What Is Aspergillosis?

Aspergillosis is a chronic mycosis caused by Aspergillus infection, which can invade the skin, mucous membranes, eyes, external ear canal, nose, sinuses, bronchus, lung, gastrointestinal tract, nervous system or bones, and in severe cases cause sepsis. Diseases caused by various Aspergillus, mainly Aspergillus fumigatus. A worldwide distribution. Aspergillus spoils in plants, soil, etc., and can produce a large number of spores. It can cause respiratory diseases through entry of the respiratory tract, and can also cause infections in the sinuses and orbits. It can cause infections after skin burns. People with poor body immunity can develop infections, and a few can spread blood throughout the body, with a poor prognosis. Respiratory aspergillosis can be divided into allergic bronchopulmonary aspergillosis, aspergillus (fungus) and invasive pulmonary aspergillosis. Systemic aspergillosis is often spread by blood.

Basic Information

English name

aspergillosis

Visiting department

Internal medicine

Multiple groups

Fur worker, bird feeder, farmer

Common causes

Inhalation of dust containing Aspergillus spores, damage to the skin and mucous membranes, and contamination with Aspergillus spores in the eyes, often causing infections

Common symptoms

Sinusitis, nasal polyps, asthma

Causes of Aspergillosis

Aspergillus is divided into 18 groups, 132 species and 18 varieties, most of which are non-pathogenic bacteria. Those who can cause human diseases are: Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus nidulans, Aspergillus nidulans, Aspergillus nidulans, Aspergillus spp., Aspergillus versicolor, Aspergillus oryzae, Aspergillus gray, Aspergillus polyhedrin, Bright white Aspergillus, Aspergillus japonicus, Aspergillus amsterium, Aspergillus constriction, Aspergillus flavus, Aspergillus flavus, Aspergillus polymyces, etc. are the most common. Many Aspergillus are pathogenic to plants and some can infect birds, insects and livestock. Fur workers, bird feeders, and farmers are often infected by inhaling dust containing Aspergillus spores, damaged skin and mucous membranes, and contamination with Aspergillus spores in the eyes.

Clinical manifestations of aspergillosis

Aspergillosis can occur at any age, gender, and race, and is more common among farmers, horticultural workers, and people with low immune function. Clinically divided into:

Pulmonary aspergillosis

It is composed of non-invasive aspergillosis and invasive pulmonary aspergillosis.

2.Aspergillus rhino-sinusitis

In fungal rhino-sinusitis, aspergillus infection is the most common, and it most often invades the maxillary sinus, ethmoid sinus, and occasionally the frontal and sphenoid sinuses. The clinical classification is similar to pulmonary aspergillosis, including non-invasive and invasive aspergillosis.

(1) Non-invasive aspergillosis Allergic aspergillus rhino-sinusitis is the most common. It occurs in young adults with a specific allergic constitution and often has a history of recurrent sinusitis, nasal polyps, or asthma. Aspergillus sinus balls are more common in women, and the course is longer, mostly single, often with headache, stuffy nose, purulent nasal discharge, and nasal discharge malodor. Nasal endoscopy showed swelling, sticky or massive secretions of mucous membranes, CT scan showed that all or most of the sinuses were nodules or masses with uneven density, and calcifications were seen in some patients. Parasitic nasal-sinus aspergillosis is usually asymptomatic, and mucosa-like crusts in the nasal cavity and sinuses are often found during nasal endoscopy. Histopathological examination showed that the fungal mycelium could be further developed into Aspergillus globus.

(2) Invasive Aspergillosis Acute invasive Aspergillus rhino-sinusitis is mainly seen in patients with severely immunocompromised bone marrow transplantation, agranulocytosis, or high-intensity tumor chemotherapy. Chronic invasive aspergillous nasal-sinus aspergillosis is more common in patients with low immunity such as diabetes. The disease progresses slowly and the early symptoms are similar to chronic rhinitis and sinusitis.

3. Cerebral aspergillosis

Cerebral aspergillosis is relatively rare, accounting for 15% to 25% of invasive aspergillosis, but the mortality rate is as high as 85% to 100%. The invasion route is mainly caused by the direct spread of nasal-sinus aspergillus infection, and some patients are caused by hematogenous spread of pulmonary aspergillosis. A few patients are caused by traumatic brain injury or direct invasion by surgery.

4. Disseminated aspergillosis

The disease can occur at any age, often secondary to patients with acute leukemia, bone marrow transplantation, systemic lupus erythematosus, solid organ transplantation, or long-term use of glucocorticoids and cytotoxic drugs.

