By JoNel Aleccia, NBC News
As the death toll and the case counts continued to climb Monday in an outbreak of fungal meningitis tied to tainted pain shots, health officials admit they've been stymied in their best efforts to treat patients.
"I don't think we have a very good handle on exactly what is happening or how this is playing out," said Dr. Tom Chiller, deputy chief of the mycotic diseases branch at the Centers for Disease Control and Prevention.
Thirty people have died and 419 have developed fungal meningitis or joint infections in 19 states after receiving injections of contaminated steroid drugs earlier this year, the CDC reported Monday.
Those numbers include dozens of patients who have developed abscesses at the infection site or another condition called arachnoiditis, an inflammation of the delicate membranes that surround and protect the nerves of the spinal cord.
In Michigan, for instance, which has logged the most cases -- 119, plus seven deaths -- 61 patients have developed fungal meningitis; 51 who developed epidural abscesses, six joint infections and one stroke.
"In some cases, those abscesses have developed into meningitis," said Angela Minicuci, a spokeswoman for the Michigan Department of Community Health.
What's particularly alarming is that some patients have become sicker even though they've been taking powerful antifungal drugs aimed at wiping out the black mold Exserohilium, which has been responsible for most of the illnesses.
"What we do know from hearing from a few centers is that around a third of patients with meningitis are having some sort of disease progression," Chiller said.
It's not clear why some patients aren't responding to the therapy. The fungi are difficult to treat, Chiller said, but tests showed that the organisms should have been killed by the drugs. Doctors don't know whether the problem is the natural progression of the disease itself, or perhaps the body's immune system kicking into action, Chiller said.
"Are we actually killing the fungi and this is a reaction?" he asked. "It's not responding to therapy that well, or it's responding very slowly."
For patients who already have been affected, that means they can expect a protracted recovery from the fungal infections. "It will be a long-term therapeutic management issue," Chiller said.
About 17,000 vials of contaminated steroids were sent out by the New England Compounding Center, the Framingham, Mass., pharmacy at the center of the outbreak. That company has lost its license. A sister firm, Ameridose LLC, is also being investigated for problems with sterility. Both companies have recalled all their products.
For the 14,000 patients who received the shots, the greatest risk of developing infections is in the first 42 days -- six weeks -- after the injections, CDC has said. Unfortunately, Chiller said, some risk of serious illness does remain.
"By 42 days, your risk is really, really low," he said. "But that doesn't mean that anyone with a symptom, a sign, shouldn't express that to their physician. Any pain that's not getting better, that's getting worse, they should report that."