Green environment and incident depression in South Africa: a geospatial analysis and mental health implications in a resource-limited setting.

BACKGROUND: Unprecedented levels of habitat transformation and rapid urbanisation are changing the way individuals interrelate with the natural environment in developing countries with high economic disparities. Although the potential benefit of green environments for mental health has been recognised, population-level evidence to this effect is scarce. We investigated the effect of green living environment in potentially countering incident depression in a nationally representative survey in South Africa. METHODS: We used panel data from the South African National Income Dynamics Study (SA-NIDS). Our study used SA-NIDS data from three waves: wave 1 (2008), wave 2 (2010), and wave 3 (2012). Households were sampled on the basis of a stratified two-stage cluster design. In the first stage, 400 primary sampling units were selected for inclusion. In the second stage, two clusters of 12 dwelling units each were drawn from within each primary sampling unit (or 24 dwelling units per unit). Household and individual adult questionnaires were administered to participants. The main outcome, incident depression (ie, incident cohort of 11 156 study participants without significant depression symptoms at their first entry into SA-NIDS), was assessed in the adult survey via a ten item version of the Center for Epidemiologic Studies Depression Scale; a total score of ten or higher was used as a cutoff to indicate significant depressive symptoms. Each participant was assigned a value for green living space via a satellite-derived normalised difference vegetation index (NDVI) based on the GPS coordinates of their household location. FINDINGS: Overall, we found uneven benefit of NDVI on incident depression among our study participants. Although the green living environment showed limited benefit across the study population as a whole, our final analysis based on logistic regression models showed that higher NDVI was a predictor of lower incident depression among middle-income compared with low-income participants (adjusted odds ratio [aOR] 0·98, 0·97-0·99, p<0·0001), although when this analysis was broken down by race, its positive effect was particularly evident amongst African individuals. Living in rural areas was linked to lower odds of incident depression (aOR 0·71, 0·55-0·92, p=0·011) compared with study participants residing in urban informal areas that often lack formal planning. INTERPRETATION: Our results imply the importance of green environments for mental wellbeing in sub-Saharan African settings experiencing rapid urbanisation, economic and epidemiological transition, reaffirming the need to incorporate environmental services and benefits for sustainable socioeconomic development. FUNDING: South African Medical Research Council, National Institutes of Health, and Academy of Finland.

Social Disequilibrium and the Risk of HIV Acquisition: A Multilevel Study in Rural KwaZulu-Natal Province, South Africa.

BACKGROUND: Few population-based multilevel studies have quantified the risks that social context poses in rural communities with high HIV incidence across South Africa. We investigated the individual, social, and community challenges to HIV acquisition risk in areas with high and low incidence of HIV infection (hotspots/coldspots). METHODS: The cohort (N = 17,376) included all HIV-negative adults enrolled in a population-based HIV surveillance study from 2004 to 2015 in a rural South African community with large labor migrancy. Multilevel survival models were fitted to examine the social determinants (ie, neighborhood migration intensity), community traits (ie, HIV prevalence), and individual determinants of HIV acquisition risk in identified hotspots/coldspots. RESULTS: The HIV acquisition risk (adjusted hazard ratio [aHR] = 1.05, 95% confidence interval [CI]: 1.01 to 1.09) was greater in hotspots with higher neighborhood migration intensity among men. In women, higher neighborhood migration intensity (aHR = 1.02, 95% CI: 1.01 to 1.02) was associated with a greater HIV acquisition risk, irrespective of whether they lived in hotspot/coldspot communities. HIV acquisition risk was greater in communities with a higher prevalence of HIV in both men (aHR = 1.07, 95% CI: 1.03 to 1.12) and women (aHR = 1.03, 95% CI: 1.01 to 1.05), irrespective of hotspot/coldspot locations. CONCLUSION: HIV acquisition risk was strongly influenced by gender (ie, young women), behavior (ie, sexual debut, contraception, circumcision), and social determinants. Certain challenges (ie, community disease prevalence) for HIV acquisition risk impacted both sexes, regardless of residence in hotspot/coldspot communities, whereas social determinants (ie, neighborhood migration intensity) were pronounced in hotspots among men. Future intervention scale-up requires addressing the social context that contributes to HIV acquisition risk in rural areas with high migration.

Proximity to healthcare clinic and depression risk in South Africa: geospatial evidence from a nationally representative longitudinal study.

Proximity to primary healthcare facilities may be a serious barrier to accessing mental health services in resource-limited settings. In this study, we examined whether the distance to the primary healthcare clinic (PHCC) was associated with risk of depression in KwaZulu-Natal Province, South Africa. Depressive symptoms and household coordinates data were accessed from the nationally representative South African National Income Dynamics Study. Distances between households and their nearest PHCCs were calculated and mixed-effects logistic regression models fitted to the data. Participants residing <6 km from a PHCC (aOR = 0.608, 95% CI 0.42-0.87) or 6-14.9 km (aOR = 0. 612, 95% CI 0.44-0.86) had a lower depression risk compared to those residing ≥15 km from the nearest PHCC. Distance to the PHCC was independently associated with increased depression risk, even after controlling for key socioeconomic determinants. Minimizing the distance to PHCC through mobile health clinics and technology could improve mental health.

Brief Report: Virologic Monitoring Can Be a Cost-Effective Strategy to Diagnose Treatment Failure on First-Line ART.

CD4 count testing is perceived to be an affordable strategy to diagnose treatment failure on first-line antiretroviral therapy. We hypothesize that the superior accuracy of viral load (VL) testing will result in less patients being incorrectly switched to more expensive and toxic second-line regimens. Using data from a drug resistance cohort, we show that CD4 testing is approximately double the cost to make 1 correct regimen switch under certain diagnostic thresholds (CD4 = US $499 vs. VL = US $186 or CD4 = US $3031 vs. VL = US $1828). In line with World Health Organization guidelines, our findings show that VL testing can be both an accurate and cost-effective treatment monitoring strategy.