Environmental Investigations and Molecular Typing of Aspergillus in a Chinese Hospital

Invasive fungal infections due to Aspergillus species have become a major cause of morbidity and mortality among immunocompromised patients. In order to determine the possible relationship between environmental contamination by Aspergillus and the occurrence of invasive aspergillosis, a 1-year prospective study was carried out in a tertiary hospital in China. Air, surface, and tap water sampling was performed twice monthly at the bone marrow transplant (BMT) department, intensive care unit (ICU), neurosurgery intensive care unit (NICU), and outdoors. Nose, pharynx, and sputum samples were collected from high-risk patients. Isolates of Aspergillus from the environment and patients were genotyped by random amplification of polymorphic DNA (RAPD) assay to investigate the origin of infection. Mean total Aspergillus count was 7.73, 8.94, 13.19, and 17.32 cfu/m³ in the BMT department, ICU, NICU, and outdoors, respectively. RAPD analysis by R108 primer demonstrated that strains isolated from patients in NICU were identical to the environmental strain. Strains isolated from patients in ICU differed from the environmental strain. Aspergillus contamination was found in the BTM department, NICU, and ICU. Clinical and environmental strains from NICU had identical genotypes. These findings suggest that Aspergillus is found in the hospital environment including the air, surface, and tap water. The genotypes of Aspergillus were identical from patients and the environment, suggesting that clinical infection may originate from the hospital environment.