EFNS‐ENS guidelines for the use of PCR technology for the diagnosis of infections of the nervous system

Abstract

Background: Polymerase chain reaction (PCR) as a means to amplify nucleic acids has become an essential element in diagnosis of infections. It has evolved into a simple and rapid, easy-to-use approach. At present there are no published guidelines for the usage of PCR technology for the diagnosis of infections of the nervous system. Methods: We reviewed the advantages and pitfalls of PCR in order to guide neurologists and infectious diseases experts in its application for the diagnosis of infections of the nervous system. Medical reference systems were searched, and original papers, meta-analyses, review papers, book chapters and guidelines recommendations were reviewed. The final literature search was performed in May 2012. Recommendations were reached by consensus. Recommendations: The reliability of PCR technology for the diagnosis of neurological infections is currently based on the pathogens. The main contribution of PCR is to the diagnosis of viral infections followed by bacterial CNS infections with the notable exception of tuberculous meningitis. Efficacy for the diagnosis of protozoal infections and helminthic infestations has also been established in many instances. Unfortunately, current molecular PCR technology is far from becoming routine in resource-poor countries where such infections are prevalent. Despite the importance of fungal infections in the context of the immune-compromised host, there is not enough data to recommend the routine use of PCR. Conclusions: PCR technology is currently a reliable method for the diagnosis of viral and bacterial (except tuberculosis) infections, and only for some protozoal infections and helminthic infestations.

Herpes Simplex Virus-1 Encephalitis in Adults: Pathophysiology, Diagnosis, and Management

“…There is considerable variation in the CSF profile of HSVE, but a typical profile includes a moderate lymphocytic pleocytosis (10-200/mm 3 ), may demonstrate elevated erythrocytes (normalminimally elevated counts are common), moderately elevated protein (50-100 mg/dl), and normal glucose (although hypoglycorrhachia may be present in a minority of patients) [60]. PCR for HSV-1 and HSV-2, which has supplanted viral cultures and other studies as the test of choice, should be obtained from the CSF and has high sensitivity (96 %) and specificity (99 %) [67,68]. False-negative PCR can occur early in the illness [98][99][100], and if the clinical suspicion is high, aciclovir should be continued empirically and repeat CSF HSV PCR obtained within 3-7 days [43].…”

Cerebrospinal Fluid Abnormalities in Viral Encephalitis

“…Noninfective CSF contains maximum 5 wight blood cells (WBC) in a mm 3 . The protein content in normal CSF does not exceed 50mg/dl and CSF glucose is 50-70 % of serum glucose levels.…”

“…Described pathogens reported as to be the causative agents for encephalitis, the majority of them are viral in origin, but sometimes bacteria or fungi or a postinfectious process. Inspite of the fact that molecular biology researches advance, new era of essentials elements in diagnosis commences, extensive tests are being used widely, the etiology of encephalitis remains unclear and unknown in a considerable degree of the patients [1][2][3].…”

Clinical Trials in Neurovirology: Successes, Challenges, and Pitfalls

“…Because of the high degree of sensitivity and specificity for HSV PCR detection in cases, failure of HSV DNA detection supports discontinuation of therapy in low-risk patients (negative imaging, absence of CSF pleocytosis) 72 h after onset of disease. However, equivocal diagnostic findings that are not explained by another condition may merit a full 14-day course of aciclovir [8,9].…”