Researchers surveyed infectious disease doctors across the United States about their use of a blood test (cryptococcal antigen screening) to detect a serious fungal infection in HIV patients before symptoms appear. Only about one-third to two-thirds of doctors regularly perform this inexpensive and accurate test, depending on the patient’s immune system status. Many doctors were unsure about the benefits and guidelines for this screening, suggesting that education and clearer guidelines could help more patients catch this dangerous infection early and receive treatment before it becomes life-threatening.