Severe Influenza-associated Respiratory Infection in High HIV Prevalence Setting, South Africa, 2009–2011

Abstract

Data on influenza epidemiology in HIV-infected persons are limited, particularly for sub-Saharan Africa, where HIV infection is widespread. We tested respiratory and blood samples from patients with acute lower respiratory tract infections hospitalized in South Africa during 2009–2011 for viral and pneumococcal infections. Influenza was identified in 9% (1,056/11,925) of patients enrolled; among influenza case-patients, 358 (44%) of the 819 who were tested were infected with HIV. Influenza-associated acute lower respiratory tract infection incidence was 4–8 times greater for HIV-infected (186–228/100,000) than for HIV-uninfected persons (26–54/100,000). Furthermore, multivariable analysis showed HIV-infected patients were more likely to have pneumococcal co-infection; to be infected with influenza type B compared with type A; to be hospitalized for 2–7 days or >7 days; and to die from their illness. These findings indicate that HIV-infected persons are at greater risk for severe illnesses related to influenza and thus should be prioritized for influenza vaccination.

The national burden of influenza‐associated severe acute respiratory illness hospitalization in Zambia, 2011‐2014

“…This was observed also in other studies conducted in Africa 19, 20, 21. Our estimates of influenza‐associated SARI hospitalization in individuals aged ≥5 years are on the lower end, but overall similar to other estimates from Africa (22 per 100 000 population in South Africa 21 and 30 per 100 000 population in Kenya 20). Underlying medical conditions including HIV infection is known risk factors for influenza‐associated severe illness 21, 22, 23, 24.…”

“…Our estimates of influenza‐associated SARI hospitalization in individuals aged ≥5 years are on the lower end, but overall similar to other estimates from Africa (22 per 100 000 population in South Africa 21 and 30 per 100 000 population in Kenya 20). Underlying medical conditions including HIV infection is known risk factors for influenza‐associated severe illness 21, 22, 23, 24. Differences in the prevalence of such conditions in different settings may explain some of the observed differences in the influenza‐associated SARI hospitalization rates in this age‐group.…”

“…Other Africa studies conducted using population‐based surveillance among children aged <5 years estimated rates of influenza‐associated SARI hospitalization of 135 per 100 000 population in Ghana,19 270 per 100 000 population in Kenya,20 and 153‐186 per 100 000 population in South Africa 21. Our finding of influenza‐associated hospitalization rates in children <5 years (187 per 100 000 population) is generally consistent with the estimates obtained from similar studies conducted in Africa, albeit higher compared to those of other regions 3…”

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

“…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. In addition, HIV‐positive South Africans have been shown to be at greater risk for severe influenza illness 6. The high prevalence of underlying high‐risk medical conditions, including HIV and tuberculosis, likely contributes to higher influenza‐associated mortality in South Africa 7, 8…”

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

“…Young children, the elderly and those with other underlying health conditions such as HIV have an increased risk of developing complications of influenza, such as pneumonia 2, 3, 4…”