Lessons from the epidemiological surveillance program, during the influenza A (H1N1) virus epidemic, in a reference university hospital of Southeastern Brazil

Abstract

Lessons from the epidemiological surveillance program, during the influenza A (H1N1) virus epidemic, in a reference university hospital of Southeastern BrazilLições aprendidas pelo programa de vigilância epidemiológica, durante a epidemia pelo vírus da influenza A (H1N1), em um hospital universitário na região sudeste do Brasil ABSTRACT Introduction: The case definition of influenza-like illness (ILI) is a powerful epidemiological tool during influenza epidemics. Methods: A prospective cohort study was conducted to evaluate the impact of two definitions used as epidemiological tools, in adults and children, during the influenza A H1N1 epidemic. Patients were included if they had upper respiratory samples tested for influenza by real-time reverse transcriptase polymerase chain reaction during two periods, using the ILI definition (coughing + temperature ≥ 38 o C) in period 1, and the definition of severe acute respiratory infection (ARS) (coughing + temperature ≥ 38 o C and dyspnoea) in period 2. Results: The study included 366 adults and 147 children, covering 243 cases of ILI and 270 cases of ARS. Laboratory confirmed cases of influenza were higher in adults (50%) than in children (21.6%) ( p < 0.0001) and influenza infection was more prevalent in the ILI definition (53%) than ARS (24.4%) (p < 0.0001). Adults reported more chills and myalgia than children (p = 0.0001). Oseltamivir was administered in 58% and 46% of adults and children with influenza A H1N1, respectively. The influenza A H1N1 case fatality rate was 7% in adults and 8.3% in children. The mean time from onset of illness until antiviral administration was 4 days. Conclusions: The modification of ILI to ARS definition resulted in less accuracy in influenza diagnosis and did not improve the appropriate time and use of antiviral medication.

Comparison of common acute respiratory infection case definitions for identification of hospitalized influenza cases at a population-based surveillance site in Egypt

“…The 2014 WHO SARI definition confers several advantages to hospitalized ARI surveillance systems. The sensitivity of this broader case definition was higher than the other four case definitions examined, consistent with multiple studies demonstrating that the inclusion of PLOS ONE respiratory symptoms beyond cough and history of fever does not improve sensitivity for influenza infection [15][16][17][18]. Additionally, extending the time from symptom onset to presentation increases sensitivity for a wide range of emerging respiratory pathogens, including COVID-19 [19].…”

Relacionamento entre bases de dados para vigilância da pandemia de influenza A(H1N1)pdm09, Brasil, 2009-2010

“…A taxa de letalidade encontrada em nosso estudo é se-melhante àquela observada em outros estudos publicados 19,26,28,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66 .…”

Neuraminidase inhibitors for influenza: a systematic review and meta-analysis of regulatory and mortality data

“…The percentages of missing data were smaller for the deaths than the survivors (0.4% vs. 36% for time to death/discharge for example), suggesting that data collection was more thorough for patients who died. 210 Poeppl 2011 198 Blumental 2011 202 Yung 2011 195 Altmann 2011 185 Enstone 2011 192 del Rosal 2011 205 Nguyen-Van-Tam 2010 186 Thompson 2011 188 Miranda-Choque 2011 197 Yokota 2011 200 Moretti 2011 208 Yang 2010 191 Mickienė 2011 Results show that when the time-dependent nature of treatment is taken into account appropriately the treatment effects change direction, although none of the results is statistically significant. Adjusting for potential confounders and imputing missing data made little difference to the results.…”