Analysis of West Coast Atmospheric Circulation Patterns and Kawasaki Disease "Dry Spells"

Background: Tropospheric winds from northeastern China have been linked to fluctuations in Kawasaki disease (KD) cases in Japan. These winds may carry aerosols that trigger KD in genetically susceptible children. We investigated whether reduced numbers of KD cases were linked to large scale circulation patterns affecting the U.S. West Coast. Methods: KD cases with either date of onset of fever or date of hospitalization (PHIS, Pediatric Health Information System) were obtained from 5 sites from Seattle to San Diego from 1995-2014. Six days were subtracted from date of hospitalization to approximate date of onset. For each site, periods from December-March were identified for which there were no KD cases for an interval of ≥10 days, called “KD dry spells”. Daily NCEP-NCAR atmospheric Reanalysis 700hPa height anomalies were used to represent the atmospheric circulation. Results: From 27-48 dry spells were defined for each site. Composites of atmospheric circulation from Day -20 to Day +10 relative to first ...