Diagnosis of cutaneous leishmaniasis in Guatemala using a real-time polymerase chain reaction assay and the smartcycler®

The polymerase chain reaction (PCR) assay has been reported for the diagnosis of cutaneous leishmaniasis (CL). Real-time (RT) PCR offers several advantages over traditional PCR, including faster processing time and decreased risk of contamination. Enhanced portability is another benefit that expands the applicability of the assay. A portable RT-PCR assay was transported from the United States to Guatemala for comparison with traditional diagnostic modalities. With the clinical diagnosis of CL as the gold standard, RT-PCR was positive in 86% (37 of 43) versus 53% (20 of 38) for microscopy and 72% (28 of 39) for culture. Negative RT-PCR samples (6) were also negative by traditional diagnostic methods (although subsequently determined to be positive by a nested kDNA PCR). Sixty-four percent (9 of 14) of cases tested and negative by microscopy and/or culture were positive by RT-PCR. This study demonstrates that a RT-PCR assay can be successfully deployed to offer enhanced sensitivity for the diagnosis of CL.