Experimenting on the Sentinels

Populations with Identifiable Risks

Risk behaviours relating to sex and injecting drug use are not easily identifiable. Sex is a private behaviour which people shy away from discussing in the public. This is particularly so when the behaviour involves marginalised communities like commercial sex workers and drug users. The challenge lies in the identification of risk-taking community groups which could be surveyed on a regular basis. Community groups identified for the development of behavioural surveillance systems are: sexually transmitted disease (STD) patients, commercial sex workers (CSW), and drug users. Prison inmates are studied as a significant proportion is known to have abused drugs before admission to the institutes. Surveillance of risk factors in men having sex with men (MSM, or homosexuals) is discussed as they have been hard hit in the pandemics, though the term itself does not imply an increased risk (Box 4.1). Under the ASSR project, surveillance activities have been attempted in four major sentinel sites: (a) Social Hygiene Clinics, (b) AIDS Counselling Service, (c) drug rehabilitation services, and (d) correctional institutes.

Social Hygiene Clinics

The risk factors for HIV transmission and other STDs are basically the same. From the perspective of intervention, there is every reason to integrate HIV and STD programmes for reducing infection in a society. Knowingly STD patients constitute a heterogeneous population. The common characteristic is that they are sexually active people who have somehow failed (at least once) to practise safer sex, leading to the infection by a sexually acquired pathogen. In Hong Kong there is a network of 10 Social Hygiene Clinics in the public service which are operated by the Government to provide free STD diagnosis and treatment to its attendees. About 20% of all STD patients[1] choose to consult these clinics in the event that they develop symptoms/signs of STDs, or are worried that they have contracted the infection. Clients of these clinics therefore make up a useful sampling frame for assessing people with a risk factor for sexually transmitted infection. The clinics are also functioning as a channel for accessing commercial sex workers (CSWs). As discussed in Chapter Three, brothels do not formally exist because illegality to live on earning of prostitution. CSWs do exist in the society, but there is a lack of means for CSWs to comfortably come together. As some of the CSWs do attend the clinics for health advice, the clinics are becoming convenient sentinel sites for evaluating their risk behaviours.

In Hong Kong, the development of a behavioural monitoring system in STD patients can be traced back to the years 1993 and 1994, when two questionnaire surveys were conducted at the Social Hygiene Service to collect information on HIV-related sex behaviours. Through the efforts of the Social Hygiene Service and the AIDS Unit, 823 and 396 clients had responded to the surveys respectively[2]. When the AIDS Scenario and Surveillance Research project was set up in 1994, these surveys became useful reference materials for facilitating the development of a regular system for tracking AIDS-related behaviours. Social Hygiene Clinics have, over the years, assumed the role of a sentinel site for monitoring behaviours in sexually active males who have been practising high risk behaviours (male clients), and female commercial sex workers (some of the female clients) in Hong Kong.

Under the ASSR project, two monitoring systems have been set up at the Social Hygiene Service. In the initial phase, clinic staff were asked to administer a questionnaire, in a format similar to that for the surveys conducted in 1993 and 1994. The questions had however been standardised, and they became the instruments for three waves from 1996 to 1998. In 1995, a separate system was set up whereby trained interviewers visited the Social Hygiene Clinics over a one-month period to collect the same information from the clients. This was both a means to validate the study conducted by clinic staff, as well as an effort to experiment on other methodology for the programme. The latter survey was repeated in 1996. As the two sets of results did not show wide discrepancies, the system administered by clinic staff is being modified for implementation as a regular programme.

AIDS Counselling Service

The AIDS Counselling Service is operated by the Department of Health's AIDS Unit as a clinical outlet for attending to people who have been exposed to the risk of HIV infection. The Service was set up in 1985, which now comprises a telephone hotline, a counselling suite, and is closely affiliated with a clinical unit for people diagnosed with HIV infection. With little exceptions, all who attended the Service have been exposed to certain risks of infection. There are clearly difficulties in using the Service as a sentinel site for behavioural surveillance. The major problem is the heterogeneity of the clientele, as both the level and the type of risk varies significantly. On one end, there are those attending the service without any risk (the worried well); while on the end of the spectrum there are those who have already caught the infection. The type of exposure differs considerably, since an open door policy has been adopted in its running. A client may be a drug user, a health care worker with needlestick injuries, or one who has had unprotected sex once or repeatedly.

Apparently, the AIDS Counselling Service is not the most ideal sentinel site for behavioural surveillance. It does, however, serve the purpose of experimenting on the feasibility of a sustainable behavioural surveillance system. Firstly, the Service provides a convenient site for field-testing the surveillance instruments, i.e. the questionnaire. Clients can be treated as representatives of subjects in other sentinel sites. Research staff could gain experience in administering the questionaire, while testing out the practicability of the protocols which have been designed. Secondly, the Service does attend to a considerable number of MSM. Over the years, researchers of the ASSR project had attempted to set up a behavioural surveillance system in MSM communities but met with difficulties. As MSM has been identified as one of the targeted communities for the next phase of Hong Kong's AIDS prevention programmes[3], a mechanism for behavioural surveillance would likely become a priority in the years to come. In the meantime, the AIDS Counselling Service provides an opening for evaluating the patterns of risk behaviours in MSM, though care must be exercised in interpreting the results in view of the limitation of the methodology.

