WASHINGTON (AP) _ Federal health experts say there are a host of problems with the design and cleaning instructions for specialized medical scopes recently linked to a series of bacterial outbreaks in hospitals nationwide.

However, the Food and Drug Administration’s advisers also say the scopes should continue to be used because they are essential to medical care and the contamination problems appear to be rare.

The agency convened the panel of medical device experts following a series of outbreaks associated with the scopes, which are used in about a half-million procedures a year. Surgeons guide the instruments into the digestive tract to diagnose and treat blockages of the bile and pancreatic ducts.

According to federal officials, since 2013 there have been eight outbreaks of antibiotic-resistant bacteria linked to the devices at U.S. hospitals.