Lax Infection Control Suspected In Fungal Meningitis Outbreak

June 12th, 2023

By Gary Evans, Medical Writer

Infection control lapses, including the contamination of multidose vials of anesthetic, are suspected in a fungal meningitis outbreak that exposed some 200 American patients who received epidural injections this year in the border town of Matamoros, Mexico.

Four of these patients have died as of June 9, 2023. Both clinics were shuttered by Mexican health officials on May 13, but the combination of a possible long incubation period and a high mortality rate has the Centers for Disease Control and Prevention (CDC) greatly concerned.

“If you had epidural anesthesia in Matamoros, Mexico, at River Side Surgical Center or Clinica K-3 from January 1 to May 13, 2023, you are at risk for fungal meningitis: Go to the nearest emergency room as soon as possible to be evaluated for fungal meningitis, even if you do not currently have symptoms,” the CDC emphasized..

The CDC reports that 207 U.S. patients are at various stages of investigation after receiving epidural anesthesia at the two clinics.

Compounding the situation, before the outbreak was recognized, one of the early deaths was an organ donor, said Dallas Smith, PharmD, an epidemiologist in the CDC mycotic diseases branch, at an advisory committee briefing.

“There's have been five recipients of organs from this patient,” Smith said. “All have been notified and are under evaluation. We are working with transplant centers and other partners to properly manage these patients.”

Overall, about 10% of the cases are in men. The primary population at risk is women from more than 20 states who underwent cosmetic procedures including liposuction and breast augmentation at the two clinics. Mexican public officials are trying to determine if any other surgical clinics are involved. Most of the patients live in Texas, but there were cases under investigation in the distant points of Alaska and Puerto Rico.

A similar outbreak that occurred in Durango, Mexico in Nov. 2022, had a striking mortality rate of almost 50%, with 39 of 80 cases dying. While that outbreak primarily involved Mexican citizens, the current outbreak including the U.S. patients appears to be caused by the same fungal pathogen: Fusarium solani species complex.

“The outbreak that we're experiencing now is pretty similar and it has the capacity to have this high mortality rate and just devastate families and communities,” Smith said. “We are not sure if these two outbreaks are linked, but the fact that the same organism is likely causing this fungal meningitis makes us worried about a high mortality rate. That's why it's so important to get patients in early.”

Though it has not been officially solved, the Durango outbreak last year also raised the issue of contaminated multidose vials. There have been press reports of Mexican officials detaining an unidentified physician who brought his own anesthetic vials to different hospitals.

“[One] hypothesis we have is poor infection control practices,” Smith said. “Oftentimes in Mexico at these clinics anesthesiologists bring their own medications and prepare them on site.”

The actual anesthesia medication is in widespread use in Mexico, and does not appear to be the source of infections in the absence of other outbreaks. However, the other critical agent used in epidural spine injections — morphine — is another story.

“There's a [morphine] shortage currently in Mexico, and there could be the potential for a ‘black market’ that could contaminate medicines,” Smith said. “There was an open vial of morphine that our colleagues in Mexico were testing, but I don't think they have results back.”

As of this report, the CDC did not have a definitive isolate identifying F. solani species complex as the causative agent. However, the CDC and two U.S. research labs have detected “fungal signals” consistent with F. solani in the cerebrospinal fluid (CSF) of case patients.

A definitive isolate would allow genomic sequences to see if there is any link between the outbreak in Durango last year and the current outbreak in Matamoros.

“You can do a bit of sequencing of the little region you get from a positive PCR, but we probably need an isolate to really understand if these two outbreaks are related,” said Luis Ostrosky-Zeichner, MD, chairman of the Mycoses Study Group, which worked with CDC to develop interim recommendations on testing and treatment of cases.

“Aggressive, dual antifungal treatment (liposomal amphotericin B and voriconazole) is recommended because of the high case-fatality rate seen during previous outbreaks of fungal meningitis involving Fusarium,” the guidelines state. “Antifungal therapy should be started as soon as possible after collection of CSF.”

The recommendation came with the caveat that optimal therapy for these infections has not been established. The course of care varies between patients, and may be complex and prolonged, the committee noted.

“Expert consultation is particularly important because overall clinical experience with these infections is highly limited,” the guidelines state. “Providers should contact their local health department if they have patients presenting for care. They can also contact CDC ([email protected]). Public health officials can reach out to CDC to connect clinicians with experts in fungal meningitis management.”

For more on this story, see the next issue of Hospital Infection Control & Prevention

Gary Evans, BA, MA, has written numerous articles on infectious disease threats to both patients and healthcare workers for more than three decades. These include stories on healthcare-associated infections like MRSA, C. diff and a panoply of emerging multidrug resistant gram negative bacteria and fungi like Candida auris. In an era of pandemic pathogens, he has covered HIV, SARS, pandemic influenza, MERS, Ebola and SARS-CoV-2. Evans has been honored for excellence in analytical reporting five times by the National Press Club in Washington, DC.