Genetic Characterization of HIV-1 Subtype A1/C/D/B/K Unique Recombinant Form from Eastern Cape, South Africa

Performance of an in-house multiplex PCR assay for HIV-1 drug resistance testing - A cheaper alternative

BACKGROUND

Currently, most HIV drug resistance PCR assays amplify the protease-reverse transcriptase (PR-RT) fragment separately from the integrase (IN) fragment. The aim of this study was to develop a multiplex PCR assay that simultaneously amplifies PR-RT and IN fragments for HIV-1 drug-resistance testing.

METHODS

The in-house multiplex PCR assay was evaluated on extracted total nucleic acids obtained from the National Health Laboratory Service (NHLS) and Lancet laboratories. Sanger sequencing was performed on amplicons, and HIV-1 drug-resistance mutations (DRMs) were assessed using HIV Stanford drug resistance database.

RESULTS

This study tested 59 patient samples with known HIV-1 viral load and DRM results; 41 from Lancet and 18 from NHLS. In-house multiplex PCR assay detected one or both fragments in most samples but had higher sensitivity for detection of IN fragment (93.2 %) compared to PR-RT fragment (83.1 %). There was 100 % concordance between Lancet assay versus in-house assay sequence data for IN DRMs, but lower concordance with PR-RT (87.0 %). The in-house multiplex PCR assay's precision and reproducibility analysis showed ≥99.9 % sequence similarity and yielded similar DRM results for both PR-RT and IN fragments.

CONCLUSIONS

The in-house multiplex PCR assay demonstrated satisfactory performance and higher sensitivity for IN fragment amplification. This could be a cost-effective method for HIV-1 drug resistance testing as both PR-RT and IN fragments are successfully amplified in one reaction in most samples.

HIV subtypes and molecular transmission characteristics among elderly HIV-infected individuals aged 50 and above: a cross-sectional study in Huzhou City, Eastern China

OBJECTIVE

To analyse the HIV-1 subtypes and molecular transmission characteristics of HIV-infected older individuals aged 50 and above in Huzhou City, and provide a scientific basis for prevention and treatment strategies for them.

DESIGN

A cross-sectional study with clustered molecular transmission network cases was performed, and basic epidemiological information was retrieved from the Chinese Centres for Disease Prevention and Control (CDC) Information System.

SETTING AND PARTICIPANTS

A molecular epidemiological study was conducted in 899 newly diagnosed HIV-infected individuals from January 2019 and March 2023 in Huzhou city, Zhejiang province, Eastern China. Out of these, HIV sequences were successfully obtained from 673 individuals, including 274 who were older individuals aged 50 and above.

PRIMARY AND SECONDARY OUTCOMES

Reverse transcription-polymerase chain reaction (PCR) and nested PCR were used to amplify the polymerase gene of HIV-1, and gene sequencing was performed. We used univariate and multivariate logistic regression to describe the association of clustered molecular transmission network cases.

RESULTS

In total, 274 valid HIV sequences of older individuals were obtained, which revealed 14 subtypes. Circulating recombinant forms (CRF) 07_BC accounted for 55.8% and CRF01_AE accounted for 20.1% of the subtypes. Data of 150 older individuals were included in the molecular transmission network, and the proportion of elderly individuals in clustered cases is 52.26% (150/287). The results of multivariable logistic regression analysis showed that the older age group (60-82 years) and CRF07_BC subtype were associated with case clustering (transmission risk).

CONCLUSIONS

The key high-risk transmission network was mainly composed of the older age group (60-82 years) and CRF07_BC subtype. It is necessary to further strengthen AIDS health promotion and education for individuals aged 60 years and above, as well as for patients with the CRF07_BC subtype, to reduce HIV transmission and clustering risk.

Molecular Epidemiology and Trends in HIV-1 Transmitted Drug Resistance in Mozambique 1999–2018

HIV drug resistance (HIVDR) can become a public health concern, especially in low- and middle-income countries where genotypic testing for people initiating antiretroviral therapy (ART) is not available. For first-line regimens to remain effective, levels of transmitted drug resistance (TDR) need to be monitored over time. To determine the temporal trends of TDR in Mozambique, a search for studies in PubMed and sequences in GenBank was performed. Only studies covering the pol region that described HIVDR and genetic diversity from treatment naïve patients were included. A dataset from seven published studies and one novel unpublished study conducted between 1999 and 2018 were included. The Calibrated Population Resistance tool (CPR) and REGA HIV-1 Subtyping Tool version 3 for sequences pooled by sampling year were used to determine resistance mutations and subtypes, respectively. The prevalence of HIVDR amongst treatment-naïve individuals increased over time, reaching 14.4% in 2018. The increase was most prominent for non-nucleoside reverse transcriptase inhibitors (NNRTIs), reaching 12.7% in 2018. Subtype C was predominant in all regions, but a higher genetic variability (19% non-subtype C) was observed in the north region of Mozambique. These findings confirm a higher diversity of HIV in the north of the country and an increased prevalence of NNRTI resistance among treatment naïve individuals over time.