Undiagnosed infections and poor retention in care mean that few US patients fully benefit from HIV treatment

Only a small minority of HIV-positive patients in the United States are gaining the full benefit of antiretroviral therapy, a study published in the November 29^th edition of Morbidity and Mortality Weekly Report shows.  Investigators calculated that only a half of all patients are retained in care and that only 28% of people infected with HIV in the US have an undetectable viral load.

“More effort is needed to ensure that…patients remain in care and to eliminate disparities between subgroups who are prescribed ART [antiretroviral therapy] and subsequently achieve viral suppression,” comment the authors.

They warn that the goals of the 2010 US National HIV/AIDS Strategy to increases access to care, improve outcomes and reduce health inequalities can only be met by “achieving high levels of engagement at every stage in the continuum of care.”

The current low proportion of patients with viral suppression would also suggest that the use of HIV treatment as prevention will have only a minimal impact on the continuing epidemic in the US until these issues can be addressed.

An estimated 1.2 million individuals were living with HIV in the US at the end of 2008. With appropriate treatment and care the prognosis of HIV-infected patients can be excellent. Moreover, therapy that suppresses viral load to below the limit of detection significantly reduces the risk of onward transmission of the virus.

To take advantages of the benefits offered by modern HIV medicine it is essential that infected patients are diagnosed, linked and retained in care, prescribed antiretroviral therapy when appropriate, and that this treatment achieves virological suppression.

Using recent surveillance data, the investigators calculated the proportion of patients in the US receiving services at various points in this care continuum.    

They calculated that a fifth of HIV infections in the country were undiagnosed. An analysis of published studies suggested that 77% of diagnosed patients were initially linked with care. However, retention rates were poor and only 51% of individuals continued to regularly access care.

Use of antiretroviral therapy among the patients remaining in care was high, with 89% of individuals taking this treatment. Moreover, 77% of these patients achieved an suppression of the virus (defined as a viral load below 200 copies/ml).

Overall, the high rate of undiagnosed infections and the large proportion of patients dropping out of care meant that only 28% of all HIV-positive patients in the US had an undetectable viral load.

Racial disparities were apparent in the use of HIV therapy and in treatment outcomes.

Of the 92% of whites who were treated with anti-HIV drugs, 84% achieved virological suppression. Use of treatment was less prevalent among Hispanic patients (89%), and the proportion with suppression of the virus was somewhat poorer than those seen in whites (79%). Lower still were rates of treatment utilisation in black patients (86%) and only 70% of these patients experienced a fall in their viral load to below 200 copies/ml.

The study also suggested that HIV prevention efforts needed to be intensified. Only 45% of patients in care had received HIV prevention counselling. There were disparities according to age, with 73% of patients aged 18 to 24 receiving such counselling, compared to 36% of those aged over 55. Over half of black (54%) and Hispanic (52%) of patients were provided with prevention counselling compared to only 29% of whites. The proportion of patients receiving counselling also differed by HIV risk group, and was higher for gay men and other men who have sex with men (MSM) compared to men reporting sex with a woman (50% vs. 39%).

“These low percentages, especially among MSM, who account for most new HIV infections in the United States, indicate a need for health-care providers to deliver HIV prevention more consistently,” suggest the authors.

“Only an estimated 28% of all HIV-infected persons in the United States are virally suppressed, largely because even among those with diagnosed infections, only 51% are receiving regular HIV care,” emphasise the investigators.

They warn: “Without substantial improvement in these percentages, 1.2 million new HIV infections would be expected to occur over the next 20 years.” This could result in $450 billion in health-related expenditure. “Only with success at each step of the continuum of HIV care…can the ultimate goals of improving health, extending lives, and preventing further HIV transmission be achieved.”