The Texas Department of State Health Services (DSHS) is reporting a significant increase in cases of pertussis, or whooping cough, in 2025. According to provisional data, Texas has had more than 3,500 reported pertussis cases through October this year, roughly four times the number reported for the same period last year. This is the second consecutive year that Texas is experiencing high year-over-year increases in reported pertussis cases and the second consecutive year DSHS has issued a health alert (see Increase in Pertussis Cases, Nov. 12, 2024).