Background: Meningitis and meningoencephalitis are very adverse drug reactions that had not been documented
in clinical studies. Nevertheless, cases were reported within the post marketing period. The aim of this study is to evaluate
the prevalence, clinical and laboratory characteristics of aseptic meningitis and meningoencephalitis following Hoshino
MMR (Mumps-Measles-Rubella) vaccine in children.
Methods: In this cross-sectional study, children who were diagnosed with meningitis following MMR vaccine in an infectious or emergency department of the Tehran Medical Center were enrolled, and their demographic information was recorded from the file. A questionnaire concerning diagnostic criteria in favor of aseptic meningitis was provided for each child
and the results of clinical examinations were recorded.
Results: This study was performed on 73 children with meningitis symptoms of aspiration, where, 46 of the children were
males and 27 were females. Prevalence of meningitis-related symptoms were: fever 66%, headache 49.3%, nausea and vomiting 74%, parotid swelling 0%, and meningeal symptoms 37%. Lab tests showed that 8.2% of patients had normal WBC
whereas, 76.7% had abnormal levels.
Conclusion: Our study showed that following MMR vaccine, in children with meningitis symptoms, nausea and vomiting
followed by fever were most commonly seen symptoms.