Survival of Bordetella pertussis in transport media.

virus were, indeed, present in the serum, and specific IgM was detected by radioimmunoassay.4 The other subject had no record of any recent clinical symptoms. His serum had traces of DNA and was negative for IgM and IgG. Antibodies shown by immunoelectroosmophoresis were found in about 25% of the contacts of the two antigen positive subjects. A similar prevalence of human parvovirus infection has been observed in the general population (study in preparation). We must point out, however, that the lack of a follow up on the antibodies in the subjects does not prove that this high incidence of viraemia was related to human parvovirus outbreaks in the two units at that time. The detection in serum of antigen and antibody at the same time, although uncommon, is of some interest and adds evidence to some previous observations on the persistence of the human parvovirus antigenemia during the initial phase of the humoral response.'5 Immunocomplex deposits cause damage leading to a variety of syndromes and some of them, such as rashes and arthralgia, may follow infection with parvovirus.' It would be interesting to find associations between immune complexes and the clinical course of the disease. Assays of circulating human parvovirus immune complexes in acute and early convalescent serum samples may provide useful information. The DNA and IgM and IgG tests were performed in the department of medical microbiology, University College Hospital, London. We thank Dr MJ Anderson for providing virus, reference sera, and research facilities.