Next to influenza viruses, other respiratory viruses represent a major public health concern because of their frequent occurrence, ease of spread in the community, and considerable morbidity and sometimes even mortality (death rate). Indeed, in about 30 to 60% of cases with influenza-like symptoms or severe acute respiratory infections (SARI), no influenza virus can be detected. The aim of this project is to analyse respiratory samples collected from the Influenza-like Illness (ILI) and the SARI surveillance networks, in order to identify the responsible viruses, the frequency of mixed respiratory infections and the impact on the severity of disease.
In addition to flu viruses, several other respiratory viruses can also circulate during the flu season and can cause symptoms and illness similar to those seen with flu infection. Respiratory virus infections are very common. They may be associated with significant morbidity and even mortality especially in young children and elderly patients. In about 30-50% of cases with influenza-like symptoms, no influenza virus can be detected, and in at least 20% of influenza virus-negative ILI cases, other respiratory viruses (such as RSV, rhinovirus, parainfluenza viruses, …) seem to be involved. Furthermore, severe influenza cases often seem to be complicated by co-infections with other respiratory viruses. We have developed 4 quadruplex real time PCRs for the detection of 16 different respiratory viruses : respiratory syncytial virus (RSVA and RSVB), parainfluenza viruses (PIV 1, 2, 3, 4), rhinoviruses/enterovirus (HRV/ENV), human metapneumoviruses (hMPV), paraechoviruses (HPeV), bocaviruses (HBoV), adenoviruses (ADV) and different coronaviruses (CoOC43, CONL63, Co229E, MERS-CoV). These different viruses have been recognised as causative agents of SARI. The aim of this project is to analyse during several seasons, the impact of the different respiratory viruses on disease severity and their distribution in different age groups.