Beginning 1995, nurse-counsellors have been administering the behavioural questionnaires to clients of the AIDS Counselling Service. This is now a continuous programme, though the results are analysed on a yearly basis. So far four waves have been documented.

Drug Rehabilitation Services

Collection of data on risk behaviours in drug users was undertaken by drug rehabilitation agencies prior to the establishment of the ASSR projects. Since 1994, these initiatives has become streamlined by the ASSR research team. There are now three sentinel 'sites' for the programme, reflecting three specific settings in accessing drug users - an outpatient setting, an inpatient setting, and the street setting. Separately, the Central Registry of Drug Abuse[b] (CRDA) collects data on reported drug users, and publishes the analysis on a half-yearly basis. This is not a survey of specific risk behaviours but it does contains figures on injectors. In the evaluation of AIDS-related behaviours, it is useful to take reference from results of all three "sentinel" sites as well as the CRDA's statistics.

The outpatient setting refers to a network of 21 methadone clinics operated by the Department of Health, providing service to some 7000 drug users on a daily basis[4]. These outpatient-based clinics are effective venues not just for realising the principles of harm reduction, but also for implementing preventive education and the surveillance of risk factors. New clients are routinely interviewed by the clinics' medical staff, who record the practice of risk behaviours on a standard questionnaire form. Data from this survey are collected by ASSR research staff for analysis on a yearly basis. Though useful there are limitations in the utilisation of the channel. Firstly, as it takes time for the data to be collated, there is often a time lag of about a year between interview and the availability of results. Secondly, the programme covers new clients rather than current clients. Interpretation must therefore be treated with care. Todate, pattern of risk behaviours in methadone clients can be tracked as from 1990.

Another channel for the collection of behavioural data is the Shek Kwu Chau Treatment and Rehabilitation Centre. Operated by the Society for the Aid and Rehabilitation of Drug Addicts (SARDA), this is the largest inpatient centre for male drug users. Through interviews, the medical superintendent of the Centre manages to collect information about the practice of risk behaviours in every newly admitted client. These data (from 1991) are collated by the research team and again analysed on a yearly basis. Problems in handling these data are similar to those of the methadone clinics, namely, time lag in obtaining the results and the difficulty in inferring current practice. As the settings and questions vary, it would not be possible to compare data from the two sources.

Whereas both the methadone clinics and Shek Kwu Chau attend to drug users who choose to receive treatment for one reason or another, those accessed on the streets represent current users of drugs. In 1991, a pilot system was launched by Pui Hong Self-Help Association[c] to provide counselling to drug users on the street. The counsellers themselves were ex-drug users who were therefore believed to be better able to identify drug users on the street. The system was expanded to include collection of behavioural risk factors, and has since 1992 become a regular yearly project, operative under the auspices of a working group of the Committee on Education and Publicity on AIDS (of Advisory Council on AIDS). Though an innovative system, the number of clients assessed per year is relatively small (300 to 500). There could also be bias of interviewers in their choice of clients and the possible impacts of their attitude in administering the questionnaire.

Correctional institutes

Correctional institutes are venues where people are detained (often over a finite period) for criminal offences. Theoretically there is no direct relationship between these offences and behavioural risk factors associated with HIV infection. The collection of behavioural data in these settings could however be meaningful in other indirect ways. Firstly, it is speculated that a considerable proportion of inmates have had history of drug use. An evaluation of the pre-admission drug taking behaviours would be a reflection of one facet of the situation in the community. Secondly, there have been studies suggesting that HIV transmission could occur in prison through the use of unclean needles as well as unprotected sex[5]. Monitoring of risk behaviours would therefore be useful in guiding the strategies for intervention activities.

It is with these beliefs that sentinel sites in penal institutes were contemplated. As in the case for other population groups, the establishment of sentinels would not be possible without the support of the very community (correctional services) working closely with the target groups (prison inmates). It was a difficult task to convince the authority of the importance of monitoring behaviors in the prisons, as the move was perceived to imply the existence of such risk behaviours. The focus was tactfully shifted to the determination of behaviour patterns of prisoners before their admission, and the development of education programmes to prepare them for their release. In 1996, the first wave of the behavioural surveillance was conducted, through the assistance of the Society for the Rehabilitation of Offenders, whose social workers visited the prisons on a regular basis. They became the interviewers who approached prisoners selected at random. The project lasted for three months. In the second wave (1997), researchers managed to gain the support of hospital staff of the Correctional Services Department to conduct the survey. Taking into consideration the concern of the correctional institutes, the questions covered only pre-admission behaviours, and there have been substantial alteration to the questionnaire in the two rounds of surveillance. Both sex and drug taking behaviours were included. Researchers were unable to organise the third wave in 1998, though a new round was finally scheduled for 1999.