A man walks down an empty street as Wyoming reported their first coronavirus disease related death on April 13, being the last of the 50 states to have reported a death from the COVID-19, in Cheyenne, Wyoming, US, April 14, 2020. (Photo: Agencies)

Wyoming, the US state with the fewest coronavirus cases and the smallest by population, plans to reopen some businesses this week though most other states remain locked down.

Officials will use metrics developed by the health department and will allow each of the state's 23 counties to make independent decisions based on local conditions. The shutdown order was issued last month.

"This will be a balanced approach that will be driven by two guiding principles: public safety and helping more people get back to work," Governor Mark Gordon said. "We are going to relax some of the restrictions, while also detailing what data we will monitor to make sure we stay on the right path."

Gordon said the new guidelines are likely to allow gyms, cosmetologists and barber shops to reopen. Possible reopening of movie theaters, bars and restaurants is under review.

Wyoming, known as the Cowboy State, has seen the fewest coronavirus cases in part because of its low population and wide-open spaces.

It is the country's least populated state with an estimated population of 577,737 in 2019.

The number of confirmed cases in Wyoming rose by 17 to 349 on Friday, an increase bolstered by a spike of cases in Fremont county after several days of relatively stable growth statewide.

A state health department spokeswoman said most of Fremont county's new cases are linked and that they come from a group known to congregate in public areas.

The percentage of known patients in Wyoming who have fully recovered continues to grow and is now 321.

Gordon did not issue a statewide stay-at-home order like many states, including neighboring Colorado and Montana but shut certain businesses. The current order expires on Thursday.

However, schools are not expected to reopen until at least mid-May.

Brian Gee, the public health officer for Fremont county, cautioned that the apparent increase in the number of people testing positive may reflect more extensive testing.

"The more testing you do, the more positives you're likely to find," he said.

"There is spread, but they're trying very hard to get that spread to slow down, and I think they have done a good job of it."

Gordon said the new rules established by the counties could be more restrictive or less stringent based on conditions reflected in local health data.

Factors to be considered in allowing businesses to reopen are: Number of new cases, percentage of cases attributed to community spread, percentage of all tests that are positive, coronavirus-related admissions to hospitals and the total number of beds available in Wyoming hospitals.

Each factor will be ranked on a three-point scale: "Improving,""stabilizing" or "concerning".