Ebola is more deadly for children under the age of 5 years than for older children and adults. This is the finding of a new study led by researchers Imperial College London in the UK and the World Health Organization.
In the current Ebola epidemic, more than 24,000 people have been infected with the virus, with the majority of cases occurring in Guinea, Liberia and Sierra Leone. Around 4,000 of these cases are among children under the age of 16.
According to the investigators – including Dr. Chris Dye, head of the Ebola epidemiology team at the World Health Organization (WHO) – over the course of the Ebola epidemic, the number of children affected by the virus has risen, but the reasons behind this have been unclear.
In an attempt to gain a better understanding, the team compared data of children under the age of 16 who were infected with Ebola during the current outbreak in West Africa with data of adults infected with the virus.
The results of the analysis – which are published in the New England Journal of Medicine – reveal that Ebola has been most fatal in young children, killing 90% of those under the age of 1 year and 80% of those aged 1-4 years.
Children aged 10-15 are most likely to survive the disease, with 52% of cases among this age group resulting in death. Individuals aged 16-44 were found to have a case fatality rate of 65%.
The investigators found that children under the age of 1 year had the shortest incubation period – the time between infection and the appearance of symptoms – at 6.9 days, while those aged 10-15 had an incubation period of 9.8 days.
In addition, the time between onset of Ebola symptoms and hospitalization or death was shortest for younger children.
On first presenting to a doctor, children infected with Ebola were also found to have different symptoms to adults; they were more likely to have a fever, but were less likely to have breathing problems, difficulty swallowing, hiccups or pain in the muscles, joints, chest or abdomen.
These findings, the researchers say, show that the way children are affected by Ebola is very different to the way adults are affected by the virus. It appears to progress faster in young children, putting them at higher risk of death from the disease.
Study co-author Dr. Robert Fowler, of the University of Toronto in Canada, says there are a number of factors that may explain why young children appear to have worse outcomes from Ebola.
One reason could be that young infants are dependent on the care of others. Since their caregivers are likely to have also contracted Ebola, it may mean that a child’s care is compromised.
What is more, Dr. Fowler notes that Ebola often causes vomiting and diarrhea, which can lead to electrolyte and metabolic abnormalities, as well as dehydration. “This is not different from adults, but children seem to have less reserve and get sick more quickly,” he explains.
In order to prevent such symptoms, Dr. Fowler says it is crucial Ebola-infected children receive adequate fluids. If they are unable to keep these fluids down due to vomiting, then fluids should be given intravenously. He points out, however, that placing intravenous catheters in young children has its difficulties. He adds:
“All of these challenges demand that we appreciate the high mortality in young children and evolve more dedicated and specialized means of caring for them in an Ebola outbreak – from nurses and doctors with expertise in pediatric care, with the support system in place in a treatment facility to provide medical and emotional care in a specialized manner.”
Dr. Dye says that as well as emphasizing the need for the “highest quality medical care” among children with Ebola, the findings raise the question as to why older children between the ages of 10 and 15 are less vulnerable to the disease than infants or adults. “This is a topic for future research,” he notes.
Last month, Medical News Today reported on a study by researchers from the National Institute of Allergy and Infectious Diseases, who found that the Ebola virus remains in victims’ bodies for up to 7 days after death.