A M Correia1, L Queirós, J Dias. 1. Epidemiological Surveillance Unit, Department of Public Health, Northern Regional Health Administration, Ministry of Health, Porto, Portugal. acorreia@arsnorte.min-saude.pt
Abstract
INTRODUCTION: In April 2009 the Centers for Disease Control and Prevention announced the identification of a novel influenza virus in two patients in California, called influenza A (H1N1) 2009. On 11 June 2009 the Director-General of the World Health Organization declared a pandemic of influenza A (H1N1). In Portugal the first case of pandemic influenza A (H1N1) was reported on 29th April and the Northern Region of the country registered the first cases soon after that. AIM: This report pretends to give an overview of the characteristics of Autumn/Winter pandemic wave in the North of Portugal. RESULTS: A total of 64 195 cases of influenza-like illness were registered in public health services in the region between week 40, 2009 and week 4, 2010. The cumulative attack rate of those cases was 17.1/1 000 inhabitants. Most of the cases occurred in females and in the under 20 years. The peak of the Autumn/Winter wave was attained in week 48, but geographic and time distribution of the pandemic was heterogeneous in the region. Hospitalization rate for influenza-like illness cases in the population was higher for the under 10 years and decreased with age. Forty four deaths in pandemic influenza A (H1N1) laboratory-confirmed cases occurred in the region (mortality rate - 1.2/100 000) and the risk of death was lower in younger age groups. The peak of deaths occurred two weeks later than the peak of cases. CONCLUSION: We can assume that the Autumn/Winter pandemic wave impact was mild in the Northern Region of Portugal. We consider the importance of pursuing and reinforcing influenza surveillance in the region.
INTRODUCTION: In April 2009 the Centers for Disease Control and Prevention announced the identification of a novel influenza virus in two patients in California, called influenza A (H1N1) 2009. On 11 June 2009 the Director-General of the World Health Organization declared a pandemic of influenza A (H1N1). In Portugal the first case of pandemic influenza A (H1N1) was reported on 29th April and the Northern Region of the country registered the first cases soon after that. AIM: This report pretends to give an overview of the characteristics of Autumn/Winter pandemic wave in the North of Portugal. RESULTS: A total of 64 195 cases of influenza-like illness were registered in public health services in the region between week 40, 2009 and week 4, 2010. The cumulative attack rate of those cases was 17.1/1 000 inhabitants. Most of the cases occurred in females and in the under 20 years. The peak of the Autumn/Winter wave was attained in week 48, but geographic and time distribution of the pandemic was heterogeneous in the region. Hospitalization rate for influenza-like illness cases in the population was higher for the under 10 years and decreased with age. Forty four deaths in pandemic influenza A (H1N1) laboratory-confirmed cases occurred in the region (mortality rate - 1.2/100 000) and the risk of death was lower in younger age groups. The peak of deaths occurred two weeks later than the peak of cases. CONCLUSION: We can assume that the Autumn/Winter pandemic wave impact was mild in the Northern Region of Portugal. We consider the importance of pursuing and reinforcing influenza surveillance in the region.