Investigators Report on Five Years of Surveillance for Invasive Aspergillosis

As the most common invasive fungal infection, invasive aspergillosis (IA) remains a serious complication in immunocompromised patients, leading to increased mortality. Antifungal therapy is expensive and may result in severe adverse effects. Karolin Graf, of the Institute for Medical Microbiology and Hospital Epidemiology at Hannover Medical School in Hannover, Germany, and colleagues, sought to determine the incidence of IA cases in a tertiary care university hospital using a standardized surveillance method.

All inpatients at the facility were screened for presence of the following parameters: positive microbiological culture, pathologist's diagnosis and antifungal treatment as reported by the hospital pharmacy. Patients fulfilling one or more of these indicators were further reviewed and, if appropriate, classified according to international consensus criteria (EORTC).

Seven-hundred and four patients were positive for at least one of the aforementioned indicators. Applying the EORTC criteria, 214 IA cases were detected, of which 56 were proven, 25 probable and 133 possible. 44 of the 81 (54 percent) proven and probable cases were considered healthcare-associated. Thirty-seven of the proven/probable IA cases had received solid organ transplantation, an additional eight had undergone stem cell transplantation, and 10 patients were suffering from some type of malignancy. All the other patients in this group were also suffering from severe organic diseases, required long treatment and experienced several clinical complications. Seven of the 56 proven cases would have been missed without autopsy. After the antimycotic prophylaxis regimen was altered, we noticed a significant decrease (p = 0.0004) of IA during the investigation period (2003-2007).

The researchers conclude that solid organ and stem cell transplantation remain important risk factors for IA, but several other types of immunosuppression should also be kept in mind. Clinical diagnosis of IA may be difficult (in this study 13 percent of all proven cases were diagnosed by autopsy only). Thus, they confirm the importance of IA surveillance in all high-risk patients.

Reference: Karolin Graf, Somayeh Mohammad Khani, Ella Ott, Frauke Mattner, Petra Gastmeier, Dorith Sohr, Stefan Ziesing and Iris F Chaberny. Five-years surveillance of invasive aspergillosis in a university hospital. BMC Infectious Diseases 2011, 11:163doi:10.1186/1471-2334-11-163