Cryptococcal infection

Introduction Cryptococcosis (torulosis) is a subacute or chronic infectious disease caused by cryptococcus neoformans. It is mainly caused by invasion of the central nervous system. In recent years, fungal meningitis, brain abscess and granuloma have been uncommon. It is easy to be confused with other intracranial diseases and delay treatment. Therefore, the mortality rate is high and should be vigilant. The disease can also affect the lungs, skin, subcutaneous tissue, callus, joints and other internal organs, tissues, etc., can occur at any age, but the incidence of children under 10 years of age is low. More men than women (3:1). Since the country officially reported the disease in 1946, it has been found in pediatrics.

Cause

The cause of cryptococcal infection:

Normal people are often exposed to the environment of Cryptococcus neoformans, but the incidence is very rare. The body's immunity to Cryptococcus includes cellular immunity and humoral immunity. Macrophages, neutrophils, lymphocytes, and natural killer cells play an important role. Humoral immunity includes: anti-capsular polysaccharide antibody and complement involved in opsonophagocytosis, assisting phagocytic cells to phagocytose cryptococcus. Only when the body's resistance is reduced, the pathogen can easily invade the human body and cause disease.

an examination

Related inspection

culture + susceptibility test culture cerebrospinal fluid cytology examination cerebrospinal fluid cell classification count

Examination and diagnosis of cryptococcal infection:

1. Central nervous system cryptococcosis: Cryptococcus neoformans is easy to invade the central nervous system, the cause is unclear, and may be related to the presence of aspartate and creatinine in the cerebrospinal fluid. It is also easy to cause subacute or chronic meningitis and meningoencephalitis. Of the 220 cases of cryptococcal infections reported by Forar in 1978, only 19 had no central nervous system involvement, so cryptococcal meningitis is the most common type of fungal-induced pleurisy. Its clinical manifestations resemble tuberculous meningitis, but sometimes cryptococcal granuloma is confined to a certain part of the brain and spinal cord, similar to brain tumors or brain abscesses.

Generally, the onset is slow, and the initial symptoms are mostly mild paroxysmal headaches. Later, they gradually increase, but they can still be relieved naturally, often repeated; more often accompanied by nausea, vomiting, dizziness and varying degrees of fever, weeks or months. After the symptoms of increased intracranial pressure, such as neck stiffness, meningeal irritation positive signs and various eye signs (visual blurred vision, dizziness, diplopia, photophobia, eyeball paralysis, tremor, amblyopia, etc.). Often accompanied by fundus edema and retinal exudative changes.

Cerebrospinal fluid examination and tuberculous meningitis are difficult to distinguish, the appearance is slightly turbid, the total number of white blood cells is about 0.05 ~ 0.5 / L, mainly for lymphocytes, cryptococcus is often mixed, if not stained by ink can be mistaken for lymphocytes, single Nuclear cells, etc. Both sugar and chloride are reduced, and the protein is often above 2g/L. It is not parallel with the inflammation of the disease. The cerebrospinal fluid is centrifuged and sedimented. After ink staining, the cryptococcal is a round spore under the microscope, with a diameter of 5-20m. There are reflective particles, a thick film on the periphery, sometimes spores, but sterile silk. Cerebrospinal fluid culture is also helpful in diagnosis.

If left untreated, it tends to worsen in three months to six months. There are a series of movement disorders such as hemiplegia, aphasia, ataxia, etc.; mental confusion and even convulsions, and finally death due to respiratory failure. Severe violent cases can die within a few weeks. Occasionally, there are more than two years of recurrent episodes and prolonged unhealed. Newborns have a shorter course of disease and a poor prognosis.

