"I want to again express our sincere sympathy to the patients, family, and friends who've become victims of this tragic situation," state health commissioner John Dreyzehner said at a press conference.

Due to the long incubation period, health officials were urging patients who had received the injection as far back as July 1 to contact their doctors for testing.

Fungal meningitis -- which inflames the protective membranes covering the brain and spinal cord -- is a rare infection which often goes undetected until it's too late because its flu-like symptoms can be mild at first.

Early detection and treatment -- which requires a hospital stay to administer intravenous anti-fungal medications -- can prevent the infection from causing permanent damage.

An initial investigation found that the Tennessee clinicians who administered the contaminated drug "had no way of knowing" there was anything wrong with it and found "no lapses" in their standards, Dreyzehner said.

"The evidence indicates this is a product issue," he told reporters.

The Food and Drug Administration said it has detected a fungal contaminant in a sealed vial of the drug produced by the New England Compounding Center.

While further testing is required to confirm it was the source of the outbreak, the company has issued a recall of all of its products and shut down all operations.

Source: AFP