Yesterday, the Pan American Health Organization (PAHO) made an announcement that, on its surface, seems like great news:
Multiple news outlets picked up the story, and are making declarations about measles being “eradicated” in the Americas.
But has the disease truly been wiped out in the region?
Let’s clear up any confusion that misleading headlines may have caused.
First – eradication and elimination are two very different things. When a disease is eradicated, it doesn’t exist anywhere. Elimination means there are no more native-borne cases, but the infection can still be imported from elsewhere to cause outbreaks.
Eradication is the ultimate goal for fighting infectious disease: It means no infections, with no possibility of further transmission, anywhere in the world. To date, only one human disease has been eradicated worldwide: smallpox.
Measles has not been eradicated in the Americas. While it may have been eliminated, it has not been truly eradicated.
The Centers for Disease Control and Prevention (CDC) reports:
From January 2 to September 10, 2016, 54 people from 16 states (Alabama, Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Illinois, Massachusetts, Minnesota, New York, North Carolina, Tennessee, Texas, and Utah) were reported to have measles.
In 2015, 189 people from 24 states and the District of Columbia were reported to have measles. In 2014, the United States experienced a record number of measles cases, with 667 cases from 27 states reported to CDC’s National Center for Immunization and Respiratory Diseases (NCIRD); this is the greatest number of cases since measles elimination was documented in the U.S. in 2000.
But the mainstream media is claiming measles has been “eradicated” and that the US is “free of measles” and that “measles has been eliminated in all of the Americas.”
The PAHO’s announcement states:
Measles transmission had been considered interrupted in the Region since 2002, when the last endemic case was reported in the Americas. However, as the disease had continued to circulate in other parts the world, some countries in the Americas experienced imported cases.
The claim that the last endemic case (native-borne) was in 2002 is also questionable, because even the CDC admits the origins of the last few outbreaks in the US are not known (all emphasis in quoted information is mine):
2015: The United States experienced a large, multi-state measles outbreak linked to an amusement park in California. The outbreak likely started from a traveler who became infected overseas with measles, then visited the amusement park while infectious;however, no source was identified.
2014: The U.S. experienced 23 measles outbreaks in 2014, including one large outbreak of 383 cases, occurring primarily among unvaccinated Amish communities in Ohio. Many of the cases in the U.S. in 2014 were associated with cases brought in from the Philippines, which experienced a large measles outbreak. (“Many” were associated? What about the ones that were not associated with cases from the Philippines?)
In 2013, there were 11 measles outbreaks in the US, three of which had more than 20 cases, including an outbreak with 58 cases. From January 1 to August 24, a total of 159 cases were reported to CDC from 16 states and New York City. Among the 159 cases, 157 (99%) were import-associated, and two had an unknown source.
Now, let’s take a look at CDC data from measles outbreaks in 2008 (again, emphasis is mine):
During January 1–July 31, 2008, 131 measles cases were reported to CDCfrom 15 states and the District of Columbia (DC): Illinois (32 cases), New York (27), Washington (19), Arizona (14), California (14), Wisconsin (seven), Hawaii (five), Michigan (four), Arkansas (two), and DC, Georgia, Louisiana, Missouri, New Mexico, Pennsylvania, and Virginia (one each). Seven measles outbreaks (i.e., three or more cases linked in time or place) accounted for 106 (81%) of the cases. Fifteen of the patients (11%) were hospitalized, including four children aged <15 months. No deaths were reported.
Among the 131 cases, 17 (13%) were importations: three each from Italy and Switzerland; two each from Belgium, India, and Israel; and one each from China, Germany, Pakistan, the Philippines, and Russia. This is the lowest percentage of imported measles cases since 1996. Nine of the importations were in U.S. residents who had traveled abroad, and eight were in foreign visitors. An additional 99 (76%) of the 131 cases were linked epidemiologically to importations or had virologic evidence of importation.The source of measles acquisition of 15 cases (11%) could not be determined.
According to the CDC, measles was declaredeliminated (defined as the absence of continuous disease transmission for greater than 12 months) from the US in 2000.
The PAHO report is for the Region of the Americas (a region that includes Canada, Cuba, the US, and South America – it encompasses the totality of the continents of North America and South America), but exploring data from recent cases and outbreaks in all of those countries would be exhaustive and beyond the scope of this article.
The PAHO report also states:
By 2002, endemic transmission had ended in the Americas, but a decision to wait on certification was made so measles and rubella elimination could be jointly declared. A measles outbreak in 2013-2015 delayed this process. Rubella was certified as eliminated in 2015. The last case of endemic measles in the Americas in the post-elimination era was reported in July 2015 in Brazil.
Over the past year, from August 2015 to August 2016, all countries in the Americas have showed documentation that endemic measles has been wiped out, according to the PAHO report. If this is entirely true, it is indeed great news.
But, based on data from the CDC, the claim that measles has been “eradicated” from the US is false, and the claim that it has been eliminated is also of questionable veracity.
Written by Lily Dane