The risk of acquiring HIV is higher for drought-exposed women in rural areas of Sub-Saharan Africa than those not exposed to drought, signalling a need for deliberate responses.

Droughts and HIV transmission in sub-Saharan Africa

The risk of acquiring HIV is higher for drought-exposed women in rural areas of Sub-Saharan Africa than those not exposed to drought, signalling a need for deliberate responses.

UN agencies have previously hypothesised that droughts could increase HIV transmission in sub-Saharan Africa. This could occur as droughts exacerbate poverty and food insecurity. This may, in turn, lead to behavioural changes, especially in sexual behaviour.

Farmers in rural areas could be especially vulnerable to droughts, which could directly impact their livelihoods. Meanwhile, people in urban areas may experience more indirect effects.

Some evidence suggests that women could be particularly impacted. Women farmers who are affected by drought may resort to “survival sex” in exchange for food or money. Figure 1 illustrates other potential mechanisms linking climate change and HIV transmission.

Figure 1. Theoretical framework illustrating the links between climate change, drought, and HIV transmission.
Credit. Author

HIV, subsistence farming, and drought

In certain sub-Saharan African countries, one in five adults has HIV. Across the region, there are around 25 million people living with HIV. Also, about 65% of Africa’s population relies on subsistence farming. This renders them particularly vulnerable to droughts.

These droughts affect large numbers of people in various African regions. Additionally, evidence suggests that the risk of droughts in Africa is increasing. This could mean that even more people in sub-Saharan Africa will be affected by droughts in the coming years, including those living with HIV.

Measuring the associations between drought and HIV transmission

In a study published in AIDS and Behavior, my co-authors and I aimed to investigate whether people in sub-Saharan Africa who had recently been exposed to drought were more likely to acquire HIV than those not exposed to drought.

This is the first study to look at people acquiring HIV during or after a drought period. Some previous studies have found some evidence of links between droughts and HIV, but these studies did not provide insight into whether HIV acquisition occurred before or after drought events. In contrast, our study utilised a measure of recent HIV acquisition, providing a more nuanced understanding of the relationship.

We combined data from five nationally-representative surveys of adults conducted in 2016 in Eswatini, Lesotho, Tanzania, Uganda, and Zambia (Figure 2). Our analysis encompassed data on over 100,000 individuals.

Subsequently, we cross-referenced these data with precipitation records to determine whether each household resided in an area that experienced much less rainfall than usual in 2014–2016 compared with 1981–2016, thus defining drought areas. We then used statistical models to ascertain whether individuals exposed to drought were more likely to have recently acquired HIV compared to their non-exposed counterparts.

Figure 2. Countries included in the study.
Credit. Author

Women in rural areas are potentially at risk

Our findings indicate that women living in rural areas recently exposed to droughts had a higher likelihood of acquiring HIV than those who were not exposed to droughts. However, this did not apply to women in urban areas or men in rural or urban areas.

These results also suggest that droughts could heighten HIV transmission among women in rural areas of sub-Saharan Africa. This could occur through exacerbating poverty, thereby influencing sexual risk behaviours, which in turn impact HIV transmission rates.

Despite potentially small changes, given the large number of people living with HIV in Africa and the large percentage experiencing drought, the cumulative effect of droughts could still result in a considerable number of new HIV cases. Moreover, climate change may increase the frequency of droughts in the future, which could lead to increased HIV transmission rates.

Figure 3. Parched land.
Credit. Author

Addressing the issue

Researchers must conduct further studies to explore the pathways linking drought and HIV transmission. Understanding the potential impact of future climate change on HIV through drought is also imperative. Since sub-Saharan African countries contribute minimally to global emissions driving climate change, addressing this issue necessitates a global response.

More localised responses may also prove effective in dealing with the effects of climate change on HIV. Evidence suggests that social protection cash transfer programmes can effectively reduce risky sexual behaviours, particularly among young women.

Additionally, further increasing coverage of HIV treatment and enhancing viral suppression levels among people living with HIV could also help reduce HIV transmission, even amidst increased risky sexual practices. Studies have shown that individuals successfully managing to suppress HIV through treatment do not transmit the virus.

Therefore, if everyone living with HIV maintained suppressed viral loads, theoretically, there would be no further HIV transmission. Many countries in sub-Saharan Africa have made significant strides towards, and in some cases achieved, UNAIDS’s 95-95-95 goals. The goals aim to ensure that 95% of people with HIV receive a diagnosis, 95% of those diagnosed receive treatment, and 95% of those on treatment achieve suppressed viral loads.

However, adherence to HIV treatment may decline in the face of food insecurity, which is strongly linked to poverty and drought. This highlights the need for additional interventions to mitigate this problem. Such interventions include better water storage and irrigation systems.


Journal reference

Trickey, A., Johnson, L. F., Bonifacio, R., Kiragga, A., Howard, G., Biraro, S., … & Vickerman, P. (2024). Investigating the Associations between Drought, Poverty, High-Risk Sexual Behaviours, and HIV Incidence in Sub-Saharan Africa: A Cross-Sectional Study. AIDS and Behavior.

Adam Trickey is a Research Fellow within the Department of Population Health Sciences at the University of Bristol, UK. He specialises in the epidemiology of bloodborne viruses, particularly HIV, and his current research focuses on examining the connections between shifting climate patterns and HIV transmission in sub-Saharan Africa.