Background

The World Health Organization defines HIV virologic failure as 2 consecutive viral loads >1000 copies/mL, measured 3-6 months apart, with interval adherence support. We sought to empirically evaluate these guidelines using data from an observational cohort.

Setting

The Uganda AIDS Rural Treatment Outcomes study observed adults with HIV in southwestern Uganda from the time of antiretroviral therapy (ART) initiation and monitored adherence with electronic pill bottles.

Methods

We included participants on ART with a detectable HIV RNA viral load and who remained on the same regimen until the subsequent measurement. We fit logistic regression models with viral resuppression as the outcome of interest and both initial viral load level and average adherence as predictors of interest.

Results

We analyzed 139 events. Median ART duration was 0.92 years, and 100% were on a nonnucleoside reverse-transcriptase inhibitor-based regimen. Viral resuppression occurred in 88% of those with initial HIV RNA <1000 copies/mL and 42% if HIV RNA was >1000 copies/mL (P <0.001). Adherence after detectable viremia predicted viral resuppression for those with HIV RNA <1000 copies/mL (P = 0.011) but was not associated with resuppression for those with HIV RNA >1000 copies/mL (P = 0.894; interaction term P = 0.077).

Conclusions

Among patients on ART with detectable HIV RNA >1000 copies/mL who remain on the same regimen, only 42% resuppressed at next measurement, and there was no association between interval adherence and viral resuppression. These data support consideration of resistance testing to help guide management of virologic failure in resource-limited settings.

The prevalence of HIV pretreatment drug resistance (PDR) is increasing in sub-Saharan Africa. We sought to describe correlates of PDR and evaluate effects of PDR on clinical outcomes in rural Uganda. We analyzed data from the Uganda AIDS Rural Treatment Outcomes study, a cohort of antiretroviral therapy (ART)-naive adults with HIV (2005-2015). We performed resistance testing on pre-ART specimens. We defined PDR as any World Health Organization (WHO) 2009 surveillance drug resistance mutation and classified PDR level using the Stanford algorithm. We fit unadjusted and sex-stratified log binomial regression and Cox proportional hazard models to identify correlates of PDR and the impact of PDR on viral suppression, loss to follow-up (LTFU), and death. We analyzed data from 738 participants (median age 33 years, 69% female). Overall, prevalence of PDR was 3.5% (n = 26), owing mostly to resistance to non-nucleoside reverse transcriptase inhibitors. PDR increased over time in women (1.8% in those enrolling in clinic in 2001-2006, vs. 7.0% in 2007-2013; p = 0.006), but not in men (1.15% vs. 0.72%, p = 0.737). Lower pre-ART log₁₀ HIV RNA was also associated with higher prevalence of PDR. We identified longer time to viral suppression among those with PDR compared with without PDR (0.5 and 0.3 years, respectively, p = 0.023), but there was no significant relationship with mortality or LTFU (p = 0.139). We observed increasing rates of PDR in women in southwestern Uganda. Implications of this trend, particularly to prevention of mother-to-child transmission programs in the region, require attention due to delayed viral suppression among those with PDR.

Objective

Dolutegravir (DTG) is now a preferred component of first-line antiretroviral therapy (ART). However, prevalence data on natural resistance to integrase inhibitors [integrase strand transfer inhibitors (INSTIs)] in circulating non-subtype B HIV-1 in sub-Saharan Africa is scarce. Our objective is to report prevalence of pre-treatment integrase polymorphisms associated with resistance to INSTIs in an ART-naive cohort with diverse HIV-1 subtypes.

Design

We retrospectively examined HIV-1 integrase sequences from Uganda.

Methods

Plasma samples were derived from the Uganda AIDS Rural Treatment Outcomes (UARTO) cohort, reflecting enrollment from 2002 to 2010, prior to initiation of ART. HIV-1 integrase was amplified using nested-PCR and Sanger-sequenced (HXB2 4230-5093). Stanford HIVdb v8.8 was used to infer clinically significant INSTI-associated mutations. Human leukocyte antigen (HLA) typing was performed for all study participants.

Results

Plasma samples from 511 ART-naive individuals (subtype: 48% A1, 39% D) yielded HIV-1 integrase genotyping results. Six out of 511 participants (1.2%) had any major INSTI-associated mutations. Of these, two had E138T (subtype A1), three had E138E/K (subtype D), and one had T66T/I (subtype D). No participants had mutations traditionally associated with high levels of INSTI resistance. HLA genotypes A∗02:01/05/14, B∗44:15, and C∗04:07 predicted the presence of L74I, a mutation recently observed in association with long-acting INSTI cabotegravir virologic failure.

Conclusion

We detected no HIV-1 polymorphisms associated with high levels of DTG resistance in Uganda in the pre-DTG era. Our results support widespread implementation of DTG but careful monitoring of patients on INSTI with virologic failure is warranted to determine if unique mutations predict failure for non-B subtypes of HIV-1.