After struggling to emerge from the Ebola outbreak, West Africa now faces a dangerous wave of measles cases because over-burdened hospitals were unable to keep up with vaccinations, researchers said on Thursday.
Some 100 000 more children could get measles, in addition to the 127 000 cases already anticipated among children who have not been vaccinated against measles in Guinea, Sierra Leone and Liberia, the three nations hardest by the Ebola epidemic, said the study in the journal Science.
Researchers forecast that on top of the 7 000 measles deaths that the countries would normally anticipate, anywhere between 2 000 and 16 000 additional children would likely die from measles, all because of a year-and-a-half of Ebola-related disruptions in the health care system.
"The large numbers we project sound pretty bad but they're not unprecedented," said lead author Justin Lessler, assistant professor in the Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health.
"Between 2010 and 2013, a measles outbreak in Democratic Republic of Congo resulted in 294 000 cases and over 5 000 deaths," he said, noting that the DRC measles outbreak followed years of unrest, not an Ebola epidemic.
Measles outbreaks often follow humanitarian crises, as vaccination rates decline because of violence, fear of infection, and health systems that are overwhelmed with casualties and deaths.
The latest outbreak of Ebola in West Africa is the worst in history, killing more than 10 000 of the more than 24 000 people infected, according to the World Health Organisation.
Researchers estimate that measles immunizations in the region, typically ranging between 60 and 80 percent of children had fallen by 75% because of the Ebola crisis.
That would mean that after 18 months of healthcare disruptions, more than 1.12 million children aged between nine months and five years would be vulnerable to measles -- up from 778 000 prior to the crisis, the study said.
Measles causes fever and rash, and complications can include pneumonia, fatal brain swelling, blindness and hearing loss.
About 84% of children worldwide are vaccinated against measles by their first birthday, according to the WHO.
But more than 90% need to be vaccinated in order to maintain herd immunity, health authorities say.
The virus's particles can remain infectious on surfaces and in the air for up to two hours.
"It's so incredibly contagious compared to other vaccine preventable diseases," said Lessler.
"It's one of the first diseases for which we lose our [herd] protection against an outbreak."
There have been some measles cases in West Africa since the Ebola outbreak began, but so far the region has avoided a large outbreak.
Researchers said the best way to ward off another public health emergency is to make a fresh push for childhood vaccinations in the region, including measles, polio and whooping cough, along with delivery of anti-malaria bed netting and medication, and doses of Vitamin A which can boost child health.
"Measles is not the only health threat that has been made worse by the Ebola crisis and may not even be the worst. But it's certainly one we can do something about," said Lessler.