Suzel Valère TALA TAGATSI1
1Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Cameroon
CaHReF 2018, Yaoundé Congres hall, 08 – 11 January 2019 , OSEP043
Background: The scale up of antiretroviral therapy (ART) is associated with increasing risks of HIV drug resistance (HIVDR) in resource-limited settings (RLS), leading to decreasing efficacy of ART. The national threshold of pre-treatment drug resistance (PDR) to non-nucleoside reverse transcriptase inhibitors (NNRTI) is 8.1% (WHO-report, 2017), without information on geographical disparities.
Objectif: We sought to determine PDR according to geographical locations in Cameroon (Southwest and West regions) and its association with HIV-1 genetic diversity.
Methodolody: A sentinel surveillance of PDR was conducted in rural and urban settings of the West and South-West regions from February to April 2018. RNA was extracted from plasma, then reverse-transcribed and amplified using a semi-nested PCR. DNA sequencing of HIV-1 protease and reverse transcriptase was performed using dye-terminators, sequence assembling and editing was processed using SeqScapev2.7, HIV-1 drug resistance mutations (DRMs) were interpreted using Stanford HIVdb.v.8.5, while molecular phylogeny was performed using BioEditv7.0.5.3 (for sequence alignment) and MEGAv7.0.26 (for phylogenetic tree construction). Statistical analyses were performed using EPI-Info v7.2.2.6, with <0.05 considered statistically significant.
Results: In total, 60 sequences were generated (30 per region; 33 urban vs. 27 rural) from ART-naïve patients (mean age: 36 ± 12 years; 65% females). Overall, PDR in both regions was 15.00% [CI 95%, 7.10%-26.57%]; 13.33% [3.76-30.72] in the West vs.16.67% [5.64-34.72] in the Southwest; p=0.76. PDR was 21% vs 7.41% respectively in urban and rural settings p=0.16. Overall, NNRTI-PDR was 10% [3.76-20.51], with 12.12% in urban vs. 7.41% in rural settings; p=0.68. Predominant mutations were: K103N (5%), T215S (3.3%) and K219E/N (3.3%). CRF02_AG was the predominant strain (67%), and PDR-level varied between CRF02_AG (10.87%) vs. non-CRF02_AG (28.57%), p=0.19.
Conclusion/Recommandation: In these Cameroonian settings, dominated by individuals in a less advanced stage of the disease, mainly infected by the recombinant 02_AG virus, the threshold of NNRTI-PDR is high (≥10%), particularly in urban settings. This urges need for either switching to NNRTI-sparing regimens (using dolutegravir-based or locally available PI-based regimens) or selecting initial ART based on genotypic resistance testing. These public health actions are very crucial for patients initiating ART in urban settings of these regions.
Key Words: HIV-1; Pre-treatment Drug Resistance; Cameroon