For the specific case of KD, at present we can make only limited progress in the diagnosis, treatment, and ultimately prevention of this disease without knowing the etiologic agent. Without a diagnostic test, KD cases continue to be missed. Without a better understanding of the causative agent, and thus pathophysiology of the disease, improved, more specific treatments and prevention strategies cannot be devised. For the larger question of tropospheric wind transport of other infectious agents, the ability to track the movement of specific agents would contribute to resource management and planning for regional increases in disease activity. For the specific case of KD, determining the etiologic agent of KD will be the missing link needed that should rapidly lead to new methods for diagnosis and treatment.
This is the first attempt to perform whole-genome sequencing to define the biome of the tropospheric wind. Trans-oceanic transport of a human pathogen has not been previously reported. This is the first proposal that KD could be triggered by an infectious agent or antigen traveling as an aerosol and transported by large-scale winds.
An international team of climate scientists, engineers, atmospheric and environmental scientists, infectious disease specialists, and molecular microbiologists will join forces to test the hypothesis that tropospheric winds can transport pathogens across vast distances that can trigger disease on a distant continent. The teams will use KD as a model system to study long-range microbial transport through large-scale air sampling using research aircraft over Japan starting this February-March 2014. Particulates trapped on filters collected during periods of high KD (winter 2014 and winter 2015) and low KD activity (summer 2014) will be compared for their organic, inorganic, and microbiologic content, and the source region for each day determined.
What are we going to do?
If successful, we will be able to answer the following questions:
1-What causes Kawasaki Disease?
2-What can the atmospheric sampling tell us about the chemical and physical conditions under which this transport of the KD agent takes place? Are they important for the resulting KD manifestation in kids?
..and perhaps most important,
3-Is it possible for micro-organisms to travel long distances on tropospheric wind currents, shielded from ultraviolet radiation while hunkered down inside microscopic dust particles, only to emerge on a distant continent and cause disease?
In the pilot experiment in March 2011, the IC3 team in collaboration with the NIES team successfully performed aerosol sampling with no contamination of the negative filters (filters handled as for the sample collection filters but without filtering air). The IC3 instrument (IC3-HSF) is specifically devised in conjunction with the MCV Catalan firm to successfully trap small airborne biological active particles and it has specifications no commercial instrument offers to date. IC3-HSF was developed for this research use, and specifically to be operated in small aircrafts. It has an independent high power supply for working during the usual flight autonomy time, without relying on aircraft power supply. It has the capacity for handling huge volumes of air with a very high filtering rate (minimum 0.5 cubic meters per minute over a flight of three hours at 3000 feet). It was designed in a way to ensure keeping out of contamination the main airway during working and flight operations (take-off, landing, etc), and with no backwards flux inside the instrument. IC3-HSF instrument filters air on a 0.4 micron pore size sterile and extremely pure quartz filter prepared for having specific care in protecting nucleic acids. Moreover, stability of the filtering pressure is regulated for living cells protection and both stepping and unusual falls in pressure are controlled.
-Collection of samples of microorganisms in the troposphere over Japan.
We will test the hypothesis that aerosol samples collected over Japan during peak vs. trough periods of KD activity will differ in their source region and their organic and inorganic chemical content. A high-volume air sampling device specifically prepared for use in the research aircraft will be implemented to be operated from a japanese aircraft by IC3 personnel. Flights over Japan will be conducted with the timing and direction of flight paths based on disease activity and wind patterns, departing from Tokyo, ten consecutive days in March 2014 (winter), July-August 2014 (summer) and January-March 2015 (winter). Flights willseek to compare the microbiome of high KD seasons (winter) with that of a low KD season (summer).
-Analysis of biological and chemical samples.
If further funding is secured, the tropospheric microbiome will be defined using fluorescence microscopy, unbiased high throughput sequencing followed by bioinformatic analysis and other techniques to identify known and novel microbes. Chemical analyses of the filters will also be performed. The biome of filters collected at different times during the seasonal cycle of the disease will be compared to identify microbial candidates for triggering KD.
We are going to sample the free troposphere between 1000-3000 meters above ground. The free troposphere is the region above 1 km altitude and it is well-known that long-range transport of aerosols around the globe occurs. Sampling in the free troposphere will avoid contamination from land surfaces and we anticipate collection of aerosols that are representative of the tropospheric biome.