U.S. health officials ramped up warnings Thursday about a Massachusetts specialty pharmacy linked to a widening outbreak of a rare kind of meningitis, urging doctors and hospitals not to use any products from the company.

A steriod product has been linked to a nationwide outbreak of fungal meningitis infections, prompting Minnesota health officials to work with local clinics and track down patients who were injected with it. The Minnesota Health Department is working with Medical Advanced Pain Specialists in Edina, Fridley, Shakopee and Maple Grove, and the Minnesota Surgery Center in Edina and Maple Grove to contact the patients. The department says they are the only providers know to have used the product in Minnesota.

At least 35 infections and five deaths have been linked to the injectable steroid. No Minnesota cases have yet been identified, "but given how rapidly this investigation is unfolding, I would not be surprised if we have cases," said Dr. Ruth Lynfield, state epidemiologist. Approximately 600 patients in Minnesota received epidural injections, but several hundred more received them at other sites, Lynfield said.

Lynfield said the clinics are contacting patients who received the injectable steroid. While the infections nationally have involved patients who received the injections in the spine, the clinics are contacting patients who received the steroid injection to any part of the body.