Influenza is a respiratory infection caused by the influenza virus. It is rife in North America, especially from December to April, and can cause major epidemics. It is transmitted through secretions from the nose or throat, when coughing or sneezing, or via contaminated hands or objects. It usually manifests itself as a sudden fever, chills, headache, aches and pains, dry cough, sore throat and generalized malaise lasting several days. In children, influenza is more often accompanied by nausea, vomiting and diarrhea. In the elderly, fever may be minimal, and influenza may manifest itself as an impairment of general condition, dizziness, confusion or prostration. Influenza usually progresses to spontaneous recovery within 5 to 7 days, although cough and fatigue may persist for 2 weeks or more.
Influenza can lead to more serious consequences, such as pneumonia, hospitalization and death. In Quebec, between 1,000 and 1,500 deaths are linked to influenza and its complications every year. This is particularly true of the elderly and those with underlying chronic health problems. Over 90% of deaths attributable to pneumonia and influenza occur in people aged 65 or over. Mortality from influenza in the elderly is 20 to 30 times higher in the presence of underlying chronic disease. Furthermore, children under 2 years of age have been found to have as high a risk of being hospitalized for influenza as the elderly or those with chronic health problems. Pregnant women are also at greater risk of hospitalization following influenza, especially during the 3rd trimester.
It’s important to distinguish influenza from common respiratory infections, such as the common cold, which have no consequences.
In 2011 and 2012, following the AH1N1 influenza epidemic, the influenza vaccine also protected against AH1N1 influenza.
DIN: 02015986