HIV/AIDS Care Continuum

What is the HIV care continuum?

The HIV care continuum—sometimes also referred to as the HIV treatment cascade—is a model that outlines the sequential steps or stages of HIV medical care that people living with HIV go through from initial diagnosis to achieving the goal of viral suppression (a very low level of HIV in the body), and shows the proportion of individuals living with HIV who are engaged at each stage. 

In 2011, Dr. Edward Gardner and colleagues observed that “for individuals with human immunodeficiency virus (HIV) to fully benefit from potent combination antiretroviral therapy, they need to know that they are HIV infected, be engaged in regular HIV care, and receive and adhere to effective antiretroviral therapy.” They acknowledged, however, that various obstacles contribute to poor engagement in HIV care, substantially limiting the effectiveness of efforts to improve health outcomes for those with HIV and to reduce new HIV transmissions. So, the researchers set out to describe and quantify the spectrum of engagement in HIV care.

The result of the researchers’ work was the HIV care continuum (or “cascade”), which they defined as having the following stages: diagnosis of HIV infection, linkage to care, retention in care, receipt of antiretroviral therapy, and achievement of viral suppression. Many in the HIV field at the Federal, state, and local levels have since used or adapted this HIV care continuum to better identify gaps in HIV services and develop strategies to improve engagement in care and outcomes for people living with HIV.

In 2013, the HIV Care Continuum Initiative was established as the next step in the implementation of the National HIV/AIDS Strategy. The Initiative directed Federal departments to accelerate efforts to increase HIV testing, care, and treatment to better address drop-offs along the HIV care continuum and increase the proportion of individuals in each stage along the continuum. An HIV Care Continuum Federal Working Group was established to support the Initiative and coordinate Federal efforts, and this Working Group developed a series of recommendations. These recommendations were fully integrated into the Steps and Actions of the National HIV/AIDS Strategy: Updated to 2020.

Different research studies present the stages of the HIV care continuum in different ways. A November 2014 Vital Signs report published by the Centers for Disease Control and Prevention (CDC) discusses the following stages of the continuum:

• HIV testing and diagnosis —The HIV care continuum begins with a diagnosis of HIV infection. The only way to know for sure that you are infected with the HIV virus is to get an HIV test. People who don't know they are infected are not accessing the care and treatment they need to stay healthy. They can also unknowingly pass the virus on to others. CDC recommends that all adolescents and adults be tested for HIV infection at least once, and that persons at increased risk for HIV infection be tested at least annually.
• Getting and staying in medical care—Once you know you are infected with the HIV virus, it is important to be connected to an HIV healthcare provider who can offer you treatment and prevention counseling to help you stay as healthy as possible and prevent passing HIV on to others. Because there is no cure for HIV at this time, treatment is a lifelong process. To stay healthy, you need to receive regular HIV medical care.
• Getting on antiretroviral therapy— Antiretrovirals are drugs that are used to prevent a retrovirus, such as HIV, from making more copies of itself. Antiretroviral therapy (ART)is the recommended treatment for HIV infection. It involves using a combination of three or more antiretroviral drugs from at least two different HIV drug classes every day to control the virus. U.S. clinical guidelines recommend that everyone diagnosed with HIV receive treatment, regardless of their CD4 cell count or viral load. Treatment with ART can help people with HIV live longer, healthier lives, and has been shown to reduce sexual transmission of HIV by 96 percent.
• Achieving viral suppression—By taking ART regularly, you can achieveviral suppression, meaning a very low level of HIV in your blood. You aren’t cured. There is still some HIV in your body. But lowering the amount of virus in your body with medicines can help you stay healthy, live longer, and greatly reduce your chances of passing HIV on to others.

Read “Understanding the HIV Care Continuum (PDF),” a CDC fact sheet that describes the HIV care continuum, discusses various approaches and data used to develop the HIV care continuum, and explains how CDC uses the continuum to help guide the nation’s response to HIV.

What does the HIV care continuum show?

According to the latest CDC data, of the 1.2 million people living with HIV in the U.S. in 2011, an estimated 86% were diagnosed. This means that 14% (approximately 1 in 7 people living with HIV) were unaware of their infection and therefore not accessing the care and treatment they need to stay healthy and reduce the likelihood of transmitting the virus to their partners.

In addition, people living with HIV are dropping off at every subsequent stage in the continuum. Of the 1.2 million Americans living with HIV in 2011, CDC data showed that 40% were engaged in HIV medical care, 37% were prescribed ART, and 30% had achieved viral suppression. In other words, only 3 out of 10 people living with HIV had the virus under control.

The CDC’s 2014 analysis also provided further information about the 70% of people living with HIV who did NOT have their virus under control in 2011. Among the nearly 840,000 who had not achieved viral suppression:

• 20% did not yet know they were infected
• 66% had been diagnosed, but were not engaged in regular HIV care
• 4% were in HIV care, but were not prescribed ART
• 10% had been prescribed ART, but had not yet achieved viral suppression.

The percentage of Americans with HIV who achieved viral suppression has remained roughly stable over the past few years (26 percent in 2009 vs. 30 percent in 2011).

This underscores the importance of continued and intensified efforts to reach more people with testing and to make sure that those with the virus receive prompt, ongoing care and treatment to help them live longer, healthier lives and prevent the spread of HIV to others.

In addition, on February 23, 2015, CDC published a study in JAMA Internal Medicine providing the first U.S. estimates of the number of HIV transmissions from people engaged at the five stages of the HIV care continuum. The study shows that 91.5 percent of new HIV infections in 2009 were attributable to people with HIV who were not in medical care, including those who didn’t know they were infected. In comparison, less than six percent of new infections could be attributed to people with HIV who were in care and receiving antiretroviral therapy. In other words, according to this research, 9 in 10 new HIV infections in the United States could be prevented through early diagnosis and prompt, ongoing care and treatment. Read more about the study.