Introduction to Cryptococcosis

Cryptococcosis is one of the most important human fungal infections. It is caused by the fungus Cryptococcus neoformans and represents a serious danger, especially for people with a weakened immune system.

What is cryptococcosis?

The pathogens are found on blades of grass and seeds, which are ingested by birds, mostly pigeons, and excreted in the excrement. The pathogens become airborne through the dried feces and are unknowingly inhaled into the lungs, where they develop granulomas. See AbbreviationFinder for abbreviations related to Cryptococcosis.

Cryptococcus neoformans is a yeast fungus that has a thick capsule made of polysaccharides that protects it from environmental influences. In particular, this prevents phagocytosis by granulocytes and macrophages. In addition, melanin is stored in the cell wall, which prevents damage caused by oxidation products of macrophages.

Cryptococcosis is an opportunistic infection, which means that people who are particularly immunocompromised are affected by Cryptococcus neoformans. AIDS patients are often affected, for example, whose body’s defense system is so weak that it can no longer fight off the pathogen. Therefore, cryptococcosis is also counted among the AIDS – defining diseases. More rarely, it occurs in people with suppressed immune systems from organ transplants or after chemotherapy. However, it can also manifest in individuals without predisposing diseases.


The pathogen Cryptococcus neoformans is usually found in soils rich in inorganic substances. In addition, cryptococci also occur on cereals and grasses. Birds eat the fungus-infested blades of grass and seeds and then excrete them again. Bird droppings are therefore a strong source of infection.

In humans, the pathogen usually uses the respiratory tract as the portal of entry. Ingestion occurs through inhalation of contaminated dusts. If Cryptococcus neoformans has got into the lungs, granulomas form there, which can also remain asymptomatic. Especially in patients with a weakened immune system, spread to other organs via the bloodstream often follows after a short time.

An infection of the central nervous system, i.e. the brain and spinal cord, is feared. The cryptococci have a strong affinity for this. They first multiply there and in turn form granulomas. The course becomes critical when it comes to cryptococcal meningoencephalitis, i.e. inflammation of the brain and meninges caused by Crytococcus neoformans. The skin can also be affected by cryptococci, but this is only rarely observed.

Symptoms, Ailments & Signs

With regard to the course of the cryptococcal infection, it can be said that in the primary stage it often does not cause any visible symptoms. This stage is referred to as a clinically inapparent state. In the further course, however, a chronic progressive fungal infection can develop, which means that the disease continues to worsen. Cryptococcosis becomes particularly dangerous as soon as it enters the bloodstream. From this point on, the secondary stage is present.

The pathogen reaches all parenchymatous organs via the bloodstream, so that symptoms of organ damage occur. Bones and joints can also be affected, resulting in dysfunction and pain. Cryptococcus neoformans also prefers to settle in the central nervous system. The acute meningoencephalitis it triggers manifests itself, among other things, in the form of headaches, psychological abnormalities and a general feeling of illness.

It can also progress to chronic meningitis. Furthermore, skin changes of all kinds can occur. This happens in a relatively unspecific form, so that the condition of the skin does not clearly indicate the cause. In most cases, cryptococcosis affects the entire body. However, they can also remain localized to a single region, which is particularly common when the infection is caused by a single injury.

Diagnosis & course of disease

Microscopy is suitable for the diagnostic detection of cryptococcosis. A liquor sediment is obtained for this purpose. This is done by taking liquor from the patient. The liquor is then centrifuged, filtered and sedimented in the laboratory so that the solid part can be obtained. It contains cells and possibly also microorganisms such as Cryptococcus neoformans. The liquor sediment is now stained with ink.

Due to their distinctive capsule, the fungal cells of the cryptococci have the property of displacing the ink around them, so that a bright halo is created in their vicinity. This allows them to be identified without a doubt. Other options for detecting Cryptococcus neoformans are an antigen test, which can be carried out using liquor, urine and serum samples, and a culture test.

However, this takes about five days, so it is used less frequently. Sabouraud agar is best suited for cultivation. Since Cryptococcus neoformans is capable of special metabolic activities such as the breakdown of urea, it can be clearly distinguished from other types of yeast in culture.


Cryptococcosis, also known as Busse-Buschke disease, is an infection caused by the fungal pathogen Cryptococcus neoformans. The pathogens are found on blades of grass and seeds, which are ingested by birds, mostly pigeons, and excreted in the excrement. The pathogens become airborne through the dried feces and are unknowingly inhaled into the lungs, where they develop granulomas. At first, the infection is unremarkable.

Different forms of complications only arise in the course of the disease. Those affected with a weakened immune system and HIV patients are particularly at risk because the pathogen can spread more easily to other organs. As soon as cryptococcosis has established itself in the central nervous system, flare-ups of fever, severe headaches, joint pain, reduced vision and hearing, and disturbances of consciousness occur. If medical attention is not sought immediately, the brain can become inflamed and progress to chronic meningitis.

