Measles in the United States, Recommendations for Health Care Providers
Summary
In 2025, there were more measles cases reported in the United States than in any one year since 1991. Three months into 2026, already more than 65% of the total number of cases in 2025 have been reported. Most cases have been associated with outbreaks, and a very small proportion of the cases were in international visitors to the U.S.
With large ongoing outbreaks occurring in the U.S. as well as internationally in Mexico and Canada, health care providers should consider measles as a potential diagnosis for individuals of all ages with a febrile rash with cough, coryza, or conjunctivitis, especially if they have had recent known exposure or travel to an affected area. To prevent spread, it is critical that health care providers promptly recognize, isolate and test patients who might have measles. Health care providers must report suspected and confirmed cases of measles to the relevant public health authority within 24 hours of identification. On March 7, 2025, CDC released a Health Alert Network (HAN) Health Advisory regarding measles and the upcoming travel season. The Nevada Division of Public and Behavioral Health (DPBH) wishes to emphasize some of the guidance in this HAN.
Background
Measles is a highly contagious viral illness and can cause severe health complications, including pneumonia, encephalitis and death, especially in unvaccinated populations. About 9 in 10 people without immunity (via vaccination or previous infection) who come into close contact with someone with measles will get it.1 The virus is transmitted through direct contact with infectious droplets or by airborne spread when an infectious person breathes, coughs or sneezes, and can remain infectious in the air and on surfaces for up to 2 hours.1
Measles typically begins with a prodrome of fever, cough, coryza and conjunctivitis, lasting 2 to 4 days before rash onset. The incubation period for measles from exposure to fever is usually about 7-10 days, while rash typically develops 10-14 days after initial exposure with a range of 7–21 days. Individuals infected with measles are contagious from 4 days before the rash starts through 4 days afterward (the day of rash onset is considered day zero).1
Measles is almost entirely preventable through vaccination. MMR vaccines are safe and highly effective, with two doses being 97% effective against measles (one dose is 93% effective).
Nevada had two confirmed measles cases in 2025, the state’s first cases since 2018. Data on vaccination coverage among the students in Nevada schools may be accessed via the state’s School Screening dashboard. In 2025, 93% of U.S. measles cases were not vaccinated or had unknown vaccination status.2 For the most up-to-date information about case counts and affected states see the CDC’s website.
Recommendations for Health Care Providers
Ensure adequate vaccination to protect patients and prevent spread
Health care providers should offer MMR (measles, mumps, rubella) vaccine in accordance with CDC recommendations. CDC recommends MMR vaccine for all children (starting at age 12-15 months) and for adults without presumptive evidence of immunity.3 For infants ages 6-11 months living in or visiting areas with active spread, consult CDC guidance or your local health authority on whether administering a bonus dose is appropriate. Additional resources are available through the Nevada State Immunization Program.
Recognize measles and respond quickly
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, especially in areas with ongoing outbreaks, or individuals with known exposure to measles. Check CDC for global travel health notices.
If measles is suspected:
- Isolate: Do not allow patients with suspected measles into common areas of a health care 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.
- Call ahead to ensure immediate isolation for patients referred to hospitals for a higher level of care. Always use the DPBH Interfacility Transfer Form when transferring patients with infectious diseases, including measles, to another facility. If releasing a patient to go home, advise the patient to isolate through the 4th day after rash onset (with the day of rash onset as day 0).
- Educate patients about the importance of calling ahead before arriving at a healthcare facility if they suspect they may have measles.
- Protect yourself: Health care providers should adhere to standard and airborne precautions when evaluating suspect cases, regardless of their vaccination status.
- Exposed health care providers (whether symptomatic or asymptomatic) without evidence of presumptive immunity should be excluded from work from day 5 after their first exposure until day 21 following their last exposure.4
- Notify: Within 24 hours, notify the local health authority for your area about any suspected or confirmed cases of measles (per NAC 441A.225) as they can help you arrange testing. If needed, they will work with you to identify potentially exposed contacts in your facility and notify them.
| Local Health Authority | County | Phone Number to Report |
| Carson City Health and Human Services (CCHHS) | Carson City, Douglas, and Lyon | (775) 434-1690 (M-F 8 a.m. – 5 p.m.) (775) 887-2190 (after hours) |
| Central Nevada Health District (CNHD) | Churchill, Mineral, Eureka, and Pershing | (775) 866-7535 (24 hours) |
| Northern Nevada Public Health (NNPH, formerly WCHD) | Washoe | (775) 328-2447 (24 hours) |
| Southern Nevada Health District (SNHD) | Clark | (702) 759-1300 (24 hours) |
| Nevada Division of Public and Behavioral Health (DPBH) Office of State Epidemiology (OSE) | All other counties | (775) 400-0333 (24 hours) |
- Test: Follow CDC’s testing recommendations and collect either a nasopharyngeal swab or throat (OP) swab for reverse transcription polymerase chain reaction (RT-PCR) and a blood specimen for serology (detection of IgM and IgG) from all patients with suspected measles.5 Collecting a urine specimen in addition to an NP/OP swab may improve testing sensitivity.
- Measles PCR, IgG, and IgM can be performed at the Nevada State Public Health Laboratory with coordination through the local health authority or commercial laboratories such as LabCorp and Quest Diagnostics.
- Rarely, individuals recently vaccinated against measles may develop symptoms that can mimic a measles infection, including fever and a mild rash. If an individual has been vaccinated with the MMR vaccine in the past 21 days and has not recently traveled or had contact with a confirmed/suspected measles case, they do not need to be tested.
- Manage: There is no specific antiviral therapy for measles, so treatment is supportive.
- Exposed close contacts without evidence of immunity should be offered post-exposure prophylaxis (PEP) as soon as possible after exposure. This should be done in coordination with the local health authority and DPBH. The options for PEP are based on elapsed time of exposure or medical contraindications to vaccination but may include MMR vaccine (within 72 hours of exposure) or immunoglobulin (IG) (within 6 days of exposure). MMR vaccine and IG should not be administered simultaneously, as this invalidates the vaccine.6 Vitamin A should only be administered under the supervision of a healthcare provider and is not a substitute for vaccination as it does not protect against measles.1,7 Overuse of Vitamin A can lead to toxicity and cause damage to the liver, bones, central nervous system, and skin. Pregnant women should avoid taking high levels of vitamin A as it has been linked to severe birth defects.
- Nevadans can visit the Nevada WebIZ public access portal to access and print vaccination records for themselves or a legal dependent.
Additional Resources
Routine MMR Vaccination Recommendations: For Providers | CDC
Measles – Nevada Public Health | The Office of State Epidemiology (nvose.org)
Questions
For updated guidance, review the Division of Public and Behavioral Health Technical Bulletin web page regularly. Email DBPHEpi@health.nv.gov for other questions regarding measles.