A report in PLOS Pathogens last week has produced new details about an unusually virulent fungal infection caused by Cryptococcus gattii, which has emerged recently in the Northwest US and Canada. The new study tracked the virulent fungus, which infected a wide array of mammals including humans, dogs, cats, sheep and alpaca, confirming a total of 18 infections in humans and 21 cases in other mammals that were isolated from Washington state and Oregon since 2005. The numerous popular press articles describing this report have delved into the outbreak’s history, attributing 40 deaths to the disease.
The C. gattii outbreak is not viewed as a major public health threat currently, as it is not contagious from person to person, symptoms can take years to develop, and the disease is treatable provided it is recognized in a timely fashion. It does, however, illustrate the security issues surrounding unknown and emerging infectious diseases, particularly for pathogens capable of infecting both humans and animals and that are stable enough to be acquired from the environment. Due to the relatively low risk and the lack of knowledge about precisely how the infection is acquired, scientists are not recommending that people change their behavior. However, these types of details may be needed to address future unknown outbreaks, whether they are naturally occurring or intentional.
Genomic tools like the ones described in this report are important because they can help speed the identification of unknown diseases and thereby assist the public health response to emerging infections.