Epidemiology of Severe Acute Respiratory Illness (SARI) among Adults and Children Aged ≥5 Years in a High HIV-Prevalence Setting, 2009–2012

Abstract

ObjectiveThere 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.MethodsWe 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.FindingsWe 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).ConclusionThe 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.

The national burden of influenza‐associated severe acute respiratory illness hospitalization in Rwanda, 2012‐2014

“…The estimated rates of SARI hospitalization among individuals aged <5 years (3066.0‐3073.6 per 100 000 population) and ≥5 years (139.8‐141.8 per 100 000 population) in Rwanda were also similar to those reported in South Africa from population‐based studies (range: 2530‐3173 per 100 000 population among children aged <5 years22 vs 325‐389 per 100 000 population among individuals aged ≥5 years23). …”

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

“…SARI hospitalization rates of 2530‐3173 per 100 000 population 18 and 325‐389 per 100 000 17 have been reported in South Africa among children aged <5 years and individuals aged ≥5 years, respectively.…”

Respiratory syncytial virus in adults with severe acute respiratory illness in a high HIV prevalence setting

“…Furthermore, we did not clinically stage patients with HIV and it is also possible that admission criteria for known HIV-infected patients may differ by attending physician and hospital; (5) One of the most common reasons for non-enrolment was that the patient was too ill to consent; this may bias our estimation of severity; Previously published data from the same surveillance programme found a 10% non-enrolment rate into the surveillance programme, of whom 50% were too ill to consent and 11% refused to participate with the remainder having a variety of reasons for refusal. 40 (6) Our confidence interval may not account for the variability in numbers due to enrolment strategies and so may be imprecise; (7) Lastly population denominators were only available for one large urban hospital site, making it difficult to generalize the findings to other sites in the country; (8) The adjustment factors used in our incidence calculation are based on a number of assumptions and this uncertainty in not captured in the confidence intervals for our estimates of incidence; (9) It is possible that health seeking behaviour is different by age and HIV status which could affect our estimation of disease incidence; (10) The true burden of RSV-associated respiratory tract infection is not complete without an estimation of outpatient burden, these data are not as yet published in our setting.…”