Fact Check: "Illegal immigrants are causing the latest measles outbreak"
What We Know
The claim that "illegal immigrants are causing the latest measles outbreak" has emerged in the context of recent measles outbreaks in the United States, particularly one associated with a migrant shelter in Chicago. According to a report by the CDC, 57 measles cases were linked to a migrant shelter in Chicago, where many residents were unvaccinated, primarily due to low vaccination rates among migrants from Venezuela, a country experiencing a decline in routine childhood immunization coverage (source-1).
The outbreak was characterized by a rapid spread of the virus in a congregate living situation, where vaccination coverage was notably low. The Chicago Department of Public Health (CDPH) implemented a mass vaccination campaign that successfully increased vaccination rates among shelter residents (source-1).
In addition, a broader measles outbreak has been reported in Texas and New Mexico, with over 250 cases linked to various communities, including some unvaccinated individuals (source-3). However, health officials have stated that they have not been able to pinpoint the source of this outbreak, and there is no direct evidence linking it to illegal immigration (source-7).
Analysis
The evidence surrounding the claim is mixed. The outbreak in Chicago is indeed associated with a migrant shelter where many residents were unvaccinated, which aligns with the assertion that illegal immigrants may be involved in the outbreak. However, it is crucial to note that the outbreak was primarily due to low vaccination rates rather than the mere presence of illegal immigrants. The CDC report emphasizes that the majority of cases were among unvaccinated individuals, not necessarily indicating that the immigrants themselves were the cause of the outbreak (source-1).
Moreover, the broader outbreak in Texas and New Mexico has been reported without a clear link to immigration. Health officials have stated that the source of the outbreak is unknown, and they have not found evidence connecting it to illegal immigration (source-6, source-8). This suggests that while there are instances where unvaccinated migrants have been involved in outbreaks, attributing the outbreaks solely to illegal immigration lacks sufficient evidence.
The sources used in this analysis are credible, primarily from public health institutions like the CDC and reputable news outlets. However, some sources that support the claim may exhibit bias, particularly those that frame the issue within a political context regarding immigration policies (source-6).
Conclusion
The claim that "illegal immigrants are causing the latest measles outbreak" is Partially True. While there is a documented outbreak linked to a migrant shelter in Chicago, the primary driver of the outbreak appears to be low vaccination rates rather than the presence of illegal immigrants per se. Furthermore, the broader outbreaks in Texas and New Mexico have not been directly connected to immigration. Thus, while there are elements of truth in the claim, it oversimplifies a complex public health issue.
Sources
- Measles Outbreak Associated with a Migrant Shelter ... (https://www.cdc.gov/mmwr/volumes/73/wr/mm7319a1.htm)
- Expanding Measles Outbreak in the United States and ... (https://www.cdc.gov/han/php/notices/han00522.html)
- The Measles Outbreak in West Texas and Beyond (https://publichealth.jhu.edu/2025/the-measles-outbreak-in-west-texas-and-beyond)
- Measles Outbreak in Gaines County, Texas (https://www.dshs.texas.gov/news-alerts/measles-outbreak-gaines-county-texas)
- Measles - United States of America (https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON561)
- Posts Make Unsupported Claims About Origin of Texas Measles Outbreak (https://www.factcheck.org/2025/03/posts-make-unsupported-claims-about-origin-of-texas-measles-outbreak/)
- Is there evidence linking the Texas measles outbreak to a surge in illegal immigration? (https://azcir.org/news/2025/03/21/is-there-evidence-linking-the-texas-measles-outbreak-to-a-surge-in-illegal-immigration/)
- Ask PolitiFact: Is Texas measles outbreak linked to 'border'? No ... (https://www.politifact.com/article/2025/mar/07/ask-politifact-did-immigration-cause-texas-measles/)
