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In Vietnam, an anatomy of a measles outbreak
Nearly 150 children died last year in an explosive measles outbreak in Vietnam.
By Leslie Roberts, in Hanoi
962
Reporting for this story was supported by the UN Foundation.
sciencemag.org SCIENCE
29 MAY 2015 • VOL 348 ISSUE 6238
Published by AAAS
PHOTO: STR/AFP/GETTY IMAGES
of pneumonia, says Kohei, who is still studying pathology and the clinical course to pinpoint the exact causes of death. Meanwhile, the virus moved south, clobbering Ho Chi Minh City. Very few deaths were reported there, perhaps, Kohei speculates, because patients were spread among several hospitals, and ventilation was better in the hot climate of southern Vietnam, with windows open and fans going. In October, the country, with the help of WHO and UNICEF, launched a nationwide campaign to reach 20 million children between the ages of 1 and 14 with measles and rubella vaccine. The first step was rebuilding trust, Eraly says. Social mobilizers canvassed the countryside, with educational materials in different dialects. The Health Ministry aired radio and TV spots. Teachers were enlisted. Borrowing a page from the polio eradication playbook, the location of every house was mapped, and volunteers followed up to see that each child had been vaccinated. WHO estimates that the campaign, which lasted about 5 months, reached 97% of the target audience. So far in 2015, only a few scattered cases of measles have been reported in Vietnam, Kohei says. But the virus is still out there, and it will find the unvaccinated, he warns. With measles, he says, “the honeymoon never continues.” ■
Downloaded from www.sciencemag.org on May 28, 2015
C
hildren were two to three to a bed, some desperately ill and on ventilators. At the National Hospital of Pediatrics in Hanoi, the intensive care unit overflowed. With waiting rooms full, anxious parents sat on the pavement outside the hospital. Most of the children were under age 5, and many were babies. Ninety percent had not been vaccinated. Last year, Vietnam was hit with its worst measles epidemic in decades, with 30,000 suspected cases and 15,000 confirmed so far. One hundred forty-six children died. The outbreak came more or less out of the blue. After Vietnam rebuilt from the war, routine childhood immunization became one of its great success stories, and the country boasts 95% coverage. But that figure masks much lower rates among the 50 or so ethnic minority groups, dirt poor and lacking the most basic services. With measles still circulating, its explosive contagiousness ensured that sooner or later, it would find an opening. One factor was a loss of public trust in vaccination, say experts at the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF). In separate incidents in 2012 and 2013, 12 children died shortly after being vaccinated with Quinvaxem, which protects against five diseases. Several investigations found no causal link between the vaccine and the fatalities; in May 2013, WHO pronounced them “coincidental health problems related in time.” But confidence in vaccines suffered another blow a few months later, when several children died after health workers injected the wrong drug instead of the hepatitis B vaccine. The incidents fed disenchantment with the government-run health system among Vietnam’s rising urban middle class, and “whole districts stopped vaccinating their kids,” says Emmanuel Eraly, a risk communications specialist in WHO’s Vietnam office. In cities, some parents went to private health providers, often delaying vaccination until their children were 18 or 24 months old and leaving them vulnerable, adds Toda Kohei in WHO’s immunization program in Vietnam, who has been investigating the measles outbreak with the Health Ministry. Kohei thinks last year’s epidemic may have begun in 2013, with a small cluster of cases among the Hmong people, an indigenous group living along the mountainous Chinese border. “We tried to contain the spread” with a rapid immunization campaign in Vietnam’s northern provinces, Kohei says. But by early 2014, the virus hit Hanoi, where it exploded. With no other pediatric hospital in the north, parents rushed their children to the one in Hanoi. “Infection control was a disaster,” Kohei says: The sick weren’t properly isolated, and ventilation was poor, with windows closed against the cold, damp weather. Children in the hospital who didn’t have measles quickly caught it. Those who were already weakened by the virus got secondary infections, both bacterial and viral. When it became clear that the hospital was an incubator for the virus, the health minister urged parents to keep children home. But panicked by the rising death toll, they kept coming. By late April, about 140 children had died at the hospital, many from repeated bouts
In Vietnam, an anatomy of a measles outbreak
Nearly 150 children died last year in an explosive measles outbreak in Vietnam.
