Association between HIV-1 subtype and drug resistance in Nigerian infants.

Background: Many lines of evidence point to HIV-1 subtype-specific differences in the development of drug resistance mutations. While variation between subtype C and others has been extensively explored, there has been less emphasis on subtypes common to West Africa. We examined a previously described national survey of pretreatment drug resistance in HIV-1-infected Nigerian children aged <18 months, to explore the association between subtypes and patterns of resistance. Methods: Five hundred and forty-nine dried blood spots, from 15 early infant diagnostic facilities in Nigeria, were amplified and HIV-1 polymerase was sequenced. Four hundred and twenty-four were analysed for surveillance drug resistance mutations (SDRMs). Associations between subtype and SDRMs were evaluated by Fisher's exact test and logistic regression analysis, controlling for geographical region and exposure. Results: Using the sub-subtypes of HIV-1 G defined by Delatorre et al. (PLoS One 2014. 9: e98908) the most common subtypes were CRF02_AG (174, 41.0%), GWA-I (128, 30.2%), GWA-II (24, 5.7%), GCA (11, 2.6%), A (21, 5.0%) and CRF06_cpx (18, 4.2%). One hundred and ninety infants (44.8%) had ≥1 NNRTI mutation, 92 infants (21.7%) had ≥1 NRTI mutation and 6 infants (1.4%) had ≥1 PI mutation. By logistic regression, 67N was more common in GWA-II/GCA than CRF02_AG (OR 12.0, P = 0.006), as was 70R (OR 23.1, P = 0.007), 184I/V (OR 2.92, P = 0.020), the presence of ≥1 thymidine analogue mutation (TAM) (OR 3.87, P = 0.014), ≥1 type 2 TAM (OR 7.61, P = 0.001) and ≥1 NRTI mutation (OR 3.26, P = 0.005). Conclusions: This dataset reveals differences among SDRMs by subtype; in particular, between the GWA-II and GCA subclades, compared with CRF02_AG and GWA-I.

High Prevalence of HIV Drug Resistance Among Newly Diagnosed Infants Aged <18 Months: Results From a Nationwide Surveillance in Nigeria.

BACKGROUND: WHO recommends protease-inhibitor-based first-line regimen in infants because of risk of drug resistance from failed prophylaxis used in prevention of mother-to-child transmission (PMTCT). However, cost and logistics impede implementation in sub-Saharan Africa, and >75% of children still receive nonnucleoside reverse transcriptase inhibitor-based regimen (NNRTI) used in PMTCT. METHODS: We assessed the national pretreatment drug resistance prevalence of HIV-infected children aged <18 months in Nigeria, using WHO-recommended HIV drug resistance surveillance protocol. We used remnant dried blood spots collected between June 2014 and July 2015 from 15 early infant diagnosis facilities spread across all the 6 geopolitical regions of Nigeria. Sampling was through a probability proportional-to-size approach. HIV drug resistance was determined by population-based sequencing. RESULTS: Overall, in 48% of infants (205 of 430) drug resistance mutations (DRM) were detected, conferring resistance to predominantly NNRTIs (45%). NRTI and multiclass NRTI/NNRTI resistance were present at 22% and 20%, respectively, while resistance to protease inhibitors was at 2%. Among 204 infants with exposure to drugs for PMTCT, 57% had DRMs, conferring NNRTI resistance in 54% and multiclass NRTI/NNRTI resistance in 29%. DRMs were also detected in 34% of 132 PMTCT unexposed infants. CONCLUSION: A high frequency of PDR, mainly NNRTI-associated, was observed in a nationwide surveillance among newly diagnosed HIV-infected children in Nigeria. PDR prevalence was equally high in PMTCT-unexposed infants. Our results support the use of protease inhibitor-based first-line regimens in HIV-infected young children regardless of PMTCT history and underscore the need to accelerate implementation of the newly disseminated guideline in Nigeria.