Journal des maladies infectieuses et de la thérapie

Abstrait

Dot-Blot Methodology for Rapid Diagnosis of Paracoccidioidomycosis Caused by Paracoccidioides brasiliensis

Kamikawa CK and Vicentini AP

Paracoccidioidomycosis (PCM), a mycosis which clinical diagnosis can be confused with other infectious diseases like leishmaniasis and tuberculosis, presents significant rates of mortality, estimated between 2-23% in severe cases, reaching 30% when associated with AIDS [1], and considered to lead mortality among mycosis in Brazil, with an average of 111.5 deaths/year, according to the Mortality Information System of the Ministry of Health [2]. Given the above, an early and accurate diagnosis of this infectious disease is very important because it allows the establishment of appropriate antifungal therapy, reduction of unnecessary use of toxic drugs; decreasing the use of empiric therapy, thereby minimizing the emergence of multidrug-resistant fungal strains. In addition, the technique used to immunodiagnostic of PCM has to combine sensitivity and specificity, so that the predictive value is high and reproducible. In this study, Dot-blot (DB) method was found to be an extremely promising tool as serologic screening technique, because of its high sensitivity, as well as a rapid diagnostic test, given the release of true negative results in less time (one day) compared to the double immunodiffusion assay in agarose gel (DI, seven days), considered the gold standard serological method and, therefore, of great diagnostic value, particularly for the disposal of clinical suspicion for the this mycosis. Furthermore, Dot-blot method shows the prospect of being transferred to laboratories of public service including those with fewer resources of facilities such as photometers, plate washers and others, or even be used directly in the field, with an excellent shelf life validity, ie membranes coated with antigen can be used for testing, without changes in the pattern of reactivity among laboratories and present reliable values of sensitivity, specificity, predictive values, accuracy and a high correlation with the serological gold standard methodology, therefore to be used in routine diagnosis for Public Health.