Measles outbreaks put U.S. at risk of losing prized ‘elimination’ status

With two large and still growing outbreaks in New York pushing the country’s measles count to a quarter-century high, public health officials are starting to grapple with an unpleasant

prospect.

The Rockland County and Brooklyn outbreaks have dragged on for eight months. If transmission from either of those outbreaks continues until late September, the United States will likely lose

a hard-fought and prized status — that of a country deemed to have “eliminated” measles.

And if that happens — Venezuela and Brazil are the only other countries in the Americas where measles is considered endemic, or constantly circulating — the implications could be profound,

experts say.

While there would be no international penalties involved, the rollback of measles elimination status would mean more than just the crossing of a psychological divide. It would be a

harbinger, experts say, that the U.S. could face far larger outbreaks in the future — epidemics that could strain the capacity of health departments that already struggle to extinguish each

and every chain of measles transmission that occurs in the country.

“An ounce of prevention is a ton of work,” said Dr. Thomas Clark, deputy director of the division of viral diseases at the Centers for Disease Control and Prevention, who has been thinking

about what might happen if the U.S. loses its measles-free status in the fall.

“In practice, you can’t respond the way our local health departments are responding to 20, and 30, and 50 cases a week,” Clark said. “If you have hundreds, you’re not calling everybody.

You’re not seeing who they exposed. You’re not recommending individuals isolate themselves in case they come down with measles. You just have endemic measles. You just understand that

everybody’s at some risk of measles from people who are unvaccinated.”

Is that where the United States is heading? Clark and others wonder.

“Do we reach a place where measles is acceptable? And some rare but real case fatality from measles is OK despite having safe and effective vaccines,” he mused. “That’s not a place we want

to get back to. We don’t want to slide back down to measles being endemic in the United States.”

After measles vaccines came onto the market in the 1960s, several efforts were made to stop transmission of the virus in this country. Those, after all, were the heady days when major

breakthroughs in vaccine development — first polio, then measles — were opening up new vistas for disease control. The ultimately successful campaign to rid the world of smallpox was

launched. Infectious diseases could be prevented.

Two attempts to stop measles transmission in the United States — the first in the 1960s, the second in the 1970s and early 1980s — failed, said Dr. Walter Orenstein, who was the director of

the U.S. Immunization Program from 1988 to 2004. But those failures pointed to problems that needed to be addressed, and galvanized the collective will to get the job done, he said. A third

attempt, in the 1990s, succeeded, and the country was declared measles-free in 2000.

Orenstein, who is now with the Atlanta-based Task Force for Global Health, said he hopes that if measles elimination status is lost, the setback will be a temporary one.

“Will we give up if measles is reestablished? My feeling is no, that public health officials will continue to work to regain elimination,” he said.

He pointed out that recent crises have provoked some positive reforms, such as legislative moves by Washington state and Maine to limit the types of exemptions parents can claim to avoid

vaccinating their children.

“I think the issue is: Can we use this failure to take constructive steps to build our immunization programs? That’s my hope,” Orenstein said. “And certainly that’s the domestic U.S.

experience in the past. Failure was helpful in terms of getting across: These things don’t need to happen.”

Dr. Kristen Ehresmann also believes the fight to regain elimination status would continue, if it lapses in the fall. As director of infectious disease epidemiology, prevention, and control

for the Minnesota Department of Health, Ehresmann has recent experience fighting a major measles outbreak. Two years ago a major epidemic occurred children of a large Somali community in her

state.

Losing the country’s measles-free status would be a wake-up call, Ehresmann said. “We’ve got to take this seriously or we’re going to move completely backwards.” But she insisted health

department would take the same all-hands-on-deck approach to containing measles outbreaks going forward as they do now.

Dr. Jeffrey Duchin fears that might become harder to do, though, if the country’s annual measles count heads back into the thousands and beyond. There were 981 cases reported to the CDC

through May 31. Before measles vaccines became available, as many as a half-million children a year in the U.S. contracted the virus and about 500 children a year died from the disease.

“I don’t think we will return to that degree of measles transmission because we still will have many people vaccinated. However what we will see is an unpredictable number of cases of

measles with consequent increases in secondary hospitalizations, cases of encephalitis, potentially deaths depending on what happens with immunization coverage in the United States over the

next decade or so,” said Duchin, chief of communicable diseases for the Seattle and King County Health Department.

Duchin, who said losing the country’s elimination status would be “a tragedy,” shares Clark’s concern that a time may be coming when health departments cannot chase down every measles case

in the way they do now, looking for everyone who might be exposed and at risk. Measles outbreaks place a huge burden on health departments, which often have to pull staff from other programs

to help with the contact tracing.

“The public health system will never ignore measles cases and the potential for high-risk persons to become infected. So there will have to be some response,” Duchin said. “But it may have

to be limited to a small subset of exposed people. Health-care system exposures, young children, infants, pregnant women, immune-compromised persons.”