VANCOUVER -- Health officials are working to contain another COVID-19 outbreak at a second poultry processing plant in Metro Vancouver.

Provincial health officer Dr. Bonnie Henry said the latest outbreak was detected at Superior Poultry in Coquitlam, where two cases of the novel coronavirus have been confirmed so far.

"There is an ongoing investigation that is happening as of yesterday, when the first case was identified," Henry said at her daily virus briefing on Thursday.

Officials described the facility as a "sister plant" to United Poultry in East Vancouver, where dozens of workers tested positive for COVID-19 this week.

Henry said the two plants are under different management, but that officials have determined there were "some people working in both places, or at least some movement of people between both places."

Officials also announced there has been one more confirmed infection in connection with the United Poultry outbreak, bringing the number of cases to 29. The first 28 were all employees of the plant, but officials did not say whether the latest case is a worker or a close contact of a worker.

Henry said she expects more cases to emerge in connection with the Superior Poultry outbreak as well.

The United Poultry outbreak has served as a reminder that the progress B.C. has made in combatting COVID-19 is fragile, and also of the importance of people staying isolated while even mildly ill.

B.C. Premier John Horgan revealed on Wednesday that multiple employees at the poultry plant came to work despite feeling unwell because they were worried about not being paid.

Dr. Henry stressed that people who have cold or flu symptoms, and even those who believe they are suffering from seasonal allergies, should not be going to work or leaving the house.

A number of precautionary measures have already been put in place to prevent further outbreaks in the industry, according to the Primary Poultry Processors Association of B.C. That includes daily temperature checks, a ban on bringing guests to plants, and increased hand hygiene and sanitation practices.

Earlier this week, the B.C. Chicken Marketing Board said the United Poultry outbreak would not impact the supply of chicken in grocery stores because the birds meant for the plant had already been diverted to other processors. The Canada Food Inspection Agency also said there's no evidence to suggest food processed at United could cause further infections.