Patricia E. Gibson

A search for a characteristic illness in children with serological evidence of viral or toxoplasma infection.

Summary Sera from approximately 200 children taken on admission to a paediatric unit were tested for long and short term antibodies to the listed agents. A clinical questionnaire was filled in at the same time. These agents were selected because the typical clinical condition is rarely manifest when primary infection occurs in childhood or because no characteristic clinical condition has yet been described at any age. The common ages for primary infection of these agents were deduced from the graphs showing the proportion of children at each year of age with long term antibody. Sera positive for short term antibody indicated current or recent infection. The clinical condition noted on admission was extracted for those with short term antibody. Primary infections with polyomavirus BK and Epstein Barr (EB) virus were common under the age of five years and indeed 90 per cent of children acquired BK antibody before five years, the majority at three or four years. Hepatitis A and parvovirus infections affected about 30 per cent of children usually between four and ten years and infections with toxoplasma and polyomavirus JC were rare before ten years of age.

An M-antibody capture radioimmunoassay (MACRIA) for detection of JC virus-specific IgM

A solid-phase M-antibody capture radioimmunoassay (MACRIA) for detecting JC-specific IgM is described. The assay is based on a JC-specific monoclonal antibody (17.7.6) and Nonidet P40-treated, glycine-extracted antigen. MACRIA is more sensitive for JC IgM detection than haemagglutination inhibition (HI) following serum fractionation on a sucrose density gradient, and can be applied to large numbers of sera. The specificity of the assay was confirmed by examining sera from several acute virus infections and also those containing rheumatoid factor. Sera collected from renal transplant recipients with known active JC virus infection were found to contain more than 5 units of JC IgM. In this group of patients JC IgM represents either primary or reactivated JC infection. JC IgM was detected by MACRIA in 15 of 100 unselected blood donors, indicating that JC IgM is frequently produced in healthy seropositive individuals. Thirteen of the 15 sera positive from blood donors contained only low levels of JC IgM (< 5 units), but the specificity of all these results was confirmed in a blocking assay. It is suggested that these low levels of JC IgM may occur in up to 28% of seropositive individuals and result from active JC antigenic stimulation in healthy immunocompetent adults.

Human papillomavirus type 31 infection of the uterine cervix in England

A total of 452 uterine cervical scrapes, from two centres in England, has been examined by dot blot hybridisation for the presence of human papilloma virus (HPV) types 6, 11, 16, 18 and 31. HPV DNA was found in 36.5% samples. Twenty-nine of the women were infected with more than one type. Of those with detectable HPV, 14.5% had HPV type 31 infections. This type appears to cause significant infection of the genital tract in England.