Expanding Measles Outbreak in Texas and New Mexico and Guidance for the Upcoming Travel Season

The Centers for Disease Control and Prevention (CDC) has issued a Health Alert Network (HAN) Health Advisory to notify clinicians, public health officials, and potential travelers about a measles outbreak in Texas and New Mexico and offer guidance for prevention and monitoring. As of March 7, 2025, Texas and New Mexico have reported 208 confirmed cases associated with this outbreak (198 in Texas and 10 in New Mexico). As a part of this outbreak, two deaths have been reported: one in Texas and one in New Mexico. More cases are expected as this outbreak continues to expand rapidly.

Consider measles as a diagnosis in anyone with fever (≥101°F or 38.3°C) and a generalized maculopapular rash with cough, coryza, or conjunctivitis who has recently traveled, either internationally or domestically to a state with measles cases. When considering measles:

• Isolate: Do not allow patients with suspected measles to remain in the waiting room or other common areas of a healthcare facility; isolate patients with suspected measles immediately, ideally in a single-patient airborne infection isolation room (AIIR) if available, or in a private room with a closed door until an AIIR is available.
• Protect healthcare workers: Healthcare providers should be adequately protected against measles and should adhere to standard and airborne precautions when evaluating suspect cases, regardless of their vaccination status. Healthcare providers without evidence of immunity should be excluded from work from day 5 after the first exposure until day 21 following their last exposure. Offer testing outside of facilities to avoid transmission in healthcare settings. Call ahead to ensure immediate isolation for patients referred to hospitals for a higher level of care.
• Report: Immediately report suspect or confirmed cases to Central District Health at 208-327-8625 or the Idaho Division of Public Health’s Epidemiology Section at 208-334-5939. Any suspected case of measles should be reported to ensure rapid testing and investigation.
• Test: The Idaho Bureau of Laboratories (IBL) accepts nasal, nasopharyngeal, or throat swabs for reverse transcription polymerase chain reaction (RT-PCR) testing. Blood specimens for IgM serology will be referred to an outside testing laboratory. Samples for RT-PCR should be collected using synthetic swabs and placed into 1-3 mL of Viral Transport Medium (VTM) or Universal Transport Medium (UTM). The specimens must be received at the laboratory within 72 hours at a temperature of 2-8°C. Samples should be frozen at ≤ -20°C and shipped on dry ice If transport is expected to exceed >72 hours post collection. Specimens collected on calcium alginate or wooden shaft swabs, or those submitted dry (without VTM/UTM) will be rejected. Additionally, any sample that exceeds the temperature requirements will not be tested. Detection of measles RNA is most successful when specimens are collected 1 to 3 days following onset of rash. Detection of measles RNA by RT-PCR may be successful as late as 10−14 days after rash onset. In addition to the sample specifics (type of virological specimen, transport media, and date collected), the following information is helpful to include on the specimen submission form: MMR vaccination history & dates (if known), clinical signs and symptoms, patient’s date of birth, rash onset date, any previous test results, and recent travel/exposure history.