Summary and Action Items

1. Provide awareness about two additional measles case confirmed in Illinois in 2025.
2. Identify public exposure locations where persons infectious with measles visited. Providers should have increased suspicion for measles in any patients with symptoms of measles who also name these locations as places attended in the 21 days before symptom onset.
3. Remind providers to immediately report to public health any suspect measles cases at the time it is first suspected and prior to clinical testing, and to take appropriate steps for diagnosis and infection control and isolation.
4. Review current vaccine and isolation/quarantine guidance for settings like schools, community members and healthcare personnel.
5. Review vaccination records prior to international travel due to global measles outbreaks and domestic travel to regions in outbreak. Provide needed vaccinations as per recommendations.
6. Recommend that healthcare providers and facilities take steps to ensure that their patient populations are up to date on their measles vaccines.
7. Remind health-care facilities that all persons who work in their facilities should have presumptive evidence of immunity to measles.
8. Healthcare clinics and hospitals should review and implement preparedness measures to reduce healthcare exposures.

Background

The first Illinois measles case in Marion, Illinois was confirmed on April 23, 2025. The patient was an unvaccinated adult. Contacts without proof of immunity are being quarantined. No secondary cases have been identified to date.

Late yesterday, IDPH confirmed two additional cases. Both cases are adults and were not hospitalized. One case is from Chicago with international travel and one prior vaccination dose. For anyone 12 months of age or older without evidence of immunity who plans to travel internationally, 2 doses are recommended at least 2 weeks prior to travel. The second case is from suburban Cook County who presented to a local hospital and was quickly isolated. A public health investigation is underway to identify locations where these patients were while infectious. Persons exposed will be contacted to determine immune status. Those susceptible will be monitored for symptoms and asked to quarantine. At this time, no evidence suggests a link between these three cases; we do not currently consider this an outbreak.

Exposure Locations:

Providers should consider any patients with measles symptoms, including prodromal symptoms of fever, cough, conjunctivitis or coryza, and who frequented one of the following locations as highly suspicious for measles.

Southern Illinois Locations:

There are eight known exposure locations. We unfortunately do not have known dates and times when the case was at most of these facilities so providers should assess from April 7 to April 15, 2025,

1. The clinic where the person sought care. Anyone exposed at this facility is being notified directly.
2. Don Sol Restaurant in Marion, Illinois
3. Legacy Fitness in Marion, Illinois
4. Walmart in Marion, Illinois
5. Kroger in Marion, Illinois
6. Wonder Wash Laundry in Marion, Illinois
7. Easy Coin Laundry in Marion, Illinois
8. Small Star Laundry in Marion, Illinois

As of April 17, 2025, there have been 884 confirmed cases reported in the U.S. in 30 states. In Canada, there have been 1,069 measles cases. Globally, measles outbreaks are occurring; therefore, unvaccinated travelers returning to the U.S. are at an increased risk and we are seeking to make providers aware of the steps to take to prevent and manage measles.

Diagnosis

Healthcare providers and facilities should be alert for possible measles cases, especially in people who could have traveled to areas where cases are occurring. The measles prodrome usually lasts for two to four days but may persist for as long as eight days. Symptoms typically include fever and malaise, followed by conjunctivitis, coryza, and cough. The prodromal symptoms typically intensify a few days before the rash appears. The measles rash is typically maculopapular and starts on the head or hairline and spreads down the body. Providers should also be suspicious in those that are ill and had recent travel to countries or U.S. counties where there are measles (See attached resources for healthcare settings).

If you suspect measles, immediately place the patient in airborne isolation, and notify infection control. Non-immune (see below in Prevention section for definition of measles immunity) contacts of measles cases can be vaccinated within three days of exposure, or in some special situations given immune globulin within six days of exposure to prevent or ameliorate the illness. Providers should consider administering a second MMR to contacts over 12 months of age who were previously vaccinated with only one dose, as long as there are 28 or more days since the last dose of live vaccine.

If you suspect measles, immediately place the patient in airborne isolation, and notify your infection control staff or clinic point person for measles response.

Reporting

Healthcare providers and facilities need to immediately (within 3 hours) report suspect measles cases to their local health department, or to IDPH. This means reporting at earliest clinical suspicion and at the point testing is requested; do not wait on laboratory confirmation or rely on laboratory reporting. Delays in reporting might result in avoidable exposures as well as missed prophylaxis options for non-immune close contacts. If unable to reach their local health department after-hours, providers can call IEMA-OHS at 217-782-7860 to reach someone at IDPH.

