This study thus intends to fill in the gaps in knowledge with regards to central nervous system infections in Singapore to give a thorough description of burden of causes of central nervous system infections and detection of outbreaks of new pathogens. Patients suspected of central nervous system infection will be recruited from 5 restructured Singapore hospitals and their blood and other clinical specimens will be sent for testing. Patients will also be followed up to assess long term outcomes and socio-economic costs of these infections. This will help clinicians, policymakers and public health officials in estimating financial and societal costs of CNs infections in Singapore.