Aspergillus spp. is ubiquitous, aerobic fungi that occur in soil, water, and decaying vegetation; the organism also survives well in air, dust, and moisture present in health-care facilities. Similar to other filamentous fungi, Aspergillus species are usually acquired from an inanimate reservoir, more commonly by the inhalation of small airborne spores. While invasive aspergillosis typically affects severely immunocompromised patients, cases of surgical site infections have been reported in immunocompetent individuals. The aim of this presentation is to summarize the world literature regarding this topic. This will be illustrated by the presentation of three cases, originated from personal knowledge of the authors, and not part of any outbreak. The first of these cases was a man who underwent elective aortic valve replacement and died of Aspergillus endocarditis. The second was a teenager who underwent elective neurosurgery for Chiari I malformation, received 4 weeks of postoperative dexamethasone and died despite amphotericin B therapy. The third was a woman who developed a cerebral abscess due to Aspergillus fumigatus after neurosurgery augmented with dexamethasone and recovered following voriconazole treatment. Medline, LILACS and EMBASE databases were searched and references from relevant articles were reviewed. Conference abstracts were reviewed as well. After Frank and Alton firstly published their study of postoperative aspergillosis in 1933, more than 500 cases have been reported. Cardiac and ophthalmologic surgery, and surgical dental procedures provided the most commonly reported cases. Postoperative cases of endocarditis and aortitis affected mostly immunocompetent male patients submitted to aortic valve replacement. Median time from the surgery to the diagnosis was 2.7 months. An antemortem diagnosis occurred in only 43.1%, and blood cultures are rarely positive (6.4%). Mortality for these conditions was 92.7%. Vascular graft aspergillosis occurred after a median time of 8 months after surgery. Aspergillus graft infections usually occur on the suture line of a previous aortotomy, and definitive diagnostic procedures for these patients were generally culture of the excised aortic graft or the peripheral embolus and biopsy of the contiguously affected vertebral disk space. Most of the patients with postoperative aspergillosis following neurosurgery had received treatment with corticosteroids, and mortality for this condition was 68.0% surprisingly low if we consider the mortality rates for immunosuppressed patients with disseminated aspergillosis involving the central nervous system. Aspergillus wound infections occurred after a median time of 17 days after surgery, and many of these patients were immunosuppressed. Aspergillus flavus was the aetiology of 36.8% of these infections. Successful treatment for postoperative aspergillosis requires rapid diagnosis, surgical debridement and antifungal therapy, probably voriconazole. In order to improve the outcome, better diagnostic methods are needed, particularly for cases of endocarditis and aortitis. In most patients, the source was presumed to be airborne infection during the surgical procedure. Prevention of these infections requires special care with the ventilation system in the operating room, proper disinfection techniques, and appropriate storage of surgical materials. A single proven postoperative case of aspergillosis is sufficient to initiate epidemiological investigations.
Full conference title:
16th European Congress of Clinical Microbiology and Infectious Diseases
- ECCMID 16th (2006)