By Gary Evans, Medical Writer 

With seven months still left in 2019, measles cases in the United States threaten to reach annual totals not seen in almost three decades.

As of May 30, 2019, there were 971 cases of measles in the United States, the most reported since 1992, when 963 cases were reported for the entire year, the Centers for Disease Control and Prevention reports.

While primarily fueled by large ongoing outbreaks in New York, measles cases have spread to a least 26 states. The CDC estimates about 4% of measles cases in outbreaks are acquired in healthcare facilities. Two doses of the MMR vaccine are about 97% effective at preventing measles. One dose is about 93% effective.

But measles is resurging in recent years, as parents decline to vaccinate their children. Some cite religious objections, unfounded fear that vaccines are linked to autism, or the perception that vaccination is unnecessary because measles is so rarely seen in the U.S. There is even false nostalgia pushed by the national antivaccine movement, as evidenced in the recent controversy over an old TV show that portrayed measles as a comic rite of passage. Public health officials are cracking down, knowing that in the prevaccine era 400 to 500 children died annually of measles.

As of May 29, 2019, there have been 550 confirmed cases in New York City since September of 2018. Most of these cases have involved members of the Orthodox Jewish community. On April 9, the Health Commissioner of New York City ordered every adult and child who works or resides in four ZIP codes in Brooklyn to be vaccinated if they had not already done so, previously had measles or have a medical exemption.

“If the Health Department identifies a person with measles or an unvaccinated child exposed to measles in one of the above ZIP codes, that individual or their parent or guardian could be fined $1,000,” New York City health officials warned.

Generally, it has been estimated that dipping below a 95% measles vaccination level in a population could undermine herd immunity and lead to ongoing transmission and sporadic cases. Public health officials have expressed concern that the U.S. is right on the margins of this epidemiological threshold, which would render the 2000 declaration of measles eradication moot and see some level of endemic disease return.

The 2019 outbreak has been fueled in large part by travelers to areas with international outbreaks returning to a U.S. community that has low measles vaccination rates. The top three countries where importations are coming from are Ukraine, Israel, and the Philippines, the CDC reports.

The top three countries where importations are coming from are Ukraine, Israel, and the Philippines, the CDC reports.

For more coverage of the U.S. measles outbreak see upcoming issues of Hospital Infection Control & Prevention and Hospital Employee Health.