Study Characterizes Aspergillus Species Found in Low Risk Patients

   In a poster presented at the 50th Interscience Conference on Antimicrobial Agents and Chemotherapy in Boston, researchers at Henry Ford Hospital/Wayne State University in Detroit characterized the invasive Aspergillus species that in the past decade have become increasingly common in patients not traditionally considered at risk for this type of infection.

   Invasive Aspergillus infections have been well described in immunocompromised patients such as those with hematologic malignancies or in hematopoietic stem cell transplant recipients, less so in patients considered low risk.

   Thirty-six patients with the documented diagnosis of invasive Aspergillus infection were identified over a five year period. After data analysis, the most common risk factors found to be associated included steroid use in 69% of patients, ICU stay 53%, use of immunosuppressive agents 39%, solid organ transplant 33%, diabetes mellitus 28%, and chronic obstructive lung disease in 22% of patients. The most common sites of infection were the lungs in 67% of patients, sinuses 19%, brain 8%, and skin 3%.

   According to principal investigator Jose A. Vasquez, MD, Aspergillus fumigatus was the most common species (identified in 61% of patients), followed by A. niger 14%. In addition, 17 patients also experienced 23 bacterial infections simultaneously. Of these, infections by streptococci were the most frequent (32%), followed by infections due to gram-negative bacilli (Pseudomonas aeruginosa and Haemophilus spp., 24%).

   Voriconazole was the first line antifungal used in 23 of the 36 patients, followed by combination therapy in eight patients. At 90 days post diagnosis and antifungal therapy initiation, clinical success was noted in 72% of patients, with an overall mortality of 19%. One isolate (A. flavus) was found to be resistant to voriconazole.

   “It is our hope that, with increased knowledge, clinicians will be able to better understand who is at risk of contracting this deadly and often difficult-to-diagnose infection and to improve the outcomes in this non-traditional patient population,” Dr. Vasquez said.