Age and gender distribution of sampled cases compared to all cases reported to NAIS in 28 provinces.

<p>Age and gender distribution of sampled cases compared to all cases reported to NAIS in 28 provinces.</p

Sample selection process.

<p>Sample selection process.</p

Chronic medical conditions, presenting signs and symptoms, laboratory testing, and chest X-ray results among persons with fatal and non-fatal influenza A(H5N1) virus infections.

<p>N/a: not applicable;</p><p>*unadjusted OR and 95% CI of a fatal H5N1 outcome among H5N1 cases;</p>†<p>dyspnea: defined as any recorded difficulty breathing or shortness of breath in any age group, or in a child less than age 5, the presence of stridor or chest in-drawing;</p>§<p>altered mental status: defined as any recorded presence of altered mental status, confusion, or unconsciousness;</p>¶<p>pneumonia: defined as the presence of alveolar infiltrates, interstitial infiltrates, or lobar consolidation on chest X-ray;</p><p>**not possible to calculate an unadjusted OR.</p

Human influenza cases and deaths reported by National Avian Influenza Surveillance.

1<p>All deaths also reviewed.</p

Comparison of clinical characteristics between persons with fatal influenza A(H5N1) virus infection and fatal human influenza virus infection.

<p>N/a: not applicable;</p><p>*unadjusted OR and 95% CI of a fatal H5N1 outcome versus a fatal human influenza outcome;</p>†<p>dyspnea: defined as any recorded difficulty breathing or shortness of breath in any age group, or in a child less than age 5, the presence of stridor or chest in-drawing;</p>§<p>altered mental status: defined as any recorded presence of altered mental status, confusion, or unconsciousness;</p>¶<p>pneumonia: defined as the presence of alveolar infiltrates, interstitial infiltrates, or lobar consolidation on chest X-ray;</p><p>**not possible to calculate an unadjusted OR.</p

Geographic distribution of human influenza cases.

<p>Geographic distribution of human influenza cases.</p

Peak risk ratio by location, age and hospitalization status.¹

<p>Peak risk ratio by location, age and hospitalization status.^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042328#nt103" target="_blank">1</a>}</p

Differences by sex in cases that were not hospitalized.

<p><b>A Men not hospitalized.</b> The smoothed risk ratio of cases among men who were not hospitalized in a single year age group compared to the overall risk in all age groups. Smoothed curves were created by a locally weighted polynomial regression with fixed bandwidth of 4. The single year of age weighted risk ratios used to create the smoothed curve are plotted as open circles and the 95% confidence bounds are shaded. The inset figure shows the truncated WRR from 0 to 29 years of age while the larger figure focuses on the ages from 30–100. <b>B Men not hospitalized.</b> SiZer plot of the second derivative of the weighted risk ratio by age among men who were not hospitalized. <b>C Women not hospitalized.</b> The smoothed risk ratio of cases among women who were not hospitalized in a single year of age compared to the overall risk in all female age groups. Smoothed curves were created by a locally weighted polynomial regression with fixed bandwidth of 4. The inset figure shows the truncated WRR from 0 to 29 years of age while the larger figure focuses on the ages from 30–100. The single year of age weighted risk ratios used to create the smoothed curve are plotted as open circles and the 95% confidence bounds are shaded. <b>D Women not hospitalized.</b> SiZer plot of the second derivative of the weighted risk ratio by age among women who were not hospitalized.</p

Confirmed cases of 2009 pandemic A/H1N1 influenza by location and hospitalization status, the associated weights used to calculate the weighted risk ratio (shown as %), and the cumulative incidence risk ratio (95% confidence intervals) of male versus female cases by hospitalization status and age group for locations where sex was known.

<p>Confirmed cases of 2009 pandemic A/H1N1 influenza by location and hospitalization status, the associated weights used to calculate the weighted risk ratio (shown as %), and the cumulative incidence risk ratio (95% confidence intervals) of male versus female cases by hospitalization status and age group for locations where sex was known.</p

Laboratory confirmed hospitalized cases.

<p><b>A</b> The smoothed risk ratio of laboratory confirmed hospitalized cases in a single year age group compared to the overall risk in all age groups. Smoothed curves for each location were created by a locally weighted polynomial regression with fixed bandwidth of 4. <b>B</b> The smoothed weighted risk ratio (WRR) of laboratory confirmed hospitalized cases in a single year compared to the risk in all age groups combined using a fixed bandwidth of 4. The single year of age WRR used to create the smoothed curve are plotted as open circles and the 95% confidence bounds are shaded. The inset figure shows the truncated WRR from 0 to 29 years of age while the larger figure focuses on the ages from 30–100. <b>C</b> SiZer plot of the first derivative of the WRR by age. The X axis represents age while the Y axis corresponds to the log of the bandwidth (h). For example, log(0.6) corresponds to the fixed bandwidth of 4 used to create Figures <i>A</i> and <i>B</i> and a black horizontal line identifies this bandwidth. The shading corresponds to the significance and direction of the slope (first derivative) of the WRR by age: red is significantly decreasing, purple is possibly zero, blue is significantly increasing, and light grey represents areas where there is insufficient data to generate a smoothed curve. The grid lines correspond to 1 year of age intervals. <b>D</b> SiZer plot of the second derivative of the WRR by age, where the shading corresponds to that described for <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042328#pone-0042328-g001" target="_blank">Figure 1C</a>.</p