“…Most studies used cerebrospinal fluid; the sensitivities were between 40 and 50% for this target (6,8,(21)(22)(23)25). In other studies brain or liver tissue, bronchoalveolar lavage, lymph nodes, and blood samples were used but, especially for the latter, only from limited number of patients (1,6,7,12,14,17,20,24,26,28). Most of these samples can be obtained only by invasive procedures, and only blood can be easily obtained from the patients.…”