Clinical Overview of Fungal Meningitis

Key points

  • Fungal meningitis is a rare but life-threatening fungal infection.
  • Fungal meningitis usually occurs in patients with immunocompromising conditions who developed a fungal infection in another part their body that spreads to the brain or spinal cord.
  • Healthcare-associated fungal meningitis is very rare. Outbreaks are likely caused by inadequate infection prevention and control practices or contaminated medications.
  • Prompt initiation of appropriate antifungal therapy is critical to improving patient outcomes.
Illustration showing a doctor performing a spinal tap on a patient.

Overview

Fungal meningitis occurs when a fungal infection causes inflammation of the fluid and membranes surrounding the brain and spinal cord. It is a rare but life-threatening condition that requires treatment with antifungal drugs.

The precise incidence of fungal meningitis is difficult to know because these conditions aren't reportable in most U.S. states. Mortality rates vary depending on the pathogen and patient characteristics, but even with treatment, mortality rates can approach 50%.

Usually, fungal meningitis occurs in patients with weakened immune systems such as people with:

  • Cancer
  • Stem cell or solid organ transplantation
  • Advanced HIV disease
  • Immunosuppression from chemotherapy and corticosteroids

Healthcare-associated fungal meningitis is very rare, but outbreaks have occurred in immunocompetent persons. These outbreaks have been associated with inadequate infection prevention and control practices or containment medications used during epidural injections.

Cause

Many fungi that can cause meningitis live in the environment, such as Cryptococcus, Histoplasma, Blastomyces, and Coccidioides. Usually, fungal meningitis develops after a fungal infection spreads from another part of the body. For example, patients may inhale fungal spores that initially cause a lung infection that spreads to the brain or spinal cord.

People at the greatest risk of fungal meningitis include:

  • Those with conditions that weaken the immune system
  • Very premature infants
  • Persons taking immunosuppressive medications (e.g., steroids, post-transplant immunosuppressive drugs).

Prevention

No specific activities are known to cause fungal meningitis. People with weakened immune systems can reduce their risk by taking these precautions:

  • Try to avoid areas with a lot of dust like construction or excavation sites.
  • Stay inside during dust storms and close windows.
  • Avoid activities that involve close contact to dirt or dust, including yard work, gardening, and digging.
  • Use air filtration measures indoors.
  • Clean skin injuries well with soap and water.
    • This reduces the chances of developing a skin infection, especially if the wound was exposed to dirt or dust.
  • Take preventative antifungal medications if prescribed.

Diagnosis and treatment

Diagnosis and treatment for fungal meningitis depends on patient characteristics and which type of fungal infection is suspected.

While rare, medical and surgical procedures can lead to fungal meningitis. This occurs if medical devices or medications are contaminated with fungi or if proper infection control practices are not observed.

Healthcare-associated fungal meningitis outbreaks have occurred among patients who received corticosteroid injections or epidural anesthesia. Appropriate manufacturing and infection control procedures can help prevent these healthcare-associated infections.

Regardless of symptom severity, consider testing any patient with signs and symptoms of meningitis who recently had epidural anesthesia or injections. Testing is especially important if medical procedures are linked to products or supplies associated with other fungal meningitis cases. Some patients with fungal meningitis initially have mild or nonspecific symptoms.

Notifications and Consultation

Notify your state or local health department about any suspected or confirmed cases of healthcare-acquired fungal meningitis and contact your jurisdiction's healthcare-associated infection program coordinator. Public health officials can email Mycotic Diseases Branch (MDB) at FungalOutbreaks@cdc.gov for assistance with recommendations and testing.

Testing for possible healthcare-associated fungal meningitis

Illustration showing a doctor performing a spinal tap on a patient.
Perform lumbar puncture to collect cerebrospinal fluid (CSF)

Diagnostic testing for fungal meningitis is challenging and susceptible to false-negative results. Fungal culture results may be negative and take up to 2 weeks to turn positive. Additionally, infections may involve multiple fungal pathogens or a combination of bacterial and fungal pathogens. Recommended diagnostic procedures for patients with suspected fungal meningitis include:

  • Diagnostic lumbar puncture (LP) unless contraindicated to collect cerebrospinal fluid (CSF)
  • Blood collection

Skin infection over the puncture site or a brain mass causing increased intracranial pressure are reasons LP may be contraindicated.

CSF and blood testing can include:

  • Fungal and bacterial cultures
  • Serum and CSF (1,3)-Beta-D-Glucan testing
  • Optional tests include serum Aspergillus galactomannan and CSF fungal polymerase chain reaction test (PCR) or other nucleic acid amplification test (NAAT)

Treatment and recovery

Consult with an infectious disease specialist when determining treatment approaches. After obtaining CSF, immediately begin treatment in patients with suspected fungal meningitis. Treatment should not be withheld because of negative fungal culture or (1,3)-Beta-D-Glucan results.

Treatment should involve broad spectrum antifungals that have adequate central nervous system penetration. Dual therapy can be considered and has been used in previous fungal meningitis outbreaks.