CDC issued a HAN Health Advisory in response to recent NWS animal cases reported in Tamaulipas, Mexico, across the border from Texas. As of January 20, 2026, no NWS infestations associated with this outbreak have been identified in people or animals in the United States. Because NWS can spread geographically, this advisory is intended to raise awareness and reinforce U.S. preparedness. It summarizes CDC recommendations for clinicians and health departments on case identification and reporting, specimen collection, diagnosis, and treatment, along with practical guidance for the public.
View the HAN Health Advisory here: HAN Health Advisory for NWS Outbreak in Northern Mexico