In Wisconsin, the Marathon County, about ten years ago, blastomycosis, a rare fungal infection, killed two people, hospitalized thirty people, and infected 55 people. The natural habitat of Blastomyces dermatitidis, the fungus, is in wet soil as well as decomposing wood all over the region of Great Lakes and the Mississippi Valley. In some cases, it can trigger flu-related illness and also death in some grave situations. In the U.S., Wisconsin is one of the states with the highest incidence rates of the disease, with 100 cases of outbreaks occurring periodically.
The Wisconsin state asks for the help of the U.S. Centers for Disease Control and Prevention, with the extent of the outbreak, to help launch an investigation. According to the investigators, the fungus that infected 20 patients was of Hmong descent. Also, they discovered that Asians included those with a disappropriate danger of developing blastomycosis infections relative to other groups in the U.S., and they ruled out recreation and gardening practices.
At present, researchers have discovered a specific genetic susceptibility among Hmong people that renders them more susceptible to the disease-causing fungus. Caitlin Pepperell and Bruce Klein, researchers at the University of Wisconsin-Madison, made this new study.
Professor of pediatrics and an infectious disease physician, Kelin, said that the situation puts them in a fix since it had not been described before. Based on population numbers alone, rates were 10-to-100 times greater than one might expect. It is indeed a holy grail question that keeps reverberating why some people are more susceptible, and what is the basis for it?
Pepperell said that they would have better outcomes when they can treat people earlier. Pepperell noted that it is sad that a classic story with blastomycosis is having a long delay to diagnosis since it is not a common disease and it is strange to people.
The researchers have published the study in the open-access journal mBio and, in the course of it, Pepperell surmised that Hmong individuals in Wisconsin could be more genetically isolated than other groups because they went through an extended series of forced migrations and displacements and as a result, have less variation powering their fight against some diseases.
Pepperell joined forces with Donny Xiong, a co-author of the study and graduate student, and together, they obtained the consent from nine of the patients affected with Hmong to collect blood and investigate their cells. Also, Pepperell searched for long stretches of homozygosity in the genome of the Hmong volunteers with Mary O'Neill, a co-author of the study and her graduate student. Their results discovered that individuals with Hmong cells have less IL-6 than the cells of European donors. Klein appreciates the results of the research, which will be useful for public health.
