Palomar Pomerado Health System has urged a few thousand of its patients to be tested for possible exposure to infections during medical procedures over a 15-month stretch, officials confirmed Monday.

In a letter dated June 9 and sent by certified mail to 3,400 patients of Palomar Pomerado Health System, officials said the risk of transmission of any virus was low.

However, they urged the at-risk patients to contact them by July 31 to get a free blood test.

The problem occurred, officials said, when PPH employees missed a few steps while cleaning equipment used in certain procedures.

"Although we were disinfecting all equipment, some of the steps as recommended by the manufacturer were not always completed," Palomar Pomerado Health spokesman Andy Hoang said in a statement issued Monday night.

He said the health care district discovered the problem during an internal oversight process.

Hoang said the review was not prompted by any increase in infections, a complaint or investigation by state officials.

PPH reported the problem to the state and also started notifying patients.

"We have no indication that there were any infections, and the risk to patients is very low, but as a precautionary measure, we have contacted those limited number of patients who may have been affected and offered them free follow-up testing," he said.

Hoang declined to say what the patients may have been exposed to ---- but one patient said it left her concerned about exposure to HIV, hepatitis or staph infections.

"I haven't seen any outward signs of an infection, and I don't feel sick, but I don't know if I have a virus or not ---- and that makes me fearful," said the patient, a 46-year-old Ramona woman who is a widow with two small children. "I mean, could I have hepatitis?"

The woman, who asked that her name not be used because she was discussing personal health concerns, said she underwent an "invasive procedure" at Palomar Medical Center in Escondido in January.

The letter ---- which the patient said had been personally signed by PPH chief executive Michael Covert ---- says the risk for possible exposure was between Dec. 1, 2008 and March 22, 2010.

"One of the things that alarmed me so much is that cleaning and disinfecting seems to be a standard procedure," the patient said. "Why did it take so long to discover it?"

Hoang said the problem was not related to sterilization, but involved cleaning the equipment for a high level of disinfection.

"We have done a complete review of all of our procedures related to the cleaning process, retrained all staff and have mechanisms in place to assure this has been addressed," Hoang said. "Appropriate follow-up with staff has been done."

He said it took two months to notify the potentially affected patients, "because we had to conduct a thorough review to identify the right patients who were potentially at risk."

Ironically, the notification to patients came as PPH has won a national award for quality from a health care-supply purchasing company known as Premier Healthcare Alliance.

The award goes to hospitals and networks that score in the top 1 percent of a complicated ranking that considers a hospital's quality and efficiency.

The Ramona patient said she had good experiences with PPH, and gave birth to both of her children at the Escondido hospital.

The letter, she said, took her by surprise.

"It is a very important public health and safety issue. It does concern me," she said.

And it left her worried that she might have contracted a serious infection.

"I am a mother with two kids," she said. "I have a fear of the unknown."

Call staff writer Teri Figueroa at 760-740-5442.