Coming home to die? The association between migration and mortality in rural Tanzania before and after ART scale-up

Abstract

BackgroundPrior to the scale-up of antiretroviral therapy (ART), demographic surveillance cohort studies showed higher mortality among migrants than residents in many rural areas.ObjectivesThis study quantifies the overall and AIDS-specific mortality between migrants and residents prior to ART, during ART scale-up, and after widespread availability of ART in Rufiji district in Tanzania.DesignIn Health and Demographic Surveillance System (HDSS), the follow-up of individuals aged 15–59 years was categorized into three periods: before ART (1998–2003), during ART scale-up (2004–2007), and after widespread availability of ART (2008–2011). Residents were those who never migrated within and beyond HDSS, internal migrants were those who moved within the HDSS, and external migrants were those who moved into the HDSS from outside. Mortality rates were estimated from deaths and person-years of observations calculated in each time period. Hazard ratios were estimated to compare mortality between migrants and residents. AIDS deaths were identified from verbal autopsy, and the odds ratio of dying from AIDS between migrants and residents was estimated using the multivariate logistic regression model.ResultsInternal and external migrants experienced higher overall mortality than residents before the introduction of ART. After widespread availability of ART overall mortality were similar for internal and external migrants. These overall mortality experiences observed were similar for males and females. In the multivariate logistic regression model, adjusting for age, sex, education, and social economic status, internal migrants had similar likelihood of dying from AIDS as residents (adjusted odds ratio [AOR]=1.14, 95% confidence interval [CI]: 0.70–1.87) while external migrants were 70% more likely to die from AIDS compared to residents prior to the introduction of ART (AOR=1.70, 95% CI: 1.06–2.73). After widespread availability of ART with the same adjustment factors, the odds of dying from AIDS were similar for internal migrants and residents (AOR=1.56, 95% CI: 0.80–3.04) and external migrants and residents (AOR=1.42, 95% CI: 0.76–2.66).ConclusionsAvailability of ART has reduced the number of HIV-infected migrants who would otherwise return home to die. This has reduced the burden on rural communities who had cared for the return external migrants.

Migration, hotspots, and dispersal of HIV infection in Rakai, Uganda

“…We also find lower levels of antiretroviral use among in-migrants irrespective of sex. The relatively low levels of ART use among mobile persons likely results in poorer clinical outcomes and AIDSrelated mortality as demonstrated in other settings 6,[16][17][18] . It is unclear whether migrants are a marginalized group with lower levels of ART initiation, or whether migration interrupts treatment use, or both.…”

“…1a). Out-migration rates ranged from 5.4 to 24 per 100 py and in-migration rates from 4.2 to 23 per 100 py, with significantly higher levels of in-migration in trading centers (median = 16 per 100 py: IQR: [11][12][13][14][15][16][17][18] and Lake Victoria fishing communities (13 per 100 py, IQR: 12-15) compared to agrarian communities (7.2 per 100 py; IQR: 6.4-8.6; Wilcoxon-rank sum p-values < 0.001 for both comparisons). Rates of in-and outmigration were positively correlated at the community-level (coef = 0.86, R 2 = 0.55, linear regression p-value < 0.001, Fig.…”

“…Educational status (%) None 1392 (17) 352 (19) 454 (20) 1684 (21) 312 (22) 371 (26) Primary 3514 (42) 757 (41) 882 (40) 3589 (45) 609 (43) 601 (41) Secondary or higher (45) 741 (40) 918 (41) 1631 21228 (16) 251 (17) Bar/Restaurant work 1133 14238 17312 22Student 1434 (17) 254 (14) 138 (6) 1923 25267 (19) 109 (8) Trader/Shop keeper 1207 (15) 294 (16) 416 (19) 1098 14201 14199 14Other 1443 (17) 400 ( 1030 (55) 1124 (51) 5132 65753 53611 (42) Trading community 1158 (14) 337 (18) 465 (21) 842 11225 (16) 251 (17) Fish landing site 1549 (19) 495 ( 571 (26) 614 (43) 821…”

“…A continued understanding of the relationship between migratory dynamics and disease spread is perhaps nowhere more important than in sub-Saharan Africa, where the burden of HIV infections and AIDS-related mortality are concentrated 7,8 . African migrants have higher HIV prevalence [9][10][11][12][13][14][15] , are less likely to be linked and adhere to antiretroviral therapy (ART), and progress to AIDS more quickly than non-migrants 6,[16][17][18] .…”

Rural/Urban Population Age and Sex Composition in sub‐Saharan Africa 1980–2015

“…; Levira et al. ). Thus, more complex models accounting for HIV and international migration by rural/urban sector may alter the effect of older adult migration on dependency ratios.…”