WATCH: Napa County Issues Mandatory Shelter-At-Home Order

NAPA COUNTY, CA — A shelter-at-home health order was issued Wednesday by Napa County Public Health Officer Dr. Karen Relucio. The order takes effect early Friday morning as part of the county’s response to the coronavirus, COVID-19, pandemic. The order will remain in place through April 7 or until it is extended, rescinded, superseded, or amended in writing by Dr. Relucio.

The shelter-at-home order requires most people to stay home as of 12:01 a.m. Friday unless they are engaged in certain "essential activities." Those who are sick should self-isolate, if possible, from others they live with, according to the county.

In a news conference held Wednesday, Dr. Relucio said the health order is a precautionary measure. To date, some 40 people in the county have been tested for the coronavirus but there have been no confirmed cases — the lone exception being a Diamond Princess cruise ship passenger who was treated for the disease in isolation at Queen of the Valley Medical Center in Napa.

WATCH: Napa County Holds News Conference To Announce Shelter-At-Home Health Order

"This order is mandatory," Napa County Public Information Officer Noel Brinkerhoff said. "All persons and other entities are required to comply if they do not fall within the exemptions that are specified in the order. It is a misdemeanor to not comply."

With the exception of first responders, emergency management personnel, emergency dispatchers, court personnel and law enforcement, all other Napa County residents are expected to adhere to the health order.

Here are the so-called "essential" activities residents are allowed to do while the health order is in effect:

• Obtaining necessary services or supplies for themselves and their family, household members, and pets, or to deliver those services or supplies to others, such as food, pet food, and any other household consumer products necessary to maintain the safety, sanitation, and essential operation of residences.
• Engaging in outdoor activity such as walking, hiking, biking or running, provided people comply with social distancing requirements of staying 6 feet away from another person.
• Working for, or as, an employer to provide essential products and services at an essential business (see list below).
• Caring for a family member or pet in another household.

Under the county's health order, "essential businesses" include, but are not limited to:

• Healthcare operations and "essential infrastructure";
• Grocery stores, farmers' markets, food banks and convenience stores;
• Businesses that provide food, shelter and social services for economically disadvantaged or otherwise needy individuals;
• Newspapers, TV, radio and other media services;
• Gas stations and auto-supply, auto-repair and related facilities; and
• Banks and related financial institutions.

An FAQ from the county provides a complete list of essential businesses and essential infrastructure.

This is a developing story; refresh your screen for the latest updates.