This photo provided by the Minnesota Department of Health shows shows vials of the injectable steroid product made by New England Compounding Center implicated in a fungal meningitis outbreak. (AP)

The number of fungal meningitis cases linked to spinal injections of a contaminated drug is up to 169, federal officials said Thursday. Fourteen people have died.

The officials also reported the first infection in a joint that may have been caused by the tainted medicine. More cases of both types of infection are expected.

About 14,000 people received either spine or joint injections with a long-acting steroid from one of three contaminated lots made by New England Compounding Center in Massachusetts. That is about 1,000 more people at risk than investigators at the Centers for Disease Control and Prevention estimated earlier this week.

Fungi that cause human disease are notoriously slow to grow and hard to identify. In 12 cases the organism identified is Exserohilum, a type of fungus not previously known to cause meningitis. In one case the organism was Aspergillus, a more common genus.

Exserohilum was identified in a patient in Virginia, said J. Todd Weber, the CDC physician leading the investigation. Virginia has 30 meningitis cases and Maryland has 13. The state with the largest number is Tennessee, with 49.

The rarity of the organism is likely to complicate diagnosis and treatment.

The current recommendations are that people who got spinal injections with suspect steroid be treated only if they have both symptoms of meningitis and abnormalities in their spinal fluid. Weber said, however, that patients and doctors “should not assume that fungal testing that is negative means that there is no infection.” For that reason, people with symptoms and an abnormal spinal tap, but with no fungus isolated, should still get treated, he said.

The average time between injection and diagnosis has been about two weeks, said Benjamin Park, another CDC physician. The longest interval has been 42 days. Whether joint infections will take longer to develop is uncertain. Why 12 of the 23 states that received the tainted drug have seen no cases is also something of a mystery.

For treatment, CDC is recommending two drugs, liposomal amphotericin B and voriconazole, that have to be given intravenously for months. The drugs “are very strong and can be very difficult for patients to tolerate,” Weber said. The agency has convened a panel of experts for advice.

“This is new territory for public health and the clinical community,” he said.

The single case of an infected joint was found by the state health department in Michigan. It is in a patient’s ankle; no further details were provided.

New England Compounding Center shipped about 18,000 vials of methylprednisolone acetate, which is used to quell inflammation and relieve pain in people with herniated disks and certain types of arthritis. Fungus has been detected in about 50 vials recovered from the company’s compounding center in Framingham, Mass., and from clinics that got the product.

Exserohilum is a so-called “brown fungus” found on plants, particularly grasses. The infection it causes, called phaeohyphomycosis, usually occurs in organs in direct contact with spores, such as skin, eyes and sinuses.

The infections are very rare. The few that occur are usually found in people with compromised immune systems, such as children being treated for cancer.