CHARLESTON, W.Va. -- Nearly 2,000 people in West Virginia and four other states and the nation's capital might be at risk of having contracted hepatitis B from a free dental clinic in Berkeley County, West Virginia health officials said Friday.

The Berkeley County Health Department has sent out notification letters to 1,137 patients and 826 volunteers who worked at or received care from the Mission of Mercy Dental Clinic in Hedgesville on June 26 and 27, 2009.

The state Bureau for Public Health was notified in November that three patients and two volunteers at the clinic had developed acute hepatitis B, said Dr. Dee Bixler, director of the state Infectious Disease Epidemiology program.

State officials followed up with an intensive investigation into the source of the infection, but were unable to determine how the five were infected, or if they contracted the disease at the clinic, Bixler said.

But officials were able to narrow the infection date to the dates of the two-day clinic, and tests showed that four people who contracted the disease -- two patients and two volunteers -- were infected by the same source, she said.

"Unfortunately, at the end of the investigation, we couldn't identify a single transmission event," Bixler said. "We talked it over and felt we were obligated to notify everyone."

In addition to West Virginia residents, notification letters were sent out to residents in Maryland, Virginia, Pennsylvania, North Carolina and Washington, D.C.

Bixler said most of the out-of-state residents notified were volunteers at the clinic.

"It's upsetting to get a letter like this," she said. "We want people to focus on who they can call about this, because there is treatment available."

The West Virginia Department of Health and Human Resources has set up a hotline for people to call with questions, and the Berkley County Health Department will hold a testing clinic for hepatitis B later this month.

The letters also recommend those who attended the dental clinic be tested for hepatitis C and HIV, because the viruses are also spread through exposure to infected blood and body fluids, according to the state Bureau for Public Health. 

No cases of hepatitis C or HIV have been reported in connection to the clinic, according to the state health bureau.

The state Bureau of Public Health will pay for testing of people who have been notified by letter, and will also pick up the tab from out-of-state health departments, Bixler said. It was unclear Friday how much the testing would cost the state.

Mission of Mercy is a traveling dental clinic that has offered free care across the nation. Bixler said the cause of the infection is "an open question," but improperly cleaned dental equipment is one possibility.

She said the Berkeley County clinic was coordinated by Dr. Terry Dickinson, executive director of the Virginia Dental Association, in conjunction with the United Way of the Eastern Panhandle and Healthy Smiles West Virginia.

West Virginia has the highest rates of hepatitis B in the nation, she said.

In 2009, the state reported 84 cases of hepatitis B, according to the state Office of Epidemiology and Prevention Services.

"It doesn't help matters," Bixler said. "If there is a higher rate of chronic hepatitis B, then it's possible to have transmission if there is any break in infection control in a health-care setting."

Hepatitis B causes inflammation in the liver. About 90 percent of people recover, but 10 percent get a chronic form of the disease that can cause cirrhosis or liver cancer.

Symptoms of hepatitis B include fever, nausea, vomiting, abdominal pain, yellow color in the skin or eyes, dark urine, light-colored stool and feeling tired or not well.

Blood tests are the only way to confirm if someone has hepatitis B. A hepatitis B vaccine is available, and many health-care professionals have been vaccinated. The vaccine does not protect against hepatitis C or HIV.

The Berkeley County Health Department will hold a clinic to test for hepatitis B from 1 p.m. to 7 p.m. on June 17 at Martinsburg High School.

For more information, call the Berkeley County Hepatitis B hotline at 304-263-4446 or 1-800-642-8244.

Reach Veronica Nett at veroni...@wvgazette.com or 304-348-5113.