Research could pave the way for more effective and targeted vaccine campaigns, and help avoid major epidemics, scientists say
LONDON (Thomson Reuters Foundation) – Scientists may soon be able to forecast disease outbreaks in sub-Saharan African’s “meningitis belt” using weather data – and use that to plan early vaccination drives to prevent or limit casualties.
In the “meningitis belt” of sub-Saharan Africa, which stretches across the Sahel from Senegal to Ethiopia, major epidemics of lethal meningitis are routine. A devastating 1996-97 outbreak killed about 25,000 people.
An effective new vaccine has driven a decrease in meningitis, but the standard procedure in the region has been to carry out vaccination drives and antibiotic treatment of the disease in districts already suffering outbreaks – and in some cases help arrives too late to make a significant impact, health officials say.
In the near future, though, scientists might be able to use climate factors such as wind and dust conditions to forecast these epidemics and develop earlier vaccination strategies to prevent or limit casualties.
New research carried out in Niger by the NASA Goddard Institute for Space Studies and Columbia University's International Research Institute for Climate and Society found that measured levels of wind and dust can be used to predict some of the annual variability in meningitis outbreaks, at both national and district levels.
“We’ve known that the disease is associated to climate and environmental issues for a long time, because it’s very seasonal,” said Carlos Perez Garcia-Pando, one of the lead authors of the report.
The challenge, he said, to figure out which climate factors were important in order to better equip public health decision makers to act.
“The idea was to try to use models and observations from satellites and all kinds of data on potential (climate-related) parameters that might be affecting the disease, and try to use that information to provide advance warning,” Perez said.
What the group of researchers found was a particularly close correlation between wind and dust levels and meningitis outbreaks.
Madeleine Thomson, another researcher involved in the project, called the strength of the relationship “astonishing.”
“A lot of experts have known for a long time that environment is important, but not how important,” she said.
MALARIA, THEN MENINGITIS
The research on meningitis follows similar work with malaria, connecting climate factors to the mosquito-borne disease.
Thomson explained that the differences between the two diseases made them well-suited for comparative studies.
“We had some experience working on malaria, and chose to work on meningitis, because one, it’s an important disease, particularly for the Sahel region in Africa, and it’s a dry season disease, instead of a wet season disease ... So it allowed us to explore some of the challenges of dealing with a different type of the disease, but again with environmental and climate factors.”
“What we’ve learned is that yes, this approach can be applied to climate sensitive diseases, writ large,” she said.
The researchers said their work was designed to help health officials make effective decisions about meningitis vaccination campaigns, and “we have been collaborating very closely with decision makers,” Perez said.
The next steps are to expand the research outside of Niger and build models for other parts of the affected region, he said.
“What we’ve created is a useful tool that can help decision makers to think, organise, distribute medicine, and make their decisions more in advance,” Perez said.
Samuel Mintz is an AlertNet Climate intern.
Our Standards: The Thomson Reuters Trust Principles.