Transmitted Antiretroviral Drug Resistance to Integrase Strand Transfer Inhibitors Class in São Paulo Metropolitan Area, Brazil.

A newer integrase strand transfer inhibitor (INSTI) cabotegravir was recently approved for both therapy and prophylaxis and can play an essential role in the fight against AIDS. It shares similar resistance profile to dolutegravir, the cornerstone of Brazilian antiretroviral (ARV) treatment, with about 600 thousand people living with HIV in Brazil currently on regimens that contain this INSTI. Health services in the São Paulo metropolitan area are responsible for a large proportion of ARV dispensation in the country. Estimating transmitted drug resistance mutation (TDRM) in the area before cabotegravir introduction may provide a useful baseline information. Partial HIV-1 pol gene was sequenced (Sanger) from 192 newly diagnosed individuals from São Paulo and nearby cities (2020 to March 2023) at integrase, with 85 also at protease/reverse transcriptase regions. Retrotranscribed plasma RNA, amplified with nested PCR, was edited (Recall or Sequencher) and analyzed at Rega and Stanford db. Surveillance drug resistance mutations (SDRM) to INSTI class was detected in three cases (1.6%; 95% CI: 0.5%-5%), two E138K and one R263K, with 7.8% (95% CI: 5%-13%) with resistance mutations (major or accessory). SDRM for nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and PI classes were identified in 7 (8.2% CI: 95% 4%-16%) cases. Subtype B predominated (69%), followed by subtype C (16%), now the second most prevalent infection in this area. Among 131 patients treated for over 6 months, 92% were virally suppressed below 200 copies/mL, with low TCD4 counts independently associated to failure. SDRM to INSTI class is rare in the area. Intermediate rates of transmitted resistance to other ARV classes are comparable to previous estimates. Viral suppression rates may depend on TCD4 counts, another negative impact of late diagnosis in care that deserves more attention.

Assessment of an in-house IgG ELISA targeting SARS-CoV-2 RBD: Applications in infected and vaccinated individuals.

The study evoluated an in-house Spike Receptor Binding Domain Enzyme-Linked Immunosorbent Assay (RBD-IgG-ELISA) for detecting SARS-CoV-2 IgG antibodies in infected and vaccinated individuals. The assay demonstrated a sensitivity of 91%, specificity of 99.25%, and accuracy of 95.13%. Precision and reproducibility were highly consistent. The RBD-IgG-ELISA was able to detect 96.25% of Polymerase chain reaction (PCR) confirmed cases for SARS-CoV-2 infection, demonstrating positive and negative predictive values of 99,18% and 91,69%, respectively. In an epidemiological survey, ELISA, lateral flow immunochromatographic assay (LFIA), and electrochemiluminescence immunoassay (ECLIA) exhibited diagnostic sensitivities of 68.29%, 63.41%, and 70.73%, respectively, along with specificities of 82.93%, 80.49%, and 80.49%, respectively. Agreement between RBD-IgG-ELISA/PCR was moderate (k index 0.512). However, good agreement between different assays (RBD-IgG-ELISA/LFIA k index 0.875, RBD-IgG-ELISA/ECLIA k index 0.901). Test performance on individuals' samples were inferior due to seroconversion time and chronicity. The IgG-RBD-ELISA assay demonstrated its effectiveness in monitoring antibody levels among healthcare professionals, revealing significant differences both before and after the administration of the third vaccine dose, with heightened protection levels observed following the third dose in five Coronavirus disease (COVID-19) vaccine regimens. In conclusion, the RBD-IgG-ELISA exhibits high reproducibility, specificity, and sensitivity, making it a suitable assay validated for serosurveillance and for obtaining information about COVID-19 infections or vaccinations.

Lamivudine-based two-drug regimens with dolutegravir or protease inhibitor: Virological suppression in spite of previous therapy failure or renal dysfunction.

BACKGROUND: Two-Drug Regimens (2DR) have proven effective in clinical trials but real-world data, especially in resource-limited settings, is limited. OBJECTIVES: To evaluate viral suppression of lamivudine-based 2DR, with dolutegravir or ritonavir-boosted protease inhibitor (lopinavir/r, atazanavir/r or darunavir/r), among all cases regardless of selection criteria. PATIENTS AND METHODS: A retrospective study, conducted in an HIV clinic in the metropolitan area of São Paulo, Brazil. Per-protocol failure was defined as viremia above 200 copies/mL at outcome. Intention-To-Treat-Exposed (ITT-E) failure was considered for those who initiated 2DR but subsequently had either (i) Delay over 30 days in Antiretroviral Treatment (ART) dispensation, (ii) ART changed or (iii) Viremia > 200 copies/mL in the last observation using 2DR. RESULTS: Out of 278 patients initiating 2DR, 99.6% had viremia below 200 copies/mL at last observation, 97.8% below 50 copies/mL. Lamivudine resistance, either documented (M184V) or presumed (viremia > 200 copies/mL over a month using 3TC) was present in 11% of cases that showed lower suppression rates (97%), but with no significant hazard ratio to fail per ITT-E (1.24, p = 0.78). Decreased kidney function, present in 18 cases, showed of 4.69 hazard ratio (p = 0.02) per ITT-E for failure (3/18). As per protocol analysis, three failures occurred, none with renal dysfunction. CONCLUSIONS: The 2DR is feasible, with robust suppression rates, even when 3TC resistance or renal dysfunction is present, and close monitoring of these cases may guarantee long-term suppression.

