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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.

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L ast month, a grand experiment was launched. Its aim? To speed up the development of COVID-19 vaccines and make sure they are distributed equitably among higher-and lower-income countries. This welcome endeavour is called the COVID-19 Vaccine Global Access (COVAX) initiative. It is co-led by the World Health Organization (WHO), the Coalition for Epidemic Preparedness Innovations (CEPI) and Gavi, the Vaccine Alliance. As of 1 October, 167 countries have signed up, covering nearly two-thirds of the global population. More have expressed interest, according to Gavi. The initiative covers several vaccines currently in testing. It aims to ensure access to whichever ones prove to be effective. Under this scheme, even poor nations should have enough vaccines to protect health-care workers and the most vulnerable 20% of their populations. Still, Africa has reasons to worry. Already, several high-income countries have signed their own contracts with individual companies to buy selected vaccines. The United States, for example, has made deals worth upwards of US$6 billion with several firms. An analysis by the international charity Oxfam finds that, even if all five of the most-advanced vaccine candidates succeed, there will not be enough vaccine for most of the world's people until 2022. We've seen a scramble for access to

Local disease burden data are necessary to set national influenza vaccination policy. In 2010 the population of South Africa was 50 million and the HIV prevalence was 11%. We used a previously developed methodology to determine severe influenza burden in South Africa.Hospitalized severe acute respiratory illness (SARI) incidence was calculated, stratified by HIV status, for four age groups using data from population-based surveillance in one site situated in Gauteng Province for 2009–2011. These rates were adjusted for each of the remaining 8 provinces based on their prevalence of risk factors for pneumonia and healthcare-seeking behavior. We estimated non-hospitalized influenza-associated SARI from healthcare utilization surveys at two sites and used the percent of SARI cases positive for influenza from sentinel surveillance to derive the influenza-associated SARI rate. We applied rates of hospitalized and non-hospitalized influenza-associated SARI to census data to calculate the national number of cases. The percent of SARI cases that tested positive for influenza ranged from 7–17% depending on age group, year, province and HIV status. In 2010, there were an estimated 21,555 total severe influenza cases in HIV-uninfected individuals and 13,876 in HIV-infected individuals. In 2011, there were an estimated 29,892 total severe influenza cases in HIV-uninfected individuals and 17,289 in HIV-infected individuals. The incidence of influenza-associated SARI was highest in children <5 years and was higher in HIV-infected than HIV-uninfected persons in all age groups. Influenza virus was associated with a substantial amount of severe disease, especially in young children and HIV-infected populations in South Africa.

Background.Data on risk factors for influenza-associated hospitalizations in low- and middle-income countries are limited.Methods.We conducted active syndromic surveillance for hospitalized severe acute respiratory illness (SARI) and outpatient influenza-like illness (ILI) in 2 provinces of South Africa during 2012–2015. We compared the characteristics of influenza-positive patients with SARI to those with ILI to identify factors associated with severe disease requiring hospitalization, using unconditional logistic regression.Results.During the study period, influenza virus was detected in 5.9% (110 of 1861) and 15.8% (577 of 3652) of SARI and ILI cases, respectively. On multivariable analysis factors significantly associated with increased risk of influenza-associated SARI hospitalization were as follows: younger and older age (<6 months [adjusted odds ratio {aOR}, 37.6], 6–11 months [aOR, 31.9], 12–23 months [aOR, 22.1], 24–59 months [aOR, 7.1], and ≥65 years [aOR, 40.7] compared with 5–24 years of age), underlying medical conditions (aOR, 4.5), human immunodeficiency virus infection (aOR, 4.3), and Streptococcus pneumoniae colonization density ≥1000 deoxyribonucleic acid copies/mL (aOR, 4.8). Underlying medical conditions in children aged <5 years included asthma (aOR, 22.7), malnutrition (aOR, 2.4), and prematurity (aOR, 4.8); in persons aged ≥5 years, conditions included asthma (aOR, 3.6), diabetes (aOR, 7.1), chronic lung diseases (aOR, 10.7), chronic heart diseases (aOR, 9.6), and obesity (aOR, 21.3). Mine workers (aOR, 13.8) and pregnant women (aOR, 12.5) were also at increased risk for influenza-associated hospitalization.Conclusions.The risk groups identified in this study may benefit most from annual influenza immunization, and children <6 months of age may be protected through vaccination of their mothers during pregnancy.

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.