This article is more than 5 years old. Information may no longer be current.
Fatal measles complication more common than previously understood
Click Here to Manage Email Alerts
NEW ORLEANS — Subacute sclerosing panencephalitis — a 100% fatal complication of measles — occurs much more often than previously thought, according to data presented at IDWeek 2016. The recent finding underscores the importance of herd immunity with the measles-mumps-rubella vaccine to protect infants and those who are immunocompromised.
“Measles is spread by unvaccinated children, many of whom are chosen to be unvaccinated by their parents,” Gary S. Marshall, MD, University of Louisville School of Medicine, Louisville, Kentucky, said during a press conference. “In their mind, parents are trying to do the right thing. Unfortunately, I think they are really misinformed. The right thing to do is to vaccinate their children to prevent them from having a complication like this.”
The MMR vaccine is not recommended in infants aged younger than 12 months because they retain maternal antibodies that would make the vaccine less effective; however, this population is still at risk for contracting measles. Infants who are infected with the virus are predisposed to subacute sclerosing panencephalitis (SSPE), a deadly neurological condition that occurs when the measles virus spreads to the brain. The virus can lay dormant for years before eventually causing SSPE. Questions on what causes the virus to reactive remain unanswered.
Previous research estimated that the risk of SSPE was one in 100,000. However, a more recent analysis in Germany established that the rate of SSPE was one in 1,700 among children infected with measles before 5 years of age. The current study suggests the prevalence may be even higher.
James D. Cherry, MD, MSc, distinguished research professor of pediatrics and infectious diseases at the David Geffen School of Medicine at the University of California, Los Angeles, and colleagues examined 17 cases of SSPE in California between 1998 and 2015 among children infected with measles prior to vaccination. The average age at SSPE diagnosis was 12 years (range, 3-35 years), with a latency period of 9.5 years (range, 2.5-34 years). In a subanalysis of children who developed measles in the United States, the incidence of SSPE was one in 1,387 among those infected before 5 years of age, and one in 609 among those infected before 12 months of age. According to the researchers, many of these patients had cognitive or movement disorders before they were diagnosed. Cherry said that all patients but one who is currently receiving hospice care died.
“This is really alarming and shows that vaccination truly is life-saving,” he said in a press release. “Measles is a disease that could be eliminated worldwide, but that means vaccinating at least 95% of all who are eligible with two doses of measles vaccine in order to protect everyone, including those who aren’t old enough to get the vaccine.”
Ninety percent of the population needs to receive two doses of MMR to establish herd immunity, according to Marshall. The CDC estimates that nearly 92% of children aged 19 to 35 months in the U.S. have been vaccinated. Cherry warned that if the immunization rate dips below the immunity threshold, there will be more cases of SSPE.
Currently, the second dose of MMR is recommended in children before they start school around 5 years of age, which means that one in 20 children between the ages of 1 and 5 years is susceptible to measles, Cherry said. However, children who are traveling to endemic areas such as Europe can be vaccinated earlier. According to the CDC, infants aged 6 to 11 months who are traveling abroad should receive one dose of MMR, then get vaccinated again between 12 and 15 months, and again between 4 and 6 years. Those aged older than 12 months require two vaccine doses spaced at least 28 days apart before travel. To fill the gap in herd immunity, Cherry suggests administering the second dose of MMR early in all children regardless of travel plans.
“There is no reason why you can’t give the vaccine earlier,” he said. “Give the first dose at 12 months and the second dose at 15 months. This is one gap in herd immunity we can fix.” – by Stephanie Viguers
Reference:
Cherry JD, et al. Abstract 916. Presented at: IDWeek; Oct. 26-20, 2016; New Orleans.
Disclosure: The researchers report no relevant financial disclosures.