Source: Carver PL. Invasive
Fungal Infections. In: DiPiro, JT, Talbert RL, Yee GC, Matzke GR,
Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic Approach.
8 ed. http://accesspharmacy.com/content.aspx?aid=8005562.
Accessed June 25, 2012.
- Spectrum of diseases attributed to allergy, colonization,
or tissue invasion caused by members of the fungal genus Aspergillus.
- Opportunistic fungal infection caused by Aspergillus species
- Generally acquired by inhalation of airborne conidia small
enough (2.5–3 mm) to reach alveoli or paranasal sinuses.
- Other causative agent: mold that grows in soil, water, decaying
vegetation, and organic debris
- Impaired phagocytosis required for development of invasive
- Three of 300 species of Aspergillus are
most commonly pathogenic: A. fumigatus, A. flavus, and A.
- Prolonged neutropenia
- Chronic administration of glucocorticoids
- Cytotoxic treatment
- Bone marrow transplant
- Recent or concurrent therapy with broad-spectrum antimicrobials
- Chronic granulomatous disease
- Acute rejection of transplanted organ
- Late HIV infection
- Lung is most common site of invasion.
- Lung is most common site of invasion. Patients often present
with classic signs and symptoms of acute pulmonary embolus:
- Pleuritic chest pain
- Friction rub
- Wedge-shaped infiltrate on chest radiographs
- Neutropenic patients develop acute necrotizing, pyogenic pneumonitis
due to hyphae invasion of walls of bronchi and surrounding parenchyma.
- In immunocompromised host:
- Vascular invasion
leads to thrombosis, infarction, necrosis of tissue, and dissemination
to other tissues and organs in the body.
- Survival beyond 2–3 weeks is uncommon.
Means of Confirmation
- Normal commensal in GI tract and respiratory secretions,
therefore definitive diagnosis is difficult.
- Demonstration of Aspergillus by
repeated culture and microscopic examination of tissue provides
most accurate diagnosis.
- Blood cultures
- Enzyme immunosorbent assay (EIA) of serum or other body fluids
used to detect galactomannan, a cell-wall polysaccharide specific
to Aspergillus species
- BG test to detect β-D-glucan in serum or other body fluids
- Chest radiograph
- CT scan may show characteristic halo sign.
- Survive invasive aspergillosis.
- Reverse correctable immunosuppression.
- Start empiric antifungal therapy in patients at highest
risk for invasive disease (acute leukemia and bone marrow transplant
recipients) in any of these conditions:
fever or progressive sinusitis unresponsive to antimicrobial therapy
- Eschar over nose, sinuses, or palate
- Presence of characteristic radiographic findings, including
wedge-shaped infarcts, nodular densities, or new cavitary lesions
- Any clinical manifestation suggestive of orbital or cavernous
sinus disease or acute vascular event associated with fever
- Isolation of Aspergillus spp.
from nasal or respiratory tract secretions confirmatory evidence
in any of previously mentioned clinical settings.
- Voriconazole is drug of choice for primary therapy:
- 6 mg/kg IV twice daily on day 1, then 4 mg/kg/day...