IAC Express 2011

• a generalized rash lasting 3 or more days, and
• a temperature of 38.3 degrees C or higher (101 degrees F or higher), and
• cough, coryza, and/or conjunctivitis.

Koplik spots, a rash present on mucous membranes, are considered pathognomonic for measles. Koplik spots occur from 1-2 days before the measles rash appears to 1-2 days afterward. They appear as punctate blue-white spots on the bright red background of the buccal mucosa.

Providers should be especially aware of the possibility of measles in people with fever and rash who have recently traveled abroad or who have had contact with international travelers.

Providers should immediately isolate and report suspected measles cases to their local health department and obtain specimens for measles testing, including viral specimens for confirmation and genotyping. Providers should also collect blood for serologic testing during the first clinical encounter with a person who has suspected or probable measles.


Q: How contagious is measles?

A: Measles is highly infectious. It is primarily transmitted from person to person via large respiratory droplets. Airborne transmission via aerosolized droplets has been documented in closed areas (e.g., office examination room) for up to 2 hours after a person with measles occupied the area.

Following exposure, up to 90% of susceptible people develop measles. The virus can be transmitted from 4 days before the rash becomes visible to 4 days after the rash appears.


Q: How long does it take to show signs of measles after being exposed?

A: It takes an average of 10-12 days from exposure to the appearance of the first symptom, which is usually fever. The measles rash doesn't usually appear until approximately 14 days after exposure, 2-3 days after the fever begins.


Q: If a susceptible person is exposed to measles, can anything prevent them from developing the disease?

A: If the person has not been vaccinated, measles vaccine may prevent disease if given within 72 hours of exposure. Immune globulin (a blood product containing antibodies to the measles virus) may prevent or lessen the severity of measles if given within 6 days of exposure.


Q: What are the recommendations for the use of MMR vaccine to prevent measles?

A: (1) MMR vaccine is recommended routinely for all children at age 12-15 months, with a second dose at age 4-6 years. The second dose of MMR can be given as early as 4 weeks (28 days) after the first dose and be counted as a valid dose if both doses were given after the child's first birthday. The second dose is not a booster, but rather is intended to produce immunity in the small number of people who fail to respond to the first dose.

(2) Adults with no evidence of immunity (defined as documented receipt of 1 dose [2 doses 4 weeks apart if high risk] of live measles virus-containing vaccine, laboratory evidence of immunity, documentation of physician-diagnosed measles, or birth before 1957) should get 1 dose of MMR unless the adult is in a high-risk group. High-risk people need 2 doses; they include healthcare personnel, international travelers, students at post-high school educational institutions, people exposed to measles in an outbreak setting, and those previously vaccinated with killed measles vaccine or with an unknown type of measles vaccine during 1963-1967.

(3) Infants age 6-11 months should receive 1 dose of MMR vaccine before international travel. Any dose of MMR administered before the first birthday should not be counted as part of the 2-dose series, and should be repeated when the child is age 12-15 months.


Q: We have measles cases in our community. How can I best protect the young children in my practice?

A: First of all, make sure all your patients are fully vaccinated according to the U.S. immunization schedule.

In certain circumstances, MMR is recommended for infants age 6-11 months. Give infants this age a dose of MMR before international travel. In addition, consider measles vaccination for infants as young as age 6 months as a control measure during a U.S. measles outbreak. Consult your state health department to find out if this is recommended in your situation. Do not count any dose of MMR vaccine as part of the 2-dose series if it is administered before a child's first birthday. Instead, repeat the dose when the child is age 12 months.

In the case of a local outbreak, you also might consider vaccinating children age 12 months and older at the minimum age (12 months, instead of 12-15 months) and giving the second dose 4 weeks later (at the minimum interval) instead of waiting until age 4-6 years.

Finally, remember that infants too young for routine vaccination and people with medical conditions that contraindicate measles immunization depend on high MMR vaccination coverage among those around them. Be sure to encourage all your patients and their family members to get vaccinated if they are not immune.


Q: My adult patient doesn't remember if he ever received MMR vaccine or had measles disease and is planning an international trip. How should I handle this situation?

A: You have the choice of testing for immunity or just giving 2 doses of MMR at least 4 weeks apart. There is no harm in giving MMR vaccine to a person who may already be immune to one or more of the vaccine viruses. If you or the patient opt for testing, and the test indicates the patient is not immune to one or more of the vaccine components, give your patient 2 doses of MMR at least 4 weeks apart. If the test result is indeterminate or equivocal, consider your patient nonimmune. ACIP does not recommend serologic testing after vaccination because commercial tests are not sensitive enough to detect vaccine-induced immunity reliably.


Q: I'm a healthcare worker. How can I ensure I am protected against measles?

A: If you do not have acceptable evidence of immunity for healthcare workers--documented receipt of 2 doses of live measles virus-containing vaccine at least 4 weeks apart or laboratory evidence of immunity--either get tested for immunity or get 2 doses of MMR at least 4 weeks apart. If you choose the testing route, and your result is negative, indeterminate, or equivocal, get 2 doses of MMR at least 4 weeks apart. ACIP does not recommend serologic testing after vaccination.


Q: Can I give my patients measles vaccine instead of MMR?

A: No. Merck has not produced single-antigen measles, mumps, and rubella vaccines for the U.S. market since 2008. Even before that time, ACIP recommended the combined MMR vaccine whenever one or more of the individual antigens were indicated.

Q: Does the increase in measles cases indicate that vaccination with MMR isn't effective?

A: No. Unvaccinated people accounted for 105 (89%) of the 118 cases. Among the 45 U.S. residents ages 12 months through 19 years who acquired measles, 39 (87%) were unvaccinated, including 24 whose parents claimed a religious or personal exemption and eight who missed opportunities for vaccination. Among the 42 U.S. residents age 20 years and older who acquired measles, 35 (83%) were unvaccinated, including six who declined vaccination because of personal objections to vaccination. Of the 33 U.S. residents who were vaccine-eligible and had traveled abroad, 30 were unvaccinated and one had received only 1 of the 2 recommended doses.