New papers spotlight bovine TB surveillance gaps in Latin America

Bovine tuberculosis is back in focus as two recent papers frame the disease not as a solved livestock problem, but as a continuing One Health gap in emerging economies. In a March 11, 2026 review in Veterinary Sciences, researchers from Mexico describe bovine TB as a neglected zoonotic disease in Mexico and Latin America, pointing to persistent cattle infection, human exposure through unpasteurized dairy, and weak coordination across veterinary, food-safety, and public health systems. A separate Preventive Veterinary Medicine meta-analysis published in late March 2026 reaches a complementary conclusion: prevalence estimates for Mycobacterium bovis in dairy cattle and humans are highly sensitive to the diagnostic methods and herd-level factors used in each study. (mdpi.com)

That framing matters because the region has not stood still. Mexico has operated a national bovine tuberculosis campaign since the 1990s, and U.S.-Mexico animal health cooperation has long tied bovine TB control to cattle movement and export standards. SENASICA has previously said that large portions of Mexican territory have reached low-prevalence or eradication-phase status, and APHIS notes that the binational committee process helped shape Mexico’s national campaign. But the new review argues that national progress can coexist with important local blind spots, especially in dairy regions, rural communities, and areas where diagnostic capacity and interagency reporting remain limited. (aphis.usda.gov)

The review’s core argument is that bovine TB remains underestimated partly because the disease is difficult to detect well in the field. The authors describe shortcomings in commonly used tests across different stages of infection and call for broader use of molecular epidemiology tools, including genotyping and whole-genome sequencing, to better map transmission among cattle, wildlife, and people. That aligns with WOAH guidance, which treats mammalian tuberculosis as a standards-based surveillance and trade issue, and with older genomic work from Mexico showing how strain typing can illuminate transmission patterns that routine surveillance may miss. (mdpi.com)

The second paper sharpens the diagnostic point. According to the Preventive Veterinary Medicine abstract, global and regional prevalence estimates from 2020 to 2024 were strongly shaped by diagnostic method, production system, regional context, and herd-level determinants. In other words, prevalence numbers are not interchangeable. For veterinarians and animal health officials, that means surveillance programs built around a single test or a single pooled estimate may miss meaningful local variation. Supporting evidence from earlier literature also shows measurable M. bovis presence in milk and bulk-tank milk in some settings, reinforcing the public health importance of dairy-chain surveillance where pasteurization is inconsistent. (sciencedirect.com)

Expert and institutional commentary outside these two papers points in the same direction. WHO’s zoonotic TB roadmap has long called for coordinated action across human and animal health sectors, and a WHO/TDR update published in March 2026 said implementation of that roadmap has remained limited in many countries, despite some encouraging signs of collaboration. CDC, meanwhile, continues to emphasize that human M. bovis infection most often follows consumption of contaminated, unpasteurized dairy products, and U.S. epidemiologic studies have repeatedly linked many cases to cheeses or other dairy products originating in Mexico. (who.int)

Why it matters: For veterinary professionals, this is a reminder that bovine TB surveillance isn't just about meeting eradication benchmarks. It's also about interpreting test results carefully, recognizing where official low-prevalence status may not capture farm-level risk, and understanding the human health implications for dairy workers, veterinarians, abattoir personnel, and pet parents consuming informal dairy products in endemic communities. The practical takeaway is that case finding, traceability, milk hygiene messaging, and collaboration with public health counterparts may matter as much as the formal testing protocol itself in higher-risk settings. (sciencedirect.com)

What to watch: The next question is whether this renewed attention translates into better regional data. Watch for follow-on studies using molecular tools in Mexico and Latin America, updates to national surveillance metrics from SENASICA and trading partners, and more explicit One Health reporting that links cattle findings with human TB surveillance rather than treating them as separate systems. If that happens, veterinary teams may get more actionable risk maps and more realistic prevalence estimates than the region has had to date. (mdpi.com)