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South Carolina’s huge measles outbreak has slowed significantly in recent weeks, raising hopes among health officials that the disease’s spread might end sooner than expected, the state’s epidemiologist said Wednesday.
Since Feb. 17, the South Carolina Department of Public Health has documented 17 new measles cases. That’s far fewer than the 100 or more new cases being identified every few days during mid-January, when the outbreak spiked following the winter holidays.
“We’re encouraged with the downward trend, particularly in the last two weeks,” said Dr. Linda Bell, who has been leading the state’s response since the outbreak was identified in October with an initial five cases.
Since then, 979 people – mostly school-age children – have been sickened with measles. All but 52 of the cases have been in Spartanburg County; about 95% have been among people who were not vaccinated.
“No one should underestimate the hard work and long hours that front-line, often entry level epidemiologists have put into this response, and [who] are largely responsible for this downward trend that is actually occurring a bit earlier than previously projected,” Bell said.
Earlier in the outbreak, Bell said that modeling had suggested the outbreak might last for as long as six months.
“The case counts per week now are really down to the level that we were seeing at the beginning of December,” she said. “We are now 22 weeks into this and we hope, with that continued downward trend, in parallel to the hope that vaccination coverage will increase, will help us end this sooner than was originally projected.”
Bell said the department has asked the Centers for Disease Control and Prevention to assist the department in the coming weeks to do studies to help learn from the outbreak, including studies that examine chains of transmission and the costs associated with the public health response to the outbreak, as well as health care costs.
Officials remain concerned, however, that the outbreak has the potential to spike yet again. “This is not over yet. It’s not nearly over yet,” Bell said. “It is these pockets of under-vaccinated people who remain susceptible. That ongoing susceptibility in our population may continue to fuel ongoing spread.”
To stop measles outbreaks from spreading in localized communities, at least 95% of people need to be vaccinated. But in Spartanburg County, state health officials have said measles vaccination rates for school children across the county are just 90% – and they are even lower within some individual schools and communities.
“Many of the schools in Spartanburg County have some of the lowest vaccination coverage rates in the state,” Bell said. “So all of those are contributing to the reason that the outbreak has been focused in Spartanburg County, because of higher risk there, because of lower coverage.”
This is also a likely contributing factor for why measles cases identified recently in a few other South Carolina counties haven’t spread widely in those locations, Bell said. Of the 979 cases in the South Carolina outbreak, 927 involve people in Spartanburg County.
“Even if we are only seeing a dozen or so cases per week, the risk we can surge remains,” Bell said.
Bell noted that schools will be going on spring break in the coming weeks, bringing with it the risk of people who have been exposed to measles becoming infectious and spreading the disease to others at tourist attractions and while traveling. “This is a great concern,” she said.
Alison Young is Healthbeat’s senior national reporter. You can reach her at ayoung@healthbeat.org or through the messaging app Signal at alisonyoungreports.48
