Cafes are closed, gyms are cancelling classes, some supermarket shelves are bare, staff are testing positive and close contacts are isolating while waiting days for tests.

Read more: How to find a RAT in the Illawarra

Kim Rimmer, owner of Fernwood Woonona, thought she was playing it safe, requiring staff to wear masks even when it was no longer mandatory.

But their end of year party turned the fitness centre into chaos and a forced temporary closure after several employees tested positive to COVID-19 - a situation just "horrific".

"Staff that were on holiday were called back in," she said. "We've had to reduce classes, but [reduced operations during] public holidays got us through. Without them we would have closed."

As well as testing positive herself, both of Ms Rimmer's daughters and husband caught the virus, all of whom work at the gym. Having to run the business remotely led to countless headaches from fixing a broken door to responding to member calls.

"Because we're isolating we had to try to rely on people to deal with that issue for us which became quite costly and very frustrating," she said.

Fernwood isn't the only casualty with numerous businesses alerting customers to temporary closures or reduced trading such as Georgia Rose cafe at Shell Cove, Seaswell Cafe at Shellharbour and North Break Cafe at Woonona.

The lengthening wait for PCR test results is causing further headaches, according to Paul Boultwood of the Corrimal Chamber of Commerce.

"Businesses are trying to do the right thing but they're being let down," Mr Boultwood said.

Read more: Five of the best Sydney theatre shows for Illawarra daytrippers

With positive case numbers soaring and thousands of people in isolation awaiting test results, it add up to a "perfect storm", said Adam Zarth, executive director of Business Illawarra

"We're in peak tourism and hospitality season, particularly in our region, and it's really come at the worst time [but] ultimately, every sector will start to find this a challenge," Mr Zarth said.

On Tuesday, Shane Jaque had to close all of his Sneaky Burger outlets due to lengthy delivery delays meaning he was without stock.

"Suppliers weren't going to be able to get to our shop by 3pm when they normally get to the shop by 10am. We weren't going to be ready to trade by 11," he said. "I don't think there's much optimism about what's going to happen. You just take the blow week by week."

Mr Jaque said Sneaky Burger would reopen for only takeaway from Wednesday, until the situation stabilises.

Meantime, supermarket shoppers across the Illawarra and beyond have been noticing bare shelves over the past week due to similar reasons.

Logistical issues caused by sick truck drivers or distribution workers awaiting negative COVID tests are impacting the supply chain, according to a Woolworths spokesman.

"We're currently experiencing delays with some of our stock deliveries to stores due to COVID-related impacts on our supply chain operations," he said.

"We have stock available within our network and our teams and suppliers are doing all they can to replenish stores as quickly as possible."

It's understood Woolworths stores in Greater Sydney are most affected as well as others around the state.

Ms Rimmer is focused on ensuring Fernwood's members receive the right information as government requirements change on the need to notify casual contacts.

"How as a business owner can you be constantly adapting to changes that happen every 24 hours," Ms Rimmer said.

"I'm just learning that COVID is part of life and how to deal with it."

The Illawarra Mercury newsroom is funded by our readers. You can subscribe to support our journalism here.