different types of serology tests, and that "there are some that are very promising."

Watch an American Sign Language translation of the news conference on the provincial government's YouTube page.

This is a developing story. Check back for updates.