The measles outbreak that led to a state of emergency in New York’s Rockland County began far away: in an annual Hasidic pilgrimage from Israel to Ukraine.
It is emblematic of a series of fierce, sometimes connected measles outbreaks — in places as diverse as Indonesia, the Philippines, Madagascar and Venezuela — that have shaken global health officials, revealing persistent shortcomings in the world’s vaccination efforts and threatening to tarnish what had been a signature public health achievement.
In 2001, the United Nations declared war on measles. With help from the federal government, the American Red Cross and big donors like Ted Turner and Bill and Melinda Gates, the U.N. began the Measles and Rubella Initiative and created Gavi, the Vaccine Alliance.
Together, they poured billions of dollars into buying vaccines and helping countries deliver it safely, which meant building refrigerated storage facilities, supplying clean needles, training vaccinators and countering other logistical obstacles common in poor countries.
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Public health officials worldwide tracked the results, monitoring cases and tracking outbreaks. The news was good: Measles declined worldwide by nearly 80 percent between 2000 and 2016, with fatalities — mostly among children younger than age 5 — plummeting to about 90,000 per year from about 550,000.
But two years ago, measles cases unexpectedly popped upward again, rising 30 percent in a single year. The virus re-invaded countries where it had been vanquished.
The biggest factor in that increase, World Health Organization officials said, was poverty: Medical systems in many countries remain too weak to vaccinate enough children year after year to wall out the virus.
To stop imported cases from spreading, about 95 percent of a country’s citizens must be immune, either through vaccination or because they had measles as children. As babies are born, new pools of potential victims are created — unless vaccination is constant.
Children with measles in a government hospital in Manila in February. The Philippines, composed of hundreds of islands, presents a unique vaccination challenge.CreditFrancis R Malasig/EPA, via Shutterstock
Anti-vaccine activists, false rumors and serious missteps by some vaccine companies have all contributed to the global rebound. Jet travel has fueled the spread, as it has with viruses like MERS and Zika.
So have “diaspora networks,” said Dr. Heidi J. Larson, director of the Vaccine Confidence Project at the London School of Hygiene and Tropical Medicine — people connected by culture around the world who share beliefs, and sometimes pathogens.
[Times reporters answered questions about the measles outbreak in Rockland County.]
Israel’s measles outbreak began in March 2018, apparently in a small Orthodox community in Tzfat, in the north, said Dr. Patrick M. O’Connor, leader of the rapid disease control team at the W.H.O.’s European office, which oversees Israel.
Resistance to vaccines was not the reason. Orthodox rabbis “have no issue with vaccination — it’s seen as a lifesaving good,” Dr. O’Connor said. And Israel’s chief health officer, Yaakov Litzman, is an Orthodox rabbi who grew up in Brooklyn; his ministry provides vaccines free.
“But there is a mismatch between Israel’s health system and the population it’s supposed to serve,” Dr. O’Connor added.
The clinics offering vaccines were often not open on convenient days or couldn’t accommodate big groups. Orthodox families may include up to a dozen children, and ensuring that all have had two measles shots on schedule can be difficult.
(To comply with Israel’s health ministry schedule, a child needs nine doctor’s appointments before age 6 to be fully vaccinated against 14 diseases. Children get measles shots at ages 1 and 6.)
Vaccination rates among the Orthodox in Israel were in the 80 percent range — better than in many other countries, but not enough to stop measles. Another contributing factor: Even if they are sick, children are often brought to Orthodox weddings or other gatherings.
At first, the virus moved slowly through Orthodox communities in Jerusalem and Tel Aviv. Then in September, Dr. O’Connor said, a major outbreak in Ukraine supercharged Israel’s modest one — and probably led, indirectly, to outbreaks in Britain and in the United States.
The Ukraine connection
Last year, Rosh Hashana fell in early September. Later that month, measles cases exploded in Israel, rising to a peak of 949 in October. The cause? Numerous pilgrims came back from Ukraine with the virus, experts believe.
New York’s outbreak began in October; the first patient was a child in the Bensonhurst section of Brooklyn who had visited Israel. At the same time, a measles outbreak began among Orthodox Jews in London.
The Israeli government responded rapidly, recruiting Orthodox Jews onto vaccine advisory groups and sending mobile clinics into their neighborhoods.
“Coverage improved immensely, and the numbers are getting smaller,” Dr. O’Connor said.
Orthodox Jews in Britain and the United States also have big families and may struggle to keep everyone vaccinated. But vaccine skepticism is more common in the United States than in Israel and much more common in Britain.
The false rumor that measles vaccines cause autism was started in 1998 by Andrew Wakefield, a British doctor whose medical license was later revoked.
Many outbreaks, many triggers
Several other measles outbreaks are crisscrossing the globe. They follow similar patterns but have unique triggers and pose individual public health challenges.
Many countries are having outbreaks bigger than Israel’s. Madagascar has seen 66,000 cases of measles, with more than 900 dead. India has had 63,000 cases; Pakistan, 31,000; Yemen, 12,000; Brazil, 10,000; and Venezuela, 5,700.
Most of these countries have chronically low vaccination rates. But some are worsened by unique constellations of challenges.
Yemen is in the middle of a civil war. Venezuela’s medical system has broken down; part of Brazil’s outbreak is in refugees from Venezuela.
Madagascar is one of the world’s poorest countries. It is an island with a high birthrate, and there had been no measles outbreak since 2003, so it had a huge pool of susceptible children and teenagers. And many of those children are dangerously malnourished.
In wealthy countries, measles kills about one in every 1,000 victims. But when children are malnourished, and when they cannot get hospital care for complications like pneumonia or encephalitis, measles can kill one in 10 children, sometimes even more in refugee camps, said Dr. Katrina Kretsinger, a W.H.O. medical officer.
Since 2000, when the United States eliminated domestic measles, all cases here have come from overseas. In the early 2000s, most arrived from Japan, where the government had made measles shots voluntary after a locally made vaccine was blamed for cases of meningitis.
In 2011, American tourists brought back 13 cases from a major outbreak in France. An outbreak in North Carolina in 2013 originated in India.
Something similar happened there in the early 1990s, said Dr. Larson of the Vaccine Confidence Project.
A conservative Catholic group heard that a new injectable contraceptive would include a protein used in tetanus vaccine. Misunderstanding the science, the group spread the alarm that tetanus vaccine was secretly a birth-control method.
The mayor of Manila banned the vaccine, and the rumor spread through Catholic anti-abortion networks as far as East Africa and South America. Ultimately, the W.H.O. had to ask the Vatican to intervene and say the vaccine was safe.
The next country in line for an epidemic that could spread to the United States, Dr. Larson predicted, is Poland.
It was the lowest-ranked European Union country on her organization’s recent “vaccine confidence survey.” Respondents are asked, for example, whether they feel vaccines are safe, effective and compatible with their religious beliefs.
Poland has a vocal anti-vaccine movement called “Stop Nop,” and its immunization rates have dropped steadily since 2010. And, Dr. Larson noted, Poland has many Ukrainian refugees, any one of whom could import the virus.
Poles in Scotland are already echoing attitudes in their homeland, she said.
“I would not be surprised if the negative sentiment and consequent vaccine refusal spread to the Polish communities in the U.S.”