Researchers working to identify the culprit of a rare condition in children known as Kawasaki disease now have a new place to look: seasonal winds from central Asia. If the experts' hypothesis is proven correct, the infectious disease would be the first viable human disease to travel great distances and across large bodies of water.
A Nature story published yesterday tells the genesis of Kawasaki disease and efforts by a team of medical and climate scientists to discern if wind is a factor in the spread of the illness. As Jennifer Frazer describes:
[The team] set up an experiment to filter the air over Japan at various altitudes during a period when the agent was suspected to be present, and then to sequence the DNA of everything on the filter - an approach known as 'metagenomics'.
At Columbia, where the metagenomic analysis is being carried out by biologist Brent Williams, progress has been slow because of the minuscule amounts of DNA present in air samples taken at high altitude. But the work is beginning to pay off, says [Ian Lipkin, MD, an epidemiologist and director of the Center for Infection and Immunity at Columbia]. Williams has found candidates for the Kawasaki agent — although Lipkin declined to discuss them before publication — and will soon be progressing to immunoassays. In these, antibodies generated to proteins predicted to be expressed by the suspected disease agent will be mixed with serum samples from children who have had Kawasaki disease and from controls who have not. If the antibodies interact significantly more strongly with the Kawasaki disease samples than with the controls, the team can be more confident that its suspected Kawasaki agent is the real thing.
The next step will be to look for DNA sequences in the blood samples of affected children that match the DNA detected in the air samples. “That would also be strong circumstantial evidence that would give us confidence that we're on the right track,” Lipkin says.
Beyond identifying the causation agent for Kawasaki disease, this work could spark new questions about the possibility of other diseases, such as avian influenza, that may be blowing in the wind.
Photo by kyle hovey