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
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
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