INTRODUCTION By the end of 2017, there were more than 28,000 individuals living with HIV in Cuba, over 80% receiving antiretroviral therapy, which dramatically reduces viral replication, improves immune status and decreases risk of transmission. These results could be jeopardized by emergence of HIV-1 drug resistance. In 2009, a test for HIV-1 genotypic resistance was introduced in routine clinical practice in Cuba.

OBJECTIVE Investigate antiretroviral resistance and its relation to subtype distribution in HIV-1 treatment-naïve and previously treated patients in Cuba.

METHODS Resistance and HIV-1 subtype distribution were determined in 342 antiretroviral treatment-naïve patients and 584 previously treated for HIV-1 whose blood specimens were sent to the Pedro Kourí Tropical Medicine Institute during 2009–2014. Transmitted drug resistance was determined using the Calibrated Population Resistance Tool v.6. Drug resistance analysis was conducted using the algorithm Rega v9.1.0.

RESULTS Prevalence of transmitted drug resistance was 11.4%, and 41% of mutated viruses exhibited dual-class resistance to nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitor. Overall, 84.9% of patients had ≥1 resistance mutation, 80% had ≥1 nucleoside reverse transcriptase inhibitor mutation, 71.4% had ≥1 non-nucleoside reverse transcriptase inhibitor mutation and 31.7% had ≥1 protease inhibitor mutation. K65R and K101E mutations were significantly more frequent in subtype C, L210W in CRF19_cpx, and M47V/I in CRF BGs (20, 23, 24). Full class resistance to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors and multidrug resistance were detected in 21.2%, 32.4%, 8% and 4.1% of patients, respectively. Average percentage resistance to nucleoside reverse transcriptase inhibitor, protease inhibitor, full class resistance to nucleoside reverse transcriptase inhibitor, protease inhibitor and multidrug resistance increased in patients failing two or more regimens. Nevertheless, after 2011, a declining trend was observed in the frequency of multidrug resistance and full class resistance to nucleoside reverse transcriptase inhibitors and protease inhibitors.

CONCLUSIONS Detected levels of transmitted drug resistance highlight the need for a national surveillance study in treatment-naïve patients. Resistance prevalence is high in previously treated patients but appears to be decreasing over time. The frequency of resistance mutations in recombinant forms of HIV in Cuba needs further study.

KEYWORDS Antiretroviral therapy, highly active antiretroviral therapy, HIV, anti-HIV agents, drug resistance, multiple drug resistance, Cuba