B07 Prevention targeting the HIV positives


In the past, efforts to prevent HIV infection have focused on reducing HIV infection risk among individuals with HIV negative or unknown status, which is often referred to as primary HIV prevention. With the availability of highly active antiretroviral therapy (HAART), many people living with HIV/AIDS (PLWHA) are living longer and leading healthier lives. In contrast to primary HIV prevention, prevention activities directed toward PLWHA, also termed secondary HIV prevention, should be specifically devised not only to address the health needs of PLWHA, but also with the intention to prevent transmission to those who are HIV negative.

With an objective of reducing onward transmission of the virus, secondary HIV prevention includes strategies to educate PLWHA regarding means to reduce the risk of HIV transmission to others, facilitate adherence to treatment and maintaining viral suppression, and engage them in acknowledging and reducing their risk practices (including sexual and/or substance use behaviours). In practice, a combination of approaches is recommended to enhance prevention efforts, including (a) partner counselling and referral, (b) screening for risky behaviours leading to HIV transmission and relevant risk reduction counselling, (c) screening for substance use (drugs and alcohol) and referral, (d) drug adherence counselling, (e) screening and treatment of sexually transmitted infections (STIs), (f) assessment of mental health and referral, and (g) addressing inadequacy of social support that might jeopardise treatment adherence. It is important to bear in mind that an ongoing risk assessment is needed as long as PLWHA are engaged in care as their sexual and substance-use behaviours, as well as their risk of transmitting HIV may change over time. This chapter provides an overview of the approach adopted by Department of Health at its Integrated Treatment Centre. Issues related to substance use, drug adherence, screening and treatment of STIs, and psychosocial needs of PLWHA are dealt with separately in Chapters F38, C12, D29 and A4 respectively.

Partner counselling and referral

Partner Counselling and Referral Services (PCRS) as an HIV prevention programme involves a series of well-defined disease prevention activities.[Box 7.1] By working with PLWHA, PCRS identifies, locates, and notifies partners at risk of infection. [HK Guidelines 7A]

Upon notification, partners are offered HIV counselling, testing, and specialist referrals whenever necessary. The purpose of HIV counselling is to empower a partner, regardless of HIV status, with knowledge of HIV prevention. HIV testing enables HIV-infected partners, who may have hitherto been unaware of their status, to seek expeditious medical care.

Currently, HIV status disclosure is central to debates in partner counselling because of its potential for HIV prevention on one hand, and its links to privacy and confidentiality concerns as human-rights issues on the other. Recent studies revealed that few people kept their status completely secret, while disclosure tended to be iterative and was higher in high-income countries. Stigmatisation increases the fears of disclosure and also discourages patients from seeking medical care. Making services available could facilitate HIV disclosure and is as important as individual approaches and counselling. As such, World Health Organization has emphasised in their latest guidelines on HIV partner notification that voluntary assisted partner notification services should be offered as part of a comprehensive package of testing and care for PLWHA.[1]

Box 7.1. PCRS Prevention

Box 7.1. PCRS Prevention

Based on the likelihood of infection, risk of rapid spread and the window of intervention, priorities are set in a PCRS action plan. Pregnant contact is, for example, one example of priority. A contact who engages in high risk activity such as needle-sharing is another. In the absence of such, PCRS generally begins with current or the most recent partners.

PCRS referral plan

After setting the priority, the counsellor helps the index client to work out his/her individual PCRS referral plan. Partner notification is provided using passive or assisted approaches. Clients should be offered multiple options for assisted partner notification, such as contract referral, provider referral or dual referral. To tie in with each client’s unique circumstances and request, referral may be simultaneous or sequential, and may involve more than one referral method. It should be emphasised that HIV partner notification is a voluntary process which is conducted with the consent of the HIV-positive clients, who are also given the opportunity to decline. PLWHA should receive counselling about the benefits and risks so that they can make safe and informed choices.

