There are few published studies describing severe acute respiratory illness (SARI) epidemiology
amongst older children and adults from high HIV-prevalence settings. We aimed to
describe SARI epidemiology amongst individuals aged 5 years in South Africa.
We conducted prospective surveillance for individuals with SARI from 2009–2012. Using
polymerase chain reaction, respiratory samples were tested for ten viruses, and blood for
pneumococcal DNA. Cumulative annual SARI incidence was estimated at one site with
population denominators. FINDINGS
We enrolled 7193 individuals, 9% (621/7067) tested positive for influenza and 9%(600/6519)
for pneumococcus. HIV-prevalence was 74% (4663/6334). Among HIV-infected individuals
with available data, 41% of 2629 were receiving antiretroviral therapy (ART). The annual
SARI hospitalisation incidence ranged from 325-617/100,000 population. HIV-infected individuals
experienced a 13–19 times greater SARI incidence than HIV-uninfected individuals
(p<0.001). On multivariable analysis, compared to HIV-uninfected individuals, HIV-infected
individuals were more likely to be receiving tuberculosis treatment (odds ratio (OR):1.7;
95%CI:1.1–2.7), have pneumococcal infection (OR 2.4; 95%CI:1.7–3.3) be hospitalised
for >7 days rather than <2 days (OR1.7; 95%CI:1.2–2.2) and had a higher case-fatality
ratio (8% vs 5%;OR1.7; 95%CI:1.2–2.3), but were less likely to be infected with influenza
(OR 0.6; 95%CI:0.5–0.8). On multivariable analysis, independent risk indicators associated
with death included HIV infection (OR 1.8;95%CI:1.3–2.4), increasing age-group, receiving
mechanical ventilation (OR 6.5; 95%CI:1.3–32.0) and supplemental-oxygen therapy
(OR 2.6; 95%CI:2.1–3.2).
The burden of hospitalized SARI amongst individuals aged 5 years is high in South Africa.
HIV-infected individuals are the most important risk group for SARI hospitalization and mortality
in this setting.