The number of people who have died after being exposed to contaminated drugs made by New England Compounding Centre (NECC) has reached 19, with another 245 patients seriously ill with infections.
The case has raised questions about the activities of so-called compounding pharmacies, which prepare medicines on demand for patients but are not required to adhere to the same rigorous process controls as pharmaceutical production plants.
The meningitis cases have been linked to fungal contamination of two injectable steroids made at NECC - methylprednisolone acetate and triamcinolone acetonide - but the FDA is also investigating other drugs made at the company including a cardioplegic solution used in heart surgery and injectable ophthalmic products.
NECC issued a recall of all products circulating in the marketplace and shut down production at its site in Framingham, Massachusetts, shortly after the meningitis outbreak, but the Centre remains under federal scrutiny.
The FDA's Office of Criminal Investigation raided the facility this week, carting away documents to help in its investigation, and the US Department of Justice has launched a probe into the incident.
NECC has insisted it is cooperating fully with the authorities, and the firm's legal counsel, Paul Cirel, said he could not understand why the FDA felt it was necessary to raid its premises.
"We've been clear that warrants weren't needed; asking would have produced the same result," he said. "Nevertheless, we continue to offer our cooperation."
The NECC incident has captured headlines because of the number of deaths, but there have been a number of other incidents in recent years that have drawn attention to the activities of compounding pharmacies.
Several outbreaks of fungal and bacterial infections of the blood caused by products made on demand, as well as serious eye infections, have been recorded since the FDA first proposed tightening up regulations on compound pharmacies in 2001.
The agency's proposals were blocked in Congress after lobbying by groups involved in compounding, including the Houston-based International Academy of Compounding Pharmacists (IACP).
In a statement on the latest incident, the IACP said all compounding pharmacists and pharmacies are already subject to oversight by State Boards of Pharmacy, the FDA and the Drug Enforcement Administration (DEA).
Meanwhile, compounding pharmacies can also seek accreditation of their quality systems and production processes from the Pharmacy Compounding Accreditation Board (PCAB), it pointed out, adding the NECC is not currently accredited by this body.