  1. Passive HIV partner notification – Provider delivers counselling and encourages a client to disclose his/her HIV status to the partner(s) and notify them of their possible HIV exposure, either in-person or by telephone call, text message, e-mail or Internet etc., and refer his/her partners to HIV counselling and testing services. The counsellor should help sum up the notification plan(s) and emphasise on the necessary precautions.
  2. Assisted HIV partner notification – A client is assisted by a trained healthcare provider to disclose his/her status or to anonymously notify the sexual and/or drug injecting partner(s) of their potential exposure HIV infection. The provider then offers HIV testing to these partner(s). Assisted partner notification can be done with the following approaches:
    1. Dual referral – when a trained provider accompanies and provides support to the client who discloses the status and the potential exposure to the partner(s). They work on a plan to bring the partner to the counselling and testing service. Partner’s emotions and confidentiality is a prime concern in such circumstance.
    2. Provider referral – with the consent of the client, a trained provider confidentially contacts his/her partner(s) directly and offers voluntary HIV testing service.
    3. Contract referral – where a client enters into a contract with a trained provider and agrees to disclose the HIV status and the potential HIV exposure to his/her partner(s) by him-/her-self and to refer the partner(s) to HIV testing service within a specific time period. When the referral does not occur within that period, with the client’s prior consent, the provider contacts the partner(s) directly and offer voluntary HIV testing service.

Randomised controlled studies have shown that assisted partner notification services (provider or contract referral) can increase uptake of HIV testing services among partners of HIV-positive individuals and result in high proportions of HIV-positive people being diagnosed, and subsequently linked to care. These studies confirmed that reported social harm and other adverse events following HIV partner notification using either passive or assisted approaches have been rare.[1]

Follow up and working with partners

In subsequent counselling sessions, the index client is followed up on the progress of partner notification and referral, unless in the case of provider-referral. The PCRS cycle ends at one year after its initiation. Another cycle is started whenever the index client has a new episode of at-risk contact with his partner(s). Thus, at any one time, nil or multiple PCRS cycles may be operative. When working with partners, the following are noted:

  1. As part of PCRS, partners shall receive HIV counselling and undertake testing. They have the options of using any available services.
  2. There is no ‘standard’ approach to PCRS. For each category of partners, adjustments are made in order to achieve the highest degree of success.
    • Marital spouse and regular sex partner – Sexual relationship with the index client may have continued in spite of knowledge of the latter’s positive HIV status. Besides encouraging partner to use condom correctly and consistently, an annual HIV screening is also advisable.
    • Non-regular, non-commercial sex partners – Risk reduction counselling should be tailor-made for the individual and which should be, above all, realistic. Although safer sex is the goal, the counsellor is reminded that behavioural modification does not necessarily follow knowledge. Individuals with multiple sex partners and unprotected sex should be advised to have regular HIV screening.
    • Regular or non-regular needle-sharing partners – Harm reduction is the key to success. These individuals would benefit from knowledge of safe drug use with sterile injection equipment and proper disposal of needles. Specifically, they are also advised against reuse of needles, syringes, and other injection equipment. They are also offered referral to methadone treatment programme or other drug treatment services.
    • Offspring – Children born to an HIV positive mother or breast-fed by a mother who seroconverted before giving birth need to be tested for HIV as they are at risk of HIV transmission. Children without risk may also be offered HIV test to allay anxiety of the index client. However, such testing is not part of PCRS.

Handling ‘resistant’ client

PCRS is not a straightforward process with certain clients, notably those who continue to put others at risk, despite the fact that they understand the potential consequences and have received intensive risk reduction counselling. Rarely, the client may confess to a malicious attempt of transmitting the infection to others.

Involuntary PCRS is a confrontational option of last resort, being beset with enormous implications, among which are a breakdown of communication with the client, evaporation of trust of other clients, and possibly deterring clients from seeking medical care. Besides, involuntary PCRS is feasible only if the partner’s contact information is both available and reliable.

Prevention of virus transmission through sex

Among those who are infected with HIV, STIs are common, and immunosuppression may further increase STI risk. In turn, the presence of an STI increases the risk of HIV transmission. In the HAART era, syphilis (all stages) has become one most important STI among PLWHA in Hong Kong as well as other Asian countries, especially among men having sex with men (MSM).[2] Many MSM preferred a supportive group intervention that addresses other coping challenges as well as sexual risk reduction.[3] The amount of time and sessions spent in counselling is important for enhancing safer sex self-efficacy and safer sexual practices among PLWHA. Moreover, motivational interviewing based prevention programmes may be needed to facilitate behaviour change.

