Research Update: A new HIV primary and secondary prevention continuum
The HIV care continuum has become an important way to visualize how well we are doing at ensuring people living with HIV achieve the best possible health and well-being outcomes and minimize the risk of transmission. An undetectable viral load is the key outcome in the HIV care continuum because it is associated with both reduced morbidity and mortality but also a substantially reduced risk for HIV transmission.
A new model, the HIV prevention continuum (Figure 1), has been proposed in the United States as another potentially valuable tool to identify the steps necessary to ensure that people who are HIV negative receive the health and support services they need to remain negative. This model is cyclical in nature.
HIV testing is conceived as the initial entry point into the continuum, where the outcome of the test—either negative or positive—moves people either into the primary HIV prevention continuum or into the HIV care continuum (renamed the secondary HIV prevention continuum).
If a person tests HIV negative, they enter the primary HIV prevention continuum. The first step after a negative test is a risk and needs assessment to better understand the person’s HIV prevention needs to help them reduce their risk in an ongoing way. The assessments could include an array of screenings for sexually transmitted infections (STIs), mental health and substance use issues, intimate partner violence, and trauma. Additionally, health insurance (which is important in the U.S. setting) and other healthcare needs were also identified.
Once assessed, people are linked to the healthcare and community-based services they need such as primary care, housing, substance use services, mental health services, and pre-exposure prophylaxis (PrEP) clinics, etc.
The final element in the cycle is engagement, retention, and adherence to high quality HIV prevention and risk reduction interventions. These were defined as PrEP, post-exposure prophylaxis (PEP), needle exchanges, substance use treatment, mental health services, housing assistance, sexual health services, and behaviour change interventions. Culturally competent case managers, patient navigators, or client-focused services should be used to optimize engagement.
At this point, the HIV prevention loop returns to testing and the cycle begins again and people’s needs are assessed, and they are linked to and engaged in appropriate services.
One of the issues identified is the ability to assess outcomes along the HIV primary prevention continuum. The data required to assess these outcomes would have to be combined from many different service systems and the ability to do so would have to be developed.
***Conceptual model reprinted with kind permission of Tim Horn and the Treatment Action Group.