From handling fruit to lining up at the checkout, Americans must change how they shop for food

While much of the American workforce is hunkered down under COVID-19, stay-at-home orders, the nation's 2.7 million grocery store employees have no such protection.

"I would say they are more vulnerable than the general population," said Jeff Pothof, chief quality and safety officer for UW Health in Madison. "Social distancing will be more difficult for them to do, especially since people don't have alternatives now that so many restaurants have closed."

Some stores have responded to the COVID-19 pandemic by installing plexiglass shields and putting tape markers at each place in the checkout line to ensure there is six feet between each customer.

Live Updates: The latest on coronavirus in Wisconsin

Daily Digest: What you need to know about coronavirus in Wisconsin

RELATED:Grocery store workers are on the front lines during coronavirus pandemic

But the fast-spreading virus will challenge the way Americans shop for and sell produce in many other ways, health experts said.

"How many people can be in a store at the same time?" asked Amita Avadhani, an associate professor at Rutgers University School of Nursing in New Jersey.

Avadhani said store owners need to be aware of how many customers their stores can hold without making it difficult for people to stay six feet apart.

She said store owners need to be vigilant about educating their employees, reinforcing rules about hand washing, disinfecting floors and counters, and monitoring their own symptoms.

"We're all used to it that when you're sick, you still have to put food on the table," she said.

To counter that ingrained response to illness, she said, companies should offer paid sick time to their workers.

Pothof said some grocery stores are turning to approaches that create fewer opportunities for employees and customers to come in contact. Some are allowing customers to place grocery orders by phone, then drive and pick them up. This means the customer never enters the store.

Other stores are taking orders and delivering them to people's homes, a practice that is especially effective in protecting elderly customers from the virus.

If customers do come to the store to shop, "maybe we only let 20 people in at a time. As one leaves, the next customer gets to go inside," Pothof said.

The pandemic also is likely to change more subtle aspects of the way food is bought and sold in this country.

Health experts are warning stores against selling loose items, such as fruits and vegetables; these items are safer when prepackaged. They also suggest self-service areas where customers use utensils to help themselves to salads and other foods be shut down for the time being.

The virus should prompt changes in customer behavior too. Picking up, squeezing and inspecting fruits and vegetables all offer opportunities to spread the virus.

"Do not touch fresh produce or other items unless you are going to purchase them," said Minhaj Husain, an infectious disease doctor at Aurora St. Luke's. "Wipe down all grocery supplies with alcohol wipes after bringing them home."

Pothof said adults should wash any fruit before handing it to children or others. To be on the safe side, he said, shoppers should assume that the virus can survive on anything from a store, including the bags, for up to two days.

Entering, paying and leaving have all become activities that require precautions. 

"Try to use a credit card for payment if possible so there is no physical contact with employees during checkout," Husain advised. "Sanitize hands on the way in and when exiting."

The virus is shed in droplets, which can emerge during coughing, sneezing or even talking. That's the reason so many health experts have stressed the importance of frequent hand washing.

Finally, health experts urged people who are sick not go out in public, even to shop.