Aspergillosis is a mycosis caused by various types of mold fungi of the genus Aspergillus and occurring with chronic toxic-allergic manifestations. With aspergillosis, the bronchopulmonary system and paranasal sinuses are mainly affected; less often – the skin, visual system, central nervous system, etc. Patients with low immune reactivity may develop disseminated aspergillosis. The leading role in the diagnosis is played by laboratory methods: microscopy, bakposev, serological reactions, PCR. It is possible to make inhalation and skin-allergic tests. Treatment is carried out with antifungal drugs.
ICD 10
B44 Aspergillosis
General information
Aspergillosis is a fungal disease, the causative agent of which is Aspergillus mold fungi. Aspergillus can cause a variety of superficial and deep mycoses of internal organs, skin and mucous membranes, so aspergillosis is studied in a number of clinical disciplines: mycology, pulmonology, otolaryngology, dermatology, ophthalmology, etc. Over the past two decades, the incidence in the population has increased by 20%, which is associated with an increase in the number of patients with congenital and acquired immunodeficiency, the spread of drug addiction and HIV infection, the irrational use of antibiotics, the use of immunosuppressive drugs in oncology and transplantation. All this once again confirms the growing relevance of aspergillosis.
Causes
The causative agents of aspergillosis in humans can be the following types of mold fungi of the genus Aspergillus: A. flavus, A. Niger, A. Fumigatus, A. nidulans. A. terreus, A. clavatus. Aspergillus are aerobic and heterotrophic; they can grow at temperatures up to 50 ° C, persist for a long time when dried and frozen. In the environment, aspergillus is ubiquitous – in soil, air, and water. Favorable conditions for the growth and reproduction of aspergillus are available in ventilation and shower systems, air conditioners and humidifiers, old things and books, damp walls and ceilings, long-stored food products, agricultural and indoor plants, etc.
Infection most often occurs by inhalation when inhaling dust particles containing mycelium of the fungus. Agricultural workers, workers of paper spinning and weaving enterprises, millers, as well as pigeon breeders are at the greatest risk of the disease, since pigeons, more often than other birds, suffer from aspergillosis. The occurrence of fungal infection is facilitated by infection during invasive procedures: bronchoscopy, puncture of the paranasal sinuses, endoscopic biopsy, etc. The contact route of transmission of aspergillosis through damaged skin and mucous membranes is not excluded. Alimentary infection is also possible when eating food contaminated with aspergillus (for example, chicken meat).
In addition to exogenous infection with aspergillus, there are cases of auto-infection (with the activation of fungi living on the skin, mucous membrane of the pharynx and respiratory tract) and transplacental infection. Risk factors for the incidence of aspergillosis include immunodeficiency of any genesis, chronic diseases of the respiratory system (COPD, tuberculosis, bronchiectasis, bronchial asthma, etc.), diabetes mellitus, dysbiosis, burn injuries; taking antibiotics, corticosteroids and cytostatics, radiation therapy. There are frequent cases of the development of mycoses of mixed etiology caused by various types of fungi – Aspergillus, candida, actinomycetes.
Classification
Thus, depending on the ways of spreading fungal infection, endogenous (autoinfection), exogenous (with airborne and alimentary transmission) and transplacental aspergillosis (with vertical infection) are distinguished.
According to the localization of the pathological process, the following forms of aspergillosis are distinguished: bronchopulmonary (including lung aspergillosis), ENT organs, skin, eye, bone, septic (generalized), etc. The primary lesion of the respiratory tract and lungs accounts for about 90% of all cases of aspergillosis; the paranasal sinuses – 5%. Involvement of other organs is diagnosed in less than 5% of patients; dissemination of aspergillosis develops in about 30% of cases, mainly in weakened individuals with a burdened premorbid background.
Aspergillosis symptoms
The most studied form of pathology to date is lung aspergillosis. The initial stages of bronchopulmonary aspergillosis are disguised as a clinic for tracheobronchitis or bronchitis. Patients are concerned about cough with grayish sputum, hemoptysis, general weakness, weight loss. When the process spreads to the lungs, a pulmonary form of mycosis develops – aspergillosis pneumonia. In the acute phase, there is fever of the wrong type, chills, cough with copious mucopurulent sputum, shortness of breath, chest pain. When breathing from the mouth, the smell of mold may be felt. Microscopic examination of sputum reveals mycelium colonies and aspergillus spores.
