The prevalence of transmitted drug resistance (TDR) in antiretroviral therapy (ART)-naïve individuals remains stable in most developed countries despite a decrease in the prevalence of acquired drug resistance. This suggests that persistence and further transmission of HIV-1 that encodes transmitted drug resistance mutations (TDRMs) is occurring in ART-naïve individuals. In this study, we analysed the prevalence and persistence of TDRMs in the protease and reverse transcriptase-sequences of ART-naïve patients within the German HIV-1 Seroconverter Study Cohort who were infected between 1996 and 2017. The prevalence of TDRMs and baseline susceptibility to antiretroviral drugs were assessed using the Stanford HIVdb list and algorithm. Mean survival times of TDRMs were calculated by Kaplan-Meier analysis. The overall prevalence of TDR was 17.2% (95% CI 15.7–18.6, N = 466/2715). Transmitted NNRTI resistance was observed most frequently with 7.8% (95% CI 6.8–8.8), followed by NRTI resistance (5.0%, 95% CI 4.2–5.9) and PI resistance (2.8%, 95% CI 2.2–3.4). Total TDR (OR = 0.89, p = 0.034) and transmitted NRTI resistance (OR = 0.65, p = 0.000) decreased between 1996 and 2017 but has remained stable during the last decade. Viral susceptibility to NNRTIs (6.5%-6.9% for individual drugs) was mainly reduced, while <3% of the recommended NRTIs and PIs were affected. The longest mean survival times were calculated for the NNRTI mutations K103N (5.3 years, 95% CI 4.2–5.6) and E138A/G/K (8.0 years, 95% CI 5.8–10.2 / 7.9 years, 95% CI 5.4–10.3 / 6.7 years, 95% CI 6.7–6.7) and for the NRTI mutation M41L (6.4 years, 95% CI 6.0–6.7).The long persistence of single TDRMs indicates that onward transmission from ART-naïve individuals is the main cause for TDR in Germany. Transmitted NNRTI resistance was the most frequent TDR, showing simultaneously the highest impact on baseline ART susceptibility and on TDRMs with prolonged persistence. These results give cause for concern regarding the use of NNRTI in first-line regimens.
HCV exhibits a high genetic diversity and is classified into 7 genotypes which are further divided into 86 confirmed subtypes. However, there are multiple isolates with unassigned subtypes. We aimed to amplify and characterize the full-length genome sequence of an HCV genotype 1 (HCV-1) divergent isolate (DE/17–0414) in Germany.
HIV-1 genotyping of larger pol-fragments from dried serum/plasma spots (DSS/DPS) is often hindered by RNA-degradation during transportation at ambient temperature. We evaluated an in-house HIV-1 DSS/DPS-genotyping assay designed in two shorter overlapping fragments covering all resistance mutations in protease and reverse transcriptase. Validation criteria such as specificity, detection limit, accuracy, reproducibility and storage conditions were assessed using reference plasma samples prepared as DPS and clinical DSS from the German molecular HIV-1 surveillance processed under real-life transportation conditions. The specificity was 100% for both samples types, and the experimental DPS detection limit of 1000 copies/ml yielded a 98.7% (3,329/3373) success rate for DSS (including all subtypes) above this detection limit. Accuracy for DPS compared to the gold standard was 99.1% and the reproducibility was 100% for DPS replicates and 99.9% for DSS pairs. Storage of DPS at room temperature was possible for 90 or 30 days and at - 20 degrees C for at least 180 or 90 days at viral loads of 10,000 or 1000 copies/ml, respectively. The HIV-1 pol-genotyping assay presented here is a sensitive, robust and subtype generic tool for a large-scale population-based HIV-1 drug resistance surveillance for the use of DSS/DPS.
BackgroundSince 2012, WHO guidelines for the prevention of mother-to-child transmission (PMTCT) of HIV-1 in resource-limited settings recommend the initiation of lifelong antiretroviral combination therapy (CART) for all pregnant HIV-1 positive women independent of CD4 count and WHO clinical stage (Option B+). However, long-term outcomes regarding development of drug resistance are lacking until now. Therefore, we analysed the emergence of drug resistance mutations (DRMs) in women initiating Option B+ in Fort Portal, Uganda, at 12 and 18 months postpartum (ppm).Methods and findings124 HIV-1 positive pregnant women were enrolled within antenatal care services in Fort Portal, Uganda. Blood samples were collected at the first visit prior starting Option B+ and postpartum at week six, month six, 12 and 18. Viral load was determined by real-time RT-PCR. An RT-PCR covering resistance associated positions in the protease and reverse transcriptase HIV-1 genomic region was performed. PCR-positive samples at 12/18 ppm and respective baseline samples were analysed by next generation sequencing regarding HIV-1 drug resistant variants including low-frequency variants. Furthermore, vertical transmission of HIV-1 was analysed. 49/124 (39.5%) women were included into the DRM analysis. Viro-logical failure, defined as >1000 copies HIV-1 RNA/ml, was observed in three and seven women at 12 and 18 ppm, respectively. Sequences were obtained for three and six of these. In total, DRMs were detected in 3/49 (6.1%) women. Two women displayed dual-class resistance against all recommended first-line regimen drugs. Of 49 mother-infant-pairs no infant was HIV-1 positive at 12 or 18 ppm.ConclusionOur findings suggest that the WHO-recommended Option B+ for PMTCT is effective in a cohort of Ugandan HIV-1 positive pregnant women with regard to the low selection rate of DRMs and vertical transmission. Therefore, these results are encouraging for other countries considering the implementation of lifelong cART for all pregnant HIV-1 positive women.