Golden Gate has closed five of its Gogi House Korean-style BBQ restaurants in Hanoi since March 11 after revenues fell by 30-40 percent. Golden Gate operates over 20 chains with 112 outlets around the country.

It also plans to shut seven Kichi-Kichi hotpot restaurants in Hanoi out of a total of 87 it has in the country.

Nhan Sushi has shut down all three of its restaurants in Hanoi for two weeks from March 10.

The owner of the chain, Luong Hoang Long, said on his Facebook page: "I only want customers to walk into my restaurants to enjoy the food, not to worry about the disease."

The closures come amid an increasing number of novel coronavirus cases, which is causing people to avoid public places. The number of confirmed cases has risen to 113.

In HCMC, restaurants in the swank Cresent Mall area in District 7 are no longer busy like before.

Even during weekends few tables are occupied, and some outlets have already closed with managers saying revenues have plummeted by half since the outbreak.

Mai Truong Giang, CEO of TGFood, which owns the fried chicken restaurant chain Otoke Chicken, said revenues at its 14 outlets in the city have fallen by up to 50 percent.

He is negotiating with landlords for a 20 percent discount on rents for three months. The company also plans to lay off staff to reduce costs.

"Reducing staff working hours, negotiating rents and requesting delays in bank repayments are what we are seeking to overcome the disease."

If the situation persists, he estimates a 30 percent staff cut and a 30 percent pay reduction for the remaining workers.

With customer numbers plummeting, restaurants are focusing on delivery to survive the outbreak.

Golden Gate now offers BBQ and hotpot delivery including kitchenware for customers who want to enjoy their food at home.

Smaller businesses have taken the same route. Phuong Mai, owner of a hotpot restaurant in Hanoi’s Cau Giay District, said in the last two weeks there has been a rising number of delivery orders for hotpots costing VND350,000-600,000 ($15-26).

Other restaurants offer free drinks with ginger or lemongrass, said to boost the immune system. They also provide hand sanitizers to customers and require staff to wear face masks.

Economist Le Dat Chi said delivery services are only a temporary solution as restaurants might have to bear higher costs if they don’t have a good strategy, he said.

"There is actually no good solution amid an outbreak like this."