The next phases of the Migrante Project: Study protocol to expand an observatory of migrant health on the Mexico-U.S. border.

Background: Mexican migrants traveling across the Mexico-United States (U.S.) border region represent a large, highly mobile, and socially vulnerable subset of Mexican nationals. Population-level health data for this group is hard to obtain given their geographic dispersion, mobility, and largely unauthorized status in the U.S. Over the last 14 years, the Migrante Project has implemented a unique migration framework and novel methodological approach to generate population-level estimates of disease burden and healthcare access for migrants traversing the Mexico-U.S. border. This paper describes the rationale and history of the Migrante Project and the protocol for the next phases of the project. Methods/design: In the next phases, two probability, face-to-face surveys of Mexican migrant flows will be conducted at key crossing points in Tijuana, Ciudad Juarez, and Matamoros (N = 1,200 each). Both survey waves will obtain data on demographics, migration history, health status, health care access, COVID-19 history, and from biometric tests. In addition, the first survey will focus on non-communicable disease (NCD), while the second will dive deeper into mental health and substance use. The project will also pilot test the feasibility of a longitudinal dimension with 90 survey respondents that will be re-interviewed by phone 6 months after completing the face-to-face baseline survey. Discussion: Interview and biometric data from the Migrante project will help to characterize health care access and health status and identify variations in NCD-related outcomes, mental health, and substance use across migration phases. The results will also set the basis for a future longitudinal extension of this migrant health observatory. Analyses of previous Migrante data, paired with data from these upcoming phases, can shed light on the impact of health care and immigration policies on migrants' health and inform policy and programmatic responses to improve migrant health in sending, transit, and receiving communities.

COVID-19 testing, infection, and vaccination among deported Mexican migrants: Results from a survey on the Mexico-U.S. border.

Background: Migrants detained and held in immigration and other detention settings in the U.S. have faced increased risk of COVID-19 infection, but data on this population is scarce. This study sought to estimate rates of COVID-19 testing, infection, care seeking, and vaccination among Mexican migrants detained by U.S. immigration authorities and forcibly returned to Mexico. Methods: We conducted a cross-sectional probability survey of Mexican migrants deported from the U.S. to three Mexican border cities: Tijuana, Ciudad Juárez, and Matamoros (N = 306). Deported migrants were recruited at Mexican migration facilities after being processed and cleared for departure. A two-stage sampling strategy was used. Within each city, a selection of days and shifts were selected during the operating hours of these deportation facilities. The probability of selection was proportional to the volume of migrants deported on each day of the month and during each time period. During the selected survey shifts, migrants were consecutively approached, screened for eligibility, and invited to participate in the survey. Survey measures included self-reported history of COVID-19 testing, infection, care seeking, vaccination, intentions to vaccinate, and other prevention and risk factors. Weighted data were used to estimate population-level prevalence rates. Bivariate tests and adjusted logistic regression models were estimated to identify associations between these COVID-19 outcomes and demographic, migration, and contextual factors. Results: About 84.1% of migrants were tested for COVID-19, close to a third were estimated to have been infected, and, among them, 63% had sought care for COVID-19. An estimated 70.1% had been vaccinated against COVID-19 and, among those not yet vaccinated, 32.5% intended to get vaccinated. Close to half (44.3%) of respondents had experienced crowdedness while in detention in the U.S. Socio-demographic (e.g. age, education, English fluency) and migration-related (e.g. type of detention facility and time in detention) variables were significantly associated with COVID-19 testing, infection, care seeking, and vaccination history. Age, English fluency, and length of detention were positively associated with testing and vaccination history, whereas detention in an immigration center and length of time living in the U.S. were negatively related to testing, infection, and vaccination history. Survey city and survey quarter also showed adjusted associations with testing, infection, and vaccination history, reflecting potential variations in access to services across geographic regions and over time as the pandemic unfolded. Conclusion: These findings are evidence of increased risk of COVID-19 infection, insufficient access to testing and treatment, and missed opportunities for vaccination among Mexican migrants detained in and deported from the U.S. Deportee receiving stations can be leveraged to reduce disparities in testing and vaccination for deported migrants. In addition, decarceration of migrants and other measures informed by public health principles must be implemented to reduce COVID-19 risk and increase access to prevention, diagnostic, and treatment services among this underserved population.

Does Acculturative Stress Influence Immigrant Sexual HIV Risk and HIV Testing Behavior? Evidence from a Survey of Male Mexican Migrants.

