In this survey, HIV-positive MSM had significantly different drug use behaviour which may explain the higher HCV burden. However, HCV was also associated with HIV-negative MSM engaging in high-risk sexual practices. All MSM attending sexual health clinics must have a risk assessment and HCV screening should be offered based on the risk. Further studies are warranted to explore the interplay between HCV and HIV risk associated with drug use versus sexual practices.

The development of an osteonecrotic (avascular necrosis) hip joint in a patient with symptomatic CDC Stage IV C2 disease is reported. The diagnosis was aided by radiological assessment and confirmed by radioisotope bone scan. This case serves as yet another musculoskeletal manifestation in association with HIV infection.

Aims-To determine whether oro-pharyngeal colonisation by Chlamydia trachomatis occurs in patients at risk of genital chlamydia infection; to determine whether screening pharyngeal specimens by polymerase chain reaction (PCR) increases detection of C trachomatis compared with isolation and the immune dot blot test; and to correlate the detection of C trachomatis and Neisseria gonorrhoeae in the pharynx with a history oforo-genital contact.Methods-Thirteen homosexuals and 11 heterosexuals were included in the study.Urogenital and pharyngeal specimens were tested for C trachomatis and N gonorrhoeae using standard clinical diagnostic procedures. Two different PCR methodologies were also used to detect C trachomatis in the pharyngeal specimens. Results were correlated with the mode of sexual practice. Results-Oro-genital sexual contact was practised by 64*9% (72/111) of heterosexuals in addition to penetrative penovaginal intercourse. Additionally, 62-1% (77/124) of all patients did not use any form of barrier protection. Of those who admitted to oro-genital sexual contact, 17*6% ofpatients with a genital chlamydial infection and 36-4% of those with genital gonorrhoea also had asymptomatic pharyngeal colonisation. C trachomatis was detected in three of 124 (2-4%) pharyngeal specimens by PCR which were reported as negative by chlamydial culture; one was positive by the immune dot blot test. Conclusion-The majority of patients practised unprotected oro-genital contact and significant pharyngeal colonisation by C trachomatis and N gonorrhoeae occurred if genital infection was present. Despite the use of PCR in a population at high risk of sexually transmitted disease, the prevalence ofchlamydia in the pharynx was very low. This indicates that transmission of C trachomatis to the oropharynx does not pose a serious health risk and that screening of patients for oropharyngeal C trachomatis is not worthwhile. (J Clin Pathol 1995;48:658-