Investigation of deaths for severe acute respiratory syndrome by Influenza A(H1N1)pdm09 (pH1N1) in metropolitan areas of the state of São Paulo – Brazil

INTRODUCTION: Infection with pH1N1 can quickly develop the Severe Acute Respiratory Syndrome (SARS), resulting in respiratory failure and as a consequence lead to death. Thus, this study was designed to describe the deaths by pH1N1according to person, time and place, as well factors associated with their occurrence and to analyze the timely initiation of antiviral treatment for cases that progressed to death.

 METHODS: Descriptive study of deaths in the metropolitan region of São Paulo between 8^th and 30^th epidemiological weeks (EW) 2013, through the review of medical records.

RESULTS: This paper reviewed 131 records of deaths by pH1N1between May and November 2013. There was a predominance of males with a median age of 49 years (ranging from zero to 89 years). The most prevalent symptoms were dyspnea, fever and cough. The deaths occurred between 8^th and 30^th epidemiological weeks, peaking at 19EW. Of the 131 cases, 81 (61.8%) deaths had a comorbidity reported in medical records, with higher prevalence of obesity, diabetes and respiratory diseases. Results showed from 119 deaths that used antiviral 11 deaths (9.2%) did in a timely manner. The median time of progression to death from the onset of symptoms was 14 days (ranging from zero to 79 days). Thirty-six cases (27.9%) were transferred from other health services for the hospital where the death occurred. And from 131 deaths, 96 cases (73.3%) required admission to the intensive care unit. Vaccination against influenza 2013 was found in four medical records, and only one had complete information about the date of vaccination.

CONCLUSIONS: Deaths showed clinical, treatment and person characteristics similar to deaths that occurred during the seasonality of the disease in previous years in Brazil, however, it was observed that there was an early occurrence in deaths this year.