Invasive aspergillosis
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief:
Synonyms and keywords:
Overview
Aspergillosis is a heterogenous group of infectious diseases caused by Aspergillus (commonly A. fumigatus), a ubiquitous fungus. Aspergillosis may be classified according to the clinical syndrome it causes into allergic bronchopulmonary aspergillosis, allergic Aspergillus sinusitis, aspergilloma, chronic pulmonary aspergillosis, invasive aspergillosis, or cutaneous aspergillosis. Aspergillus is primarily transmitted to the human host by either inhalation of airborne conidia (usually during dust exposure during building renovation or construction) or by contaminated biomedical devices, but not from one individual to another. The pathogenesis of aspergillosis varies according to the associated clinical syndrome. Allergic bronchopulmonary aspergillosis and allergic Aspergillus rhinosinusitis are thought to be caused by both type I and type III hypersensitivity immune responses. On the other hand, the development of aspergilloma, chronic pulmonary aspergillosis, and invasive aspergillosis is directly related to the growth and expansion of the Aspergillus hyphae in the lungs. Lastly, cutaneous aspergillosis may result either from direct access of the Aspergillus through a skin break (primary) or dissemination of the Aspergillus to the skin from a distant infected organ (secondary). Immunocompromised status (e.g. organ or stem cell transplant recipient) and history of prior lung disease are the most important risk factors in the development of aspergillosis. Other risk factors include history of asthma, burn or surgical site wounds, and exposure to healthcare settings or construction sites. Following transmission, the majority of patients do not develop any clinical manifestations. The incubation of Aspergillosis is highly dependent on the host immune factors. The incubation period may range from a few days to years, during which the host is asymptomatic. Among immunocompetent hosts, Aspergillosis may result in a localized pulmonary infection, allergic bronchopulmonary aspergillosis, or allergic Aspergillus sinusitis. Accordingly, patients usually appear healthy but develop symptoms of asthma or sinusitis. Among immunocompromised hosts, Aspergillosis progresses faster and has a more invasive course, and patients are often sick-looking and lethargic. If aspergillosis among immunocompromised patients is left untreated, it often progresses, and patients report worsening fever, chest pain, and hemoptysis. Specifically, invasive aspergillosis eventually disseminates to non-pulmonary organs and results in life-threatening complications. PCR is the method of choice for the diagnosis of aspergillosis. A single negative PCR result is sufficient to rule out aspergillosis, whereas two positive test results are required to confirm the diagnosis. Laboratory findings consistent with the diagnosis of aspergillosis include positive aspergillus antibody test, positive galactomannan test, elevated concentration of IgE immunoglobulin, and positive culture from sputum or bronchoalveolar lavage. Imaging may also be helpful, particularly in the diagnosis of aspergilloma, whereby a mobile mass (fungus ball) within a pulmonary cavity is characteristic. Treatment usually includes antifungal pharmacotherapy. Steroid administration and surgical intervention may also be indicated in some clinical syndromes. There is no vaccine against Aspergillus. Effective preventive measures include avoiding exposure to Aspergillus by personal protective equipment in dusty environments around construction sites, avoiding activities that require exposure to soil (such as yard work or gardening), and properly cleaning wounds. Prophylactic antifungal drugsis not recommended for the general population. Pharmacologic prophylaxis may be helpful in individual cases among immunocompromised patients.[1][2]
Historical perspective
- Aspergillus is an ancient mold first it was describe in animals later it was discovered in human.
- The exact date of discovery of aspergillus as pathogenic organism is unknown.
Pathophysiology
Risk Factor
Aspergillosis is cause by Aspergillus fumigatum, flavus and terreus.
respiratory system is root of entry. Aspergillus fumigatus is cause of invasive aspergillosis.
In an immunosuppressed host, infection present as allergic sinusitis, bronchitis or localized pulmonary infection.
- The major predisposing factor developing invasive aspergillosis are
- Agglutinating surface surfactant protein deficiency
- Deficiency of C3, C5 complement factors
- Inhibition of anti-conidial macrophage
- Thrombocytopenia and neutropenia
- Low count of CD4+ T lymphocytes or
- Failure to produce IL-12 , Interferon or tumor necrosis factor
- Prolong antibiotic or steroid use.[3]
Natural History, Complications, and Prognosis
Diagnosis
Medical Treatment
Surgical Treatment
References
- ↑ Cuenca-Estrella M, Bassetti M, Lass-Flörl C, Rácil Z, Richardson M, Rogers TR (January 2011). "Detection and investigation of invasive mould disease". J. Antimicrob. Chemother. 66 Suppl 1: i15–24. doi:10.1093/jac/dkq438. PMID 21177400.
- ↑ Kradin RL, Mark EJ (April 2008). "The pathology of pulmonary disorders due to Aspergillus spp". Arch. Pathol. Lab. Med. 132 (4): 606–14. doi:10.1043/1543-2165(2008)132[606:TPOPDD]2.0.CO;2. PMID 18384212.
- ↑ Vaideeswar P, Prasad S, Deshpande JR, Pandit SP (2004). "Invasive pulmonary aspergillosis: A study of 39 cases at autopsy". J Postgrad Med. 50 (1): 21–6. PMID 15047994.