The CDC has released a new report showing the world's progress (or lack thereof) in eradicating measles, the most contagious of all human infectious diseases. While the bigger (global) picture is good news, the smaller (regional) picture is devastating.

First, the good news. Globally, measles incidence has fallen by 2/3, from 145 cases per 1 million people in 2000 to 49 cases per 1 million people in 2018. This was driven by large reductions in measles in Africa, South-East Asia, and the Western Pacific. The CDC estimates that more than 23 million lives were saved by vaccines from 2000 to 2018.

Now, the bad news. Measles cases have surged elsewhere, particularly in Europe and the Americas. In the former, measles incidence has nearly doubled in two decades; in the latter, measles has increased by 1100%.

Worse, from 2016 to 2018, measles incidence increased in five of the regions, not just Europe and the Americas. The reason is not a mystery: The measles vaccine can wear off over time (as it did for me), and -- despite tremendous global progress in vaccination rates -- not enough people are being vaccinated. Also, even if a country's overall vaccination rate is high, there can be communities where the vaccination rate is very low, making it susceptible to an outbreak. This explains an outbreak among an ultra-Orthodox Jewish community in New York City, for instance.

Currently, there is a measles outbreak in Congo that has infected roughly a quarter million people and killed 5,000. Unlike in rich countries, where people are rejecting vaccines, citizens in countries like Congo are suffering from poverty, war, and lack of access to healthcare.

Rest assured, one of these days, measles will follow smallpox into the dustbin of history. It's sad and frustrating, though, that its eradication will be delayed due to factors that are at least partially preventable.

Source: Patel MK, Dumolard L, Nedelec Y, et al. Progress Toward Regional Measles Elimination — Worldwide, 2000–2018. MMWR 68 (48): 1105–1111. Published: 5-Dec-2019. DOI: 10.15585/mmwr.mm6848a1