As public health officials warn it's only a matter of time before Ottawa sees its first confirmed case of COVID-19, some supplies are already running low as people stock up their cupboards.

By Tuesday, there were 29 confirmed cases of COVID-19 in Canada including 20 in Ontario and one in Quebec, and health officials were warning the public to be prepared.

"You have to think about your basic needs for yourself for your family," said Paola Parenti, Ottawa's emergency management program coordinator.

In the event of self-isolation or quarantine, people should have enough food, water and anything else they'd store in an emergency kit to keep themselves and their families safe and warm, Parenti said.

This pharmacy in downtown Ottawa was out of hand sanitizer on Tuesday. (Matthew Kupfer/CBC )

"Hand sanitizers, Kleenex, wet wipes to wipe stuff down, extra food, especially the non-perishable foods, or if you have a big freezer you can make stuff ahead of time and put it in your freezer," she said.

Parenti said people should also come up with a communication plan, and figure out who could drop things off in the event they're stuck at home.

Meanwhile at local stores, certain items are already in short supply.

My daughter in Ottawa went to Walmart to pick up some things her family needed. First pic is of the dry/canned beans isle, the second was disinfectants/hand sanitizers. <a href="https://twitter.com/hashtag/COVID19?src=hash&ref_src=twsrc%5Etfw">#COVID19</a> <a href="https://t.co/G2tLd3yld5">pic.twitter.com/G2tLd3yld5</a> —@lisakirbie Scene at my Costco last night. This is where the paper products used to be. I was told a limited number of pallets arriving in a.m. And they expect it to sell out quickly. <a href="https://t.co/dC1sLk0qfF">pic.twitter.com/dC1sLk0qfF</a> —@LaurieLovesIt

Some stores, including Brisson Pharmacy in the ByWard Market, are rationing hand sanitizer from behind the counter.

"People ask for it and we make sure that we provide them with a limited quantity, just because we have only limited stock available and we'd like to distribute that fairly among people," said co-owner Sara Azad.

Paola Parenti, emergency management program coordinator with the City of Ottawa, urges people to think about what they'd need to stay home comfortably for two weeks. (Natalia Goodwin/CBC )

Azad said her store is currently out of face masks, and she can't order any more.

Meanwhile, she's encouraging customers not to panic and keep washing their hands.

"Something as simple as that could make a big difference, I think."