OBJECTIVE: Migration is a structural factor that increases HIV vulnerability. Acculturative stress represents a possible mechanism through which migration may negatively impact HIV risk. This study investigated socio-ecological factors associated with acculturative stress levels and examined the association between acculturative stress and HIV-related behavior among Mexican im/migrants. METHODOLOGY: We used data from a probability survey of Mexican im/migrants (N = 1383) conducted in Tijuana, Mexico, in 2009-2010. The sample included migrants returning to Mexico via deportation or voluntarily after a recent stay in the USA. Linear regression models were estimated to identify individual, migration, and contextual factors independently associated with overall acculturative stress levels. Logistic regression models were used to test for associations between acculturative stress, sexual HIV risk, and HIV testing history behavior. RESULTS: We found that levels of acculturative stress were significantly and independently related to socio-economic markers, acculturation level, legal residence status, and sexual minority status. The analyses also showed that acculturative stress was positively related to sexual HIV risk behavior and negatively related to recent HIV testing. CONCLUSIONS: The results underscore that both individual and environmental factors contribute to levels of acculturative stress among Mexican im/migrants. In turn, acculturative stress may exacerbate sexual HIV risk and impede testing among this im/migrant population. Targeted interventions to prevent and decrease acculturative stress represent a potential strategy to reduce sexual HIV risk behavior and promote HIV testing among this vulnerable population of im/migrants in the USA.

Understanding the Impact of Migration on HIV Risk: An Analysis of Mexican Migrants' Sexual Practices, Partners, and Contexts by Migration Phase.

HIV risk among Mexican migrants varies across migration phases (pre-departure, transit, destination, interception, and return), but there is limited knowledge about specific sexual behaviors, characteristics of sexual partners, and sexual contexts at different migration stages. To fill the gap, we used data from a cross-sectional population-based survey conducted in Tijuana, Mexico. Information on migration phase and last sexual encounter was collected from 1219 male migrants. Our findings suggest that compared to pre-departure migrants, repeat migrants returning from communities of origin were more likely to have sex with male partners, use substances before sex, and not use condoms; migrants in the transit phase in the Mexican border were more likely to have sex with casual partners and sex workers; and migrants in the interception phase were more likely to engage in anal sex and use substances before sex. Sexual behaviors, partners, and contexts vary significantly among migrants at different migration phases. Tailored HIV prevention programs targeting Mexican migrants need to be developed and implemented at all migration phases.

Risk behaviours for HIV infection among travelling Mexican migrants: The Mexico-US border as a contextual risk factor.

The Mexico-US border region is a transit point in the trajectory of Mexican migrants travelling to and from the USA and a final destination for domestic migrants from other regions in Mexico. This region also represents a high-risk environment that may increase risk for HIV among migrants and the communities they connect. We conducted a cross-sectional, population-based survey, in Tijuana, Mexico, and compared Mexican migrants with a recent stay on the Mexico-US border region (Border, n = 553) with migrants arriving at the border from Mexican sending communities (Northbound, n = 1077). After controlling for demographics and migration history, border migrants were more likely to perceive their risk for HIV infection as high in this region and regard this area as a liberal place for sexual behaviours compared to Northbound migrants reporting on their perceptions of the sending communities (p < .05). Male border migrants were more likely to engage in sex, and have unprotected sex, with female sex workers during their recent stay on the border compared to other contexts (rate ratio = 3.0 and 6.6, respectively, p < .05). Binational and intensified interventions targeting Mexican migrants should be deployed in the Mexican border region to address migration related HIV transmission in Mexico and the USA.

Moving Beyond Salmon Bias: Mexican Return Migration and Health Selection.

Despite having lower levels of education and limited access to health care services, Mexican immigrants report better health outcomes than U.S.-born individuals. Research suggests that the Mexican health advantage may be partially attributable to selective return migration among less healthy migrants-often referred to as "salmon bias." Our study takes advantage of a rare opportunity to observe the health status of Mexican-origin males as they cross the Mexican border. To assess whether unhealthy migrants are disproportionately represented among those who return, we use data from two California-based studies: the California Health Interview Survey; and the Migrante Study, a survey that samples Mexican migrants entering and leaving the United States through Tijuana. We pool these data sources to look for evidence of health-related return migration. Results provide mixed support for salmon bias. Although migrants who report health limitations and frequent stress are more likely to return, we find little evidence that chronic conditions and self-reported health are associated with higher probabilities of return. Results also provide some indication that limited health care access increases the likelihood of return among the least healthy. This study provides new theoretical considerations of return migration and further elucidates the relationship between health and migration decisions.

