For people living with HIV, knowing your status is an important first step to accessing care and, when ready, treatment. Advances in our understanding of how antiretroviral treatment improves the long-term health of people living with HIV and how it reduces the risk of passing HIV to others has created a renewed resolve by many working in HIV to investigate ways to diagnose those living with HIV who don't know it (the undiagnosed). This is essential to ensure both the health and prevention benefits of antiretroviral treatment are optimized.
Using the recent example of the Seek and Treat for Optimal Prevention of HIV/AIDS (STOP) Project in Vancouver BC, this article will explore two approaches to diagnosing the undiagnosed: routine testing and targeted testing. For many working in HIV there are strong opinions on both sides. We look at how these strategies may be complementary to one another.
The Shifting Reality of HIV
As of 2011, it was estimated that 25% of people living with HIV in Canada were not aware they were living with HIV (17,980 people).¹ Furthermore, many people are being diagnosed later in their infection.²˒³ In 2012 in Manitoba, for example, 41% of people had CD4 counts of fewer than 200 at the time of diagnosis.⁴ A study conducted between 1998 and 2003, predominantly among Aboriginal peoples, found that 28% of clients had a CD4 count of fewer than 200 at the time of diagnosis.⁵⁻⁷ These data suggest that current testing strategies are inadequate. It is essential that we address this gap because missed and late diagnoses have health and prevention implications.
Antiretroviral treatment (ART) has evolved dramatically since it first became available in 1996. Newer medications are more potent, less toxic and easier to take than ever before. We now know that early initiation of ART has benefits for both the long- and short-term health of people living with HIV. In addition, research shows that people living with HIV are much more likely to take significant steps to avoid passing on HIV once they know they have HIV.⁸˒⁹
We have also learned that HIV testing has other implications for HIV prevention. Early diagnosis may help identify people in the early or acute stages of HIV infection, when prevention counselling can be particularly important. During acute HIV infection, people have higher amounts of virus in their bodily fluids making them more likely to pass HIV to their sexual partners. Early diagnosis can also identify more people who meet the guidelines for starting treatment. Successful treatment drastically reduces a person's viral load, which significantly decreases the likelihood that they will pass HIV to others. This means that if enough people living with HIV know their status, practice safer sex and begin treatment, there is a possibility to significantly reduce the number of new infections.
Understanding Targeted and Routine Testing
Targeted Testing
In Canada, our main testing approach has been targeted HIV testing -- one in which testing is conducted with people/populations identified as at high risk for exposure to HIV. Targeted testing can take two main forms: provider-initiated testing, where a healthcare provider identifies certain risk factors that prompt them to offer an HIV test to their patient, or client-initiated testing (sometimes called voluntary counselling and testing -- VCT),¹⁰ where individuals who feel they are at risk for HIV, or who believe they may have been exposed to HIV, seek out and request HIV testing.
There are many benefits to targeted testing approaches. Targeted testing provides a good opportunity for service providers to provide counselling to people from higher-risk populations, who test negative, about their HIV risk and how they can protect themselves in the future. Resources can also be specifically targeted for testing of communities most affected by HIV. This ensures that testing reaches those most at risk for HIV. Targeted testing approaches are less likely to result in patients being tested without their knowledge due to the pre- and post-test counselling procedures and the requirements for informed consent. Finally, these approaches do not rely on people accessing healthcare services; they can be tailored to delivery in a range of venues such as bathhouses and needle exchange sites.
