A small measles outbreak recently made national news, yet another testament to our progress in eradicating disease. Measles is serious stuff. It leads to hacking cough, a spotty rash, and sometimes, death. The disease is so contagious that it will infect nine out of ten unvaccinated people exposed. The outbreak started when a Christian mission brought the disease back from the Philippines. The infected passed it along to several Americans who refused to get vaccinated or those too young to be vaccinated.

Contagious, deadly diseases like measles were once common, even among the wealthiest. For example, King Louis XIV of France lost his son, grandson, great-grandson, and brother to smallpox. Smallpox used to kill some 400,000 Europeans annually in the late 18th century, and in the 20th century alone, it claimed hundreds of millions of lives across the globe.

Now, these diseases are rare and cause far fewer deaths:

In this recent measles outbreak, only 68 people were infected. Despite the low number, that constitutes an 18-year high of measles infections in the United States. And that number may have been lower if doctors hadn’t misdiagnosed their patients, which occurred because the disease is so unusual nowadays. This is all good news. That such a small outbreak makes national news and constitutes an 18-year high is a testament to the human progress we have made in eradicating disease.