In patients with concomitant diseases of the respiratory system (pulmonary fibrosis, emphysema, cysts, lung abscess, sarcoidosis, tuberculosis, hypoplasia, histoplasmosis), lung aspergilloma is often formed – an encapsulated focus containing fungal hyphae, fibrin, mucus and cellular elements. Death of patients with aspergilloma may occur as a result of pulmonary hemorrhage or asphyxia.
Aspergillosis of the ENT organs can occur in the form of external or middle otitis, rhinitis, sinusitis, tonsillitis, pharyngitis. With aspergillosis otitis media, hyperemia, peeling and itching of the skin of the external auditory canal initially occur. Over time, the auditory canal is filled with a loose grayish mass containing filaments and spores of the fungus. Possible spread of aspergillosis to the eardrum, accompanied by sharp stabbing pains in the ear. Lesions of the maxillary and sphenoid sinuses, the latticed bone, and the transition of fungal invasion to the orbits are described. Ocular aspergillosis can take the form of conjunctivitis, ulcerative blepharitis, nodular keratitis, dacryocystitis, blepharomeibomitis, panophthalmitis. Complications in the form of deep corneal ulcers, uveitis, glaucoma, vision loss are not uncommon.
Aspergillosis of the skin is characterized by the appearance of erythema, infiltration, brownish scales, moderate itching. In the case of onychomycosis, there is a deformation of the nail plates, a change in color to dark yellow or brownish-greenish, crumbling of the nails. Aspergillosis of the gastrointestinal tract occurs under the guise of erosive gastritis or enterocolitis: the smell of mold from the mouth, nausea, vomiting, diarrhea are typical for it.
The generalized form of aspergillosis develops with hematogenous dissemination of aspergillus from the primary focus to various organs and tissues. In this form of the disease, aspergillosis endocarditis, meningitis, encephalitis occur; abscesses of the brain, kidneys, liver, myocardium; damage to bones, gastrointestinal tract, ENT organs; aspergillosis sepsis. The mortality rate from the septic form of aspergillosis is very high.
Diagnostics
Depending on the form of mycosis, patients are referred for consultation to a specialist of the appropriate profile: pulmonologist, otolaryngologist, ophthalmologist, mycologist. In the process of diagnosis of aspergillosis, much attention is paid to anamnesis, including professional, the presence of chronic pulmonary pathology and immunodeficiency. If a bronchopulmonary form of aspergillosis is suspected, radiography and CT of the lungs, bronchoscopy with sputum sampling, bronchoalveolar lavage are performed.
The basis for the diagnosis is a complex of laboratory studies, the material for which can be sputum, rinsing water from the bronchi, scrapings from smooth skin and nails, discharge from the sinuses of the nose and the external auditory canal, prints from the surface of the cornea, feces, etc. Aspergillus can be detected by microscopy, culture examination, PCR, serological reactions (ELISA). It is possible to conduct skin-allergic tests with aspergillus antigens.
Differential diagnosis of pulmonary aspergillosis is carried out with inflammatory diseases of the respiratory tract of viral or bacterial etiology, sarcoidosis, candidiasis, pulmonary tuberculosis, cystic fibrosis, lung tumors, etc. Aspergillosis of the skin and nails has similarities with epidermophytia, rubromycosis, syphilis, tuberculosis, actinomycosis.
Aspergillosis treatment
Depending on the severity of the patient’s condition and the form of this disease, treatment can be carried out on an outpatient basis or in a hospital of the appropriate profile. Antifungal therapy is carried out with drugs: amphotericin B, voriconazole, itraconazole, flucytosine, caspofungin. Antifungal drugs can be administered orally, intravenously, in the form of inhalations. With aspergillosis of the skin, nails and mucous membranes, local treatment of foci with antifungal agents, antiseptics, enzymes is carried out. Antifungal therapy lasts from 4 to 8 weeks, sometimes up to 3 months or longer.
With aspergilloma of the lungs, surgical tactics are indicated – economical lung resection or lobectomy. During the treatment of any form of aspergillosis, stimulating and immunocorrective therapy is necessary.
Prognosis and prevention
The most favorable course is observed with aspergillosis of the skin and mucous membranes. Mortality from pulmonary forms of mycosis is 20-35%, and in people with immunodeficiency – up to 50%. The septic form has an unfavorable prognosis. Measures to prevent infection with aspergillosis include measures to improve sanitary and hygienic conditions: fighting dust in production, wearing personal protective equipment (respirators) by workers of mills, granaries, vegetable storages, weaving enterprises, improving ventilation of workshops and warehouses, regular mycological examination of persons from risk groups.
