Environment/Climate Change
Quantifying extreme rainfall events as health-related exposures in HIV care populations: an analysis using precipitation and flood data at 382 sub-Saharan Africa HIV clinics in 20 countries, from 1981-2022 Avantika Srivastava* Avantika Srivastava
Extreme weather events (EWE) can disrupt access to HIV care and related services and shift patient priorities, but little is known of how EWEs shape HIV care engagement and treatment outcomes. Understanding these associations can help elucidate how climate change impacts HIV care utilization and outcomes now and in future decades. With this in mind, we developed measures for EWE exposures using events captured in global precipitation and flood databases.
We integrated high spatiotemporal resolution rainfall and flood data with HIV clinic data from 1981-2022 for 382 clinics across 20 countries in sub-Saharan Africa (SSA). Variables were developed based on gridded daily precipitation, available at 0.05° spatial resolution from Climate Hazards InfraRed Precipitation with Station data (CHIRPS) that combine satellite imagery with weather station data, and on the Global Active Archive of Large Flood Events (GALFE), which uses government reports, news, and remote sensing to capture timing and characteristics of large flood events.1,2 Exposures were defined as days with: flood events, precipitation over site-specific thresholds of the top percentile of historical 10-day rolling averages, and precipitation over 50mm.
From 1981-2022, there were 2,366 periods (62,460 days) of flood-based extreme wet weather, averaging 26.4 days. Floods increased in frequency and duration, with 58 events averaging 5.4 days from 1990-1994 and 267 events averaging 12.9 days from 2015-2019. CHIRPS covered 13,377 EWEs (57,551 days), with 1,281 EWEs (4,759 days) from 1990-1994 and 1,899 EWEs (8,136 days) from 2015-2019. EWEs increased in intensity, with mean total precipitation of 69.6mm from 1990-1994 and 83.7 from 2015-2019.
Extreme wet weather burden at SSA HIV clinics is substantial and has steadily increased in frequency, duration, and intensity. Assessing EWE exposure impact on short- and long-term HIV care outcomes is an important next step to inform climate change adaptation strategies.