Same-day testing for human immunodeficiency virus antibodies.

We analysed the specificity of a screening enzyme-linked immunosorbent assay for human immunodeficiency virus antibodies, and found that 18 of 1878 serum specimens (1.0%) from an open access clinic gave false reactive results. Introduction of true same-day testing therefore required the use of more than one assay before a reactive result could be reported. A testing strategy was devised with a 4 h turn-around time which gave accurate results for 11 positive and 119 negative specimens.

Computer network for a diagnostic virology laboratory.

A data base for a large diagnostic virology laboratory is described. The system uses a network of personal computers. It allows the entry, long-term storage, and subsequent retrieval of specimen and patient records (comprising personal identifiers and specimen and result information), and hard-copy results reporting. Sited entirely within the laboratory, the network is not connected to a modem. Within the laboratory there is restricted access to human immunodeficiency virus test results to guarantee patient confidentiality. Retention of a hard-copy of specimen request cards ensures the availability of the original clinical information. The data base is copied on a second file server to facilitate searches, and daily streaming onto magnetic tape provides system protection in the event of hard disc failure. Matching of old and new patient records is done by surname, date of birth, and sex, and therefore duplicate records accumulate when patient names are misspelt on specimen request forms. The system requires further development to speed searches of the data base and to achieve automatic generation of laboratory worksheets. Future goals are the replacement of hard-copy records of clinical information and hard-copy reporting with on-line access to hospital data bases and on-line requesting by and reporting to the clinician.

Screening of bone marrow and kidney transplant donors and recipients for cytomegalovirus antibody by commercial latex agglutination or competitive enzyme-linked immunosorbent assays.

A commercial competitive enzyme-linked immunosorbent assay and a sensitive in-house radioimmunosorbent test detected cytomegalovirus (CMV) antibody in similar numbers of serum specimens (66 and 67 of 152, respectively) obtained from bone marrow and renal transplant donors and recipients. In contrast a commercial latex agglutination assay for CMV antibody apparently gave false positive results when testing serum specimens obtained from organ donors. The implications for CMV screening of organ transplant donors and recipients are discussed.

The production of human parvovirus capsid proteins in Escherichia coli and their potential as diagnostic antigens.

We have expressed a number of polypeptides derived from the capsid proteins of the human parvovirus B19 in Escherichia coli. These include native VP1 (84K) and VP2 (58K) proteins and also fusions to beta-galactosidase containing differing amounts of the amino terminus of the VP1/2 polypeptide. Although each of these was expressed at high levels and the majority were produced as full-length proteins, only one was soluble. This soluble polypeptide, p132, is a beta-galactosidase fusion protein that includes 145 amino acids from B19 which are entirely derived from the region unique to VP1. Despite containing such a small portion of VP1, which itself constitutes only 4% of total capsid protein, p132 reacted with all our known anti-B19 IgM-positive human serum samples. We conclude that this region contains epitopes which must be prominently exposed on the intact virus. We have demonstrated the use of this recombinant antigen in a simple diagnostic assay for B19-specific antibodies which can be used for initial screening of human serum samples. In a survey of 103 serum specimens, our ELISA positively identified all samples (19/19) which were positive by IgM antibody capture radioimmunoassay. The recombinant p132 antigen is efficiently produced and readily purified from E. coli, and its use as a diagnostic antigen should increase the availability of routine clinical testing for human parvovirus infection.

A large outbreak of keratoconjunctivitis due to adenovirus type 8.

A large nosocomial outbreak of keratoconjunctivitis due to adenovirus type 8 is described. Two hundred cases were identified, 123 by isolation of the virus and 77 by detecting HI antibodies in convalescent sera. Infection usually presented as a severe keratoconjunctivitis, and 107 (54%) of infected patients developed sub-epithelial corneal opacities. The majority (66%) of infections were acquired at the accident and emergency department attached to a large urban eye hospital when patients attended for other reasons; trauma to the eye, especially corneal foreign bodies, was the most frequent cause for the initial attendance. Transmission of virus within the family occurred in 13% of cases, but there was little spread outside family or hospital environments. The outbreak lasted from May to September, 1982, but it was not confirmed by isolation of the virus until the end of June when control measures were instituted. Delay in applying control measures was probably the major factor accounting for this large, prolonged outbreak of epidemic keratoconjunctivitis.