Isolation Period for Adults with Measles

Adults with measles should be isolated until at least 4 days after the onset of rash to prevent transmission to susceptible individuals. 1

Infectious Period and Transmission

Measles is highly contagious and is transmitted through the respiratory route 2
Infected individuals are contagious from 4 days before rash onset through 4 days after rash onset 1
The virus spreads through airborne transmission, making proper isolation critical to prevent outbreaks 3

Maintain isolation for at least 4 days after rash onset 1
During healthcare visits, patients should:
- Wear a medical mask immediately 1
- Be placed in an airborne-infection isolation room (negative air-pressure) when available 1
- If no isolation room is available, place in a private room with door closed 1

Healthcare workers who develop measles should be excluded from work until ≥4 days following rash onset 1
Healthcare workers without evidence of immunity who are exposed to measles should:
- Be offered MMR vaccine and excluded from work from day 5-21 following exposure 1
- If not vaccinated after exposure, be excluded from day 5 after first exposure through day 21 after last exposure, even if they received immune globulin 1

During outbreaks in educational settings, susceptible individuals who are exempt from vaccination should be excluded until 21 days after the onset of rash in the last case 1
For healthcare facility outbreaks, exposed susceptible workers should be excluded from the 12th day after first exposure through the 26th day after last exposure 1

If immune globulin is administered to an exposed person, observation should continue for 28 days (rather than 21) as immune globulin may prolong the incubation period 1

Classic measles presents with:
- Prodrome: fever, cough, coryza (runny nose), conjunctivitis 2, 4
- Koplik spots may appear on buccal mucosa before rash onset 2
- Characteristic rash appears 3-4 days after fever onset, starting on face and spreading downward 4, 5
Laboratory confirmation is recommended, particularly for isolated cases not part of an outbreak 3, 6

Implement airborne precautions immediately when measles is suspected 1
Only staff with presumptive evidence of immunity should enter the room of a person with suspected or confirmed measles 1
All staff entering the room should use respiratory protection (N95 respirator or equivalent) regardless of immunity status 1
Post-exposure prophylaxis with MMR vaccine (within 72 hours) or immune globulin (within 6 days) should be considered for susceptible contacts 1

Failing to recognize measles early, before the characteristic rash appears 3
Inadequate isolation measures during the 4 days before rash onset when patients are already contagious but not yet diagnosed 1
Not maintaining isolation for the full 4 days after rash onset 1
Allowing healthcare workers without proper immunity to care for patients with measles 1
Not implementing proper airborne precautions (regular surgical masks are insufficient) 1