Reduction of Invasive Aspergillosis Incidence among Immunocompromised Patients after Control of Environmental Exposure

Invasive Aspergillus infections in allo-SCT recipients: environmental sampling, nasal and oral colonization and galactomannan testing

A study was performed to investigate the air quality of a haematopoietic SCT ward, colonization of the upper airways with Aspergillus spp. and the role of galactomannan (GM) ELISA testing in serum in the diagnosis of invasive aspergillosis (IA). In 102 allo-SCT recipients, two cases of IA (one proven and one probable) were seen. Of 2071 serum samples, 12 were positive, two in a patient with proven IA and 10 in patients without IA. Of the 2059 negative samples, 22 were taken from the patient with probable IA. Of the 245 environmental samples, 20 (8.2%) were positive for filamentous fungi. Aspergillus fumigatus was seen in 14 samples. A total of 657 oral and nasal swabs were taken. Seven nasal samples and one oral sample were positive for Aspergillus species (A. fumigatus 4, A. niger 4) in four patients, one of whom had probable IA. In summary, most environmental samples were negative, colonization of the oral and nasal cavities was rare and IA was diagnosed in only 2% of patients. The GM ELISA test remained negative in one of two patients with IA and does not seem useful in a population of patients with a low incidence of IA.

Rapid detection and quantification of Aspergillus fumigatus in environmental air samples using solid-phase cytometry

Aspergillus fumigatus is an ubiquitous fungus capable of causing severe infections such as aspergilloma, allergic bronchopulmonary aspergillosis, and invasive aspergillosis, especially in immunocompromised patients. Monitoring the number of Aspergillus fumigatus spores in the air is crucial for infection control. In the present study, a novel approach for the quantification of Aspergillus fumigatus, based on solid-phase cytometry (SPC) and immunofluorescent labeling, was developed. The sensitivity and specificity of the assay were confirmed by testing pure cultures. Paecilomyces variotii and Rhizopus stolonifer were codetected but could be excluded on the basis of morphology of the microcolonies. The SPC method has considerable advantages compared to the culture-based method, including its low detection limit (4 cells/m3), its speed (results are obtained within 24 h), and the straightforward microscopic identification of Aspergillus fumigatus. Additionally, comparison of results obtained with both methods demonstrated that they are equally accurate for the quantification of Aspergillus fumigatus in environmental air samples.

Aspergillosis prophylaxis and treatment for pediatric HSCT patients: environmental and pharmacologic options

Hematopoietic stem cell transplant (HSCT) recipients are at increased risk of viral, bacterial, fungal, and parasitic infections both pretransplant and post-transplant. One of the most dangerous infections that can be acquired during this time is aspergillosis. Several drugs are available for prophylaxis, though no particular regimen has been proven to be superior; although the CDC has clear recommendations regarding prophylaxis for many other infections (such as cytomegalovirus, herpes simplex, toxoplasmosis, and Candida) for HSCT patients, there are none for aspergillosis. Researchers have varying opinions as to which drugs are best for prophylaxis. In this article, pharmacologic and environmental options for prophylaxis are discussed as well as antifungals currently in use, and recommendations on how nurses can help keep their patients safe from this infection are given.