Increasing prevalence of HIV-1 Transmitted Drug Resistance in Portugal: implications for first line treatment recommendations
AbstractBackgroundTreatment for all recommendations has allowed access to antiretroviral (ARV) treatment to an increasing number of patients. This minimizes transmission of infection but can potentiate the risk for development of transmitted drug resistance (TDR) and acquired drug resistance (ADR).ObjectiveTo study the trends of TDR and ADR in patients followed in Portuguese hospitals between 2001 and 2017.Method11911 patients of the Portuguese REGA database were included. TDR was defined as the presence of one or more surveillance drug resistance mutations according to the WHO surveillance list. Phenotypic resistance to ARV was evaluated with Standford HIVdb v7.0. Patterns of TDR, ADR and prevalence of mutations over time were analysed with logistic regression.ResultsThe prevalence of TDR increased from 7.9% in 2003 to 13.1% in 2017 (pfor-trend<0.001). This was due to a significant increase of both resistance mutations to nucleotide reverse transcriptase inhibitors (NRTIs) and non-nucleotide reverse transcriptase inhibitors (NNRTIs) from 5.6% to 6.7% (pfor-trend=0.002) and 2.9% to 8.9% (pfor-trend<0.001), respectively. TDR to Protease Inhibitors decreased from 4.0% in 2003 to 2.2 in 2017 (pfor-trend =0.985). Paradoxically, the prevalence of ADR declined from 86.6% in 2001 to 51.0% in 2017 (pfor-trend<0.001) caused by a declining drug resistance to all ARV classes (pfor-trend<0.001).ConclusionsWhile ADR is declining since 2001, TDR has been increasing, reaching a value of 13.1% by the end of 2017. It is urgent to develop public health programs to monitor levels and patterns of TDR in newly diagnosed patients.