Vancouver Coastal Health's Nick Losito says most restaurants in Metro Vancouver have been keeping up with required health standards. (CBC)

Forty-nine restaurants in Metro Vancouver have been temporarily shut down since January because of health violations.

Common reasons include pest and rodent infestations, and failure to protect food from contamination and unsanitary conditions, according to Vancouver Coastal Health.

The authority updated its list of food establishment closures on Friday, advising business owners to be extra vigilant during summer, said Nick Losito, a regional director of health protection.

Losito said most restaurants have been keeping up with required health standards but the number of health violations has increased one per cent over the last year.

Twenty-five public health inspectors cover more than 6,000 food establishments in Metro Vancouver, he said.

"We try to keep up with the growth [of restaurant businesses]," he said. "With the growth that we've seen, we lag behind a little but we categorize restaurants in terms of relative risk."

Food inspectors will visit restaurants with previous health violations two to three times a year. For restaurants with a clean record, inspections will be carried out once a year, Losito said.

In summer, restaurant owners should ensure their new supplies are immediately and properly checked.

"It's a matter of staying on top of it, checking your shipments when they come to your back door before they come in," Losito said.

Unwanted pests or rodents can easily hide in the shipments, he said.