Letters from a national dental and vision insurer hit mailboxes Monday informing patients of a data breach potentially involving their personal information - including members in western Pennsylvania.

The Virginia-based insurer Dominion National, a business associate of UPMC Health Plan, announced a “security incident” that could compromise information stored about its members.

“On April 24, 2019, through our investigation of an internal alert, with the assistance of a leading cybersecurity firm, we determined that an unauthorized party may have accessed some of our computer servers,” the company announced Monday in a news release.

The release went on to report that the data breach may have occurred as early as August 2010. According to its website, Dominion National provides dental plans and administrative services for a variety of insurance plan participants, including some UPMC Health Plan members.

"After learning of this, we moved quickly to clean the affected servers and implement enhanced monitoring and alerting software. We also contacted the FBI and will continue to work with them during their investigation," the company said in the press release issued on its website.

Dominion National sent letters Friday to members who could have been affected by the security breach.

Membership information that could have been compromised includes names, addresses, email addresses, dates of birth, social security numbers, member ID numbers, group numbers and subscriber numbers.

According to the company's press release, for customers enrolled in the company's online services, bank account and routing number information could also have been breached.

“We have no evidence that any information was in fact accessed, acquired or misused,” the release said.

The company has established a dedicated incident response line to answer any questions. The incident response line is open Monday through Friday, 8 a.m. to 8 p.m., and can be reached by calling (877) 503-8923.