In-Country Migration and Risk Factors for HIV Acquisition among Pregnant Women in Tijuana, Mexico.

OBJECTIVE: To compare HIV prevalence and HIV acquisition risk behaviors between pregnant women residents and migrants. DESIGN: A cross-sectional study of pregnant women of unknown HIV status seeking care at Tijuana General Hospital, Mexico. METHODS: Pregnant women attending the labor and delivery unit or the prenatal clinic had a rapid HIV test drawn, with positive results confirmed by Western blot. Migrants were defined as women who had resided in Tijuana for less than 5 years. RESULTS: Between 2007 and 2008, a total of 3331 pregnant women consented to participate. The HIV seroprevalence did not differ between Tijuana residents (18 of 2502, 0.72%) and migrants (3 of 829, 0.36%, P = .32). In multivariate regression analyses, HIV acquisition risk behaviors included methamphetamine use (adjusted odds ratio [OR]: 6.03, 95% confidence interval [CI]: 2.3-15.8, P < .001) and first presentation at labor (adjusted OR: 5.0, 95% CI: 1.6-15.3, P = .005), adjusted for migrant status, age, and history of sexually transmitted infections. CONCLUSION: The overall HIV seroprevalence was 0.63% and did not differ between Tijuana residents and migrants.

Substance Use Across Different Phases of the Migration Process: A Survey of Mexican Migrants Flows.

This study examined the levels of substance use and changes across different migration stages, including pre-departure, travel, destination, and return, among Mexican migrants converging on the US-Mexico border. A cross-sectional survey was conducted in Tijuana, Mexico, between 2009 and 2010 among Mexican migrants returning from the US and those travelling from other Mexican regions. The overall prevalence of last 12-month at-risk drinking, illicit drug use, and current smoking, was 42.3, 17.7 and 31.4%, respectively. Compared to pre-departure migrants, males were at increased risk for illicit drug use at the destination and return stages. In contrast, females' alcohol consumption at the destination stage was lower than at pre-departure (p < 0.05). The level of smoking was stable across all stages for both genders. In the destination stage, undocumented migrants were more likely to use illicit drugs relative to their documented peers (p < 0.05). Binational interventions promoting substance use reduction are needed among this mobile population.

Seasonal influenza vaccination among Mexican migrants traveling through the Mexico-US border region.

OBJECTIVE: Mobile populations are at high risk for communicable diseases and can serve as a bridge between sending and receiving communities. The objective of this study is to determine the rates of, and factors associated with, seasonal influenza vaccination among Mexican migrants traveling through the US-Mexico border. METHODS: We used a 2013 cross-sectional population-based survey of adult mobile Mexican migrants traveling through the Mexico-US border region (N=2313; weighted N=652,500). We performed a multivariable logistic regression analysis to model the odds of receiving an influenza vaccination in the past year by sociodemographics, migration history, health status, and access to health care. RESULTS: The seasonal influenza vaccination rate in this population was 18.6%. Gender, health status, and health insurance were associated with the likelihood to receive an influenza vaccination. CONCLUSION: Overall, the rates of seasonal influenza vaccination in circular Mexican migrants are low compared to adults in Mexico and the US Efforts are needed to increase influenza vaccination among this highly mobile population, particularly in adults with chronic conditions.

Healthcare access among circular and undocumented Mexican migrants: results from a pilot survey on the Mexico-US border.

BACKGROUND: Temporary and unauthorized migrants may face unique obstacles to access health care services in the U.S. OBJECTIVE: This study estimated levels of health care access among Mexican migrants returning to Mexico from the U.S. and factors associated with access to health care, with emphasis on the role of modifiable, enabling factors. METHODS: We conducted a pilot probability health care survey of migrants in the border city of Tijuana, Mexico (N=186). RESULTS: Approximately 42% of migrants reported having used health care services in the U.S. during the past year. Only 38% had a usual source of care and approximately 11% went without needed medical care in the U.S. About 71% of migrants did not have health insurance in the U.S. Lack of health insurance and transportation limitations were significantly related to various access indicators. CONCLUSION: These results have implications for future policies and programs aimed to address modifiable health care access barriers faced by these vulnerable and underserved segments of the Mexican migrant population.