Problems of laboratory diagnosis of respiratory syncytial virus infection in childhood

Summary

During December, 1962 to March, 1963 the Glasgow area experienced an epidemic of RS virus infection amongst young children. Throat swabs for virus isolation and two or more serial specimens of sera were obtained from each of 42 children (41 under 3 years of age) with acute respiratory infections.

A higher proportion of infections were diagnosed serologically by CF than by virus isolation, a four-fold or greater rising titre being obtained in 47% of the cases. However, two factors were of importance in obtaining optimal results by CF — namely (a) collection of convalescent serum after the fourteenth day of illness, preferably between the fourth and sixth weeks, and (b) the use of a potent antigen. Some difficulties in the preparation of high-titre antigen were studied.

Higher neutralizing antibody levels were obtained in some cases against the current epidemic strain than against the prototype strain; however, they were generally much lower than the corresponding CF titres.

For virus isolation throat swabs were inoculated directly after collection into tissue culture tubes in the ward. One major disadvantage of this method was that cultures from 12 swabs had to be discarded because of fungal contamination. Of the remaining 29, RS virus was isolated from 28%.