Lamivudine-based two-drug regimens with dolutegravir or protease inhibitor: Virological suppression in spite of previous therapy failure or renal dysfunction

Abstract Background Two-Drug Regimens (2DR) have proven effective in clinical trials but real-world data, especially in resource-limited settings, is limited. Objectives To evaluate viral suppression of lamivudine-based 2DR, with dolutegravir or ritonavir-boosted protease inhibitor (lopinavir/r, atazanavir/r or darunavir/r), among all cases regardless of selection criteria. Patients and methods A retrospective study, conducted in an HIV clinic in the metropolitan area of São Paulo, Brazil. Per-protocol failure was defined as viremia above 200 copies/mL at outcome. Intention-To-Treat-Exposed (ITT-E) failure was considered for those who initiated 2DR but subsequently had either (i) Delay over 30 days in Antiretroviral Treatment (ART) dispensation, (ii) ART changed or (iii) Viremia > 200 copies/mL in the last observation using 2DR. Results Out of 278 patients initiating 2DR, 99.6% had viremia below 200 copies/mL at last observation, 97.8% below 50 copies/mL. Lamivudine resistance, either documented (M184V) or presumed (viremia > 200 copies/mL over a month using 3TC) was present in 11% of cases that showed lower suppression rates (97%), but with no significant hazard ratio to fail per ITT-E (1.24, p= 0.78). Decreased kidney function, present in 18 cases, showed of 4.69 hazard ratio (p= 0.02) per ITT-E for failure (3/18). As per protocol analysis, three failures occurred, none with renal dysfunction. Conclusions The 2DR is feasible, with robust suppression rates, even when 3TC resistance or renal dysfunction is present, and close monitoring of these cases may guarantee long-term suppression.

Diagnóstico laboratorial da infecção pelo HIV em travestis e mulheres transexuais no Brasil, 2019-2021 / Laboratory diagnosis of HIV infection in travestis and transgender women in Brazil, 2019-2021

A prevalência de HIV em travestis e mulheres transexuais (TrMT) é desproporcionalmente maior quando comparada com a população geral do Brasil. O objetivo deste estudo foi analisar ­ por meio de ensaios molecular e sorológicos convencionais para o diagnóstico da infecção pelo HIV ­ amostras de sangue de uma população TrMT de cinco capitais brasileiras que apresentaram resultado reagente em testes rápidos (TR). Um total de 435 amostras com resultado reagente em pelo menos um TR foi encaminhado ao laboratório de referência do estado de São Paulo ­ o Instituto Adolfo Lutz (IAL) ­ para que fossem analisadas, por meio de testes laboratoriais convencionais. Das amostras avaliadas, 99,3% (432/435) foram reagentes para HIV nos testes laboratoriais convencionais, e destas, 22,7% (98/432) apresentaram carga viral HIV-1 acima de 5.000 cópias/mL e 77,3% (334/432) mostraram-se reagentes em testes sorológicos (imunoensaio de quimioluminescência ou ELISA e imunoblot rápido). As três amostras restantes (0,7%) foram classificadas como "indeterminada para HIV", com base em ensaios molecular e sorológicos convencionais. A sensibilidade analítica dos diferentes ensaios ­ molecular e sorológicos ­ utilizados neste estudo pode ter variado pela influência da imunossupressão viral do HIV-1 resultante da terapia antirretroviral (TARV). Estudos complementares são necessários para melhor entender o impacto da terapia no diagnóstico do HIV

HIV prevalence among travestis and transgender women (TrTW) is disproportionately higher when compared to the overall Brazilian population. The objective of this study was to evaluate, through conventional serological and molecular tests for the diagnosis of HIV infection, blood samples of TrTW residents of five Brazilian capitals with previous reactive HIV point-of-care rapid tests (RT). A total of 435 samples with at least one reactive HIV result on point-of-care tests were sent to the HIV reference laboratory in São Paulo State ­ the Adolfo Lutz Institute ­ for further evaluation by conventional laboratory tests. From total, 432 (99.3%) samples were reactive for HIV infection in conventional laboratory assays, comprising 98/432 (22.7%) with HIV-1 viral load over 5,000 copies/ml, and 334/432 (77.3%) reactive to serological tests (chemiluminescence immunoassay or ELISA, and rapid immunoblotting). The three remaining samples (0.7%) were classified as "indeterminate for HIV" based on conventional serological and molecular assays. Analytical sensitivity of different molecular and serological assays used in this study may have varied due to HIV-1 viral suppression resulting from antiretroviral therapy (ART). Additional studies are needed to better understand the impact of therapy on HIV diagnosis

Impact of covid-19 on people living with HIV-1: care and prevention indicators at a local and nationwide level, Santo André, Brazil.

