Twenty-five Years of Outpatient Influenza Surveillance in South Africa, 1984–2008

Abstract

The program has provided valuable data on the timing of the influenza season each year that can be useful to direct the timing of vaccination and assist clinicians in deciding whether to prescribe empirical antiviral therapy.

Knowledge, attitudes, and practices about influenza illness and vaccination: a cross‐sectional survey in two South African communities

“…The study was conducted from August through September 2012, near the end of a typical influenza season,3 in two South African sites. Soweto, an urban township near Johannesburg in Gauteng Province, has an population of approximately 1·3 million people; Klerksdorp, in North West Province, includes peri‐urban gold mining townships Jouberton, Alabama, Sakhrol, Kanana, Khuma, Tigane, Dominionville, and Vaal Reefs, which have a combined population of over 274 000 12…”

“…It is estimated that more than 450 children <5 years old and 9000 individuals ≥5 years old die each year from influenza in South Africa 1, 2. Influenza infections are responsible for 43–67% of outpatient visits for influenza‐like illness during the peak of influenza season 3. Among South Africans of 65 years of age or older, the rate of excess mortality due to pneumonia and influenza is estimated at 340 deaths per 100 000 population;4 this influenza‐attributable mortality rate is even higher among young adults with AIDS in South Africa, at an estimated 570 deaths per 100 000 5.…”

Trivalent and quadrivalent influenza vaccination effectiveness in Australia and South Africa: results from a modelling study

“…The specific viral strain and lineage for each subtype are updated on an bi‐annual cycle (for the Northern and Southern Hemispheres) based on currently circulating strains 8. Since 2001, two distinct influenza B lineages (Yamagata and Victoria) have cocirculated, with one or both lineages causing a significant proportion of influenza infection in each year 9, 10, 11, 12, 13, 14, 15. In years when the predominant B lineage is incorrectly predicted, or where it is correctly predicted but there is a significant proportion of the other lineage, the TIV for that year leaves vaccinated individuals vulnerable to influenza infection from the ‘missing’ B lineage, since cross‐protection between B lineages is limited 16.…”

Estimating vaccine effectiveness in preventing laboratory‐confirmed influenza in outpatient settings in South Africa, 2015

“…The start of the influenza season was defined as two consecutive weekly influenza detection rates of ≥10%, and the end as when the detection rate dropped below 10% for two consecutive weeks, or <10 specimens per week were received 1. The season was divided into three equal parts as follows: early (weeks 19‐24); mid (weeks 25‐31); late (weeks 32‐37).…”

“…Sites are mainly general practitioners in the private healthcare setting, who submit the majority of specimens during the influenza season. Since 2005, it has also been used to estimate influenza vaccine effectiveness (VE) 1, 2, 3, 4. Recommendations for the use of influenza vaccine are published annually in South Africa 5.…”