Molecular Typing of Enterovirus Isolates

AUTHORS: Chris Holmes, Husam Osman (HPA, Birmingham Heartlands Hospital)

ABSTRACT: Enterovirus is a genus of viruses that includes the poliovirus and the hand foot and mouth virus. Enteroviruses cause a wide range of illnesses from mild fever to meningitis with flaccid paralysis. The occurrence of enteroviruses peaks in the summer months, and was especially high in 2008. The historical method for detecting enterovirus in clinical specimens was by cell culture, followed by neutralisation with specific antisera to type the virus (serotyping). At HoEFT, cell culture has now been replaced by real-time PCR, which, although it has increased sensitivity and turn-around times, does not routinely include typing and has resulted in a loss of epidemiological data. A number of typing methods based on the sequence of viral capsid proteins have been described in the literature, one of which is being developed for use in the routine laboratory here. Sequence typing is superior to serotyping as it allows typing of hitherto ‘untypable’ strains. Early findings indicate a dominance of certain species (most notably echovirus 30) in CSF specimens that have tested positive for enteroviruses by Real-time PCR in summer 2008.