To prevent sexual transmission of HIV and STI, sexual behaviours of PLWHA are monitored on a regular, for example, yearly basis, through the following means.

  1. Assessment with standardised questionnaire: The counsellors assess patients’ sexual behaviours regularly. Intensive behavioural counselling and PCRS is provided if there are reports of unprotected sex, multiple or anonymous sex partners and symptoms of STIs. They are then monitored and reassessed for sexual risks, progress of behavioural change and needs on an ongoing basis. Multiple sessions of HIV risk reduction counselling and the offering of positive reinforcement may be necessary to maintain patients’ preventive behaviours. For those patients whose sexual risk is related to emotion or substance abuse, referral to supportive services such as psychological treatment, substance abuse treatment, STI treatment and appropriate social services are considered.
  2. Screening for STIs: Routine Venereal Diseases Research Laboratory carbon antigen test (VDRL) screening for syphilis is provided to new patients and then yearly. More frequent screening to detect early syphilis may be necessary for MSM. Screening for gonorrhoea and chlamydia according to exposed anatomic sites, i.e. use of nucleic acid amplification test (NAAT) of pharyngeal, rectal or urine specimen should be offered to those who are sexually active. Yearly cervical examination, apart from the purpose of cancer screening, is indicated for female patients for screening of gonorrhoea and chlamydia. The subject of STI screening is elaborated in Chapter D29.
  3. Treatment and management of symptomatic patient and patient diagnosed STIs: refer to Chapter D29.

Prevention of virus transmission through needle-sharing

For people who inject drugs (PWID), transmission of HIV can occur through direct or indirect sharing. Direct sharing means injecting drugs with a syringe already used by another PWID. Indirect sharing happens when drug solution is contaminated during mixing or distribution. Drug use may also increase the likelihood of engaging in unsafe sexual behaviours.[3] Overseas studies suggested that PWID may use alcohol and/or crack cocaine, which is often associated with increased frequencies of unprotected sex. Some of them may lack the awareness of treatment for STI. On the other hand, drug use may affect adherence to antiretroviral therapy. Some illicit drugs also interact with antiretroviral drugs. Poor adherence can lead to treatment failure, resistance to antiretroviral drugs, increase of viral load leading to ongoing HIV transmission.


HIV-positive PWID should be engaged in a personalised assessment of one’s own risk behaviours. They should be counselled and assisted to (a) identify barriers to quit illicit drug use, (b) identify resources available to help change risk behaviours, and (c) formulate specific and achievable strategies to protect themselves and others.

Motivational interviewing is a counseling approach frequently employed for individuals struggling with addiction. Identification of the push and pull factors of illicit drug use is particularly important. The counsellor must understand the role of illicit drug use in the context of clients’ life. Given the opportunity to discuss these factors may allow the clients to express their concerns honestly instead of feeling obliged to say what they believe the counsellor would want to hear. Building better rapport is crucial and the counsellor would then proceed to facilitate the client to overcome ambivalence or a fear of change and to increase their own motivation.


Effective prevention requires more than simply passing on information, which must be tailored for each patient. Intervention targeting injection risk must address not only the sharing of syringes, but also injection equipment. Sharing of equipment presents a potential route of HIV infection. Sharing drug solutions poses also a significant, but frequently overlooked, HIV transmission risk. Targeted intervention can enable PWID to reduce the risks associated with sharing injection equipment and drug solutions. PWID and their sex partners should be counselled about sexual risks for HIV and the importance of avoiding unprotected sex. PCRS activities should be offered if there is report of sharing of needles or unprotected sex. Advice on harm reduction treatment such as methadone maintenance is needed to reduce drug injection and risk of HIV spread. [Chapter F38]

Prevention of mother-to-child transmission [HK Guidelines 7B]

Perinatal transmission can occur during pregnancy (intrauterine), during labour and delivery (intrapartum), or after delivery through breast-feeding (postpartum). Breastfeeding by an infected mother increases the risk of transmission. Mother-to-child transmission (MTCT) of HIV can be prevented by addressing the prevention needs in women, identifying HIV infection before pregnancy or as early as possible during pregnancy for appropriate interventions (refer to Chapter F33).

