The Maryland Department of Health has declared a measles outbreak that includes St Mary’s county after confirming 14 new cases, all among unvaccinated residents, bringing the state's 2026 total to 31 confirmed cases. The latest announcement, issued on Thursday, said the new infections are split among St Mary’s (13), Carroll (8) and Cecil (5) counties, with an additional case reported earlier in Charles county.
What officials say
State health officials told reporters that most of the recent infections have occurred among household contacts rather than at community exposure sites, and that investigators have not identified any public locations tied to the new cases. That pattern, they say, has limited wider community spread so far.
“Measles is highly contagious and we are actively working with healthcare professionals and local health departments to support impacted communities, respond to cases and mitigate further spread,” said Maryland Health Secretary Dr. Meena Seshamani. “The overall risk remains low if you are fully vaccinated.”
Numbers, trends and context
The state’s jump to 31 cases this year represents a sharp escalation after a period of very low measles activity. Maryland recorded just one case in both 2023 and 2024 and three in all of 2025. As recently as mid-July the year’s total was in single digits; 27 of the 31 cases were confirmed since 15 July.
| County | Cases in 2026 |
|---|---|
| St Mary’s | 13 |
| Carroll | 8 |
| Cecil | 5 |
| Charles | 1 |
Public-health officials highlight two key reasons the outbreak has not become yet more widespread: the concentration of cases among unvaccinated people, and Maryland’s relatively high levels of vaccine-derived protection. The department reports that roughly 96% of Marylanders have vaccine-based protection against measles, and that 96.7% of kindergartners were reported vaccinated for the 2025–2026 school year.
Risk, travel and what this means locally
Measles is one of the most contagious infectious diseases known: an unvaccinated person exposed to measles has about a 90% chance of becoming infected, according to the health department. The current outbreak also follows a larger national pattern — more than 2,300 confirmed cases had been reported across 44 states and Washington, D.C., by early August, with significant outbreaks in neighbouring states such as Virginia and Pennsylvania.
For residents of St Mary’s county, the immediate public-health message is straightforward. Local health teams say they are working with clinicians and partners to identify and support affected households, to trace contacts where possible, and to reduce the chance of onward transmission. Because most recent cases occurred within households and no public exposure sites have been named, the department has not advised widespread closures or mass restrictions at this stage.
- All 14 new cases were in unvaccinated people.
- No public exposure sites have been identified linked to the new cases so far.
- Household transmission appears to be the predominant pattern in the recent cluster.
Local clinics and GPs are the first point of contact for concerned residents. Vaccination remains the primary defence: those unsure of their immunisation status, parents of young children, or people planning travel to areas with known outbreaks should consult a healthcare professional for advice on vaccination or post-exposure prophylaxis.
While Maryland’s high vaccination coverage has so far limited sustained community transmission, the speed of the recent rise serves as a reminder that measles can resurge quickly where pockets of unvaccinated people exist. Health officials say continued vigilance and rapid response are essential to containing this outbreak.
