Health officials in Missouri and Illinois are investigating potential measles exposures at St. Louis Lambert International Airport and a church in Collinsville, Illinois. The cases stem from a single individual traveling from out of state.
The Missouri Department of Health and Senior Services reported that the individual, a resident of another state, passed through the airport on . Specifically, the exposure occurred in Terminal 2, the baggage claim area and while utilizing Parking Spot shuttle No. 3 between and . Those who were on the affected flight are being directly contacted by health authorities.
The Illinois Department of Public Health (IDPH) has identified an additional potential exposure site: Good Shepherd Lutheran Church in Collinsville. Individuals who attended services at the church between and on , may have been exposed. The church has been notified and is cooperating with health officials to inform its members.
“Measles is not just a routine childhood illness — it is a highly contagious and potentially serious disease,” stated City of St. Louis Department of Health Commissioner Victoria Anwuri. This underscores the importance of vigilance and preventative measures.
Understanding Measles and its Risks
Measles is a highly contagious airborne virus spread through respiratory droplets produced when an infected person coughs or sneezes. According to the Centers for Disease Control and Prevention (CDC), if one person is infected, up to nine out of ten people nearby who are not protected can also become infected. This high rate of transmission is why public health officials are taking these exposures seriously.
Initial symptoms of measles typically appear 10-14 days after exposure and include fever, cough, runny nose, and irritated eyes. A characteristic flat, red rash usually develops within three to five days of symptom onset, starting near the hairline and spreading downwards across the body.
While often considered a childhood illness, measles can lead to severe complications, including pneumonia and inflammation of the brain (encephalitis). These complications are particularly dangerous for young children, pregnant individuals, and people with weakened immune systems.
Prevention and What to Do If You Suspect Exposure
The most effective way to protect against measles is vaccination. The measles, mumps, and rubella (MMR) vaccine is highly effective, and two doses are recommended for most individuals, typically administered in early childhood. Unvaccinated adults can receive a “catch-up” vaccination from their healthcare provider.
Individuals who may have been exposed at St. Louis Lambert International Airport or Good Shepherd Lutheran Church should monitor themselves for symptoms for up to three weeks from the date of potential exposure – meaning through the end of . If symptoms develop, it is crucial to immediately isolate oneself and contact a healthcare provider. Patients are advised to contact their provider *before* seeking care to allow medical personnel to take appropriate precautions to prevent further spread.
The IDPH Director, Sameer Vohra, emphasized the importance of vaccination, stating, “This first reported case of measles in Illinois in 2026 is a reminder to our Illinois residents that this disease can be prevented with up-to-date vaccination.” He also urged clinicians to consider measles as a diagnosis in patients presenting with consistent symptoms and to promptly alert their local health department if a case is suspected.
Health officials are continuing to work to identify any additional locations visited by the infected individual while they were contagious. Local health departments will directly notify individuals who may have been exposed at these locations.
In 2025, Illinois reported 14 cases of measles statewide, while Missouri documented seven confirmed cases, none of which were in the St. Louis region. These recent exposures serve as a reminder of the ongoing threat posed by measles and the importance of maintaining high vaccination rates to protect both individual and community health.
