One third of people living in a regional Victorian town are isolating due to a coronavirus outbreak, reducing access to food and other essentials.

A regional Victorian town's coronavirus outbreak is becoming increasingly dire, with isolation orders hitting supermarket staff, creating limited access to essential supplies.

Five out of Victoria's 41 cases reported on Wednesday live in Shepparton, bringing that cluster to 50.

The region's health service estimates 17,000 people are isolating, with more than 80 local exposure sites and 5800 primary close contacts.

Many supermarkets have closed for cleaning after being listed as an exposure site, including a large IGA in the town's north.

Coles has confirmed its stores in Shepparton, Mooroopna and Shepparton South are operating on reduced hours "due to team member availability", with a number of home delivery and click and collect orders cancelled in recent days.

In response to the crisis, Shepparton's community and volunteer organisations joined to create the GV Cares network on Monday, part of the Greater Shepparton Lighthouse Project.

"Within the first 48 hours we've responded to 250 requests for food, formula, medicine, all sorts of things," Project executive officer Lisa McKenzie told AAP.

"People are distressed, they're are hungry and they are fast running out of options."

Many of those isolating are aged in their 30s and 40s, which Ms McKenzie says is "the backbone of our workforce".

Shepparton Independent MP Suzanna Sheed says the community is "very anxious" about their increasingly limited access to food and other essentials.

"Due to the number of workers in isolation, many local food suppliers and the logistics they need to deliver food, are unable to provide the community with its basic needs," she told AAP.

"The town is now in a situation where we've gone from always being able to help ourselves, and help each other, to a crisis."

Ms Sheed wants Premier Daniel Andrews to send more support, including 100 Defence personnel by Thursday for logistics including truck driving, packing and delivering supplies.

She has sent a "critical needs list" to the state government, which also includes requests for more healthcare staff, testing stations and and better resourcing of the state's COVID hotline.

On Wednesday afternoon, GV Health chief executive Matt Sharp said he was expecting more cases and exposure sites to pop up and called for people to get tested.

He said about 400 GV Health staff were isolating and 50 Defence personnel had arrived to support the health service with testing and door-to-door checks.

Health Minister Martin Foley said the government was working with Victoria's Emergency Management Commissioner,and further Defence support would be provided if needed.

He said the government was "well and truly engaged" with health, aged care and school services, and food supply groups in the area.

The Shepparton outbreak has been genomically linked to an earlier outbreak at Glenroy in Melbourne's outer north.

Eleven new exposure sites have also been listed between Geelong and Little River after six cases were connected to a household in Lara.

These cases are yet to be epidemiologically linked but are believed to be related to the Newport cluster.