Patients treated at a Tennessee dental clinic should get tested for hepatitis B and C, and HIV after problems with infection control could have put thousands of people at risk for the diseases, health officials said Monday.

The Shelby County Health Department is strongly recommending the testing for patients of SPT Dental Clinic, which was closed down on July 1. No specific infections have been linked to the Memphis clinic, but more than 3,000 patients who have been treated there since 2007 could be at risk, said Alisa Haushalter, director of the health department.

State health officials have reached out to colleagues in Arkansas and Mississippi to advise them that people may be contacting them about the testing, said Dr. Tim Jones, state epidemiologist at the Tennessee Department of Health. Health officials nationwide also are being notified as some patients may have moved out of the Memphis area, Jones said.

Health officials began investigating the clinic after a patient complained to the Tennessee Board of Dentistry. Officials found problems with hand-washing techniques and sanitation of dental instruments, Haushalter said, adding that such problems with dental clinics in Memphis are unusual.

“The conditions found there were less-than-optimally hygienic, and strongly suggested there could be transmission of blood-borne diseases,” said Dr. Helen Morrow, a Shelby County Health Department official.

The health department is contacting patients directly. But officials say some records may be incomplete so patients should not wait to be contacted before they are tested.

Free testing is available at the Cawthon Public Health Clinic in Memphis.

Dr. Alfred Brown, the dentist who operated the clinic, has been cooperating with health officials, Haushalter said. His license has been suspended, state records show. The Associated Press could not immediately reach Brown for comment.

A hotline has been set up for people with questions at 901-222-9299