Benedict Kaitlin, Gold Jeremy A W, Dietz Stephanie, Anjum Seher, Williamson Peter R, Jackson Brendan R
Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Division of Health Informatics and Surveillance, Center for Surveillance, Epidemiology, and Laboratory Services, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Open Forum Infect Dis. 2022 May 16;9(7):ofac253. doi: 10.1093/ofid/ofac253. eCollection 2022 Jul.
Cryptococcosis is a serious opportunistic fungal disease, and the proportion of cases among patients with immunosuppressive conditions other than HIV or organ transplant has increased. Understanding laboratory testing patterns for cryptococcosis is useful for estimating its true burden and developing testing guidance.
We identified cryptococcosis tests (cryptococcal antigen [CrAg], cryptococcal antibody, and fungal cultures) performed at a major national commercial laboratory ordered during March 1, 2019-October 1, 2021, and analyzed test results, patient and provider features, reasons for testing, geography, and temporal trends.
Among 29 180 serum CrAg tests, 4422 (15.2%) were positive, and among 10 724 cerebrospinal fluid (CSF) CrAg tests, 492 (4.6%) were positive. Frequent reasons for serum CrAg testing in nonhospital settings (10 882 tests) were HIV (44.6%) and cryptococcosis (17.0%); other underlying conditions were uncommonly listed (<10% total). Serum CrAg positivity declined from 25.6% in October 2019 to 11.3% in September 2021. The South had the highest positivity for serum CrAg tests (16.6%), CSF CrAg tests (4.7%), and fungal cultures (0.15%). Among 5009 cryptococcal antibody tests, 5 (0.1%) were positive.
Few outpatient serum CrAg tests were performed for patients with immunocompromising conditions other than HIV, suggesting potential missed opportunities for early detection. Given the high positive predictive value of CrAg testing, research is needed to improve early diagnosis, particularly in patients without HIV. Conversely, the low yield of antibody testing suggests that it may be of low value. The decline in CrAg positivity during the COVID-19 pandemic warrants further investigation.
隐球菌病是一种严重的机会性真菌病，在除艾滋病毒或器官移植以外的免疫抑制患者中病例比例有所增加。了解隐球菌病的实验室检测模式有助于估计其真实负担并制定检测指南。
我们确定了2019年3月1日至2021年10月1日期间在一家主要的全国性商业实验室进行的隐球菌病检测（隐球菌抗原[CrAg]、隐球菌抗体和真菌培养），并分析了检测结果、患者和提供者特征、检测原因、地理位置和时间趋势。
在29180次血清CrAg检测中，4422次（15.2%）呈阳性，在10724次脑脊液（CSF）CrAg检测中，492次（4.6%）呈阳性。非医院环境中血清CrAg检测（10882次检测）的常见原因是艾滋病毒（44.6%）和隐球菌病（17.0%）；其他潜在疾病很少被列出（总计<10%）。血清CrAg阳性率从2019年10月的25.6%降至2021年9月的11.3%。南部地区血清CrAg检测阳性率最高（16.6%），脑脊液CrAg检测阳性率最高（4.7%），真菌培养阳性率最高（0.15%）。在5009次隐球菌抗体检测中，5次（0.1%）呈阳性。
除艾滋病毒外，免疫功能低下患者的门诊血清CrAg检测很少，这表明早期检测可能存在错失机会的情况。鉴于CrAg检测的高阳性预测价值，需要开展研究以改善早期诊断，尤其是在非艾滋病毒患者中。相反，抗体检测的低阳性率表明其价值可能较低。COVID-19大流行期间CrAg阳性率的下降值得进一步调查。
