There is one new case of COVID-19 in Manitoba, chief provincial public health officer Dr. Brent Roussin says.

That brings the total of confirmed and probable cases of the coronavirus in Manitoba to 21.

The latest case is a Winnipeg man in his 40s. Investigations continue into whether he contracted the virus while travelling, Roussin said at the province's daily news conference Tuesday.

WATCH | Full news conference on COVID-19 | March 24, 2020:

Provincial officials give update on COVID-19 outbreak: Tuesday, March 24, 2020. 50:37

As of Monday, more than 4,500 tests for the coronavirus that causes COVID-19 had been completed at Cadham Provincial Laboratory. There were 278 tests done on Monday.

Cadham lab hopes to increase testing later this week, Roussin said.

A drive-thru coronavirus testing site will open at the Winkler Centennial Arena on Wednesday, bringing the total number of testing sites in Manitoba to 12. The Winkler site will operate from 9 a.m. to 3 p.m. every day.

Patients must be referred for testing; they are not walk-in clinics.

Testing capacity is affected by a shortage of a chemical reagent used to determine whether someone tests positive for the coronavirus that causes COVID-19, Roussin said.

"It's really all about capacity. As that capacity increases, those priorities will be people with respiratory illness in hospital, all health care workers with respiratory illness (despite their travel history), and those priority groups in potentially closed settings such as First Nations, possibly corrections," he said.

WATCH | Dr. Brent Roussin talks about returning travellers:

Dr. Brent Roussin talks about returning travellers and how important it is to self-isolate. 1:17

All returning travellers continue to be tested, but their tests are being delayed to prioritize the other groups.

"As our capacity expands, [we will be] focusing on returning travellers and contacts, and at some point all symptomatic people if we have that capacity," Roussin said.

Roussin said, however, that testing is just one step in preventing the spread of COVID-19.

"All of the strategy put together — the self-isolation, testing, case isolation, contact investigation and social distancing — we need that all together to work," he said.

"Testing is definitely an important piece of that, but it's not the only piece."

Manitoba Premier Brian Pallister is not worried the possible true number of COVID-19 cases in Manitoba may be unknown due to restricted testing, he said, at a news conference Tuesday afternoon.

However, Manitoba's relatively low number of COVID-19 cases will only stay that way if people follow protocols such as social distancing, he said.

No one is in hospital and there have been no deaths in Manitoba due to the virus.

Health Links received 2,400 calls on Monday, and the average wait time for callers in the queue was 29 minutes, said Manitoba Shared Health chief nursing officer Lannette Siragusa.

"If you are calling and keep getting a busy signal, keep calling, because the wait is not what it used to be," Siragusa said.

New technology will be put in place by Wednesday morning to get rid of the busy signal for callers who are waiting, she said.

Now is not the time for non-essential travel outside of Manitoba. - Dr. Brent Roussin, chief provincial public health officer

There's also an online self-assessment tool. In its first week, it had 260,000 views.

Roussin on Tuesday reiterated his call to postpone or cancel all non-essential travel plans.

"The pandemic is developing and escalating with each passing day," he said.

"Now is not the time for non-essential travel outside of Manitoba."

On Monday, he urged Manitobans returning from domestic travel as well as international trips to self-isolate for 14 days, because all COVID-19 cases in the province were travel-related up to that point.

Commercial truckers, people who live in border communities and travel in and out of the province for work, and personal travel in border communities, including trips to the cottage, are all exceptions to the self-isolation.

Non-essential and routine tests, including imaging such as X-rays, and non-invasive cardiac services will be postponed, health officials said Tuesday.

But urgent diagnostic testing will continue with appropriate screening and precautions in place.

Those affected will be contacted and appointments will be rescheduled, but if symptoms get worse, people should immediately contact their doctor.

If a patient is not contacted, they should still attend their appointment, said Siragusa.

Similar to early stages of B.C., Ontario outbreaks

Public gatherings in Manitoba are currently limited to 50 people. But some jurisdictions are imposing far stricter limits, such as Quebec and Germany, where gatherings are limited to two people.

Roussin said Tuesday health officials here are looking at the possibility of a stricter limit, but noted that other areas put their stricter restrictions in place once there was evidence of secondary transmission.

"In the jurisdictions that were first hit with cases — B.C. and Ontario — their first cases looked exactly like ours — all international travel-imported," he said Tuesday, when asked why no community transmission has been reported here so far.

"As you get more and more introduction of the virus into your jurisdiction, then the more likely it becomes that community transmission will occur. So we look just like [the other provinces]. We're just at different stages of the outbreak than them."

To date, there has been no reported community transmission in Manitoba of the coronavirus that causes COVID-19, public health officials say.

Public health officials are expecting community transmission to eventually occur, but Manitoba has already enacted its prevention strategy (in particular, social distancing) to mitigate the impact, Roussin said, adding that those measures will be expanded in the future as appropriate.

It is unclear when exactly community transmission will occur, but Roussin said based on experience it other areas, it usually occurs about three weeks after a virus is introduced.

Manitoba's first presumptive case of the coronavirus that causes COVID-19 was announced on March 12.

Pallister said he's been briefed on possible hypothetical scenarios in terms of COVID-19 case numbers, projected facility needs and frontline health care worker availability.

He did not go into specifics on Tuesday.

Christmas in March?

On a brighter note, residents of the Town of Neepawa have turned on their Christmas lights "to light up people's moods," Siragusa said.

One resident set up a radio frequency that plays Christmas music, she said.

WATCH | Lanette Siragusa on acts of kindness in Neepawa:

Neepawa, Man., residents turned their Christmas lights back on to light up the mood, said Lanette Siragusa, Manitoba Shared Health's chief nursing officer. 0:59

Coun. Darrel Gerard got the idea from communities in other parts of Canada and the United States, Siragusa said.

"It's another example of how small efforts can make a world of difference in improving the moods of others."