Multiple Viral Load Value Testing May Better Inform HIV Transmission Potential

Blood sample, test tubes
Blood sample, test tubes
Viral loads can fluctuate over time depending on patients' access and response to HIV treatment, their medication adherence behavior, and care status.

SEATTLE — Assessing multiple viral load (VL) values across time may better inform treatment response and potential for HIV transmission, according to researchers at the Centers for Disease Control and Prevention (CDC). They presented new data at the Conference on Retroviruses and Opportunistic Infections (CROI 2017) underscoring the need for intensified efforts to ensure that effective care and treatment reaches everyone who needs it.

They looked at data from the National HIV Surveillance System reported from 33 jurisdictions among individuals age ≥13 years with HIV infection. All the individuals were diagnosed by year-end 2013 and alive at year-end 2014.  The investigators examined viral suppression and patients were never suppressed in 630,965 individuals with diagnosed HIV.

They found the percentage of individuals “never suppressed” was higher among females than males (11.1% compared with 7.7%). The study also showed that blacks had the highest percentage of individuals in HIV care who were never virally suppressed. The researchers found that the racial/ethnic disparity was observed in men who have sex with men (MSM) and injection drug users (IDUs) in both sexes. 

“Viral loads can fluctuate over time depending on patients’ access and response to HIV treatment, their medication adherence behavior, and care status,” said study investigator Nicole Crepaz, PhD, an epidemiologist in the CDC’s division of HIV/AIDS prevention, Atlanta, Georgia.

She said the most common measure of HIV viral suppression is the most recent VL lower than 200 copies in the past 12 months. However, Dr Crepaz said this single-value measure only provides a cross-sectional snapshot of VL status and does not capture VL dynamics over time. Consequently, it may have the potential of giving an inaccurate picture of HIV burden and transmission risk in a population.

“We found that a single viral load measure overestimates durable viral suppression (people who had HIV virus consistently under control throughout a year). We also confirmed disparities in durable viral suppression and never virally suppressed by sex, race/ethnicity observed in the continuum of care,” Dr Crepaz told Infectious Disease Advisor.

In this study, Dr Crepaz and her team examined individuals who had at least 2 VLs in 2014, which was considered an indication of being in HIV care. They calculated the percentage of individuals never virally suppressed (all VLs >200 copies/mL) and created 4 groups based on the first and last VLs in 2014. The 4 categories included both suppressed, first unsuppressed and last suppressed (improved), first suppressed and last unsuppressed (worsened), and both unsuppressed.

They found that viral suppression status was achieved in 75.4% of patients (first and last VL suppressed), 10.5% improved, 4.2% worsened, and 9.9% first and last VL unsuppressed. The researchers also found that among 339,515 patients in HIV care, 28,782 patients (8.5%) never had suppressed VLs in 2014.

“Assessing durable viral suppression and never virally suppressed [patients] can better inform treatment response and potential for HIV transmission. Clinicians may benefit from close examination of a patient’s historical context of clinic attendance, missed visits, medication adherence, and viral load patterns in order to identify patients who may be at risk of not achieving or not maintaining durable viral suppression,” said Dr Crepaz.

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Crepaz N, Tang T, Marks G, Hall I. Viral-load dynamics among persons with diagnosed HIV: United States, 2014. Presented at: CROI 2017. Seattle, WA; February 13-16, 2017. Abstract 31.