The incidence of coccidioidomycosis, or “valley fever,” increased eightfold in the endemic area of the U.S. from 1998 through 2011, according to MMWR. The endemic area comprises Arizona, California, Nevada, New Mexico, and Utah.
Analyzing data from the National Notifiable Diseases Surveillance System, CDC researchers found that the incidence in this region rose from 5.3 to 42.6 cases per 100,000 population over the study period. The increase was seen among all age groups, but those aged 60 and older were most affected.
Speculating on the reasons for the increase, MMWR‘s editors note thatCoccidioides spores, which live in the soil, might have spread readily because of drought, rainfall, temperatures, or construction activity. They also acknowledge that changes in disease surveillance might have affected the numbers. Nonetheless, they conclude that clinicians “should be aware of this increasingly common infection when treating persons with influenza-like illness or pneumonia who live in or have traveled to endemic areas.”