2.2. HPV Testing

All samples were tested by PCR using the CLART^® HPV2 PCR kit (Genomica, Madrid, Spain) according to manufacturer’s recommendations. This molecular test detected up to 35 different low- and high-risk HPV genotypes (17 low-risk HPV 6,11,40,42,43,44,54,61,62,70,71,72,81,83,84,85,89 and 18 high-risk HPV 16,18,26,31,33,35,39,45,51,52,53,56,58,59,66,68,73,82). Sampling and assays were validated using internal controls (human cellular detection and amplification control). An external positive control, part of an external control procedure, was added to each experiment. To assess the absence of contamination, a no-template negative control, a mixture of water and human DNA, was tested at the same time as other samples.