Federal health officials have, for the first time, linked the measles outbreak that began in Texas to an ongoing cluster in Utah and Arizona using genetic sequencing. This connection could cost the United States its World Health Organization “elimination status” if the same strain continues to transmit through the end of January, according to The New York Times.
The genetic sequence identified as “9171” first took hold on Jan. 20 in Gaines County, Texas, and has continued “across multiple jurisdictions,” Dr. David Sugerman, who leads the Centers for Disease Control and Prevention’s (CDC) measles response, said on a multiagency call, The Times reported.
Download the SAN app today to stay up-to-date with Unbiased. Straight Facts™.
Point phone camera here
Countries lose elimination status after 12 months of sustained transmission of the same measles virus. The United States has held that designation for 25 years; Canada lost its status last week after a separate outbreak persisted for more than a year, the Times reported. Loss of status would be “deeply embarrassing” for a high-resource country, experts told the Times, even if it may not trigger immediate travel restrictions.
What the latest numbers show
According to the CDC, 2025 has seen a record 45 measles outbreaks nationwide. As of Nov. 18, there were 1,753 confirmed cases, with the vast majority — roughly 92% — occurring in people who were unvaccinated or had an unknown vaccination status, The New York Times reported.
The largest active cluster is in Utah and Arizona, where more than 180 cases have been reported. Officials note that about 7% of those infections were tied to large gatherings like festivals, though the origin of nearly a quarter of the cases remains unknown.
How the Southwest outbreak shaped the year
The surge in cases began with just two infections in Gaines County, Texas, in January. From there, the virus spread across the region, eventually infecting at least 762 people in Texas alone. The outbreak, which state officials declared over on Aug. 18, resulted in the deaths of two unvaccinated children.
Neighboring New Mexico also faced a significant outbreak, which lasted until September, resulting in one adult death and seven hospitalizations among 100 confirmed cases across nine counties, according to The Times.
What officials are doing now
Despite the surge, Sugerman describes the overall national risk as “low,” though he warns that close-knit communities with low vaccination rates remain vulnerable. The Times reports that local efforts to boost vaccination rates in Arizona and Utah have had limited success. Meanwhile, federal officials are collaborating with counterparts in Mexico and Canada to track the virus through genetic sequencing and share best practices.
If the 9171 lineage continues to transmit across jurisdictions into late January, the one-year mark from the Texas onset, the U.S. could lose WHO measles elimination status, the Times reported.
