(FOX 2) - Michigan state health officials have reduced the statewide measles count from 41 to 39, following further testing of the two cases.
The two redacted cases are of children in Washtenaw County and Oakland County, which authorities said had a false positive test result.
Officials say both children had been recently vaccinated and that initial testing came back positive for measles, but that actually their vaccine had caused just a mild rash and fever - not an actual measles diagnosis. The MMR vaccine contains a weakened live virus that cannot cause measles but can result in positive lab tests.
The MMR vaccine also has the potential to cause a mild rash and fever, the Michigan Department of Health and Human Services says. This is a vaccine reaction, not measles, and the individual is not infectious.
The measles vaccine is highly effective and very safe. A single dose of measles vaccine protects about 95 percent of children, but after two doses, almost 100 percent are immune. The first of two routine childhood measles vaccine doses is given at 12-15 months of age.
A second vaccine dose is given before the start of kindergarten, between ages 4 and 6 years. MDHHS follows Centers for Disease Control and Prevention guidance and does not recommend routine measles vaccinations for children less than 12 months of age unless there is a suspected measles exposure; there is thought to be an imminent measles exposure such as being in areas of known measles; or international travel planned.
This is the highest number of measles in the state since 1991 when 65 cases were reported. So far this year, there have been 387 cases of measles confirmed in 15 states.
The virus can live for up to two hours in the air where the infected person was present. Symptoms of measles usually begin 7-14 days after exposure, but can appear up to 21 days after exposure and may include:
High fever (may spike to over 104˚F).
Red, watery eyes (conjunctivitis).
Tiny white spots on the inner cheeks, gums, and roof of the mouth (Koplik Spots) 2-3 days after symptoms begin.
A rash that is red, raised, blotchy; usually starts on face, spreads to trunk, arms, and legs 3-5 days after symptoms begin.
If symptoms develop, residents are urged to call their doctor or emergency room before arriving so they can take precautions to prevent exposure to other individuals.