Enzyme immunoassay for the detection of Chlamydia trachomatis antigen in urethral and endocervical swabs.

An enzyme immunoassay technique based on the direct detection of Chlamydia trachomatis antigen in urethral or cervical swabs was used for the rapid diagnosis of chlamydial genital infection. Urethral and cervical samples from 140 patients were tested in parallel by enzyme immunoassay and cell culture using iodine staining. The direct test had a sensitivity of 92.5% and specificity of 97.2% when compared with the cell culture system. The enzyme immunoassay technique provides a rapid and simple method for diagnosing chlamydial genital infection and may be performed on a large number of samples in laboratories which do not have tissue culture facilities or a trained microscopist.

Immunocompromise syndrome in homosexual men. Prevalence of possible risk factors and screening for the prodrome using an accurate white cell count.

The immunocompromise syndrome in homosexual men in the USA is thought to be associated with cytomegalovirus (CMV) infection and nitrite intake. Such men often have a lymphopenia. In a clinic in London 76% of 46 unselected homosexual men and 50% of 76 heterosexual controls had serum CMV IgG antibody at a titre of 1/16 or more (p less than 0.01). No case of excretion of CMV in the urine was found. Thirty per cent of the homosexual men admitted to using nitrites. These figures suggest that this population of homosexual men uses nitrites less often than their counterparts in the USA and is less likely to have evidence of active or past CMV infection. In addition, these male homosexual patients seem to be less promiscuous than those reported from the USA. Mean accurate total and differential white blood cell counts, using the Haemalog D automatic white cell counter, were no different in homosexual men (and various at risk subgroups of them) than heterosexuals, suggesting that the prodrome to the immunocompromise syndrome was not present in the London clinic population.

Comparison of ELISA, SPACE, and electron microscopy for the routine diagnosis of rotavirus infection.

Previous studies on the serological diagnosis of rotavirus infection have utilised locally produced antibodies. In this study we have compared two commercially produced assays, an ELISA (Rotazyme, Abbott) and a newly developed assay--solid phase aggregation of coupled erythrocytes (SPACE) (Wellcome Research Laboratories), with electron microscopy (EM). The SPACE test appeared less sensitive than EM. The ELISA was shown to be as sensitive as EM but more versatile. Our experience suggests that the ELISA could be successfully incorporated into the routine of any diagnostic laboratory.