[Development of duplex real-time RT-PCR for detection of influenza virus A and B]. / Mise au point d'une technique de RT-PCR duplex en temps réel pour la détection des virus influenza A et B.

Influenza viruses continue to be accountable for winter outbreaks. The potential for developing complications is higher in certain risk groups, such as children, the elderly and individuals with chronic medical conditions. We have presented a duplex real-time RT-PCR for detection of influenza A and B. The sensibility of our method was estimated at 0.01TCID(50)/ml for detection of influenza A and 0.1TCID(50)/ml for influenza B. Any other viruses with respiratory tract tropism were detected with our method. After that, we tested our duplex RT-PCR on 119 samples (nasal aspirates and liquids of broncho-alveolar washes) collected in the CHRU of Lille between November 2005 and January 2006 from patients aged one month to 81 years. Conventional methods such as direct immunofluorescence (IF) assay and/or cell culture were applied on these samples. Four samples were positive for influenza A virus detection and, in particular, one liquid of broncho-alveolar wash for which the direct IF assay was negative. Thus, our method is adapted to diagnosis of flu infections. Nevertheless, our duplex RT-PCR will be tested during a flu outbreak.