919 Epidemiological Profile of the a (H1N1) Pandemic Influenza in the State of Sao Paulo, Brazil, for the April-September 2009 Timeframe

• Published in: Pediatric research Vol. 68; no. Suppl 1; pp. 459 - 460
• Main Authors: Carvalhanas, T R M P, Ribeiro, A F, Yu, A L F, Okai, M I G, Timenetsky, M C S, Aranda, C M S S, Sacchi, C
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01-11-2010
• Subjects: Medicine; Medicine & Public Health; Pediatric Surgery; Pediatrics
• ISSN: 0031-3998; 1530-0447
• DOI: 10.1203/00006450-201011001-00919

Background: On April 2009, the emergence of a new influenza virus strain set the stage for the first pandemic in the 21st century. We have analyzed the epidemiological profile of the A/H
1
N
1
pandemic influenza virus - the reported number of cases and deaths, confirmed by lab tests. The geographical scope of the analysis comprised the state of Sao Paulo, Brazil, during the Autumn-Winter season.
Methods: Epidemiological data was obtained from the National System of Acute Notifications which aggregates reported cases and are analyzed with the Epi Info/Win and Excel software. Laboratory confirmation tests were processed at Adolfo Lutz Institute in São Paulo, using real-time reverse transcriptase-polimerase chain reaction in nasal or oropharyngeal specimens.
Results: There were 25,082 reported cases still September 2009, from these, 53% had ARS criteria, 29% influenza like illness. Among the 13,651 cases with ARS, 28% were positive for Influenza A(H
1
N
1
) and 4% for seasonal flu. The majority of reported and confirmed cases were notified in July and August, declining in September. Infants ≤ 24 months and young adults 20-29 years of age were the groups more affected. Case fatality rates were greater in children ≤ 2 years and adults (20-59 y).
Cases tested positive for A(H
1
N
1
) varied from 20- 35% within this period. High risk groups included children ≤ 24 months and young adults, chronic pulmonary disease, smokers, metabolic disease and pregnant women.
Conclusion: The characteristics and evolution of the cases were similar to those occurring in the northern hemisphere, predominant circulation of the pandemic influenza virus.