Background. In Vietnam, there has been an increase in efforts to monitor and prevent mother-to-child transmission of HIV since 2013. However, data on HIV drug resistance among HIV-1 infected children younger than 18 months of age remain limited. The study fills a critical knowledge gap by providing important insights into the prevalence of resistance among this population in the Southern and Central Highland provinces of Vietnam.Objective. This study aimed to determine the prevalence of HIV drug resistance and patterns of mutation among treatment-naïve children under the age of 18 months who had been recently diagnosed with HIV.Material and methods. Between May 2017 and May 2021, stored remnant DBS samples were collected from children under the age of 18 months who had been diagnosed with HIV through routine Early Infant Diagnosis testing in Central Highland and Southern Vietnam. HIV drug resistance tests were performed, and interpretation was done using the Stanford algorithm.Results and discussion. Overall, 111 samples with eligible viremia for sequencing (ct value <31) were collected for genotyping, in which 110 protease sequences and 106 complete reverse transcriptase regions were generated. Males were 61.3%, 52.3% were aged from 6 weeks to <9 months and 37.0% were breastfed. Access to mother-to-child intervention was reported in 60.3%. The accumulation of major drug resistance mutations was found in 43.8% of infants and most of them were resistant to Non-nucleoside Reverse Transcriptase Inhibitors (NNRTI) (37.7%). High-level resistance to Nevirapine was present in 40% of cases. The risk factors associated with NNRTI resistance were antiretroviral prophylaxis (aOR: 3.68, 95% CI: 1.83–7.45) and breast-feeding history (aOR: 2.16, 95% CI: 1.03–4.53). CRF01-AE was the predominant subtype.Conclusion. The study identified a high prevalence of resistance to NNRTIs among HIV-1 infected infants less than 18 months of age in the Southern and Central Highland provinces of Vietnam. This highlights the need for further investigation and a potentially larger national survey to confirm the extent of this issue in Vietnam. Our findings support the current actions of the Vietnam Ministry of Health, which prioritize integrase inhibitor-based regimens as the preferred first line of ART for children to achieve durable viral suppression and minimize treatment failure. This approach aligns with the recommendations of the World Health Organization.

The aim of the study was to determine the tropism of the human immunodeficiency virus in patients with virological failure of antiretroviral therapy (ART) from the Arkhangelsk Region based on the analysis of the env gene V3 loop nucleotide sequence.Materials and methods. We used blood plasma samples obtained from 76 HIV-infected persons from the Arkhangelsk Region with virological failure of antiretroviral therapy. The nucleotide sequences of the HIV env gene C2-V3-C3 region were studied by PCR followed by sequencing. The genotype of the studied strains was determined based on the analysis of their phylogenetic relations with reference sequences from the international GenBank database, as well as using specialized programs. To predict viral tropism, the Garrido rule and the online bioinformatic tool Geno2Pheno[coreceptor] were used. The Geno2Pheno[coreceptor] algorithm, determines the false positive rate (FPR) based on the analysis of the env gene V3 loop nucleotide sequence. Results and discussion. Significantly lower representation of R5X4/X4-tropic HIV variants in long-term infected persons with subsubtype A6 virus compared to subtype B virus has been shown. For all FPR cut-off algorithms, a significant correlation between subtype and HIV tropism was observed (p=0.0014 and p=0.013 for FPR 10 % and FPR 20 %, respectively). While among subtype B strains, at least 57 % were identified as R5X4/X4-tropic variants (for an FPR of 10 %), including two strains classified as X4-tropic; among HIV subsubtype A6 even at an FPR of 20 %, the frequency of R5X4/X4-tropic samples only slightly exceeded 22 %. It can be assumed that the dynamics of changes in HIV tropism depends on the virus subtype. Significant differences in the distribution of amino acid residues of the V3 region sequences in the examined group between R5-tropic and R5X4/X4-tropic strains of subsubtype A6 for positions 18 (χ2=7.616, p=0.0058), 21 (χ2=7.281, p=0.007), 24 (χ2=5.587, p=0.0181), and 34 (χ2=5.144, p=0.0233) have been demonstrated. Among the R5X4/X4-tropic strains of the A6 subsubtype, amino acid substitutions were registered at positions 6, 19, 21, 26, 29, 30, which were not found in the R5-tropic A6 strains. The high occurrence frequency of a number of mutations previously described as presumably associated with resistance to maraviroc and similar drugs may indicate a natural polymorphism characteristic of the A6 subsubtype, which does not correlate with resistance to CCR5 co-receptor antagonists.

