Enterovirus typing by immune electronmicroscopy.

A simple method of typing enteroviruses by immune electronmicroscopy (IEM) is given. Forty-four of 50 picornavirus strains typed by both IEM and neutralisation in cell culture gave identical results. Four strains could not be typed by one or other method. Two rhinovirus isolates were untypable by both methods. There were no discrepant results. The IEM method is convenient and has considerable savings in time and reagents.

A microtitre plate method for isolation and typing of poliovirus using a blue-cell ELISA.

A simple, sensitive, specific and rapid procedure for isolating and typing polioviruses is described. Specimens are inoculated onto confluent monolayers of cell lines (Hep-2C, L20B or RD) seeded into microtitre plates. After 24-48 h, the infected cells are stained with monoclonal antibodies specific for poliovirus types 1,2,3 or a blend of the three antibodies followed by an anti-mouse IgG-horseradish peroxidase conjugate. On addition of substrate, infected cells stain an intense blue colour and are easily distinguished from uninfected cells by light microscopy. Poliovirus infection can be detected before the appearance of cytopathic effects (CPE). This Blue-Cell ELISA test was evaluated against conventional culture and seroneutralisation on a range of polio isolates and clinical specimens. The sensitivity and specificity of the Blue-Cell ELISA compared to neutralisation was 100% (87/87) on culture supernatants of poliovirus isolates sent to our reference laboratory for confirmation. All the poliovirus isolates were typed within 24 h of specimen inoculation using the new method compared to 6-10 days by conventional culture and neutralisation. The method proved to be more sensitive than conventional culture when clinical specimens were examined. Of 43 clinical specimens from which poliovirus had been previously isolated by various laboratories in the U.K., 30/43 (69.8%) were positive for poliovirus by the Blue-Cell ELISA compared to 29/43 (67.4%) by conventional culture and neutralisation. Neutralisation of specimens exhibiting CPE indicated that all of the polioviruses were correctly typed with the new method. CPE was not observed by conventional culture in any specimen that was negative in the Blue-Cell ELISA. There were no cross-reactions with a range of other enteroviruses.

Viral meningitis in Cyprus and England : summer 1996.

An outbreak of viral meningitis began in Cyprus on 5 July 1996. By 28 August a total of 316 cases had been admitted to hospital, most of whom were infants and young children; 55 (17%) were less than 1 year of age, 117 (37%) were aged 1 to 4 years, 103 (33