Risk Stratification With Coccidioidal Skin Test to Prevent Valley Fever Among Inmates, California, 2015

Two California state prisons (A and B) have very high rates of coccidioidomycosis (Valley Fever). The prison health care service sought to improve their prevention strategy by risk stratification with a newly available spherulin-based Coccidioides delayed-type hypersensitivity test. Of the 36,789 voluntarily screened inmates, 4.7% experienced adverse reactions. A positive test (8.6% of those tested) was independently associated with (1) incarceration at prisons A and B, (2) admission to prison from a Coccidioides-endemic county, (3) length of stay at prisons A and B, and (4) increasing age. These findings suggest that the test is safe and performing well at risk stratification; the prison system now restricts inmates with negative tests from prisons A and B. This novel use of the test might benefit other coccidioidomycosis prevention programs.