‘It never rains, but it pours’–Disasters triggered by natural hazards, sexual risk-taking behavior, and the role of health systems: A worldwide ecological analysis

Natural hazards have become more frequent and more severe as a result of climate change. Their increasing impact has a negative effect on people's health, including mental health. The aim of this ecological study is to investigate the association between exposure to disasters triggered by natural hazards and higher sexual risk-taking behavior as measured by one of its consequences, increased human immunodeficiency virus (HIV) incidence, at the country-level, worldwide. All data were extracted from publicly available sources. Crude and adjusted linear regression models were built to explore the association between the proportion of people affected by natural hazards and HIV incidence. Multivariable models included socio-demographic variables (literacy, income and age), and therapy coverage and the healthcare access and quality index. In the crude regression model, the total number of people affected by natural hazards over a 5 year time period is positively associated with HIV incidence. For every 10 new people per 100,000/year affected by natural hazards, the HIV incidence in the country was 1.5 higher per 1,000 uninfected. However, when adjusting for socio-demographic variables, the association is lost. In the fully adjusted multivariable model, only antiretroviral therapy coverage and health care access and quality were significantly positively and negatively associated with HIV incidence. No interaction was found by income groups, world regions or categories of high and low HIV prevalence. No association between exposure to natural hazards and increased sexual risk-taking behavior at country level worldwide was detected after accounting for socio-demographic variables. Nonetheless, countries with a higher proportion of the population affected by disasters triggered by natural hazards were also those witnessing a higher incidence rate of HIV, possibly through the mediating effect of disrupted health system coverage, highlighting the coexistence of different vulnerabilities for public health.