Clinical aspects of influenza A(H1N1)pdm09 cases reported during the pandemic in Brazil, 2009-2010

Abstract

Objective:To describe the clinical aspects of cases of influenza A(H1N1)pdm09 in Brazil.Methods:A descriptive study of cases reported in Sistema de Informação de Agravos de Notificação (SINAN), 2009-2010.Results:As the final classification, we obtained 53,797 (56.79%) reported cases confirmed as a new influenza virus subtype, and 40,926 (43.21%) cases discarded. Fever was the most common sign, recorded in 99.74% of the confirmed and 98.92% of the discarded cases. Among the confirmed cases, the presence of comorbidities was reported in 32.53%, and in 38.29% of the discarded cases. The case fatality rate was 4.04%; 3,267 pregnant women were confirmed positive for influenza A new viral subtype and 2,730 of them were cured. The case fatality rate of pregnant women was 6.88%.Conclusion:The findings suggested concern of the health system with pregnant women, and patients with comorbidities and quality of care may have favored a lower mortality. We recommend that, when caring for patients with severe respiratory symptoms, with comorbidities, or pregnant women, health professionals should consider the need for hospital care, as these factors make up a worse prognosis of infection by the pandemic influenza virus.

Factors associated with death due to severe acute respiratory syndrome caused by influenza: Brazilian population study

“…Other common symptoms such as dyspnea and respiratory discomfort were present in 76.7% and 61.8%, respectively, in those who presented the negative outcome (death). These symptoms appear as the main and most frequently presented, according to the results of this study, corroborating the findings of previous studies [20] , [21] . On the other hand, Mazon et al reported that cough was not a main symptom [22] .…”

“…In addition, the influenza A subtype most found in the patients of this study was H3N2, of which 53.9% died, as in the study by Fielding et al, which reported most cases of H3N2 subtype influenza [25] . On the other hand, the results of Araújo et al, Rossetto and Luna, and Silveira et al [20] , [21] , [23] showed that the predominant subtype of influenza A was H1N1, as well as the Australian study, which analyzed influenza outbreaks, showing that H1N1 was predominant [26] . The study by Muscatello et al also found the most recorded influenza A in the studied period with a rate of 70%, but did not analysis the specific subtype [24] .…”

Viral detection profile in children with severe acute respiratory infection

“…The H1N1-positive subgroup presented a higher frequency of fever, cough and tachypnea and lower leukocyte count when compared to the H1N1-negative subgroup. Cough is a characteristic of H1N1 infection, [21][22][23] as well as leukopenia. 9 In Taiwan, leukopenia was found in 64.2% of cases and was more frequent in H1N1positive.…”

Análise epidemiológica comparativa entre as pandemias causadas pelos vírus Influenza A(H1N1)pdm09 e SARS-CoV-2 no estado do Pará, Brasil

“…No Brasil, houve em torno de 40.000 casos de síndrome respiratória aguda grave (SRAG) e, aproximadamente, 1.700 mortes no período de oito meses, desde a Declaração de Emergência de Saúde Pública de Importância Internacional (ESPII) pela OMS em abril de 2009 11 . A gravidade da pandemia, ainda que com recursos médicos e científicos superiores aos cenários anteriores, revelou a necessidade e a urgência de uma nova abordagem de vigilância epidemiológica, e, como requisito básico, uma maior eficiência na detecção e monitoramento de novos casos 12 .…”