Diagnostic value of cytological and microbiological methods in cryptococcal meningitis

The aim of this study was to investigate diagnostic methods for cryptococcal meningitis (CM). A retrospective analysis was conducted for 31 patients with CM confirmed by etiologic detection of cerebrospinal fluid in our hospital in the past 5 years. Nineteen cases in 31 patients were confirmed with CM in the first diagnosis, with a misdiagnosis rate of 38.7%. The positive rates of cryptococcus detection in cerebrospinal fluid with May-Grünwald-Giemsa (MGG)-, ink-, and Alcian blue-staining methods were 86.9, 70.9, and 80.6%, respectively. The misdiagnosis rate of CM is high during the early stage of disease. The total positive rate of cryptococcus diagnosis using the MGG-staining method was significantly higher than that using the ink-staining method. These results are important for diagnosing CM.