Number of specimens testing positive for influenza and detection rates by year, Viral Watch, South Africa, 2005–2009.

<p>Number of specimens testing positive for influenza and detection rates by year, Viral Watch, South Africa, 2005–2009.</p

Comparison of vaccine composition to circulating viruses, South Africa, 2005–2009.

<p><b>Predominating circulating strains in bold.</b></p><p><b>Predominating B strains indicated.</b></p

Vaccination coverage^* and vaccine effectiveness by year, Viral Watch, South Africa: 2005–2009.

<p><b>Statistically significant values in bold.</b></p>*<p>The proportion of individuals who received at least one dose of influenza vaccine in the relevant period.</p><p>Age groups: <50 and ≥50 years.</p

Influenza detections and detection rates for seasonal influenza (N = 2490) and influenza A(H1N1)pdm09 (N = 496) by age group, Viral Watch, South Africa: 2005–2009.

<p>Influenza detections and detection rates for seasonal influenza (N = 2490) and influenza A(H1N1)pdm09 (N = 496) by age group, Viral Watch, South Africa: 2005–2009.</p

Percentage of influenza positives by age group and virus type, Viral Watch, South Africa; 2005–2009.

<p>Percentage of influenza positives by age group and virus type, Viral Watch, South Africa; 2005–2009.</p

Detection rates for influenza viruses in the three surveillance program, Viral Watch (VW), Illnesses-like influenza surveillance in public health clinics (ILI/PHC) and severe acute respiratory illnesses (SARI) in South Africa, 2005–2014.

<p>Detection rates for influenza viruses in the three surveillance program, Viral Watch (VW), Illnesses-like influenza surveillance in public health clinics (ILI/PHC) and severe acute respiratory illnesses (SARI) in South Africa, 2005–2014.</p

Proportion of typed samples by influenza B Ct-value among patients with SARI.

<p>Proportion of typed samples by influenza B Ct-value among patients with SARI.</p

Monthly number of influenza-positive specimens in South Africa.

<p>(<b>A</b>) Viral Watch program (2005–2014), (<b>B</b>) Severe acute respiratory illness surveillance program (2009–2014), and (<b>C</b>) Influenza-like illness surveillance program in public health clinics (2012–2014).</p

Demographic and clinical characteristics associated with influenza B lineages, determined by multivariable logistic regression analysis, among influenza B-positive patients hospitalized with severe acute respiratory illness, South Africa, 2009–2014.

<p>Demographic and clinical characteristics associated with influenza B lineages, determined by multivariable logistic regression analysis, among influenza B-positive patients hospitalized with severe acute respiratory illness, South Africa, 2009–2014.</p