Incidence of influenza and influenza vaccine effectiveness in the 2004-2005 season

To quantify the incidence of flu in different groups of the population of Navarra in the 2004-2005 season, and to evaluate the effectiveness of anti-flu vaccination. The analysis of influenza cases in the system of compulsory notificable diseases was complemented by the individualised notifications in the network of sentinel doctors that covers a population of 22,339 inhabitants. The coverage and effectiveness of the vaccine was studied. Vaccine coverage in (3)65 year olds reached 62%. The incidence of influenza was 42.6 cases per 1,000 inhabitants. It reached a maximum in mid-January, exceeding 750 weekly cases per 100,000 inhabitants and 1,900 cases per 100,000 children. The highest rate of influenza was observed in under-15 year olds (49.4 cases per 1,000 inhabitants) and the lowest in non-institutionalised (3)65 year olds (2.6 per 1,000 inhabitants), although it was higher in geriatric residences (62.1 per 1,000; p