Browsing by Author "Herbst, Kobus"

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    Effect of HIV infection on pregnancy-related mortality in sub-Saharan Africa: secondary analyses of pooled community based data from the network for Analysing Longitudinal Population-based HIV/AIDS data on Africa (ALPHA)
    (The Lancet, 2013) Zaba, Basia; Calvert, Clara; Marston, Milly; Isingo, Raphael; Nakiyingi-Miiro, Jessica; Lutalo, Tom; Crampin, Amelia; Robertson, Laura; Herbst, Kobus; Ronsmans, Carine
    Model-based estimates of the global proportions of maternal deaths that are in HIV-infected women range from 7% to 21%, and the eff ects of HIV on the risk of maternal death is highly uncertain. We used longitudinal data from the Analysing Longitudinal Population-based HIV/AIDS data on Africa (ALPHA) network to estimate the excess mortality associated with HIV during pregnancy and the post-partum period in sub-Saharan Africa. Methods The ALPHA network pooled data gathered between June, 1989 and April, 2012 in six community-based studies in eastern and southern Africa with HIV serological surveillance and verbal-autopsy reporting. Deaths occurring during pregnancy and up to 42 days post partum were defi ned as pregnancy related. Pregnant or postpartum person-years were calculated for HIV-infected and HIV-uninfected women, and HIV-infected to HIVuninfected mortality rate ratios and HIV-attributable rates were compared between pregnant or post-partum women and women who were not pregnant or post partum. Findings 138 074 women aged 15–49 years contributed 636 213 person-years of observation. 49 568 women had 86 963 pregnancies. 6760 of these women died, 235 of them during pregnancy or the post-partum period. Mean prevalence of HIV infection across all person-years in the pooled data was 17·2% (95% CI 17·0–17·3), but 60 of 118 (50·8%) of the women of known HIV status who died during pregnancy or post partum were HIV infected. The mortality rate ratio of HIV-infected to HIV-uninfected women was 20·5 (18·9–22·4) in women who were not pregnant or post partum and 8·2 (5·7–11·8) in pregnant or post-partum women. Excess mortality attributable to HIV was 51·8 (47·8–53·8) per 1000 person-years in women who were not pregnant or post partum and 11·8 (8·4–15·3) per 1000 person-years in pregnant or post-partum women. Interpretation HIV-infected pregnant or post-partum women had around eight times higher mortality than did their HIV-uninfected counterparts. On the basis of this estimate, we predict that roughly 24% of deaths in pregnant or post-partum women are attributable to HIV in sub-Saharan Africa, suggesting that safe motherhood programmes should pay special attention to the needs of HIV-infected pregnant or post-partum women.
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    InterVA-4 as a public health tool for measuring HIV/AIDS mortality: a validation study from five African countries
    (Global Health Action, 2013) Byass, Peter; Calvert, Clara; Nakiyingi-Miiro, Jessica; Lutalo, Tom; Michael, Denna; Crampin, Amelia; Gregson, Simon; Takaruza, Albert; Robertson, Laura; Herbst, Kobus; Todd, Jim; Zaba, Basia
    Reliable population-based data on HIV infection and AIDS mortality in sub-Saharan Africa are scanty, even though that is the region where most of the world’s AIDS deaths occur. There is therefore a great need for reliable and valid public health tools for assessing AIDS mortality. Objective: The aim of this article is to validate the InterVA-4 verbal autopsy (VA) interpretative model within African populations where HIV sero-status is recorded on a prospective basis, and examine the distribution of cause-specific mortality among HIV-positive and HIV-negative people. Design: Data from six sites of the Alpha Network, including HIV sero-status and VA interviews, were pooled. VA data according to the 2012 WHO format were extracted, and processed using the InterVA-4 model into likely causes of death. The model was blinded to the sero-status data. Cases with known pre-mortem HIV infection status were used to determine the specificity with which InterVA-4 could attribute HIV/AIDS as a cause of death. Cause-specific mortality fractions by HIV infection status were calculated, and a person-time model was built to analyse adjusted cause-specific mortality rate ratios. Results: The InterVA-4 model identified HIV/AIDS-related deaths with a specificity of 90.1% (95% CI 88.7 91.4%). Overall sensitivity could not be calculated, because HIV-positive people die from a range of causes. In a person-time model including 1,739 deaths in 1,161,688 HIV-negative person-years observed and 2,890 deaths in 75,110 HIV-positive person-years observed, the mortality ratio HIV-positive:negative was 29.0 (95% CI 27.1 31.0), after adjustment for age, sex, and study site. Cause-specific HIV-positive:negative mortality ratios for acute respiratory infections, HIV/AIDS-related deaths, meningitis, tuberculosis, and malnutrition were higher than the all-cause ratio; all causes had HIV-positive:negative mortality ratios significantly higher than unity.
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    Mortality in women of reproductive age in rural South Africa
    (Global Health Action, 2013) Nabukalu, Dorean; Klipstein-Grobusch, Kerstin; Herbst, Kobus; Newell, Marie-Louise
    Objective: To determine causes of death and associated risk factors in women of reproductive age in rural South Africa. Methods: Deaths and person-years of observation (pyo) were determined for females (aged 15 49 years) resident in 15,526 households in a rural South African Demographic and Health Surveillance site from 2000 to 2009. Cause of death was ascertained by verbal autopsy and ICD-10 coded; causes were categorized as HIV/TB, non-communicable, communicable/maternal/perinatal/nutrition, injuries, and undetermined (unknown). Characteristics of women were obtained from regularly updated household visits, while HIV and self-reported health status was obtained from the annual HIV surveillance. Overall and cause-specific mortality rates (MRs) with 95% confidence intervals (CI) were calculated. TheWeibull regression model (HR, 95% CI) was used to determine risk factors associated with mortality. Results: A total of 42,703 eligible women were included; 3,098 deaths were reported for 212,607 pyo. Overall MRwas 14.6 deaths/1,000 pyo (95% CI: 14.1 15.1), peaking in 2003 (MR 18.2/1,000 pyo, 95% CI: 16.4 20.1) and declining thereafter (2009: MR 9.6/1,000 pyo, 95% CI: 8.4 10.9). Mortality was highest for HIV/TB (MR 10.6/1,000 pyo, 95% CI: 10.2 11.1), accounting for 73.1% of all deaths, ranging from 61.2% in 2009 to 82.7% in 2002. Adjusting for education level, marital status, age, employment status, area of residence, and migration, all-cause mortality was associated with external migration (adjusted hazard ratio, or aHR), 1.70, 95% CI: 1.41 2.05), self-reported poor health status (aHR 8.26, 95% CI: 2.94 23.15), and HIV-infection (aHR 7.84, 95% CI: 6.26 9.82); external migration and HIV infection were also associated with causes of mortality other than HIV/TB (aHR 1.62, 95% CI: 1.12 2.34 and aHR 2.59, 95% CI: 1.79 3.75). Conclusion: HIV/TB was the leading cause of death among women of reproductive age, although rates declined with the rollout of HIV treatment in the area from 2004. Women’s age, external migration status and HIV-positive status were significantly associated with all-cause and cause-specific mortality.