Eight persons became ill with salmonella poisoning last week after eating at Middleburg's Red Fox Inn, Loudoun County public health officials said yesterday.

The 150-seat, rustic country restaurant closed voluntarily early Wednesday, and its procedures, food and 100 employes are being checked by state and local officials, according to Robert Montgomery, a spokesman for the county's Public Health Department.

Though none of the investigations has been concluded, the common element in all of the cases was a potato dish at the inn.

Turner Reuter, owner of the well-known establishment, said yesterday he believes he has traced the problem to infected eggs used in Duchess Potatoes, a fried hot dish made with eggs, milk, oil and mashed potatoes. "Everyone who became sick had eaten them," he said. The illnesses were reported on April 9, 10 and 11, health officials said.

The names of the eight persons who were infected were not available yesterday.

Salmonella, which Montgomery described as a common organism associated with poultry and eggs, is estimated to affect about 2 million Americans each year, causing fever, nausea and diarrhea. Infected milk is suspected to be the cause of more than 8,000 reported salmonella poisoning cases in six Midwestern states. Five deaths have been linked to the current outbreak there.

Reuter said he became aware of a possible food poisoning problem Tuesday morning when he received a call from a patron who had become ill.

He notified the health department that afternoon, he said.

"We have completely removed every bit of food in our kitchen, totally disinfected the entire kitchen from top to bottom, and had every employe that handled food -- including the waiters and kitchen staff -- tested for any kind of bacteria," he said.

If an employe has a positive test, he will not be allowed back to work, Reuter said.

He also said he has offered to pay the medical bills for any patrons who were sick.

"I am the one who is ultimately responsible because it happened in my restaurant," he said, "but it could happen to anyone."

Reuter said yesterday he believes that with the discovery of the allegedly bad eggs, he has "nipped the problem in the bud" and plans to reopen for breakfast on Saturday.

"I am a very self-conscious person when it comes to customers," he added, "and when it comes to customers, I would not want to subject anyone to bacteria."