Measles: Not just a childhood rash
ABSTRACTIn recent years, the number of US measles cases has increased, and outbreaks in adults continue to be reported in communities with a high number of unvaccinated people. These trends underscore the need for high overall measles vaccination coverage, and for physicians to entertain the diagnosis of measles in adult patients with a febrile illness and rash.
KEY POINTS
- Measles is one of the most contagious infectious diseases, with a secondary attack rate of at least 90% in susceptible household contacts.
- Since 1993, most reported cases of measles have been directly or indirectly linked to international travel, and many have occurred in adults.
- Acute measles encephalitis, a neurologic complication of measles, is more common in adults than in children and is characterized by the resurgence of fever during the convalescent phase, along with headaches, seizures, and altered consciousness.
ADVERSE EFFECTS OF MEASLES VACCINE
Live-virus measles vaccine has an excellent safety record. A transient fever, which may be accompanied by a measles-like rash, occurs in 5% to 15% of people 5 to 12 days after vaccination. The rash may be discrete or confluent and is self-limited.
Although measles vaccine is a live-attenuated vaccine, vaccinated people do not transmit the virus to susceptible contacts and are not considered contagious, even if they develop a vaccine-associated rash. Thus, the vaccine can be safely given to close contacts of immunocompromised and other susceptible people. Encephalitis is exceedingly rare following vaccination.
There is no scientific evidence that the risk of autism is higher in children who receive measles or MMR vaccine than in unvaccinated children.37 An Institute of Medicine report in 2001 rejected a causal relationship between MMR vaccine and autism spectrum disorders.38
CONTRAINDICATIONS TO MEASLES VACCINATION
Measles vaccine is contraindicated for:
- People who have cell-mediated immune deficiencies (except patients wtih HIV infection—see discussion just below)
- Pregnant women
- Those who had a severe allergic reaction to a vaccine component after a previous dose
- Those with moderate or severe acute illness
- Those who have recently received immune globulin products.
HIV-infected patients with severe immunosuppression should not receive the liveattenuated measles vaccine. However, because patients with HIV are at risk of severe measles, and because the vaccine has been shown to be safe in HIV patients who do not have severe immunosuppression, the vaccine is recommended for those with asymptomatic or mildly symptomatic HIV infection who do not have evidence of severe immunosuppression. 39
After receiving immune globulin
Anyone who has recently received immune globulin should not receive measles vaccine until sufficient time has passed, since passively acquired antibodies interfere with the immune response to live-virus vaccines. How long to wait depends on the type of immune globulin, the indication, the amount, and the route of administration. In general, the waiting period is:
- At least 3 months after intramuscular immune globulin or tetanus, hepatitis A, or hepatitis B prophylaxis
- At least 4 months after intramuscular immune globulin for rabies, or 6 months after intravenous immune globulin for cytomegalovirus (dose, 150 mg/kg)
- At least 8 months after intravenous immune globulin as replacement or therapy for immune deficiencies (dose, 400 mg/kg), or after intravenous immune globulin for immune thrombocytopenic purpura (400 mg/kg)
- At least 10 months after intravenous immune globulin for immune thrombocytopenic pupura at a dose of 1 g/kg.39
Egg allergy is not a contraindication
Although measles vaccine is produced in chick embryo cell culture, the vaccine has been shown to be safe in people with egg allergy, so they may be vaccinated without first being tested for egg allergy.39,40
