Decades after the height of the measles epidemic we continue to learn about its complications. One deadly result is more common than we assumed. It's called SSPE, which stands for sclerosing panencephalitis. It can show up a decade after a measles infection and recovery. It's also more prevalent in those who got measles when they were younger than two years old.
With SSPE, the virus persistently infects the brain. At first the symptoms are subtle involving mild mental deterioration such as forgetfulness. But then motor functions are affected where the arms or legs or even head make jerking movements. Seizures occur and some people become blind. In the advanced stages, people can't walk because their muscles stiffen or spasm. Eventually they go into a coma and die within one to three years.
There's no cure. The assumption was that one in a hundred thousand measles patients develop SSPE, but new analysis suggests the number goes up to one in fourteen hundred in kids who get measles before age five. Those infected before they turn one see their risk jump to one in six hundred.
This highlights the importance of timely vaccination. However, since the first dose of the measles vaccine is given when children are 12-15 months old, babies under one are susceptible. They depend on others being vaccinated for protection, something called herd immunity.
Herd immunity is effective for measles only if 83 to 94% of the population is vaccinated. In the US, we're at 91% percent. Talk about vaccination with others to maintain this vitally important protection for our communities.
More Information
Deadly Measles Complication More Common Than Doctors Thought
A deadly complication of the measles, which can occur years after a person is infected with the virus, is more common than researchers previously thought, according to a new study.
Measles History
The first written account of measles dates back to the 9th century. Find out more about measles at this CDC site.
What is Herd Immunity?
The term "herd immunity" refers to a means of protecting a whole community from disease by immunizing a critical mass of its populace. Vaccination protects more than just the vaccinated person. By breaking the chain of an infection's transmission, vaccination can also protect people who haven't been immunized. But to work, this protection requires that a certain percentage of people in a community be vaccinated. What factors determine where that critical-mass threshold lies? And once it's in place, how does herd immunity cocoon the most vulnerable among us?