By Leslie Roberts, in Hanoi
962
Reporting for this story was supported by the UN Foundation.
sciencemag.org SCIENCE
29 MAY 2015 • VOL 348 ISSUE 6238
Published by AAAS
PHOTO: STR/AFP/GETTY IMAGES
of pneumonia, says Kohei, who is still studying pathology and the clinical course to pinpoint the exact causes of death. Meanwhile, the virus moved south, clobbering Ho Chi Minh City. Very few deaths were reported there, perhaps, Kohei speculates, because patients were spread among several hospitals, and ventilation was better in the hot climate of southern Vietnam, with windows open and fans going. In October, the country, with the help of WHO and UNICEF, launched a nationwide campaign to reach 20 million children between the ages of 1 and 14 with measles and rubella vaccine. The first step was rebuilding trust, Eraly says. Social mobilizers canvassed the countryside, with educational materials in different dialects. The Health Ministry aired radio and TV spots. Teachers were enlisted. Borrowing a page from the polio eradication playbook, the location of every house was mapped, and volunteers followed up to see that each child had been vaccinated. WHO estimates that the campaign, which lasted about 5 months, reached 97% of the target audience. So far in 2015, only a few scattered cases of measles have been reported in Vietnam, Kohei says. But the virus is still out there, and it will find the unvaccinated, he warns. With measles, he says, “the honeymoon never continues.” ■
Downloaded from www.sciencemag.org on May 28, 2015
C
hildren were two to three to a bed, some desperately ill and on ventilators. At the National Hospital of Pediatrics in Hanoi, the intensive care unit overflowed. With waiting rooms full, anxious parents sat on the pavement outside the hospital. Most of the children were under age 5, and many were babies. Ninety percent had not been vaccinated. Last year, Vietnam was hit with its worst measles epidemic in decades, with 30,000 suspected cases and 15,000 confirmed so far. One hundred forty-six children died. The outbreak came more or less out of the blue. After Vietnam rebuilt from the war, routine childhood immunization became one of its great success stories, and the country boasts 95% coverage. But that figure masks much lower rates among the 50 or so ethnic minority groups, dirt poor and lacking the most basic services. With measles still circulating, its explosive contagiousness ensured that sooner or later, it would find an opening. One factor was a loss of public trust in vaccination, say experts at the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF). In separate incidents in 2012 and 2013, 12 children died shortly after being vaccinated with Quinvaxem, which protects against five diseases. Several investigations found no causal link between the vaccine and the fatalities; in May 2013, WHO pronounced them “coincidental health problems related in time.” But confidence in vaccines suffered another blow a few months later, when several children died after health workers injected the wrong drug instead of the hepatitis B vaccine. The incidents fed disenchantment with the government-run health system among Vietnam’s rising urban middle class, and “whole districts stopped vaccinating their kids,” says Emmanuel Eraly, a risk communications specialist in WHO’s Vietnam office. In cities, some parents went to private health providers, often delaying vaccination until their children were 18 or 24 months old and leaving them vulnerable, adds Toda Kohei in WHO’s immunization program in Vietnam, who has been investigating the measles outbreak with the Health Ministry. Kohei thinks last year’s epidemic may have begun in 2013, with a small cluster of cases among the Hmong people, an indigenous group living along the mountainous Chinese border. “We tried to contain the spread” with a rapid immunization campaign in Vietnam’s northern provinces, Kohei says. But by early 2014, the virus hit Hanoi, where it exploded. With no other pediatric hospital in the north, parents rushed their children to the one in Hanoi. “Infection control was a disaster,” Kohei says: The sick weren’t properly isolated, and ventilation was poor, with windows closed against the cold, damp weather. Children in the hospital who didn’t have measles quickly caught it. Those who were already weakened by the virus got secondary infections, both bacterial and viral. When it became clear that the hospital was an incubator for the virus, the health minister urged parents to keep children home. But panicked by the rising death toll, they kept coming. By late April, about 140 children had died at the hospital, many from repeated bouts
