Polymerase chain reaction-miniexon: a promising diagnostic method for XXXX .

@entity1 @entity13556 @entity982 @entity17566 @entity1282 @entity85 @entity204
BACKGROUND: @entity17566 is a chronic disease caused mainly by @entity13556 species that belong to Viannia subgenus. It affects upper respiratory airways and may lead to @entity85 , @entity1282 , and even @entity204 in severe cases. Diagnosis is a challenge because clinical and histopathologic changes are easily confused with other diseases, and conventional methods for parasite identification and culture have a low sensitivity. Molecular methods have been used in the last two decades. In 2007, we published a validation study using internal transcript spacers and kinetoplast DNA as molecular targets with satisfactory results. In this research, we tested miniexon gene as the target. METHODS: Mucosal tissue samples from 60 Colombian @entity1 with clinical signs of @entity17566 were included. A composite reference standard defined 30 cases and 30 controls. Two blind observers performed @entity1 classification and test application independently. Miniexon gene amplification generated: 226-230 bp fragment for subgenus Viannia; 308 bp fragment for L. amazonensis; 340 bp fragment for L. mexicana; and 418 bp fragment for @entity13556 -chagasi. RESULTS: Polymerase chain reaction (PCR) sensitivity for fresh samples was 87.5% (95% confidence interval [CI] 72.2-100), specificity, 95% (95% CI 83.0-100), and positive likelihood ratio was 17.5 (95% CI 2.58-118.93), similar to results obtained with @entity982 -embedded samples. Agreement between observers was 96% (kappa = 0.912; 95% CI 0.815-1.000) for both subgenus Viannia and @entity13556 . CONCLUSIONS: We consider PCR-miniexon as a diagnostic method of first choice for @entity17566 due to its excellent diagnostic performance and its ability to discriminate between @entity13556 and Viannia subgenera as well as between species belonging to @entity13556 subgenus.