The world has been dealing with Aids for forty years, covid-19 accentuated societal inequalities and promoted a rupture in care and prevention, including for people living with HIV. We compiled official HIV indicators, analyzed the impact of covid-19 in Brazil, at São Paulo State (SP), and compared it to the municipality of Santo André (in the state of São Paulo), which adopted linkage/retention strategies to mitigate the impact of covid-19. From 2019 to 2020, suppression/adhesion rates remained stable. The number of new treatments decreased both in Brazil (-19.75%) and São Paulo (-16.44%), but not in Santo André, where 80% of new patients started treatment within 30 days from their first TCD4 test (70% in São Paulo and 64% in Brazil). However, PrEP dispensing increased during this period. The distribution of 2,820 HIV self-tests in Santo André lead to only one documented new HIV diagnosis linked to care. Synergistic strategies to swiftly diagnose and connect new cases, ensuring retention as well as rescuing missing patients deserve priority in the fight against HIV, especially in times of covid-19.

Recent HIV infections: evaluation of a simple identification score for newly diagnosed patients.

OBJECTIVE: Recognize incident infection to better characterize the groups that fuel HIV epidemic. We propose a simple score to identify recent infections among newly diagnosed patients as a HIV surveillance tool. METHODS: Newly diagnosed patients were defined as recent infections when a negative serological test in the previous year was available. Laboratory tests, such as the avidity index (Bio-Rad, according to the CEPHIA protocol), chemiluminescent intensity (CMIA, architect, Abbott), and the nucleotide ambiguity index of partial pol sequences were used as proxies of recency. A simple score based on clinical symptoms of acute retroviral syndrome during the previous year, CD4+ T cell count, and viral load at admission was tested to assess the predictive power, using receiver operating characteristic (ROC) curves, to identify recent cases of infection. RESULTS: We evaluated 204 recently diagnosed patients who were admitted to the Ambulatório de Referência em Moléstias Infecciosas de Santo André (Santo André Reference Infectious Diseases Outpatient Clinic), in the metropolitan region of São Paulo, Brazil, recruited between 2011 and 2018. An HIV-negative test in the year prior to enrollment was documented in 37% of participants. The proportion of cases classified as recent infections (less than one year), according to the laboratory proxies were: 37% (67/181) for an avidity index < 40%, 22% (30/137) for a CMIA < 200, and 68% (124/181) for an ambiguity index < 0.5%. Using different combinations of recency definitions, our score showed an area under the ROC curve from 0.66 to 0.87 to predict recency. CONCLUSIONS: Using data from patients' interviews and routine laboratory tests at admission, a simple score may provide information on HIV recency and thus, a proxy for HIV incidence to guide public policies. This simple for the Brazilian public health system and other low- and middle-income countries.

SARS-CoV-2 testing among patients and healthcare professionals in an HIV outpatient clinic in Brazil.

The COVID-19 pandemic in Brazil has been marked by high infection and death rates. The immune response generated by current vaccination might be influenced by previous natural infection, and baseline estimates may help in the evaluation of vaccine-induced serological response. We evaluated previous SARS-CoV-2 testing (RT-PCR), and performed rapid diagnostic tests (RDT) and high throughput electrochemiluminescence immunoassay (ECLIA) before vaccination among people living with HIV (PLWH), users of antiretroviral prophylaxis (PrEP/PEP), and healthcare professionals in an HIV outpatient clinic (HCP-HC). RDT was positive in 25.7% (95% CI: 19-33%) overall, 31.3% (95% CI : 18-45%) among PLWH, 23.7% (95% CI : 14-34%) in PrEP/PEP users and 21.4% (95% CI : 05-28%) in HCP-HC (p=0.548). Diagnostic RT-PCR testing was very limited, even for symptomatic individuals, and whereas all HCP-HC had one test perfomed, only 35% of the patients (PREP/PEP/PLWH) were tested (p<0.0001). Adequate monitoring of post-vaccination humoral response and breakthrough infections including those in asymptomatic cases are warranted, especially in immunologically compromised individuals.