One major barrier to the success of provider-initiated targeted testing is that it relies on the ability of a healthcare provider to identify risk factors for, or symptoms of, HIV. Healthcare providers may not be able to do this because risk factors or symptoms were not disclosed by the client or because the provider did not know what risk factors or symptoms should prompt them to offer an HIV test.¹¹⁻¹³ In busy healthcare settings, a healthcare provider might decide not to offer an HIV test because they don't feel they have the time to conduct risk assessments (to figure out if a patient might be at risk for HIV) or pre- and post-test counselling.¹⁴ While building the capacity of healthcare providers to conduct targeted HIV testing is possible, its reliance on assessments and actions at the individual level (of either service providers or clients) makes it difficult for this strategy to be employed evenly and on a widespread basis.¹⁵
One major barrier to the success of client-initiated targeted testing is that it relies on a person's ability to understand and accept their risk of getting HIV.¹⁶ In other words, for client-initiated testing to work, an individual has to know what HIV infection is, understand how HIV is transmitted, evaluate their risk, and be able to ask for an HIV test, which some people don't do out of a fear of stigma and discrimination. Studies in both Canada and the U.S. have suggested that often people don't accurately assess their own risk and, therefore, don't seek out testing.¹⁷⁻¹⁹ Even if a client is able to adequately assess their risk for HIV infection, clients may be denied HIV testing by a healthcare provider. This can be due to a lack of knowledge about HIV transmission, because a client has not openly shared the sources of risk for HIV infection in their lives, or because the healthcare provider fears having to give their client an HIV-positive diagnosis.²⁰
Routine Testing
In the broadest sense, routine testing differs from targeted testing in that HIV testing is made a component of periodic routine medical care and that no assessment of risk for HIV is required for a test to be offered to the patient. Routine testing may mean offering to test every person in a particular setting or healthcare environment, such as a hospital emergency room or a family physician's office.
Routine HIV testing is already considered a best practice for pregnant women in Canada. In 2002, the Public Health Agency of Canada (PHAC) recommended routinely offering an HIV test to every pregnant woman in Canada.²¹⁻²³ Every province and territory in Canada has a routine testing approach for pregnant women. This has led to a significant reduction in the number of infants who acquire HIV during pregnancy and childbirth.²⁴
In 2006, the U.S. Centers for Disease Control (CDC) changed their HIV testing guidelines to recommend that HIV testing be conducted as a normal part of medical practice, similar to other treatable conditions.¹⁴ Canada followed suit in 2013 with PHAC developing a new HIV Screening and testing guide, which recommends that consideration and discussion of HIV testing be made a component of periodic routine medical care. However, since the direct delivery of most medical services is exclusively a provincial responsibility the impact of these guidelines on the routine offer of an HIV test is unknown.
Advocates for routine testing strategies argue that this blanketed approach to HIV testing is the "missing ingredient" that is required to identify the significant number of people living with HIV who have not yet received a diagnosis.³˒²⁵˒²⁶ They suggest that offering HIV testing routinely, regardless of a person's real or perceived risk of contracting HIV, will help avoid some of the challenges with targeted testing. Routine testing strategies could also increase HIV diagnoses for those people who access healthcare primarily through walk-in clinics or emergency rooms. They further suggest that making HIV testing a routine part of everyone's healthcare will help de-stigmatize HIV by normalizing HIV and HIV testing. Others argue that testing strategies that rely heavily on routine HIV testing may give the false impression that HIV affects everyone equally. However, some populations are disproportionately vulnerable to HIV transmission and, therefore, should receive the specific opportunities for prevention counselling that arise from targeted testing approaches.
The Question of Cost
Many studies assessing the cost-effectiveness of routine testing suggest that, even in populations with relatively low HIV prevalence, routine testing can be a cost-effective strategy.²⁷⁻³⁰ This is primarily due to the money saved when a person's HIV infection is identified early (avoiding the significant costs that can be associated with late diagnosis) and the savings associated with the prevention of ongoing HIV transmissions. An internationally recognized standard for cost-effectiveness is 0.1%, in other words for every 1000 tests, one test must be positive.³⁰
However, some health economists suggest that the number of routine HIV tests that would need to be performed in order to identify just one HIV infection costs more than simply beefing up targeted testing (and other prevention strategies).³¹ This has led some to question whether it is a practical shift.³²˒³³
Implementing Routine Testing and Protecting Basic Human Rights
Until recently, PHAC recommended that each time an HIV test is offered to a patient, healthcare providers must first obtain informed consent by providing pre-test counselling.³⁴ Pre-test counselling is expected to cover information on confidentiality, the different types of HIV tests and how they work, how results are conveyed, what confirmatory testing is, how HIV is transmitted, specific HIV risk behaviours, risk-reduction strategies, and how to prepare for a positive result.
Research into barriers to increasing the uptake of HIV testing has shown that these counselling requirements (and consent procedures) are perceived by many healthcare providers as too onerous to make routine offers of HIV testing feasible, given the limited amount of time available to counsel clients.²˒³⁵ To address these concerns, the new PHAC HIV screening and testing guide recommends simplified risk assessments, reviews requirements for informed consent, and offers a more flexible approach to pre- and post-test counselling.
