​Infectious Diseases and Microbiology -Aspergillosis (Aspergillus species)

​Infectious Diseases and Microbiology -Aspergillosis (Aspergillus species)
The Aspergillosis
Aspergillus species are the cause of aspergillosis. Dust exposure or inhaling aerosolized conidia from the soil are the two main ways that aspergillosis is spread. The primary risk factor for the development of aspergillosis is severe, prolonged neutropenia. Patients with hematologic malignancies are frequently at risk for infection and accompanying mortality due to aspergillosis.

Aspergillus is a major cause of fungal sinusitis and allergic bronchopulmonary aspergillosis in immunocompromised individuals, which is characterized by increased IgE antibodies, eosinophilia, and asthma. In the lungs of sick people, Aspergillus creates fungus balls (aspergillomas), a noninvasive mass of hyphae that colonizes an ancient hollow (such as a tuberculous cavity). The most typical symptom is hemoptysis, or coughing up blood.
Invasive pulmonary aspergillosis, caused by Aspergillus species, can spread to any organ in patients taking high doses of immunosuppressive medication, bone marrow or solid organ transplant recipients, and individuals with hermatologic malignancies.

Conidia inhaled into the lung alveoli germinate into angioinvasive filamentous hyphae, which spread to distant locations and cause bleeding, infarction, and necrosis. Patients who are receiving corticosteroid and cytotoxic medication or have an underlying condition that impairs these innate cellular defense mechanisms become neutropenic and more vulnerable to invasive aspergillosis. T-cell immunity activation is essential for infection control.

 An accurate test for diagnosing invasive aspergillosis is the enzyme immunoassay, which detects Aspergillus antigen (galactomannan) in serum. A preliminary diagnosis of invasive fungal disease can be made from direct microscopic observation of septate hyphae in tissue biopsy specimens; however, identification requires culture confirmation.

Treatment for invasive aspergillosis involves caspofungin, amphotericin B, itraconazole, and voriconazole for prevention. It is a challenging and highly customized condition. One possible treatment is to remove the fungus ball surgically.