The aim of this study was to assess the prevalence and study of the molecular genetic characteristics of the human immunodeficiency virus in pregnant women of the Republic of Guinea.Materials and methods. The material for the study was blood plasma samples of 972 pregnant women from the Republic of Guinea. The patients were examined for the presence of HIV infection serological (Ag+Ab) and molecular markers (RNA). For patients with a positive PCR result and a sufficient viral load (>500 c/ml), the genetic sequences of the pol gene fragment responsible for the synthesis of pro and rev proteins were obtained by Sanger sequencing. These sequences were used for phylogenetic analysis and examined for drug resistance mutations.Results and discussion. 12.96% of patients was positive in ELISA. Among women who were positive in ELISA, RNA was detected in 76.98% of cases, however, in 11 cases, RNA was detected in patients without serological markers of HIV infection, so the incidence of HIV RNA in the entire surveyed population was 11.11%. In the vast majority of cases, the circulating recombinant form 02_AG is found. Based on the analysis, we assume a significant contribution of recombinant forms of HIV to the genetic diversity of the virus in the region under study.The incidence of DR mutations was quite high (26.80%). The most frequent substitutions were in position 20 of the protease (70.10%, 95% CI 59.96–78.98%), of which the K20I mutation was dominant. In addition, the L10I/V mutation was relatively common, increasing the replication of viruses with other PI resistance mutations. Among the mutations associated with HIV resistance to NNRTIs, a non-polymorphic mutation V179T was found.Conclusion. An important factor influencing the effectiveness of Prevention of Mother to Child Transmission identified in this study was the high prevalence of PDR among pregnant women in Guinea. The high prevalence of drug resistance mutations found in this study in pregnant women, as well as in ART-naive women, indicates that current regimens in Guinea are insufficient to prevent vertical HIV infection.

Introduction. The spread of the human immunodeficiency virus type 1 (HIV-1) has become a global concern and has approached the pandemic status. St. Petersburg, a major transportation, tourist, cultural, industrial center, and a border city, is characterized by high migration of the population. The growing number of migrants can contribute to importation and spread of new genetic variants of the virus and trigger recombination processes in the virus population in St. Petersburg and the Leningrad Region.The aim is to characterize the present-day HIV-1 subtype-specific profile and drug-resistance mutations among patients with virological failure on antiretroviral therapy (ART) in the Leningrad Region.Materials and methods. The study performed in 2016–2018 was based on clinical material from HIV-infected individuals living in the Leningrad Region and having confirmed virological failure on ART. The genetic diversity and distribution of drug-resistance mutations of the HIV-1 isolates were assessed through analysis of nucleotide sequences of the virus pol gene fragment that included regions encoding protease and the reverse transcriptase region.Results. In the group (n = 138), most of the patients had sub-subtype A6 (97.4%) common in Russia, though a few patients had subtype B and a recombinant containing circulating recombinant form CRF_03AB and sub-subtype A1. The tests showed that 95.79% of patients had at least one significant drug-resistance mutation; in most cases (73%) the virus was resistant to 2 classes of antiretroviral drugs and in some cases (8%) — to 3 classes. A total of 105 different drug-resistance mutations were found at 35 positions of the virus genome.Conclusions. The high prevalence of HIV-1 drug-resistance mutations among ART patients with virological failure calls attention to surveillance of drug resistance of the virus both among ART-experienced patients and ARTnaïve individuals.

The aim of the work is to assess the prevalence of hepatitis B virus drug resistance mutations and immune escape mutations in pregnant women in the Republic of Guinea. Materials and methods. Blood plasma samples obtained from 480 pregnant women from different regions of the Republic of Guinea with laboratory-confirmed viral hepatitis B were studied. Nucleotide sequences for genotype identification and mutation detection were obtained using nested-PCR followed by Sanger sequencing, based on overlapping pairs of primers spanning the complete genome of the virus. Results and discussion. In the examined group, the viral genotype E was the most prevalent (92.92%) compared with subgenotypes A1 (1.67%), A3 (1.46%), D1 (0.63%), D2 (1.04%) and D3 (2.29%). Among the examined HBV-infected pregnant women, 188 (39.17%) had undetectable HBsAg. Drug resistance mutations were detected in 33 individuals, which amounted to 6.88%. The following mutations were found: S78T (27.27%), L80I (24.24%), S202I (15.15%), M204I/V (42.42%). The presence of polymorphic variants not described as drug resistant has also been shown in positions associated with the development of drug resistance to tenofovir, lamivudine, telbivudine and entecavir (L80F, S202I, M204R). When analyzing the MHR and the region of a determinant, mutations were detected in 318 (66.25%) of pregnant women. In 172 of them, which amounted to 54.09%, multiple mutations were found. The amino acid substitutions in 13 positions associated with HBsAg-negative hepatitis B and/or potentially affecting HBsAg antigenicity were identified. Conclusion. The high prevalence of immune escape and drug resistance mutations potentially associated with false-negative result of HBsAg screening, prophylaxis failure, and virological failure of therapy that has been identified among treatment naive pregnant women imposes a serious problem.