Infections in the central nervous systemwith focus on meningococcal disease : clinical and epidemiological aspects

Sammanfattning: Infections in the central nervous system (CNS) include meningitis and encephalitis and are associated with high mortality and morbidity. A large number of different pathogens can cause these infections, including Neisseria meningitidis. It’s crucial to find the causative pathogen in order to provide the best treatment to the patient and for disease surveillance. In Paper I, molecular methods were used to investigate the microbial etiology in patients presenting with CNS infections at United Mission Hospital in Tansen, Nepal. Although the cerebrospinal fluid samples were analyzed for a large number of microbes using two commercial multiplex PCR panels and additional in-house real-time PCR, the etiology of the infections was still unknown in a large number of patients. This calls for further development of diagnostic methods for CNS infections.Neisseria meningitidis, the meningococcus, is a strictly human commensal but also capable to cause severe disease, typically in the form of sepsis and meningitis. The aim of Paper II and III was to study the clinical presentation of N. meningitidis serogroup Y and W infections, which increased unexpectedlyin Sweden from 2007 and 2014, respectively. By reviewing medical records of these infection episodes, the conclusion was drawn that atypical presentations with respiratory and gastrointestinal symptoms were common, rather than meningitis and petechiae.In Paper IV, meningococcal carriage was studied among students at Örebro University. Age ≤22 years, smoking, previous tonsillectomy, frequent partying and male gender were associated with higher carrier rates. The so far longest observation of carriage of the same meningococcal strain was presented, with a duration of at least one year.In conclusion, the results from these studies highlight the importance of early detection of meningococcal infections with atypical presentations and the need of improved diagnostics for CNS infections