[Comparison of mycological and chemical analytical laboratory methods for detecting mold damage in indoor environments].
To evaluate frequently used methods that discriminate between moldy and nonmoldy indoor environments, 45 homes with visible mold growth and 47 definitively non-infested homes, both confirmed by inspection, were investigated by microbiological and chemical analytical methods. The study was laboratory blinded in relation to the confirmed mold status of the rooms. Statistical evaluation of the results of the applied mycological methods with the Receiver Operating Characteristic (ROC) curve analysis showed that these methods (impaction, open Petri dish method, and determination of mold spores in house dust samples) performed very well in discriminating between rooms with visible mold growth and nonmoldy rooms when the sum score of the mold genera Aspergillus and Penicillium was used as an indicator. The calculated areas under the ROC curves (AUC) of the three mycological methods were: 0.992 (95% CI 0.942-0.997) for mold spores in house dust samples, 0.996 (95% CI 0.940-0.998) for the open Petri dish method, and 0.999 (95% CI 0.957-1.000) for the determination of airborne spores with the Andersen impactor, respectively. A perfect discrimination would lead to an AUC of 1. These results were obtained with DG 18-agar as well as with malt extract agar. In contrast to the results of the mycological methods, the chemical analytical method under the same study conditions showed a distinctly lower performance in discriminating rooms according to their mold status when a sum score (concentration of eight typical MVOC) was used as an indicator. The area under the ROC curve (AUC) had a value of 0.620 (95% CI 0.509-0.723). A completely useless test would have an AUC of 0.5. As the lower limit of the 95% confidence interval of the area under the ROC curve is close to 0.5, the results obtained with the MVOC method do not differ from the classification results which can be obtained simply by chance. Possible methodological biases which could have lead to this interpretation are discussed.
Laussmann
D
D
Robert Koch-Institut, Berlin. LaussmannD@rki.de
Eis
D
D
Schleibinger
H
H
D016902:Air Pollution, Indoor / Q000032:analysis*; D001230:Aspergillus / Q000302:isolation & purification; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D015169:Colony Count, Microbial / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods*; D005658:Fungi / Q000302:isolation & purification*; D016533:Mycological Typing Techniques / Q000379:methods; D010407:Penicillium / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity