Kawasaki Disease (KD) is a feverish childhood disease that many parents, even some doctors, mistake for an inconsequential infection. In fact, if not diagnosed or treated in time, it can lead to irreversible heart damage. It is more common in Hawai‘i and Japan than anywhere else in the world. After 45 years of research, including genetic studies, scientists have been unable to pinpoint the cause of the disease.
Now, surprising findings of an international team of scientists including Dr. Marian E. Melish, Professor of Pediatrics at the University of Hawai‘i at Mānoa John A. Burns School of Medicine, suggest that KD cases may be linked to large-scale wind currents that track from Asia to Japan and also traverse the North Pacific. This study was published November 10, in Scientific Reports .
Dr. Melish reports, “Although KD is often considered to be a rare disease, it is a particular problem in Hawai‘i where there are at least 50-100 new cases in Hawai‘i children each year. KD is seen in young children of all races but is most common in children of Japanese and Korean ancestry. There is a striking age-related incidence with 50% of children under the age of two years, 80% younger than four, and uncommon over the age of 12.”
KD starts abruptly in a previously healthy child with fever followed by rash, redness of the whites of the eyes, mouth, lips and tongue, swollen hands and feet, and swollen glands in the neck. The disease causes damage to the coronary arteries in 25% or one out of four untreated children and may lead to serious heart problems in early adulthood. Early recognition and treatment can prevent heart damage in most children but coronary artery damage occurs in about one in 10 children and death in one in 1,000 children. There is no diagnostic test for Kawasaki disease but most doctors in Hawai‘i recognize the disease and refer for early treatment. As the cause is unknown, it is not understood how children get it or how it could be prevented.
Seasonality of the disease has been noted in many regions with most cases occurring in fall, winter and early spring. Small clusters and large epidemics have occurred, particularly in Japan, the country of highest incidence for KD. Japan has had three dramatic nationwide epidemics, each lasting several months and peaking in April 1979 (6,700 cases), May 1982 (16,100 cases) and March 1986 (14,700 cases). These three peaks represent the largest KD epidemic events ever recorded in the world. Smaller community wide outbreaks have occurred in several U.S. regions, including Honolulu, Denver and San Diego.
Because of the strong seasonality of KD, Dr. Jane C. Burns, Professor of Pediatrics at the University of California at San Diego, organized an investigation of a possible climate connection. This team includes Xavier Rodó and Joan Ballester of the Institut Català de Ciències del Clima and the Institució Catalana de Recerca (IC3) in Barcelona, Spain; Daniel R. Cayan, Climate Atmospheric Science and Physical Oceanography (CASPO) at Scripps Institution of Oceanography in La Jolla, California; Dr. Melish; and Yoshikazu Nakamura and Ritei Uehara, both of Jichi Medical University, Toshigi, Japan.
Funding for the study was provided in part by a grant from the National Heart, Lung and Blood Institute, part of the National Institutes of Health, by the NOAA Regional Integrated Sciences and Assessments program, and by a grant to Rodo from La Marató de TV3 Foundation.