British Columbia recently faced challenges such as these when the health authorities in Vancouver worked with healthcare providers to integrate the routine offer of HIV testing into care in family practice and in hospitals. Physicians cited pre-test counselling guidelines as a significant barrier to routine offers of HIV testing to all patients. The B.C. Centre for Disease Control responded by updating its pre-test counselling guidelines. Under the new guidelines, healthcare providers must provide written information about HIV and HIV testing to their patients. This is considered sufficient for informed consent. Healthcare providers continue to be required to provide verbal pre-test counselling to anyone who requests it and they must obtain verbal consent to order an HIV test.
Some organizations, such as the Canadian HIV/AIDS Legal Network and the B.C. Civil Liberties Association have expressed concern that a client's rights to informed consent may be compromised with changes to pre-test counselling procedures and informed consent practices.³³˒³⁴ Furthermore, these organizations strongly support that any changes to testing need to respect a client's right to confidentiality and to opt-out of HIV testing. These are important parts of responding to the HIV epidemic in an ethical and responsible way.
The Vancouver Seek and Treatment for Optimal Prevention of (STOP) HIV/AIDS Project
Since 2010, Vancouver's STOP Project, with funding from the provincial government, has implemented a pilot research project that involves offering both targeted and routine testing as part of a larger seek and treat strategy. This was a two-pronged, complementary approach: City health officials, in collaboration with clinicians and other service providers, significantly expanded opportunities for client and provider-initiated offers of HIV testing (targeted testing) at 88 sites where high-risk populations can be reached. These sites included primary care clinics, bathhouses, mental health and addictions services, youth and abortion clinics, and in three First Nations communities.
At the same time, the Vancouver STOP Project worked closely with physicians to expand provider-initiated offers of testing in family practices and hospitals to all adults who have ever had sex but who have not had an HIV test in the last year (routine testing). In the first year of routine hospital-based testing, 10,102 tests were performed, a four-fold increase from pre-STOP HIV testing rates in hospitals.³⁶
As the number of tests has increased, both types of testing strategies have demonstrated that they are cost effective. Sites providing provider-initiated routine testing services in venues that serve people who may be at high risk for HIV have had an average 0.4% positivity rate (for every thousand tests performed four are positive).⁴ This is well above the cost-effectiveness threshold of 0.2% that Vancouver uses.³⁷ The routine offer of HIV testing in hospitals has also proven cost effective, where the percentage positivity at each of the four hospitals integrating testing into care has ranged between 0.3 and 0.8%.³⁶
In addition, an electronic chart review of people diagnosed with HIV between 2009 and 2011 in Vancouver demonstrated that routine testing could have resulted in earlier diagnoses of HIV. Of the people who were diagnosed late in their infection (defined as a CD4 count below 500 cells/ml), 55% had at least one interaction with the healthcare system where an HIV test could have been offered and performed in the three years before their diagnosis.⁵ By integrating the routine offer of HIV testing, Vancouver has increased the likelihood of early HIV diagnosis, the ultimate goal of HIV testing.
Vancouver achieved this through strong collaboration between Vancouver STOP Project staff and clinical and organizational partners across dozens of sites. In so doing, the city has significantly shifted its HIV testing model from one of exclusive targeted testing to one that provides both targeted and routine testing in an integrated way.
To Target or Routinize Testing?
Although targeted and routine testing are often seen as opposing strategies, they can also be seen as complementary approaches. Instead of thinking about targeted or routine testing, we should probably consider these approaches as two aspects of an integrated testing strategy designed to meet regional or local needs. Integrating routine offers of testing into regular health care does not mean that high-quality provider- or client-initiated targeted testing shouldn't be offered to people with known risk factors. Likewise, targeted testing initiatives alone will not necessarily reach those at highest risk for HIV because of the inherent challenges to accurate risk assessment. Research might help us better understand how these two approaches work together.
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Len Tooley is coordinator of the National Gay Men's Sexual Health Project at CATIE, which aims to facilitate pan-Canadian capacity building and knowledge translation among service providers working with gay/bi/queer/2-spirit men. He is also an HIV/AIDS and sexual health counsellor at the Hassle Free Clinic in Toronto, Ontario.
Logan Broeckaert holds a Master's degree in History and is currently a researcher/writer at CATIE. Before joining CATIE, Logan worked on provincial and national research and knowledge exchange projects for the Canadian AIDS Society and the Ontario Public Health Association.