The Ebola crisis has a knock-on effect for the prevention of other serious infectious diseases.
The disruption of the Ebola virus may be wreaking havoc on the measles vaccination programs in the three affected nations, and such secondary effects are potentially "as devastating in terms of loss of life as the disease itself," says Justin Lessler, PhD, leader of a study that models the knock-on impact.
The study, published today in Science, is a warning, says Dr. Lessler - an assistant professor in epidemiology at the Johns Hopkins Bloomberg School of Public Health - that:
"While the downstream effects of Ebola are many, we can actually do something about measles relatively cheaply and easily, saving many lives by restarting derailed vaccination campaigns."
The study estimates that, before the Ebola outbreak, lack of measles vaccination affected about 778,000 children in the relevant age group in the three affected nations of Guinea, Liberia and Sierra Leone - amounting to roughly 4% of the population.
That estimate rises to 1,129,000 unvaccinated children between the ages of 9 months and 5 years after a year-and-a-half of "Ebola-related disruptions to the health care system" - or a 45% rise in lost vaccine coverage.
The researchers summarize the picture: for every month of interruption in the health care system, "an additional 20,000 children" in this age group become susceptible to the measles.
To reach the estimates in the analysis, Dr. Lessler and his colleagues used data-driven models of the region. The 18-month forecasts are based on geospatial mapping and age-related patterns of measles susceptibility.
They modeled the potential toll of measles, including for death rates, resulting from 4 levels of disruption to health care services in the region:
- 25% reduction in health care services due to Ebola outbreak
- 50% effect
- 75% health care reduction - where the researchers believe the level of disruption has peaked
- 100% disruption.
The focus on Ebola's disruptive effects was in terms of measles in the study, but Dr. Lessler believes the crisis has also slowed delivery of vaccines against other infectious diseases.
Dr. Lessler estimates that between 600,000 and 700,000 children in the region are not receiving these vaccines: the oral polio vaccine, tuberculosis vaccine, and the pentavalent vaccine, which protects against meningitis, pneumonia and otitis caused by Haemophilus influenzae type b, whooping cough or pertussis, tetanus, hepatitis B and diphtheria.
Dr. Lessler has this warning about the bigger picture:
"These setbacks have the potential to erode the substantial gains in the control of these diseases over recent decades.
It could be a long time before the health care systems in the region recover from this."
The Ebola news topic is a hot one, and among the most recent stories, a case study revealed last week that a needle stick-injured Ebola doctor from the US was free of the virus after an experimental vaccination. And last month, scientists determined that the Ebola virus can survive in victims' bodies for days.