Assessment of population-based HIV RNA levels in a rural east African setting using a fingerprick-based blood collection method

Abstract

Background: Population-based human immunodeficiency virus type 1 (HIV-1) RNA levels (viral load [VL]) are proposed metrics for antiretroviral therapy (ART) program effectiveness. We estimated population-based HIV RNA levels using a fingerprick-based approach in a rural Ugandan community implementing rapid ART scale-up.

Methods: A fingerprick-based HIV RNA measurement technique was validated against standard phlebotomy. This technique was deployed during a 5-day community-wide health campaign in a 6300-person community. Assessments included rapid HIV antibody testing, VL, and CD4+ T-cell count via fingerprick. We estimated population HIV RNA levels and the prevalence of undetectable RNA, assessed predictors of VL via linear regression, and mapped RNA levels within community geographic units.

Results: During the community-wide health campaign, 179 of 2282 adults (7.8%) and 10 of 1826 children (0.5%) tested seropositive for HIV. Fingerprick VL was determined in 174 of 189 HIV-positive persons (92%). The mean log(VL) was 3.67 log (95% confidence interval [CI], 3.50-3.83 log copies/mL), median VL was 2720 copies/mL (interquartile range, <486-38 120 copies/mL), and arithmetic mean VL was 64 064 copies/mL. Overall, 64 of 174 of individuals had undetectable RNA (37% [95% CI, 30%-44%]), 24% had VL 486-10 000; 25% had VL 10 001-100 000; and 15% had VL>100 000 copies/mL. Among participants taking ART, 83% had undetectable VL.

Conclusions: We developed and implemented a fingerprick VL testing method and provide the first report of population HIV RNA levels in Africa. In a rural Ugandan community experiencing ART scale-up, we found evidence of population-level ART effectiveness, but found a substantial population to be viremic, in need of ART, and at risk for transmission.

Figures

Figure 1.

Standard correlational and Bland-Altman plots assessing relationship of human immunodeficiency virus (HIV)–1 plasma RNA values from phlebotomy-derived samples with fingerprick-derived samples among 15 HIV-positive persons. A, Standard correlation of log-transformed fingerprick–derived plasma HIV-1 RNA (ie, viral load) levels (y-axis) vs phlebotomy-derived plasma HIV-1 RNA levels (x-axis). The y-axis is truncated at 6 logs, though the assay limit of detection is 7 logs. B, Bland-Altman plot. The y-axis displays the difference between the 2 measurements (phlebotomy vs fingerprick) and the x-axis displays the mean of the 2 measurements. Dashed lines indicate 95% limits of agreement for all pairwise comparisons. Abbreviation: VL, viral load.

Figure 2.

Geographic mapping of mean human immunodeficiency virus (HIV) RNA levels among 165 individuals with undetectable, midrange, and high levels of HIV-1 plasma RNA within villages of a rural parish of southwestern Uganda. Mean viral load (VL) for each of 7 villages (names given) within the parish are displayed in 4 categories. Individual adults (circles, n = 156) and children aged <15 y (squares, n = 9) are depicted in each region according to VL as follows: undetectable (486 copies/mL) VL (open circles/squares), detectable VL <100 000 copies/mL (black circles/squares), detectable VL ≥100 000 copies/mL (red circles/squares). The location of the parish's level IV government health center is marked at the eastern boundary of the region (white letter “H” in blue square). Abbreviation: VL, viral load.