In some cases, cryptococcosis can only affect an injured area of ​​the skin and cause an unpleasant dermatological reaction. Diagnosis of the symptom is microscopic. After clarification, a drug-based triple combination of different liquid preparations is given for a period of four to eight weeks. However, male patients receive lifelong fluconazole therapy, since the fungal pathogen always settles in the prostate as a consequence of complications and is reactivated from there.

When should you go to the doctor?

If symptoms such as headaches or a general feeling of illness are noticed over a longer period of time, which cannot be attributed to a specific trigger, the person concerned should go to the doctor. The signs of the disease indicate a serious illness that must be diagnosed and, if necessary, treated in any case. If the causative condition is cryptococcosis, further visits to the doctor are indicated. By the time signs of chronic meningitis appear, the disease may be advanced.

A doctor’s visit is necessary if chronic nausea, migraines and an increasing malaise are noticed. Conspicuous skin changes also require clarification by the doctor. Anyone who notices warning signs of cryptococcosis after contact with potentially infected animals should also consult their doctor. At the latest when fever and circulatory problems occur, the disease must be diagnosed and treated immediately. In addition to the family doctor, an internist or a specialist can be consulted. In the event of a medical emergency, emergency medical treatment is always required.

Treatment & Therapy

An effective therapy for cryptococcosis is very important, since the CNS infestation can be the cause of major problems. In addition, the pathogen has the ability to persist in certain tissues such as the prostate. If this happens, reactivation of the cryptococcal infection is possible, which sometimes takes a more serious course. For this reason, lifelong prophylactic medication should also be considered, particularly in people with immunosuppression.

Basically, cryptococcosis is treated with a triple therapy consisting of fluorocytosine, amphotericin B and fluconazole. These medicines must be taken for four to eight weeks. Since the drugs pass through the liquor, they can easily cross the blood-brain barrier and can therefore also be used to treat meningoencephalitis.

Outlook & Forecast

The prognosis for patients with cryptococcosis has now improved somewhat. This yeast infection almost always occurs in people whose immune systems are already compromised.

Most of those affected suffer – known or not yet diagnosed – from the immune deficiency AIDS. Organ transplanted people and cancer patients are also at risk of contracting cryptococcosis. In the latter, Hodgkin’s lymphoma or the various forms of leukemia are usually the cause of the favorable immune deficiency. Healthy people are affected only to a small extent.

The problem for the diagnosis is that the beginning of the infection is usually symptom-free. Therefore, cryptococcosis is usually well advanced when it is discovered. Cryptococcal meningitis is often fatal. The healthy organism can usually fight cryptococci successfully. But with an immune deficiency, this is no longer possible. Therefore, early identification and treatment of the potentially deadly trigger is essential.

Rapid treatment is the only way to improve the prognosis for cryptococcosis. However, if this occurs in the final stages of leukemia or Hodgkin’s lymphoma, the patients usually have no chance. The underlying disease, the degree of its progression and the degree of immune deficiency define how good or bad the prognosis is. In healthy people, the infection can almost always be treated successfully.


Cryptococcosis can be prevented by avoiding infectious substances. An important step in reducing the occurrence of this disease is to combat any plagues of pigeons in cities, as bird droppings are one of the main sources of infection.


In most cases, the person affected with cryptococcosis has only a few or no special aftercare measures available. The infection should be recognized and treated by a doctor very early on, so that no further complications or other symptoms can occur. Those affected should therefore consult a doctor at the first signs and symptoms of the disease so that a quick diagnosis can be made.

Most of those affected are dependent on taking various medications. The doctor’s instructions should always be followed, and if you have any questions or are unclear, you should contact a doctor first. It is also important to ensure that it is taken regularly and that the dosage is correct so that the symptoms can be permanently alleviated.

Regular visits to the doctor are also very important in order to detect further damage at an early stage. Contact with other cryptococcosis patients can also be useful in order to exchange information about treatment successes and symptoms.

You can do that yourself

Treatment for cryptococcosis focuses on the causes of the fungal infection. Those affected can support the therapy with a number of measures. First and foremost, conservation is important.

People who have cryptococcosis are particularly susceptible to further infection and should avoid exercise and contact with other people whenever possible. If necessary, the diet must also be changed. A healthy and balanced diet that contains all the necessary vitamins and minerals has proven its worth. Sick people should also drink a lot, ideally herbal teas or juice spritzers, to expel the virus as quickly as possible. Furthermore, stimulants should be avoided. Alcohol and cigarettes in particular have a very negative effect on a fungal infection and should therefore be avoided.

In addition to these general measures, which primarily counteract the causative disease, specific action can be taken to counteract the individual symptoms. Fresh air and cooling pads help with recurring headaches. Naturopathy offers soothing essential oils that prevent tension headaches and reduce stress. Should a general feeling of illness accompany this, a doctor must be consulted. In any case, cryptococcus patients require comprehensive medical supervision.