Over 44 million immigrants live in the US, and nearly half (44%) are Latinx. Historically, US immigrants have been reluctant to engage in public health infectious disease control measures such as testing, contact tracing, vaccination, and prompt medical care. Yet the public's cooperation is essential if infectious disease control measures are to succeed, especially among a marginalized subpopulation such as Latinx immigrants. Increasingly, commentators have noted the potential for immigration laws and concerns to deter immigrants from engaging in communicable disease control measures. This may be especially true for conditions of immigration significance that can be shrouded with negative legal and social connotations. Findings from our studies of Latinx immigrants' immigration concerns related to largely individual-level public health interventions--specifically use of services for HIV testing, substance use disorders and intimate partner violence--confirms commentators' concerns, (1R01MD011573 PI: Galletly) and our preliminary study of Latinx immigrants' legal concerns relevant to COVID testing, contact tracing, and treatment (R01MH091875-S1 PI: Galletly) strongly suggest this influence applies to large scale, population-level disease control efforts as well. The proposed study will extend our research on the influence of actual, and importantly, perceived, immigration-related laws on Latinx immigrants' use of HIV prevention services to examine the influence of these on Latinx immigrants' ability and willingness to engage in population-level disease control efforts where government direction is more prominent. Specifically, we propose to leverage the recent increased public awareness of public health disease control measures to examine the influence of actual and perceived immigration-related laws on Latinx immigrants' willingness to engage in testing, contact tracing, and treatment as recommended by public health representatives when indicated for tuberculosis, hepatitis C, and COVID-19. Our interdisciplinary team of researchers, attorneys, community health workers and public health representatives will collaborate on this mixed-methods, community-engaged study. Formative legal and qualitative inquiry to identify the nature, extent, and influence of immigration-related law concerns will inform the development of a de novo immigration law concerns measure to be administered to 1200 Latinx immigrants living in two US regions with diverse immigration environments. Participants with diverse documentation statuses, countries of origin, time spent in the US, and residence in rural/agricultural and urban settings will be purposively sampled to further inform analysis of these complex behaviors. Identifying actual and perceived legal barriers to immigrants' engagement in disease control measures can only be useful if results are transferred to practice. We will explore, with public health personnel, how best to support the rapid transfer of findin...