5. Other

Such as skin, external ear canal, eye aspergillosis and so on.

Aspergillosis check

Direct microscopy

Take sputum, pus, scabies, ulceration of skin lesions, bronchoalveolar lavage fluid or biopsy tissue samples for direct microscopy.

2. Cultivate

The colonies on the Shaw medium at room temperature grow quickly and are hairy, with yellow-green, black, brown and so on. The characteristic structures of Aspergillus such as conidia heads and podocytes can be seen under the microscope.

3. Histological examination

The histopathological response of aspergillosis is usually a purulent or mixed inflammatory response.

4. Aspergillus immunoassay

(1) Aspergillus specific antibody detection is mainly used in people with normal immune function. Methods include immunodiffusion test (ID), convection immunoelectrophoresis (CE) or latex agglutination test (LPA). Can be used to diagnose allergic aspergillosis, pulmonary aspergillosis, chronic necrotizing aspergillosis and other invasive aspergillus infections in normal immune function, including endocarditis. The positive rate of allergic aspergillosis is more than 70%, while the positive rate of pulmonary aspergillus is greater than 90%, but the positive rate of invasive aspergillosis is low.

(2) Specific antigen detection Serum Aspergillus specific antigen detection, referred to as GM test, is mainly used for the early diagnosis of invasive aspergillosis in patients with hematological malignancies, and has good sensitivity and specificity, and it can also be used for solid organs. Transplant patients.

(3) The molecular biology test mainly uses real-time PCR (polymerase chain reaction) technology to detect Aspergillus-specific DNA fragments in blood and bronchoalveolar lavage fluid, which has good sensitivity and specificity. However, the technology has not yet been officially approved for clinical routine use, mainly due to its false positives and standardization issues that have not yet been completely resolved.

Aspergillosis diagnosis

Allergic aspergillosis

Allergic nasal-sinus aspergillosis diagnostic criteria: including history, skin test, and type I allergies confirmed by serology, pathological confirmation of allergic mucin in the nasal cavity and sinuses, and mucin found in histology or fungal culture Have fungal mycelia, and exclude other pathogens and invasive fungal infections.

2. invasive aspergillosis

Because the clinical manifestations of Aspergillus infection are not specific, they are often easily covered by primary or secondary bacteria, viral infections, and the traditional positive rate of fungal culture is low. Contamination makes clinical diagnosis very difficult.

The correct diagnosis is based on a comprehensive consideration of the patient's clinical manifestations, laboratory tests, imaging findings, and underlying diseases. The key is to find and isolate Aspergillus from clinical specimens and confirm that it is indeed in the tissue. The isolation of Aspergillus from sterile samples and the identification of Aspergillus mycelium in pathological tissues are of diagnostic significance. Serological tests are helpful for diagnosis.

Aspergillosis treatment

1. Treatment of pulmonary aspergillosis

Parasitic pulmonary aspergillosis Surgical resection is recommended when hemoptysis is frequent or large. If the underlying disease is not suitable for surgery or the lung function is impaired, the bronchial artery embolization can be used to stop bleeding. Corticosteroids are preferred for allergic pulmonary aspergillosis . It is recommended to use voriconazole, itraconazole, caspofungin, and amphotericin B lipid-containing preparations, or common preparations for invasive pulmonary aspergillosis .

2.Aspergillus rhino-sinusitis

Allergic rhino-sinusitis treatment should be combined with surgery and drug treatment. Nasal endoscopy is used to remove nasal polyps to maintain smooth drainage. Allergic mucin and diseased sinus mucosa are completely removed. Oral glucocorticoids can reduce inflammation, Eliminate edema and effectively prevent recurrence. Generally, prednisone begins to reduce the amount after it has taken effect.

3. Cerebral aspergillosis

The drugs that can be used are voriconazole, itraconazole, posaconazole, high-dose amphotericin B lipid preparation intravenously, combined with stereotactic abscess drainage or craniocerebral lesion removal, the effect is better.

4.Aspergillosis such as skin, eyes, ears

Give active antifungal drug treatment, such as voriconazole, itraconazole, amphotericin B, caspofungin, etc. In addition to drug treatment, the primary can also be debridement treatment. Endophthalmitis can be treated with amphotericin B or voriconazole intravenously. If surgery is needed, amphotericin B can also be injected locally. Keratitis should be treated topically with amphotericin B eye drops, voriconazole can also be applied locally or systemically, and different surgical treatments should be selected according to the condition. Aspergillus canal infection can be topically applied with boric acid, acetic acid lavage solution, or azole antifungal ointment.