Detection of viruses in spinal fluid.

Among the confirmed cases of viral meningitis and encephalitis, the most commonly diagnosed agents are enteroviruses, arboviruses, and herpes simplex virus. Definitive diagnosis of a viral infection often affects patient management, length of hospitalization, and antibiotic use. Laboratory diagnostic methods include microscopic examination of clinical specimens, virus culture, serologic studies, and immunologic detection of virus or viral antigens. Microscopic examination of cerebrospinal fluid is nonproductive, and, except for enteroviruses, culture almost always gives negative results. Viral culture of the cerebrospinal fluid, throat, and feces is the diagnostic method of choice for enteroviruses. Definitive diagnosis of herpes simplex virus encephalitis must be based on virus isolation from brain biopsy material. Arbovirus infection is diagnosed serologically. Although none of the newer rapid immunologic techniques is commercially available, some do hold great promise. These include measurement of virus-specific immunoglobulin M (IgM) and detection of viral antigens by enzyme or radioimmunoassay. A sensitive and specific procedure for early detection of herpes simplex virus antigens in cerebrospinal fluid would be of great benefit.