5.12 Cryptococcal meningitis

Type of infection

Cryptococcus is found in soil from bird droppings that are breathed in as dust. It can not be passed in the air from one infected person to another. Infection can be dormant for many years.

Cryptococcus is only a problem if your CD4 count drops to below 100 cells/mm³. Smokers and people who work out of doors have higher risk of cryptococcus.

Main symptoms

If cryptococcus infects the blood, it can cause cryptococcal meningitis which can be very serious. Symptoms of cryptococcal meningitis include:

In the lungs, symptoms can be similar to PCP and include coughing and shortness of breath, fever and fatigue.

Diagnosis

Diagnosis is made by testing spinal fluid or blood – either for antigens (parts of the fungus) or by growing the fungus in culture.

Spinal fluid is more difficult to test and requires a lumbar puncture (spinal tap).

Treatment

Moderate to severe initial infection

When crypto attacks the brain, it is treated with amphotericin B or liposomal (fat-coated) amphotericin B. Treatment is through a central line (Hickman or Portacath) into a deep vein. This is complicated and difficult and can last up to six weeks.

If meningitis causes pressure in the spinal fluid this may be drained to reduce the risk of brain damage.

Once the infection is cleared a second stage of maintenance treatment (secondary prophylaxis) is essential to prevent the infection returning. This is with oral fluconazole capsules at 400 mg/day for the first eight weeks, reduced to 200 mg/day for as long as CD4 count remains below 100 cells/mm³.

Maintenance therapy can be safely stopped if response to ARVs increases CD4 count above 100. If CD4 count drops again, maintenance therapy should be restarted.

Mild infection

Fluconazole or itraconazole tablet are active against cryptococcus but are not as effective, and are only used in cases of mild infection.

Timing of ART

Cryptococcus is one of the few OIs which are treated directly first with a short 4 to 6 week delay before beginning ART. This was because of a higher risk of mortality when both are treated at the same time, This was due to higher rates of IRIS.

In July 3023. a new study and related editorial suggested that these risks depended on the country and health setting. This paper found no increased risk of IRIS when starting both treatments at the same time, in Europe and the US.

Prophylaxis

If you are in a country where cryptococcus is common and you have a CD4 count under 100, then prophylaxis with fluconazole (200mg/day) or itraconazole may protect you from infection. This has to be balanced against the risk of resistance and cost. ARV therapy to raise your CD4 count to a safer level would be better value if this is available.