2. Pulmonary cryptococcosis: often complicated by central nervous system cryptococcosis, can also occur alone, or secondary to tuberculosis, bronchiectasis, chronic bronchitis. The lesions are diffusely infiltrated around the bronchi, or miliary or isolated lesions, and the primary is often overlooked because of no obvious clinical manifestations. In recent years, chest surgery and autopsy can only find a small granuloma in the lungs. It is confirmed by pathological examination as cryptococcal infection, but there is no clinical symptoms. Therefore, it is considered that the cryptococcal granuloma of the lung can be the primary. The stove will spread to the central nervous system and other places in the future. Pulmonary disease alone and symptoms are rare, once the symptoms appear, it is not easy to distinguish from tuberculosis, such as low fever, cough, mucous sputum, chest pain, chest tightness, burnout, weight loss, etc., but tend to self-heal, severe rare. A small number of patients may show acute pneumonia. Chest radiographs show a single (more common) or multiple nodules in the lower lungs. There is no significant inflammatory infiltration around them. It has an isolated large circular shadow and is easily misdiagnosed as a tuberculoma or tumor. Sometimes There may be void formation. Early diagnosis of pulmonary cryptococcosis should be given sufficient attention.

3. Skin mucosal cryptococcosis: cutaneous cryptococcal disease rarely occurs alone, often a local manifestation of systemic cryptococcosis, which may be caused by dissemination of meninges, lungs and other lesions, mainly as facial acne-like The rash, induration, or necrosis at the center as the lesion enlarges, forming an ulcer. It may also occur on mucous membranes such as hard palate, soft palate, tongue, gums, pharynx, and nasal cavity. The symptoms are not serious and the course is long.

4. Bone cryptococcosis: good invasion of the skull and spine, but the joints are often not affected. Bone damage is a chronic, multiple, destructive lesion with no periosteal hyperplasia, but may have swelling and pain. X-ray has no special performance.

5. Visceral cryptococcosis: caused by dissemination. Heart, testis, prostate, eye, etc. can often spread, but does not affect the kidney, liver, spleen, lymph nodes and other parts. Infections in the gastrointestinal tract and genitourinary system are similar to tuberculosis. Sometimes through the subarachnoid space of the arachnoid, it can directly invade the eye or spread through the bloodstream into the pigmented layer of the eye, the retina, the lens, and the like. In some cases, it can invade the heart and cause endocarditis.

Differential diagnosis

Symptoms of cryptococcal infection that are confusing:

Candida infection: Candida is a common species in the vagina. When the vaginal acidity decreases and the normal balance between mold and bacteria is destroyed before and after the menstrual period, menopause or after production, the number of Candida will be rapid. Increased and caused infection. It is characterized by a grayish white cheese-like leucorrhea, which is extremely itchy. It is most common in women with poor immunity such as diabetes, pregnant women, or trousers that are too tightly worn.

Fungal infections: The diseases caused are called fungal diseases. The highest incidence of candidiasis and dermatophytosis is caused by the fungus of the normal flora of the human body. The infection can be distinguished as: surface infection, skin infection, subcutaneous tissue infection, deep infection and Conditional infection. Observe the patient's teeth closed, paroxysmal convulsions, sneer, angulation, generalized tonic and paroxysmal spasm, pay special attention to whether the airway is unobstructed, and there is no throat. After the patient is quiet, check for pulmonary complications and necessary auxiliary examinations.

Bacterial infections: Bacilli, cocci, Gram-positive and negative bacteria, various organs of the body, bacterial infections can occur in all systems. It is generally necessary to combine symptoms (mostly systemic symptoms are obvious) and laboratory diagnosis.

Mold infection: fungal vaginitis, caused by mold infection. Its incidence is higher than trichomonas vaginitis. Medically, the mold infection is called Candida infection, so fungal vaginitis is also called Candida vaginitis. More common in young girls, pregnant women, diabetic patients, and patients who have been treated with larger doses of estrogen after menopause. Candida albicans infection, often manifested as vaginitis. Candida vaginitis is a common vaginitis, known as mold vaginitis, the incidence rate is second only to trichomonas vaginitis. Infection caused by Candida albicans in Candida. The fungus is in the shape of an egg, having spores and pseudohyphae formed by germination elongation of the cells, and the pseudohyphae is connected with the spores into a chain or a branch. Candida is not very resistant to heat and can be killed by heating to 60 ° C for 1 hour; but it is more resistant to dryness, sunlight, ultraviolet light and chemical preparation.

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