Pre-conception counselling should be provided to HIV infected women, which includes family planning counselling and supports to make decisions on conception and contraception. HIV infected pregnant women should receive information about all reproductive options. Health care providers should be aware of the complex issues that HIV infected women must consider when making decisions about their reproductive options and should be supportive of any decision made by the woman. Whatever, the woman’s choice, the counsellor must understand her reproductive intentions and perspective before making any contraceptive recommendations. There should be a discussion of various methods of contraception. The client will need information on the advantages and disadvantages of each method, her responsibilities in preventing future unwanted pregnancies, and available help in initiating and following through on a programme of effective contraception. Interventions to reduce MTCT are discussed in Chapter F33.

Treatment as prevention (TasP) and Undetectable equals untransmittable (U=U)

Treatment as prevention has been a hot area of research, discussion and application in HIV field in the past decade. Early epidemiological studies and ecologic studies had confirmed the importance of plasma HIV-1 viral load in transmission and the role of HAART in averting the HIV epidemic. In 2011, the interim results of HPTN 052 study, a multi-centre randomised controlled trial with over half of the study subjects recruited from Africa, reported a 96% reduction of linked HIV transmission in stable HIV serodiscordant couples who were prescribed early HAART when CD4 was 350-550/μL vs delayed therapy when CD4 fell to <250/μL.[4] Importantly, all study participants were given ongoing counselling on risk behaviours reduction, condom use, and STI diagnosis and treatment. The final results published in 2016 reported that there had been no HIV transmissions within these serodiscordant couples when the HIV-positive partner had a suppressed viral load. WHO has already issued guidance on treatment as prevention for serodiscordant couples, supporting the role of HAART as a public health measure to prevent HIV infection.

Based on more recent studies, including PARTNER, Opposites Attract, and PARTNER2 that were undertaken between 2007 and 2016 involving thousands of serodiscordant couples engaging in condomless sex, both heterosexual and homosexual, there was not a single case of sexual transmission of HIV to the HIV-negative partner while the HIV-positive partner remained virally suppressed.[5][6][7] The US Department of Health and Human Services (DHHS) workgroup, thus, agreed on an updated prevention message that ‘People with HIV who take HIV medicine as prescribed and get and keep an undetectable viral load have effectively no risk of transmitting HIV to their HIV-negative sexual partners’.[8] It is believed that TasP is one of the most powerful prevention strategy to stop new transmissions of HIV and that this message should be integrated into existing comprehensive interventions for HIV prevention and control. Apart from offering regular viral load monitoring, healthcare providers should support clients’ ability to adhere to their HIV medications and maintain viral suppression, empowering them to get maximal benefit from this prevention strategy.

UNAIDS also endorses the concept of Undetectable = Untransmittable (U=U) in 2018, acknowledging the evidence that PLWHA who are taking effective antiretroviral therapy and whose level of HIV is suppressed to undetectable levels do not transmit HIV sexually.[9] It is believed that recognition of U=U can respond to stigma and motivate efforts to become virally suppressed and continue follow-up care among PLWHA.


