[Optimization of processing and storage of clinical samples to be used for the molecular diagnosis of pertussis]

Pertussis or whooping cough is an acute, highly contagious respiratory infection, which is particularly severe in infants under one year old. In classic disease, clinical diagnosis may present no difficulties. In other cases, it requires laboratory confirmation. Generally used methods are: culture, serology and PCR. For the latter, the sample of choice is a nasopharyngeal aspirate, and the simplest method for processing these samples uses proteinase K. Although results are generally satisfactory, difficulties often arise regarding the mucosal nature of the specimens. Moreover, uncertainties exist regarding the optimal conditions for sample storage. This study evaluated various technologies for processing and storing samples. Results enabled us to select a method for optimizing sample processing, with performance comparable to commercial methods and far lower costs. The experiments designed to assess the conservation of samples enabled us to obtain valuable information to guide the referral of samples from patient care centres to laboratories where such samples are processed by molecular methods.