Testing

IDPH laboratory provides PCR testing of throat or nasopharyngeal swabs for measles at no cost to the patient or provider. It is recommended that testing of suspect measles cases by PCR be conducted at the state lab as testing at commercial laboratories can delay results by multiple days which then delays a public health response if the case is positive (see instructions for submission). Measles could be tested using measles-specific IgM antibody in serum via commercial lab and measles RNA by real-time polymerase chain reaction (RT-PCR) in a respiratory specimen. Healthcare providers should obtain both a serum sample and a throat swab (or nasopharyngeal swab) from patients suspected to have measles. Swabs should be placed in viral transport media (VTM). (see IDPH Measles Testing Flowchart)

Transmission and Infection Control

The measles virus spreads easily through contact with respiratory droplets and via airborne spread. The virus can remain airborne for up to two hours after an infectious person leaves an area. Measles is highly contagious. Up to 90% of susceptible people who have contact with someone with measles will develop measles. Patients are contagious starting four days before through four days after rash onset (with rash onset date being day zero). Anyone with measles should isolate during that time except to seek necessary medical care. If medical care is required, patients should call to notify the facility of their diagnosis in advance.

Health care personnel should follow CDC’s Interim Guidelines on Measles Infection Control in Healthcare settings when dealing with potential measles cases and determining degree of exposure (Appendix A in the guidance document).

Prevention and Post-Exposure Prophylaxis

Vaccination is the best protection against measles. Those traveling internationally, especially to countries where there are known measles outbreaks, should ensure they are up to date on all of their vaccinations. Those traveling within the U.S. to areas with measles outbreaks should also ensure they are up to date on their measles vaccinations. MMR is a measles containing vaccine that is highly effective in providing measles immunity. It is recommended that facilities keep records of their employees’ vaccinations to facilitate a prompt response to a measles exposure, should one occur.

Post-exposure prophylaxis: Non-immune (see below for definition of measles immunity) contacts of measles cases can be vaccinated within three days of exposure (if over six months and no contraindications), or in some special situations given immune globulin within six days of exposure to prevent or ameliorate the illness.

In settings of community transmission of measles or outbreaks, providers should consider administering a second MMR to children over 12 months of age who were previously vaccinated with only one dose, as long as there are 28 or more days since the last dose of live vaccine.

There are no recommendations at present for receiving a third MMR dose during outbreak settings. Health care providers should ensure all patients are up to date on MMR vaccine.

1. Children: Continue to give MMR vaccine at 12-15 months of age, and 4-6 years of age.
2. Adults (non-high risk): Adults born during or after 1957 should have at least one dose of the MMR vaccine, or presumptive evidence of immunity.

Additional recommendations for certain high-risk populations include:

1. Students at post-high school educational institutions: Should have two doses of MMR, spaced out by at least 28 days, or evidence of immunity.
2. For individuals who are traveling internationally.
   1. Infants 6 through 11 months of age should be given one dose of MMR vaccine. These children will still need their regularly scheduled MMR doses.
   2. Individuals 12 months of age or older should have two doses of MMR, separated by at least 28 days.
3. Healthcare personnel (HCP) (all paid and unpaid persons working in health-care settings): Should have presumptive evidence of immunity to measles.

Presumptive evidence of immunity is defined as:

1. written documentation of vaccination with 2 doses of live measles or MMR vaccine administered at least 28 days apart,
2. laboratory evidence of immunity (positive serum IgG),
3. laboratory confirmation of disease, or
4. birth before 1957. (According to CDC, although birth before 1957 is considered as presumptive evidence of immunity, for unvaccinated HCP born before 1957 that lack laboratory evidence of measles immunity or laboratory confirmation of disease, health care facilities should consider vaccinating personnel with two doses of MMR vaccine at the appropriate interval.)
5. healthcare personnel who are non-immune should be excluded from work from Day 5 of first day of exposure till day 21 from last (not first) day of exposure.

Additional Resources & References:

• CDC Measles
• CDC: Measles Vaccination Information
• IDPH: Measles Testing Instructions
• CDC: Plan for Travel
• Infection Control Guidelines
• CDC Questions about Measles

Target Audience: Healthcare Providers, Hospital Infection Preventionists, Emergency Departments, Local Health Departments

Date Issued: April 30, 2025