  1. World Health Organization. Guidelines on HIV self-testing and partner notification: supplement to consolidated guidelines on HIV testing services. Geneva: WHO, 2016. link
  2. Ahn JY, Boettiger D, Kiertiburanakul S, Merati TP, Huy BV, Wong WW, Ditangco R, Lee MP, Oka S, Durier N, Choi JY; Treat Asia HIV Observational Database. Incidence of syphilis seroconversion among HIV-infected persons in Asia: results from the TREAT Asia HIV Observational Database. J Int AIDS Soc 2016;19(1):20965. link
  3. Vanable PA, Carey MP, Brown JL, Littlewood RA, Bostwick R, Blair D. What HIV-positive MSM want from sexual risk reduction interventions: Findings from a qualitative study. AIDS Behav 2012;16(3):554-63. link
  4. Cohen MS, Chen YQ, McCauley M, Gamble T, Hosseinipour MC, Kumarasamy N, Hakim JG, Kumwenda J, Grinsztejn B, Pilotto JH, Godbole SV, Mehendale S, Chariyalertsak S, Santos BR, Mayer KH, Hoffman IF, Eshleman SH, Piwowar-ManningE, Wang L, Makhema J, Mills LA, de Bruyn G, Sanne I, Eron J, Gallant J, Havlir D, Swindells S, Ribaudo H, Elharrar V, Burns D, Taha TE, Nielsen-Saines K, Celentano D, Essex M, Fleming TR; HPTN 052 Study Team. Prevention of HIV-1 infection with early antiretroviral therapy. N Engl J Med 2011;365(6):493-505. link
  5. Rodger AJ, Cambiano V, Bruun T, Vernazza P, Collins S, van Lunzen J, Corbelli GM, Estrada V, Geretti AM, Beloukas A, Asboe D, Viciana P, Gutiérrez F, Clotet B, Pradier C, Gerstoft J, Weber R, Westling K, Wandeler G, Prins JM, Rieger A, Stoeckle M, Kümmerle T, Bini T, Ammassari A, Gilson R, Krznaric I, Ristola M, Zangerle R, Handberg P, Antela A, Allan S, Phillips AN, Lundgren J; PARTNER Study Group. Sexual activity without condoms and risk of HIV transmission in serodifferent couples when the HIV-positive partner is using suppressive antiretroviral therapy. JAMA 2016;316(2):171-81. link
  6. Bavinton BR, Pinto AN, Phanuphak N, Grinsztejn B, Prestage GP, Zablotska-Manos IB, Jin F, Fairley CK, Moore R, Roth N, Bloch M, Pell C, McNulty AM, Baker D, Hoy J, Tee BK, Templeton DJ, Cooper DA, Emery S, Kelleher A, Grulich AE; Opposites Attract Study Group. Viral suppression and HIV transmission in serodiscortant male couples: an international, prospective, observational, cohort study. Lancet 2018;5(8):e438-e447. link
  7. Rodger AJ, Cambiano V, Bruun T, Vernazza P, Collins S, Degen O, Corbelli GM, Estrada V, Geretti AM, Beloukas A, Raben D, Nwokolo N, Coll P, Antinori A, Gerstoft J, Prins JM, Raffi F, Rieger A, Blaxhult A, Weber R, van Eeden A, del Romero J, Clarke A, Brockmeyer NH, Leclercq V, Leon A, Kitchen M, Jessen H, Brinkmann K, Bogner J, Gutiérrez F, Phillips AN, Lundgren J for the PARTNER Study Group. HIV transmission risk through condomless sex in gay couples with suppressive ART: The PARTNER2 Study extended results in gay men. Presented at the 22nd International AIDS Conference; July 23-27, 2018; Amsterdam, the Netherlands. link
  8. Centers for Disease Control and Prevention. Evidence of HIV Treatment and Viral Suppression in Preventing the Sexual Transmission of HIV. Atlanta: CDC National Center for HIV/AIDS, Viral Hepatitis and TB Prevention, 2018. link
  9. Joint United Nations Programme on HIV/AIDS. UNAIDS Explainer: Undetectable = Untransmittable – public health and HIV viral load suppression. Geneva: UNAIDS, 2018. link

Hong Kong Guidelines

  1. Committee on Promoting Acceptance of People Living with HIV/AIDS (CPA). Recommended ethical principles on partner counselling and referral for HIV infected individuals in Hong Kong. Hong Kong: Advisory Council on AIDS, 2004. Available from: APPENDIX II: X15 and link
  2. Scientific Committee on AIDS & STI. Recommended clinical guidelines on the prevention of perinatal HIV transmission. Hong Kong: Centre for Health Protection, 2018. Available from: APPENDIX II: X1 and link