Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 47 3 2009 06 15 171 174 EN Samileh Noorbakhsh Department of Pediatric, School of Medicine, Research Center of Pediatric Infection Disease, Iran University of Medical Sciences, Tehran, Iran. Naser Javahertrash Department of Pediatric Immunology and Allergy, School of Medicine, Research Center of Pediatric Infection Disease, Iran University of Medical Sciences, Tehran, Iran. Hassan Tonekaboni Department of Pediatric Neurology, School of Medicine, Research Center of Pediatric Infection Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Azardokht Tabatabaei Department of Pediatric, School of Medicine, Research Center of Pediatric Infection Disease, Iran University of Medical Sciences, Tehran, Iran. Mohammad Ali Fatoorechi Department of Pediatric, School of Medicine, Research Center of Pediatric Infection Disease, Iran University of Medical Sciences, Tehran, Iran. 2015 09 28 Mumps infection is endemic in Iran. Our objective was to evaluate the presence of anti mumps antibodies ( IgM & IgG) in cerebrospinal fluid in mumps meningoencephalitic children. A prospective/cross-sectional study was performed in Tehran, Iran (2003 to 2004) and serum anti mumps antibodies (IgM) were detected (quantitive; ELISA) in meningoencephaltis patients. Specific anti mumps antibodies (IgM & IgG) were detected in cerebrospinal fluids of mumps meningoencephalitis cases. 43 meningoencephalitic patients were tested (59.2% male and 40.8% female). The age of patients was 79.96 ± 4.7 month. 23 (78.7%) cases had specific mumps IgM in serum. None of cases had IgM antibodies in CSF. Anti mumps IgG antibody was detected in CSF of 7.5% (2/23) cases. We detected lower than expected frequency of local immunity to mumps virus in CSF of our cases. For better serologic diagnosis we recommend more sensitive methods like virus detection (PCR) or short-term culture of lymphocytes from cerebrospinal fluid in future studies. https://acta.tums.ac.ir/index.php/acta/article/view/3569 https://acta.tums.ac.ir/index.php/acta/article/download/3569/3545