Aspergillus fumigatus is a pathogenic fungus responsible for more than 80% of aspergillosis. It is a very ubiquitous filamentous fungus (widely distributed). It is especially abundant in humid areas with organic remains, such as dead leaves or manure. It is also found in stored grains and marijuana leaves.
Therefore, aspergillosis are all those diseases caused by fungi of this genus. It usually affects people with weakened immune systems; that is, people with low defenses.
Transmission occurs through inhalation of the spores of the fungus and invades mainly the blood vessels
- The treatments with immunosuppressive drugs, for example
- Hematological neoplasms (leukemias, lymphomas, unclassifiable myeloproliferative neoplasms, among others)
- Immunosuppression post-transplant. In patients who need an organ transplant, a previous immunosuppression is necessary to reduce the chances of rejection.
- Immunological diseases, which directly affect the defenses, such as AIDS. This is the reason why aspergillosis is common in patients with HIV.
In addition to the risk factors related to the immune system and defenses, there are chronic lung diseases that predispose to suffer this type of infection, such as cystic fibrosis or chronic obstructive pulmonary disease (COPD).
Main clinical forms of aspergillosis
There are several paintings in whose pathogenesis the Aspergillus fungus participates. The appearance of one or the other depends on the degree of immune involvement and the location of the fungus . We will now show the most characteristic aspergillosis:
- Non-invasive aspergillosis:
- Allergic bronchopulmonary aspergillosis (ABPA).
- Invasive aspergillosis:
- Invasive pulmonary aspergillosis.
- Tracheobronchial aspergillosis.
- Other pictures of aspergillosis.
In this case, the fungus grows in existing lung cavities (eventually they can appear in the paranasal sinuses), of different etiologies, along with cellular debris, mucus and fibrin. A delimited collection (capsule) appears without symptoms in 20% of patients.
The clinic of these patients, if it exists, usually consists of a nonproductive cough (without sputum or mucus emission) and sometimes bloody (called hemoptysis).
The diagnosis is given by a chest radiograph in which the cavities will be seen. Sometimes, the cultures for the fungus are negative , so it can be confirmed by the presence of specific immunoglobulins against it. The treatment is usually surgical in cases that occur with repetitive hemoptitis. Antifungal drugs can be associated.
Allergic bronchopulmonary aspergillosis (ABPA)
It is an allergic reaction against Aspergillus species . It is a pathology that appears mainly in obstruction of the airway, with productive cough (expel mucus) associated or not with fever and anorexia , in addition to the asthmatic clinic. If left untreated it can progress to pulmonary fibrosis with
The diagnosis is suspected by the clinic in asthmatic patients, confirming it with allergic cutaneous tests for Aspergillus as well as the measurement of precipitins, eosinophilia and other parameters that support the allergy. It is treated with corticosteroids.
Invasive pulmonary aspergillosis
It is a serious and frequent condition, appears mainly in patients with neutropenia and bone marrow transplantation. When the fungus reaches the pulmonary alveolus, the macrophages can not stop the infection and it spreads. It produces necrosis of the lung tissue and can spread through the pulmonary vessels, the main destination is the brain; and produce hemorrhagic infarcts in the injured areas.
These patients will present with fever, chest pain, non-productive cough, hemoptysis and dyspnea (difficulty breathing). The halo sign , a nodule surrounded by a radiolucent disk (seen more clearly on the radiograph), is characteristic of pulmonary radiography. It can cavitate.
Without treatment, the prognosis is fatal, mortality is close to 100%. It is treated with antifungal drugs.
Although it is an invasive infection, it has a better prognosis than invasive pulmonary aspergillosis. 10% affect subjects without immunosuppression. In this case the presence of Aspergillus causes ulcerative lesions and pseudomembranes in the mucosa of the respiratory tract.
Alveolar involvement is scarce. In addition to the clinic of cough, hemoptitis and fever, a deep stridor due to the occupation of the airway stands out. It is a serious condition, if left untreated it can end the death of the patient due to the extension of the infection. Sometimes, it can break the airway.
Other paintings by Aspergillus
Although less common, aspergillosis may have other locations besides the lung. When the fungus is acquired by the bloodstream, it can affect any structure.The symptoms of paranasal sinuses, acute or chronic; and aspergillosis of , which presents with brain abscesses.