Low levels of HIV-1 drug resistance mutations in patients who achieved viral re-suppression without regimen switch: a retrospective study.

BACKGROUND: We identified a HIV-positive cohort in virologic failure (VF) who re-suppressed without drug switch. We characterized their drug resistance mutations (DRM) and adherence profiles to learn how to better manage HIV drug resistance. A retrospective cohort study utilizing clinical data and stored samples. Patients received ART at three Nigerian treatment centres. Plasma samples stored when they were in VF were genotyped. RESULT: Of 126 patients with samples available, 57 were successfully genotyped. From ART initiation, the proportion of patients with adherence ≥90% increased steadily from 54% at first high viral load (VL) to 67% at confirmed VF, and 81% at time of re-suppressed VL. Sixteen (28%) patients had at least one DRM. Forty-six (81%) patients had full susceptibility to the three drugs in their first-line (1 L) regimen. Thirteen (23%) were resistant to at least one antiretroviral drug but three were resistant to drugs not used in Nigeria. Ten patients had resistance to their 1 L drug(s) and six were fully susceptible to the three drugs in the recommended second-line regimen. CONCLUSION: This cohort had little drug resistance mutations. We conclude that if adherence is not assured, patients could exhibit virologic failure without having developed mutations associated with drug resistance.

Changes in liver stiffness after ART initiation in HIV-infected Nigerian adults with and without chronic HBV.

BACKGROUND: There are limited data from sub-Saharan Africa on long-term liver fibrosis changes in HIV- and HIV/HBV-infected individuals. OBJECTIVES: To assess the effects of ART on liver stiffness measurement (LSM) using transient elastography (TE) in HIV- and HIV/HBV-infected Nigerian adults and examine factors associated with fibrosis regression. METHODS: We included ART-naive HIV- and HIV/HBV-infected adults (≥18 years) enrolled in a prospective, longitudinal study of liver disease between July 2011 and February 2015 at Jos University Teaching Hospital HIV Care and Treatment Centre in Nigeria. Patients initiated ART and had TE at baseline and follow-up (year 3). LSM cut-offs for Metavir scores were 5.9, 7.6 and 9.4 kPa for moderate fibrosis, advanced fibrosis and cirrhosis, respectively. We used multivariable regression to identify factors associated with TE (≥1 Metavir) stage decline. RESULTS: A total of 106 HIV- and 71 HIV/HBV-infected patients [70.5% female and median age = 34 years (IQR = 29-42 years)] were studied. Baseline LSM and median LSM decline were significantly higher in HIV/HBV- versus HIV-infected patients; 41% of HIV/HBV-infected patients regressed ≥1 Metavir stage versus 17% of HIV-infected patients (P < 0.01); LSM scores at year 3 were not significantly different between HIV- and HIV/HBV-infected patients. In multivariable analyses, patients with baseline CD4+ T cells ≥200 (versus <200) cells/mm3 and lower BMIs were more likely to experience LSM stage decline. CONCLUSIONS: HBV coinfection does not attenuate LSM declines in HIV-infected patients after ART initiation despite being a risk factor for more advanced liver disease prior to therapy. The inverse association between BMI and TE stage decline needs further investigation.

Continued Transmission of Zika Virus in Humans in West Africa, 1992-2016.

First identified in 1947 in Uganda, Zika virus (ZIKV) has remained largely unstudied until the recent outbreak in Latin America. This study aimed to measure the prevalence of ZIKV in febrile patients in Senegal and Nigeria in samples collected from 1992 to 2016. The seroprevalence of ZIKV was 6.2% based on ZIKV immunoglobulin M and negative for dengue reactivity. ZIKV envelope was amplified from 4 samples. Phylogenetic analysis showed that the ZIKVs belonged to the African lineage, grouping with either the Nigerian or MR766 sublineages. This study provides evidence that ZIKV has been silently circulating in West Africa for 2 decades.

Pretreatment and Acquired Drug Resistance in Children With Human Immunodeficiency Virus Type 1 in Jos, Nigeria.

We determined pretreatment and acquired human immunodeficiency virus (HIV) drug resistance among children with HIV type 1 (HIV-1) in Jos, Nigeria. The majority (71%) of those who failed first-line antiretroviral therapy were on a nevirapine-containing regimen. The prevalence of pretreatment (48%) and acquired (76%) HIV drug resistance mutations was high in our study. Wider access to HIV drug resistance testing after treatment failure is necessary to optimize second-line treatment options among children with HIV in Nigeria.

HBV co-infection is associated with persistently elevated liver stiffness measurement in HIV-positive adults: A 6-year single-centre cohort study in Nigeria.

BACKGROUND: In Nigeria, the effect of Hepatitis B virus (HBV) on long-term liver outcomes in persons with HIV (PLH) has not been described. We determined changes in liver stiffness measure (LSM) using transient elastography over 6 years in HIV mono-infected and HIV-HBV co-infected Nigerians initiating antiretroviral therapy (ART) and factors associated with LSM decline. METHODS: This single centre, cohort study enrolled ART-naïve HIV mono- and HIV-HBV co-infected adults (≥18 years) at the APIN Public Health Initiatives-supported HIV Care and Treatment Centre at Jos University Teaching Hospital, Nigeria, from 7/2011 to 2/2012. LSM at baseline, Years 3 and 6 were analysed using longitudinal models to estimate changes over time and their predictors. RESULTS: Data from 100 (31%) HIV-HBV co-infected and 225 (69%) HIV mono-infected participants were analysed. Median LSM at baseline was 6.10 (IQR: 4.60-7.90) kPa in co-infected and 5.10 (IQR: 4.40-6.10) kPa in mono-infected participants. In adjusted analyses, average LSM was not significantly different between Year 0 and 3 (ß = 0.02, -0.22 to 0.26, p = 0.87 and Year 0 and 6 (ß = -0.02, -0.23 to 0.27, p = 0.88) in both groups (p>0.05), but co-infected participants had significantly higher LSM than mono-infected throughout follow-up (ß = 0.018, 0.019-0.28, p < 0.001). Year 3 LSM differed according to ART initiation status by Year 3 (initiators - non-initiators: -0.87, -1.70 to -0.29). CONCLUSION: In this cohort, LSM remained higher among HIV-HBV co-infected versus HIV mono-infected participants throughout follow-up. Our findings emphasize the continuing need for monitoring of liver outcomes in HIV-HBV co-infected populations on ART and the importance of preventing HBV infection among PLH to optimize liver health.

