Texas health officials declared an end to the state’s massive measles outbreak Monday, while New Mexico continues to battle ongoing transmission with more than 100 cases reported statewide.
The Texas Department of State Health Services announced Monday it had been more than 42 days since a new measles case was confirmed in any county with evidence of ongoing transmission. The 42-day milestone is significant because public health professionals consider an outbreak over after that period—double measles’ maximum incubation time of 21 days.
“It has been more than 42 days since a new case was reported in any of the counties that previously showed evidence of ongoing transmission,” the Texas Department of State Health Services said in announcing the end of the outbreak that ultimately infected 762 people.
Meanwhile, New Mexico’s outbreak continues with cases still being reported as recently as August 10 in Santa Fe County, according to New Mexico Department of Health data. The state has confirmed 100 cases across nine counties, with seven hospitalizations and one death.
However, five New Mexico counties have already passed their own 42-day milestones and could potentially be considered past their outbreak phase.
Chaves County’s last case was April 5, Eddy County’s was April 20, Dona Ana County reported its final case April 24, Curry County’s was May 3, and Sandoval County hasn’t seen a new case since May 19—all well beyond the July 7 cutoff date that would mark 42 days before today.
The contrasting situations highlight different stages of the same regional outbreak that began in late January. Texas bore the brunt with 762 cases, 99 hospitalizations, and two deaths in school-aged children. New Mexico’s cases have been concentrated in counties bordering Texas, particularly Lea County with 67 cases.
Both states mounted significant vaccination campaigns in response. New Mexico health officials report nearly 49,000 residents received measles, mumps and rubella (MMR) vaccines between February 1 and August 13—a substantial increase compared to the same period in 2024.
Dr. Miranda Duran, the Chief Medical Officer at the New Mexico Department of Health credits vaccination with blunting the impact of the outbreak. “We remain grateful New Mexicans continue to get their measles vaccination in an effort to slow the spread of the virus,” she said in a statement last week. “Without that, measles outbreaks are more likely to last longer and grow over time.”
New Mexico counties with the most recent cases—and still within the 42-day window—include Santa Fe County (August 10), Luna County (June 27), San Juan County (May 27), and Lea County (May 27). Only these four counties remain within the active outbreak timeframe based on the 42-day standard.