Background:

The incursion of Chikungunya (CHIKV) and Zika (ZIKV) viruses into Latin America and the Caribbean (LAC) after 2013 created complex epidemics with high attack rates, severe complications, and persistent transmission. While individual aspects have been studied, a synthesized understanding of the interacting viral, ecological, and social drivers sustaining these arboviruses in the region remains lacking.

Objectives:

To critically synthesize evidence on the incursion and establishment of CHIKV and ZIKV in LAC through an integrative framework examining the interaction between viral adaptation and structural vulnerabilities.

Design:

Systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines.

Data sources and methods:

We systematically searched PubMed, EMBASE, Scopus, and LILACS, supplemented by gray literature from PAHO, WHO, and CDC, for studies published between January 2013 and December 2025. Eligible studies included observational studies, surveillance data analyses, outbreak reports, modeling studies, and genomic epidemiology focusing on CHIKV/ZIKV incursion, transmission dynamics, establishment, burden, or socio-ecological determinants in LAC populations. Two independent reviewers performed screening, data extraction, and quality assessment using Joanna Briggs Institute tools. A critical narrative synthesis was conducted using the novel Structural Vulnerability and Pathogen Plasticity framework.

Results:

Eighteen studies met inclusion criteria. Pathogen plasticity—evidenced by multiple independent introductions, genetic variability, and cryptic transmission (e.g., an unreported 2017 ZIKV outbreak in Cuba uncovered through travel-genomic surveillance)—exploited profound structural vulnerabilities. These included weak surveillance systems (detection rates as low as 1%–6% for ZIKV), inadequate water and sanitation infrastructure driving a knowledge-practice gap (75.2% knowledge vs 30.7% adequate practices), and socioeconomic inequities that concentrated disease burden. Severe impacts were disproportionately borne by marginalized groups, quantified by a 9.0-year disparity in average Years of Life Lost between Black (22.0 years) and White (13.0 years) Brazilians with Chikungunya. Despite the epidemic’s waning, 58% of analyzed locations remain at high risk for future ZIKV outbreaks due to discrepancies between environmental suitability and population immunity. A critical geographical evidence bias was identified: 13 studies (72%) were conducted in Latin America (primarily Brazil and Colombia), while only 5 (28%) focused on the Caribbean region, limiting generalizability to smaller island states.

Conclusion:

The establishment of CHIKV and ZIKV in LAC represents a biosocial process wherein adaptable pathogens exploit and reinforce structural inequities. Achieving durable resilience requires integrated surveillance platforms that monitor both pathogens and social vulnerabilities, coupled with fundamental investment in water, sanitation, waste management, and equitable healthcare infrastructure to interrupt the vicious cycle of arboviral emergence.

Trial registration:

PROSPERO CRD420251242134 (available at: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251242134).

Plain language summary

Why Chikungunya and Zika Hit Hardest in Poor Neighborhoods and What Must Change to Stop Them

This review examined how two mosquito-borne diseases (Chikungunya and Zika) spread and became established in Latin America and the Caribbean after 2013. We studied not only the viruses themselves but also how they interacted with social and environmental conditions. Our key finding is that the spread and impact of these diseases were heavily shaped by social inequality. The viruses spread fastest and caused the most severe harm in areas with weak infrastructure: neighborhoods with unreliable tap water, poor waste collection, and limited healthcare access. For example, people without reliable water are forced to store it in containers, which become breeding sites for mosquitoes. We also found that the burden of severe illness and death fell disproportionately on poorer communities and marginalized racial groups. In Brazil, Black individuals lost an average of nine more years of life to Chikungunya than White individuals. Although the major Zika outbreak has faded, our analysis shows that over half of the locations studied remain at high risk for future outbreaks, because immunity in the population is uneven and poorly understood. The central message is that controlling diseases like Chikungunya and Zika requires more than vaccines, insecticides, or public health advisories. Lasting protection depends on fixing the foundation: investing in reliable water systems, regular waste collection, equitable healthcare, and stronger community-focused disease monitoring. Only by addressing these root social and environmental causes can we break the cycle of outbreaks and build healthier, more resilient communities.

Graphical Abstract