The science of partner notification: A review of the available evidence

Introduction

Partner notification is the voluntary and anonymous public health activity of telling the partners of an index case (someone who is diagnosed with HIV or AIDS) that they have been exposed to HIV. Partners are persons with whom the index case has had unprotected sex, shared injecting equipment (needles, rigs), or engaged in some other high-risk activity. Partner notification is a purely voluntary activity. The index case does not have to disclose his or her partner’s identity and is in control of the information he or she chooses to disclose to public health professionals. Partner notification is anonymous because after the index case chooses to disclose his or her partners’ contact information, without consent to do so, the index case’s identity is usually not revealed to the partner or partners.

An obvious exception to anonymity would be if the index case is the partner’s sole contact. This would allow the partner to readily deduce who exposed him or her to HIV and, thus, the index case’s anonymity would be necessarily compromised. These considerations should be discussed fully prior to the initiation of partner notification interventions. In the event that a partner makes this deduction, the health care professional should not confirm or deny these suspicions.

The literature pertaining to partner notification and HIV provides compelling evidence that notifying partners of patients newly diagnosed with HIV/AIDS is an important ethical duty. Partner notification provides vital information to identified contacts and enhances the ability of public health professionals to contain the spread of HIV in the general population.

Methods of partner notification

There are three basic methods of partner notification: patient referral, provider referral, and conditional referral.

Patient referral

Patient referral is when the index case decides to tell his or her partners that they have been exposed to HIV. If this method is chosen, public health professionals will counsel the index case about how to approach partners, what to tell them, and where to refer them for services (testing, counseling, and treatment if needed).

Provider referral

Provider referral is when the index case gives the public health professional the names and locating information of his or her partners. The public health professional will then contact the partners, tell them of their potential exposure, and refer them to services. In all circumstances the provider will protect the anonymity of the index case.

Conditional referral

Conditional referral is a combination of patient and provider referral. Index cases choose to notify partners themselves but make an agreement with their public health professional that if they cannot locate some partners, or if some of those partners do not report to public health for follow-up, the provider will contact the partners directly.

Partner notification is often confused with the ethical and legal requirement known as the duty to warn, but the two are fundamentally different.[1,2] The duty to warn occurs when the health care professional has reason to believe that the index case is going to expose (or is exposing) an identified partner to a significant risk of acquiring HIV without disclosing, beforehand, his or her HIV infection. In the case of a spouse or close relation, this third party risk is usually ongoing. The duty to warn is not a voluntary activity and when it is done it is not easy to protect the index case’s anonymity to the same extent that partner notification can protect anonymity.

Benefits of partner notification

There are a number of good reasons for partner notification. For instance, partner notification can identify partners who have been infected with HIV but who are unaware of their infection.[1-15] The partners of index cases (people newly diagnosed with HIV) are at extremely high risk for having contracted HIV. In fact, some studies have revealed that the prevalence of HIV among partners of index patients could range from 15% to 30%.[4,16] One study published in the Lancet[17] revealed that of 350 named contacts (partners) who received HIV testing and counseling, 53 (15%) were HIV-positive and previously unaware of their status. Another study presented to the XI International Conference on AIDS (1996)[10] explained that of 560 contacts who received HIV counseling and testing, 122 (22%) were HIV-positive and were previously unaware of their HIV-positive status. This suggests that partners of index cases are at high risk of contracting HIV and are generally unaware of their exposure.

Another benefit of partner notification is that it can help modify the high-risk behaviors of partners who may not be infected but were unaware of their exposure to HIV.[18-20] A study presented to the Fourth Conference on Retrovirus and Opportunistic Infections (1997)[19] explained that in a randomized controlled trial, condom use was significantly higher and the number of new sexual partners was fewer in the group of sexual partners who received enhanced HIV counseling and education than in the control group who did not receive this enhanced intervention. An international study conducted in Zaire found that discordant couples who were offered intensive counseling resulted in substantially increased condom use, from less than 5% at baseline to 71% at 1 month follow-up and 77% at 18 month follow-up.[20]

There is also evidence to suggest that most partners who are told about their exposure to HIV appreciate this information.[21] A 1990 US study published in JAMA revealed that of 132 partners located, 87 stated that the health department did the right thing by telling them about their exposure, and 92% said that the health department should continue with this valuable activity.

It is also possible to make some loose generalizations about the efficacy of the different models of partner notification. Most of the literature suggests that provider referral is a lot more effective in contacting partners and revealing undiagnosed HIV than patient or conditional referral.[1,3,4,8] A study published in the New England Journal of Medicine[1] compared the results of provider referral and patient referral. In the provider referral group, 78 of 157 partners (50%) were successfully notified, whereas in the patient referral group 10 of 153 (7%) were notified. It was further found that of the partners notified through the provider referral group, 94% were unaware that they had been exposed to HIV.

Another important finding is that, generally, most index cases are willing to participate in partner notification programs if their anonymity can be guaranteed.[22] A study of 25 HIV-positive women in the US revealed that 68% of the participants were willing to give the names of their partners as long as the index case’s confidentiality was maintained. Interestingly, 20% were willing to participate in a partner notification program even if their names were disclosed to the partner.

Limitations of partner notification

There are a number of limitations associated with partner notification. For instance, the ability to notify partners of index cases is only as good as the contact information the index case can or will disclose.[3,21,23,24] The index case may not be able to identify a particular partner because of an anonymous encounter where high-risk behavior took place, or perhaps the index case simply does not want to disclose this information at all. Since partner notification requires the voluntary participation of the index case, there is no way to get around this limitation. The index cases’ refusal to participate in partner notification should in no way limit their ability to access health services they require.

Patient referral is very cost effective, but since it requires index cases to initiate contact with past partners themselves, their anonymity is necessarily compromised, and concern has been expressed about the vulnerability of index cases to emotional or physical harm.[22,25,26] For some partners their only possible exposure to HIV may be the index case, so it will allow that partner to identify who put them at risk of infection. Domestic violence screening must be part of post-test counseling before any form of partner notification can be initiated.

Competing interests

None declared.

Timothy K.S. Christie, PhD and Perry R.W. Kendall, MBBS, FRCPC

Dr Christie is a health care ethicist with the BC Centre for Excellence in HIV/AIDS and Providence Health Care. Dr Kendall is BC’s provincial health officer.