Environmental Determinants and Spatiotemporal Co-occurrence Patterns of Periodontitis and HIV: A Global Burden...

Periodontal disease and HIV infection are interconnected global health challenges that share common environmental pathways. Although a bidirectional relationship between the 2 conditions has been documented, comprehensive analyses of their co-occurrence patterns and underlying environmental drivers remain scarce. The present study characterised the global spatial distribution of periodontitis-HIV comorbidity and identified its principal environmental determinants.

Incidence data for adults aged ≥25 years were obtained from the Global Burden of Disease Study 2021 for 204 countries and territories. A total of 68 candidate risk factors were evaluated. Countries were classified into concordant, periodontitis-dominant or HIV-dominant strata. Shapley Additive exPlanations (SHAP) analysis and negative binomial regression were used to quantify risk-factor effects. Temporal trends from 1990 to 2021 were assessed using 6580 country-year observations. Country-level similarity networks were constructed using Gaussian similarity measures and analysed with Louvain community detection.

In 2021, periodontal disease incidence (1740.92 per 100,000) exceeded HIV incidence (26.07 per 100,000) by approximately 67-fold. Of the 204 countries assessed, 41.87% exhibited HIV dominance, 35.47% periodontal dominance, and 22.66% a concordant pattern. Unsafe sanitation was the strongest risk factor for HIV (RR 1.032 [95% CI 1.013-1.052]). For periodontal disease, environmental pollutants demonstrated significant associations: lead exposure (RR 1.008 [1.003-1.012]), particulate matter (RR 1.007 [1.002-1.011]) and ozone pollution (RR 1.006 [1.001-1.011]). Network analysis identified 21 distinct country communities, 71% of which showed regional-epidemiological clustering. Concordant zones exhibited the strongest temporal correlations (ρ = 0.933, P < .001).

Environmental factors - poor sanitation for HIV and ambient air pollution for periodontal disease - emerged as critical modifiable determinants of disease burden. Integrated environmental interventions targeting infrastructure and pollution could substantially reduce the burden of both conditions in high-burden regions, particularly Sub-Saharan Africa and South Asia.

Unsafe sanitation and ambient air pollutants represent the principal modifiable population-level risk factors for HIV and periodontitis, respectively. Dental and HIV-care clinicians are encouraged to (1) screen patients in high-PAF regions for environmental co-exposures during routine periodontal assessment, (2) advocate for water-sanitation-hygiene (WASH) infrastructure investment as a complementary HIV-prevention strategy and (3) integrate environmental-health counselling into oral-health and HIV-care pathways. Integrated environmental-health policies are projected to deliver greater population-level impact than disease-specific clinical interventions alone, particularly in Sub-Saharan Africa and South Asia.