Browsing by Author "Low, Andrea"

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    Associations of inter-annual rainfall decreases with subsequent HIV outcomes for persons with HIV on antiretroviral therapy in Southern Africa: a collaborative analysis of cohort studies.
    (2023-Dec-19) Trickey, Adam; Johnson, Leigh F.; Fung, Fai; Bonifacio, Rogerio; Iwuji, Collins; Biraro, Samuel; Bosomprah, Samuel; Chirimuta, Linda; Euvrard, Jonathan ; Fatti, Geoffrey; Fox, Matthew P.; Von, Groote P.; Gumulira, Joe; Howard, Guy; Jennings, Lauren; Kiragga, Agnes; Muula, Guy; Tanser, Frank; Wagener, Thorsten; Low, Andrea; Vickerman, Peter
    BACKGROUND: Periods of droughts can lead to decreased food security, and altered behaviours, potentially affecting outcomes on antiretroviral therapy (ART) among persons with HIV (PWH). We investigated whether decreased rainfall is associated with adverse outcomes among PWH on ART in Southern Africa. METHODS: Data were combined from 11 clinical cohorts of PWH in Lesotho, Malawi, Mozambique, South Africa, Zambia, and Zimbabwe, participating in the International epidemiology Databases to Evaluate AIDS Southern Africa (IeDEA-SA) collaboration. Adult PWH who had started ART prior to 01/06/2016 and were in follow-up in the year prior to 01/06/2016 were included. Two-year rainfall from June 2014 to May 2016 at the location of each HIV centre was summed and ranked against historical 2-year rainfall amounts (1981-2016) to give an empirical relative percentile rainfall estimate. The IeDEA-SA and rainfall data were combined using each HIV centre's latitude/longitude. In individual-level analyses, multivariable Cox or generalized estimating equation regression models (GEEs) assessed associations between decreased rainfall versus historical levels and four separate outcomes (mortality, CD4 counts < 200 cells/mm RESULTS: Among 270,708 PWH across 386 HIV centres (67% female, median age 39 [IQR: 32-46]), lower rainfall than usual was associated with higher mortality (adjusted Hazard Ratio: 1.18 [95%CI: 1.07-1.32] per 10 percentile rainfall rank decrease) and unsuppressed viral loads (adjusted Odds Ratio: 1.05 [1.01-1.09]). Levels of rainfall were not strongly associated with CD4 counts < 200 cell/mm CONCLUSIONS: Decreased rainfall could negatively impact on HIV treatment behaviours and outcomes. Further research is needed to explore the reasons for these effects. Interventions to mitigate the health impact of severe weather events are required.
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    Drought and Syphilis Exposure in Zambia, Uganda, and Tanzania: Are There Urban/Rural Disparities?
    Simo, Fotso A.; Maltat, Charline; Gbaguidi-Sekpon, Baurice; Marzouk, Hakim; Trickey, Adam; Low, Andrea; Becquet, Valentine
    Eastern and southern Africa are highly affected by drought, and projections indicate that droughts will become more common in the coming decades. Whilst there has been research on the impact of drought on HIV, attributable to its effect on food insecurity and increased risky sexual behaviour, the link between drought and other sexually transmitted infections (STIs), particularly syphilis, remains largely unexplored. This study therefore assesses the association between drought and active syphilis, history of syphilis, and recovery from syphilis in Zambia, Uganda, and Tanzania, while examining disparities between urban and rural settings. It uses data on 75,225 people from Population-based HIV Impact Assessment surveys (2016-17), which include biomarker information, combined with rainfall data from the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) dataset to define drought in the two years prior to the survey. Multivariate logistic regression models with country-level fixed effects show that in urban areas, drought was associated with a significant increase in the probability of having active syphilis (average marginal effects (AME) = 0.5%, 95% confidence interval (CI): 0.2%–1.0%) and of having ever had syphilis (AME = 2%, 95% CI: 0.8%–4%). No significant association was found in rural areas. Exposure to drought was not associated with recovery from syphilis in either setting, though confidence intervals were wide. Our results underscore the importance of strengthening healthcare systems to make them more resilient to drought shocks in urban areas, and the need to reinforce syphilis prevention and treatment programmes in those areas when such shocks occur.