The entire hospitality industry is being warned to brace for a drop in business following the coronavirus outbreak after a series of functions were cancelled at one of the country's most famous breweries, while patronage continues to plummet at Chinese restaurants.

Key points: Chinese restaurants say they have seen a record decline in patrons

Chinese restaurants say they have seen a record decline in patrons The drop in custom is blamed on fewer students, travellers and "irrational" fear

The drop in custom is blamed on fewer students, travellers and "irrational" fear The business lobby warns it's a sign of what's to come across the board

The ABC understands Fremantle's Little Creatures Brewing, one of Australia's pioneering microbreweries, had 300 people across three functions recently cancel because of restrictions on travel.

It comes as the number of cases diagnosed in the city jumped to six this week, including the first human-to-human transmission.

WA's peak business group, the Chamber of Commerce and Industry (CCI), warned businesses right across the hospitality sector would soon feel significant short-term impacts from the outbreak.

The Little Creatures brewery is a popular destination for tourists and locals. ( ABC News: Giulio Saggin, file photo )

"Restaurants right across the board will be feeling the pinch to some extent," chief economist Aaron Morey said.

"However I think the greatest impacts are probably in those Chinese restaurants because there may be a bit of irrational fear."

Mr Morey said more restaurants and cafes would likely feel the drop if the share market continued to experience sustained falls, because people would cut back on discretionary spending and eating out would be where they first looked to save money.

He said a local outbreak of the virus would also rock the industry.

"The real risk on the horizon for spending of local consumers is if there's a widespread local outbreak and people stay home through a fear of contracting the virus," he said.

The CCI said a loss of international visitor expenditure alone because of the virus would cost the state about $350 million over six months.

Chinese restaurant owners see bleak times ahead

Many Chinese restaurants in Perth's busy Northbridge entertainment strip, which should be filled with crowds of hungry patrons, sat empty on the weekend.

Some owners said they had already experienced falling patronage for weeks in the wake of the global spread of COVID-19.

On a typical Saturday night at Perth's City Garden Chinese Restaurant, free tables are usually few and far between.

But in the 15 years Michelle Xian has run City Garden, she said last Saturday night was one of the quietest she had seen as more seats were empty than occupied.

"It's very, very bad," Ms Xian said.

"Normally upstairs, downstairs, outside, all full house, very, very busy."

Ms Xian says this is the quietest she has seen the City Garden Chinese Restaurant in 15 years. ( ABC News: Evelyn Manfield )

She said just a few weeks ago the restaurant was thriving as tourists and West Australians celebrated the Fringe and Perth festivals, as well as Chinese New Year.

But as those annual summer events came to an end and awareness of coronavirus increased, Ms Xian said it culminated in a sudden 40 per cent drop.

It had forced her to consider what she would do if the decline in customers continued.

"If another 20 per cent drops down then we will close for a few weeks maybe, because once I open the door, I need to pay a lot," she said.

Usual patrons too scared to dine out

Other restaurants in Chinatown told the ABC their businesses were much quieter than usual.

At 7:20pm on Saturday, some of them were nearly empty.

One manager said they usually attracted droves of Chinese students, but many had been unable to return to university in Australia from their summer break.

Good Fortune Roast Duck House restaurant in Northbridge lies almost empty on a weekend. ( ABC News: Evelyn Manfield )

Another manager said he thought it was because people were scared to dine out due to fear of being in public places.

At Good Fortune Roast Duck House in Northbridge, management said business had slowed, largely due to a decline in international visitors.

Manager Quan Chen said 40 tour group bookings had been cancelled since the Federal Government's travel bans took hold.

"We've had about 30-40 per cent downturn in numbers compared to December and January and over the Chinese New Year break, mainly because of the Government travel ban," he said.

Quan Chen runs the Good Fortune Roast Duck House in Perth. ( ABC News: Evelyn Manfield )

At 6:00pm on Saturday few people sat inside the restaurant, but a constant stream of takeaway orders flew out the door.

Mr Chen said Saturday night patronage had fallen by 20 per cent, but weekdays had taken an even bigger hit, prompting the restaurant to offer discounted meals.

Other economic factors at play, hotels lobby says

Australian Hotels Association WA chief executive Bradley Woods said it was hard to know whether restaurants were quieter because of coronavirus or other economic factors.

He said after a busy holiday season, Chinese New Year and a rise in international visitors to the state last year, for some restaurants the downturn might feel more significant than it is.

"With the bushfires and then coronavirus on top of that, we've certainly seen a substantive downturn in international visitation and that might be why some of these specific ethnic cuisines restaurants are finding it a little bit tougher," Mr Woods said.

Half a dozen pubs and restaurants across Northbridge who spoke to the ABC on background said there had been a slight downturn in patronage in recent weeks, but all blamed recent stormy weather and the end of a busy festival season.

Co-manager at Govinda's restaurant Nicholas Francis said he had not noticed an effect on business from coronavirus, but said it might become problematic down the track.

"I think it will have an effect if the coronavirus breaks out seriously in Western Australia," Mr Francis said.

But he said it had been difficult sourcing some supplies because of bare supermarket shelves.

WA Premier Mark McGowan said the State Government would launch a tourism campaign to encourage people to holiday in the state.

In the meantime, he said West Australians should continue to dine out to help sustain local businesses.

"Don't change your behaviour, make sure you support our economy and our community if you don't have any symptoms," Mr McGowan said.