Whole genome deep sequencing (WGS) could improve understanding of treatment failure and the emergence of resistance by revealing the distribution of mutations throughout the viral population over time.
Adult patients receiving 1L ART (2 NRTI and 1 NNRTI) at the University of Abuja Teaching Hospital, Nigeria, were included if they had experienced virological failure (HIV-1 RNA >1000 copies/mL, at least 6 months after ART initiation, confirmed by clinician-driven testing), and had a stored plasma sample available for WGS.
Sixty participants were sampled during 1L failure (73% female; median age 30 (interquartile ratio [IQR] 28–35); median CD4+ cell count 110 cells/mm3 (IQR 63–191); median 28 months after ART initiation (IQR 18–41)). At 1L failure, 57% of participants had thymidine analogue mutations (TAMs), with 30% harbouring 3 or more TAMs, 95% had other (non-TAM) NRTI mutations and 100% had NNRTI mutations. The most common mutations were M184V, Y181C, G190A, K65R and K103N. Overall, 17% (61/367) of the mutations identified were low-level minority variants (present at 2%–20% of the intra-host viral population), which would not have been detected by standard resistance testing methods, 24% (88/367) were present at 20%–90% frequency, and 59% (218/367) were dominant majority variants representing >90% of the participant's viral population.
Diverse Nigerian HIV clades exhibit multi-class drug resistance at 1LART failure. The predominance of high-frequency mutations suggests that emergent resistance had become fixed in the viral population by the time of sampling.
*Institute of Human Virology Nigeria;
†Division of Infection and Immunity, University College London, London, United Kingdom;
‡Department of Infection and Population Health, University College London, London, United Kingdom;
§University of Abuja Teaching Hospital, Abuja, Nigeria;
‖US Centers for Disease Control and Prevention, US Embassy, Abuja, Nigeria; and
¶Institute of Human Virology, University of Maryland School of Medicine