Incorporation of regularised urine-based HIV testing in methadone treatment programme for enhancing the effectiveness of HIV prevention in drug users

Abstract

Methadone maintenance is an effective means of preventing HIV transmission in drug users, through the reduction of injection and needle-sharing. In Hong Kong, a low threshold approach has been adopted in the introduction of methadone maintenance since over 30 years ago. The methadone treatment programme (MTP) now reaches about 9000 drug users regularly. HIV prevalence has remained low at below 1%. The rising HIV prevalence in neighbouring cities calls for an enhancement of the MTP in Hong Kong. The provision of HAART (highly active antiretroviral therapy) in conjunction with counseling in a specialized care setting could potentially reduce the chance of virus dissemination from known positive drug users. Early diagnosis of HIV infection and their prompt referral to care are however the pre-requisites. A new programme was introduced to offer urine-based HIV testing on an opt-out basis. Over a three-month pilot in 2003, 74.7% (1834) of 2456 methadone users were tested. During the full-year programme in 2004, attendees of 20 methadone clinics were tested in four clusters. A total of 8905 tests were provided in the clinics, amounting to 90% of the active caseload during the testing periods. The coverage varied in different clinics, ranging from 71.9% to 100%. Large clinics with higher turnover were liable to have a lower coverage. The general acceptance of drug users to the new testing programme was high. Lack of motivation was determined to be the single most important reason for refusing the test. The testing nevertheless has provided a new opportunity for arousing AIDS awareness in methadone users, including those who chose to opt out. Surveillance was enhanced: HIV prevalence was 0.5% in the 2003 pilot and 0.2% during the 2004 full-year programme. The difference might have arisen from the self-exclusion of known positive individuals in the second year. A total of 32 drug users, 24 of which newly diagnosed, were tested positive in the urine-based HIV testing programme. The provision of clinical management, and the linkage with public health interventions are additional benefits brought about by the programme, which may also lead to better control of the epidemic. In conclusion, the incorporation of urine-based HIV testing in a conventional methadone clinic network is feasible. The testing would, in the next phase, be regularized by repeating in yearly cycles. The wide coverage, adoption of a routine but voluntary testing strategy, and the integration of clinical and public health intervention, are lessons learned from the programme. The maintenance of a low HIV prevalence in drug users, amidst potential changes in HIV epidemiology and pattern of drug use, remains a challenge for Hong Kong.