Suppression of HIV plasma viral load reduces HIV-related morbidity and mortality and can prevent onward transmission of HIV. However, less than 30% of individuals living with HIV in the United States have a suppressed viral load. Viral suppression is the outcome of sequential steps in the continuum of care, including diagnosis, linkage and retention in HIV care, and antiretroviral treatment prescription and adherence (Hall et al., 2013).
Every HIV-infected patient entering into care should have a complete medical history, physical examination, and laboratory evaluation and should be counseled regarding the implications of HIV infection. The goals of the initial evaluation are to confirm the diagnosis of HIV infection, obtain appropriate baseline historical and laboratory data, ensure patient understanding about HIV infection and its transmission, and to initiate care as recommended in HIV primary care guidelines and guidelines for prevention and treatment of HIV-associated opportunistic infections (AIDSInfo, 2013).
The initial evaluation also should include introductory discussion on the benefits of antiretroviral therapy. Baseline information then can be used to define management goals and plans. In the case of previously treated patients who present for an initial evaluation with a new healthcare provider, it is critical to obtain a complete antiretroviral history (including drug resistance testing results, if available), preferably through the review of past medical records. Newly diagnosed patients should also be asked about any prior use of antiretroviral agents for prevention of HIV infection (AIDSInfo, 2013).
A number of laboratory tests are important for initial evaluation of HIV-infected patients upon entry into care, during followup (if antiretroviral therapy has not been initiated), and before and after the initiation or modification of therapy to assess virologic and immunologic efficacy of antiretroviral therapy and to monitor for laboratory abnormalities that may be associated with antiretroviral drugs (AIDSInfo, 2013).
The following laboratory tests performed during initial patient visits can be used to stage HIV disease and to assist in the selection of antiretroviral drug regimens:
A complete list of recommendations for the frequency of testing can be found at this source.
Antiretroviral therapy for the treatment of HIV infection has improved steadily since the advent of potent combination therapy in 1996. New drugs that offer new mechanisms of action; improvements in potency and activity, even against multidrug-resistant viruses; dosing convenience; and tolerability have been approved. Antiretroviral therapy has dramatically reduced HIV-associated morbidity and mortality and has transformed HIV disease into a chronic, manageable condition (AIDSInfo, 2013).
Effective treatment of HIV-infected individuals with antiretroviral therapy is highly effective at preventing transmission to sexual partners. However, less than one-third of HIV-infected individuals in the United States have suppressed viral loads, which is mostly a result of undiagnosed HIV infection and failure to link or retain diagnosed patients in care. Despite remarkable improvements in HIV treatment and prevention, economic and social barriers that result in continuing morbidity and mortality, as well as new HIV infections, persist (AIDSInfo, 2013).
Before 1996 there were three medications available to treat HIV—they were used individually and were of limited benefit. Researchers soon discovered that using these medications in combination, along with new medications (either protease inhibitors or non-nucleoside reverse transcriptase inhibitors) dramatically reduced the amount of HIV (viral load) in the bloodstream of the infected person. When used in combination, each drug targets a separate part of the HIV virus and its replication.
The reduction of deaths from AIDS in the United States has been primarily attributed to this combination therapy, called highly active antiretroviral therapy (HAART). The drugs currently approved for clinical use by the U.S. Food and Drug Administration and used to treat HIV infection belong to six distinct classes. Each of these drug classes act at different steps in the HIV replication cycle:
Despite these tremendous advances in HIV management there remain several important complications related to antiretroviral drug use, one of the most notable being drug-related adverse events and toxicities , which can negatively impact patients’ quality of life, contributing to non-adherence and drug resistance and ultimately effectiveness. Adverse drug reactions to antiretrovirals are a major reason for discontinuing or changing therapy. Furthermore, these drug-related complications can significantly contribute to morbidity, hospitalizations, and mortality in this population (Loutfy et al., 2013).
Antiretroviral drug design, resistance research, and interpretation systems have been largely based on HIV-1 subtype B because of its predominance in the wealthy countries in which antiretroviral drugs were first introduced. However, HIV-1 B subtype represents only about 10% of the overall subtypes in the world. The extreme variability and the high evolution rate of HIV-1 favor the development of antiretroviral resistance (Santoro & Perno, 2013).
Continuum of care in HIV care is a framework for understanding the status of HIV care and treatment. The continuum of care includes diagnosis, linkage and retention in HIV care, and antiretroviral treatment (ART) prescription and adherence. Among those diagnosed with HIV in the United States, an estimated 1 in 5 are not promptly linked to care and less than half are in regular HIV care (Hall et al., 2013).
Studies have shown that individuals who enter care soon after diagnosis and maintain regular care initiate antiretroviral therapy earlier, have better adherence to ART, and have better health outcomes. In addition, adherence to clinic visits was associated with earlier viral suppression and lower cumulative viral load burden (Hall et al., 2013).
Only 25 percent of people living with HIV in the United States have achieved viral suppression. Three out of four people living with HIV in the United States have not been successfully supported in navigating the entire HIV care continuum. Source: CDC, 2012.
Recently, President Barack Obama signed into law the HIV Care Continuum Initiative, which focuses on accelerating federal efforts to increase HIV testing, care, and treatment. CDC and its partners are seeking to advance the goals of the National HIV/AIDS Strategy and maximize the effectiveness of current HIV prevention and care methods. Testing is a critical first step of entry into the HIV continuum of care (MMWR, 2014b).
To reduce the impact of HIV in the United States, improvements are needed at each stage of the process—with particular efforts to reduce disparities by race and age. HIV testing is a first critical step in HIV prevention, and the only way to identify the more than 200,000 Americans with HIV who do not know they are infected. In addition, ensuring that people have access to care, stay in care, and remain on treatment will increase the proportion of HIV-infected individuals who achieve and maintain viral suppression, which is critical to improve health and realize the full potential prevention benefits of treatment (CDC, 2012).
Women constitute one of the fastest-rising population groups at risk for infection with HIV, representing over 50% of cases worldwide, and approximately 25% of new cases in the United States and 28% of new cases in Canada. Surprisingly, little is known about the efficacy and toxicity of various antiretroviral drugs in women compared to men. This gap in knowledge is a result of the initial exclusion and continued under-representation of women in antiretroviral clinical trials. This circumstance has slowly started to change, and there are now more longitudinal studies examining women-specific issues (Loutfy et al., 2013).
Many studies in the general population have shown that adverse events are more common in women than in men. In the HIV-infected population, higher incidence rates of increased systemic symptoms (eg, nausea, vomiting, diarrhea), as well as organ toxicity (including anemia, hepatotoxicity, pancreatitis, lactic acidosis, peripheral neuropathy, and notable lipodystrophy), have been observed in women compared to men. For nevirapine, female gender and higher CD4+ cell counts were risk factors for fatal hepatitis, and this observation has led regulatory authorities to release warnings on its use in certain female populations (Loutfy et al., 2013).
For more information please visit www.AIDSinfo.NIH.gov for Adult, Adolescent, Pediatric, and Perinatal Guidelines, which include detailed information about current antiretroviral therapies for the treatment of HIV infection.