Nested PCR for rapid detection of mumps virus in cerebrospinal fluid from patients with neurological diseases

In this study, we have de,eloped a reverse transcription (RT)-nested polyme rase chain reaction (n-PCR) for the detection of mumps virus RNA in cerebro spinal fluid (CSF) from patients with neurological infections. A specific 1 12-bp fragment was amplified by this method with primers from the nucleopro tein of the mumps virus genome. The mumps virus RT-n-PCR was capable of det ecting 0.001 PFU/ml and 0.005 50% tissue culture infective dose/ml. This me thod was found to be specific, since no PCR product was detected in each of the CSF samples from patients with proven non-mumps virus-related meningit is or encephalitis. Mumps virus RNA was detected in all 18 CSF samples conf irmed by culture to be infected with mumps virus. Positive PCR results were obtained for the CSF of 26 of 28 patients that were positive for signs of mumps virus infection (i.e., cultivable virus from urine or oropharyngeal s amples or positivity for anti-mumps virus immunoglobulin M) but without cul tivable vints in their CSF, Overall, mumps virus RNA was detected in CSF of 96% of the patients with a clinical diagnosis of viral central nervous sys tem (CNS) disease and confirmed mumps virus infection? while mumps virus wa s isolated in CSF of only 39% of the patients. Furthermore, in a retrospect ive study, we were able to detect mumps virus RNA in 25 of 55 (46%) CSF sam ples from patients with a clinical diagnosis of viral CNS disease and negat ive laboratory evidence of viral infection including mumps virus infection, The 25 patients represent 12% of the 236 patients who had a clinical diagn osis of viral CNS infections and whose CSP was examined at our laboratory f or a 2-year period. The findings confirm the importance of mumps virus as a causative agent of CNS infections in countries with low vaccine coverage r ates. In summary, our study demonstrates the usefulness of the mumps virus RT-n-PCR for the diagnosis of mumps virus CNS disease and suggests that thi s assay may soon become the "gold standard" test for the diagnosis of mumps virus CNS infection.