Distinct Pattern of Thymidine Analogue Mutations with K65R in Patients Failing Tenofovir-Based Antiretroviral Therapy.

Historically, in HIV patients, the K65R mutation and thymidine analogue mutations (TAMs) have been reported to rarely coexist. We retrospectively reviewed genotype data from paired samples in a cohort of HIV-1-infected Nigerian patients failing first-line antiretroviral therapies containing zidovudine (AZT) or tenofovir (TDF). Samples for each patient were taken at initial confirmed virological failure ≥1000 copies/ml (S1) and then at the latest available sample with viral load ≥1000 copies/ml before switch to second line (S2). Among 103 patients failing AZT, 19 (18.4%) had TAM-1s, 29 (28.2%) TAM-2s, and 21 (20.4%) mixed TAMs by S2. In contrast, in the 87 patients failing TDF, drug resistance mutations at S2 included K65R in 56 (64.4%), TAM-1s in 1 (1.1%), and TAM-2s in 25 patients (28.7%). Interestingly, 30.4% of patients with K65R in our study developed TAMs. These were exclusively K219E ± D67N and were not predicted to confer a resistance cost to future AZT-containing regimens.

Implication of First-Line Antiretroviral Therapy Choice on Second-Line Options.

BACKGROUND: Although there are a number of studies comparing the currently recommended preferred and alternative first-line (1L) antiretroviral therapy (ART) regimens on clinical outcomes, there are limited data examining the impact of 1L regimen choice and duration of virologic failure (VF) on accumulation of drug resistance mutations (DRM). The patterns of DRM from patients failing zidovudine (AZT)-containing versus tenofovir (TDF)-containing ART were assessed to evaluate the predicted susceptibility to second-line (2L) nucleoside reverse-transcriptase inhibitor (NRTI) backbone options in the context of an ongoing programmatic setting that uses viral load (VL) monitoring. METHODS: Paired samples from Nigerian ART patients who experienced VF and switched to 2L ART were retrospectively identified. For each sample, the human immunodeficiency virus (HIV)-1 polymerase gene was sequenced at 2 time points, and DRM was analyzed using Stanford University's HIVdb program. RESULTS: Sequences were generated for 191 patients. At time of 2L switch, 28.2% of patients on AZT-containing regimens developed resistance to TDF, whereas only 6.8% of patients on TDF-containing 1L had mutations compromising susceptibility to AZT. In a stratified evaluation, patients with 0-6 months between tested VL samples had no difference in proportion compromised to 2L, whereas those with >6 months between samples had a statistically significant difference in proportion with compromised 2L NRTI. In multivariate analyses, patients on 1L AZT had 9.90 times higher odds of having a compromised 2L NRTI option than patients on 1L TDF. CONCLUSIONS: In the context of constrained resources, where VL monitoring is limited, we present further evidence to support use of TDF as the preferred 1L NRTI because it allows for preservation of the recommended 2L NRTI option.

Short communication: Transmitted HIV drug resistance in antiretroviral-naive pregnant women in north central Nigeria.

The World Health Organization (WHO) recommends periodic surveillance of transmitted drug resistance (TDR) in communities in which antiretroviral therapy (ART) has been scaled-up for greater than 3 years. We conducted a survey of TDR mutations among newly detected HIV-infected antiretroviral (ARV)-naive pregnant women. From May 2010 to March 2012, 38 ARV-naive pregnant women were recruited in three hospitals in Jos, Plateau state, north central Nigeria. Eligible subjects were recruited using a modified version of the binomial sequential sampling technique recommended by WHO. HIV-1 genotyping was performed and HIV-1 drug resistance mutations were characterized according to the WHO 2009 surveillance drug resistance mutation (SDRM) list. HIV subtypes were determined by phylogenetic analysis. The women's median age was 25.5 years; the median CD4(+) cell count was 317 cells/µl and the median viral load of 16 was 261 copies/ml. Of the 38 samples tested, 34 (89%) were successfully genotyped. The SDRM rate was <5% for all ART drug classes, with 1/34 (2.9%) for NRTIs/NNRTIs and none for protease inhibitors 0/31 (0%). The specific SDRMs detected were M41L for nucleoside reverse transcriptase inhibitors (NRTIs) and G190A for nonnucleoside reverse transcriptase inhibitors (NNRTIs). HIV-1 subtypes detected were CRF02_AG (38.2%), G' (41.2%), G (14.7%), CRF06-CPX (2.9%), and a unique AG recombinant form (2.9%). The single ARV-native pregnant woman with SDRMs was infected with HIV-1 subtype G'. Access to ART has been available in the Jos area for over 8 years. The prevalence of TDR lower than 5% suggests proper ART administration, although continued surveillance is warranted.