Nov 7, 2012 (CIDRAP News) – A public health investigation into an unusual fungal meningitis death in Tennessee quickly uncovered other related cases and expedited detection and treatment that probably saved lives, while drawing national attention to the problem, according to a report yesterday from some of the state officials who worked on the probe.
The group's report on the first 66 case-patients in the Tennessee also offers findings about exposure to the contaminated steroids, the clinical course of infections, and treatment. They published the details of the investigation yesterday in an early online report from the New England Journal of Medicine (NEJM).
The outbreak's index patient was a Tennessee man in his 50s who died from Aspergillus fumigatus meningitis after receiving an epidural injection of the steroid methylprednisolone acetate produced by New England Compounding Center (NECC). The doctors who treated that patient described his infection in an Oct 19 NEJM case report.
So far 424 infections and 31 deaths, most of them involving the fungus Exserohilum rostratum, have been linked to three recalled lots of contaminated steroids from NECC, the US Centers for Disease Control and Prevention (CDC) said in an update today. The total reflects an increase of 5 infections and 1 death since the CDC's last update on Nov 5. The number of affected states remained at 19, and the number of peripheral joint infections stayed at 10.
According to the new NEJM report, a clinician reported the A fumigatus infection to the Tennessee Department of Health (TDH) on Sep 18, and the department launched an epidemiologic investigation that identified other puzzling meningitis cases in healthy adults who had received epidural steroid injections at the same clinic as the first patient.
Authorities found no obvious source of environmental contamination at the clinic, and by Sep 25, they identified a total of eight possible case-patients, all with connections to the clinic. Multiple common products were used for the patients, including preservative-free methylprednisolone acetate from NECC. In hopes of identifying other sick patients, Tennessee officials asked colleagues in Massachusetts to help identify other facilities that had received potentially contaminated steroid injections.
The following day, NECC recalled three lots of methylprednisolone acetate, which had been sent to 76 facilities in 23 states. The TDH activated its emergency operations center and launched a larger investigation to find patients who had been exposed to the drug.
As of Oct 19, investigators had found 66 patients who met the fungal meningitis case definition. Their median age was 69. While A fumigatus was confirmed in clinical samples from the index patient, E rostratum was identified in 21 of the cases. The median time between injection and symptom onset was 18 days.
Among 13 patients who had strokes, 8 initially presented with posterior circulation stroke, and strokes were involved in 7 of the 8 deaths in the Tennessee patients.
When investigators explored the details of the drugs the patients received, they found that in one clinic, the age of the vials seemed to be associated with the infection rate, and they suggested that contamination could have increased over time, with fungal levels higher in the older vials. The group also found a possible link between higher infection rates and the volume of drug administered.
One of the most striking features of the cases was the high incidence of strokes, which were more common early in the outbreak, the group noted. They said that stroke incidence dropped off as fungal meningitis infections were identified earlier, prompting aggressive therapy earlier in the illness course.
"Stroke did not develop in any patients in this report in whom therapeutic doses of antifungal medications were instituted within 48 hours after the initial presentation," they wrote, adding that all eight of the Tennessee deaths occurred in patients who received minimal, no, or delayed treatment.
The aggressive public health response to the initial case triggered the identification of the multistate outbreak and a rapid recall of the products, underscoring the importance of close collaboration between public health and the medical community and the need to adequately support public health systems.
"Maintaining a strong public health infrastructure is critical to ensuring that there is capacity to investigate such outbreaks quickly and effectively," the authors concluded.
See also:
Nov 7 N Engl J Med abstract
Nov 7 CDC fungal meningitis outbreak update
Oct 19 CIDRAP News story "Report describes case that launched meningitis outbreak probe"
