Pennsylvania has reported more than 1,300 measles cases across 43 counties this year, according to new numbers from the state health department, which also revealed 31 new cases and five measles-associated deaths.
Lancaster County continues to see a rise in cases, with 12 reported since Monday.
Scientists are working to determine why the measles outbreak in Pennsylvania is deadlier than usual. The disease typically kills one to three out of every 1,000 unvaccinated individuals it infects.
Researchers believe the age of those infected may play a role. Another challenge is the lack of recent data, forcing scientists to rely on historical information as a baseline.
The Centers for Disease Control and Prevention has sent a special “disease detective” to Pennsylvania this week to examine the outbreak more closely.
This content is imported from infogram. You may be able to find the same content in another format, or you may be able to find more information, at their web site.