A simple algorithm for selecting cases to investigate acute and early HIV infections in low- and middle-income countries.

We documented the outcome of an over 10-year (2011-2021) effort to diagnose acute and early HIV infections (AEHI) in an Infectious Diseases Outpatient Clinic with limited resources. Of a total of 132, 119 HIV-RNA tests were performed from 2017 to 2020, 12 cases were identified, using a simple algorithm: risk exposure of 6 weeks or less before the visit and/or symptoms compatible with acute retroviral syndrome 7-30 days after exposure and/or undetermined 3rd generation rapid diagnostic test or serology. AEHI diagnoses varied from 2.4% among asymptomatic to 25% for undetermined serology cases using this simple screening applicable to different settings.

Impact of covid-19 on people living with HIV-1: care and prevention indicators at a local and nationwide level, Santo André, Brazil

ABSTRACT The world has been dealing with Aids for forty years, covid-19 accentuated societal inequalities and promoted a rupture in care and prevention, including for people living with HIV. We compiled official HIV indicators, analyzed the impact of covid-19 in Brazil, at São Paulo State (SP), and compared it to the municipality of Santo André (in the state of São Paulo), which adopted linkage/retention strategies to mitigate the impact of covid-19. From 2019 to 2020, suppression/adhesion rates remained stable. The number of new treatments decreased both in Brazil (-19.75%) and São Paulo (-16.44%), but not in Santo André, where 80% of new patients started treatment within 30 days from their first TCD4 test (70% in São Paulo and 64% in Brazil). However, PrEP dispensing increased during this period. The distribution of 2,820 HIV self-tests in Santo André lead to only one documented new HIV diagnosis linked to care. Synergistic strategies to swiftly diagnose and connect new cases, ensuring retention as well as rescuing missing patients deserve priority in the fight against HIV, especially in times of covid-19.

Recent HIV infections: evaluation of a simple identification score for newly diagnosed patients

ABSTRACT OBJECTIVE Recognize incident infection to better characterize the groups that fuel HIV epidemic. We propose a simple score to identify recent infections among newly diagnosed patients as a HIV surveillance tool. METHODS Newly diagnosed patients were defined as recent infections when a negative serological test in the previous year was available. Laboratory tests, such as the avidity index (Bio-Rad, according to the CEPHIA protocol), chemiluminescent intensity (CMIA, architect, Abbott), and the nucleotide ambiguity index of partial pol sequences were used as proxies of recency. A simple score based on clinical symptoms of acute retroviral syndrome during the previous year, CD4+ T cell count, and viral load at admission was tested to assess the predictive power, using receiver operating characteristic (ROC) curves, to identify recent cases of infection. RESULTS We evaluated 204 recently diagnosed patients who were admitted to the Ambulatório de Referência em Moléstias Infecciosas de Santo André (Santo André Reference Infectious Diseases Outpatient Clinic), in the metropolitan region of São Paulo, Brazil, recruited between 2011 and 2018. An HIV-negative test in the year prior to enrollment was documented in 37% of participants. The proportion of cases classified as recent infections (less than one year), according to the laboratory proxies were: 37% (67/181) for an avidity index < 40%, 22% (30/137) for a CMIA < 200, and 68% (124/181) for an ambiguity index < 0.5%. Using different combinations of recency definitions, our score showed an area under the ROC curve from 0.66 to 0.87 to predict recency. CONCLUSIONS Using data from patients' interviews and routine laboratory tests at admission, a simple score may provide information on HIV recency and thus, a proxy for HIV incidence to guide public policies. This simple for the Brazilian public health system and other low- and middle-income countries.

SARS-CoV-2 testing among patients and healthcare professionals in an HIV outpatient clinic in Brazil

ABSTRACT The COVID-19 pandemic in Brazil has been marked by high infection and death rates. The immune response generated by current vaccination might be influenced by previous natural infection, and baseline estimates may help in the evaluation of vaccine-induced serological response. We evaluated previous SARS-CoV-2 testing (RT-PCR), and performed rapid diagnostic tests (RDT) and high throughput electrochemiluminescence immunoassay (ECLIA) before vaccination among people living with HIV (PLWH), users of antiretroviral prophylaxis (PrEP/PEP), and healthcare professionals in an HIV outpatient clinic (HCP-HC). RDT was positive in 25.7% (95% CI: 19-33%) overall, 31.3% (95% CI : 18-45%) among PLWH, 23.7% (95% CI : 14-34%) in PrEP/PEP users and 21.4% (95% CI : 05-28%) in HCP-HC (p=0.548). Diagnostic RT-PCR testing was very limited, even for symptomatic individuals, and whereas all HCP-HC had one test perfomed, only 35% of the patients (PREP/PEP/PLWH) were tested (p<0.0001). Adequate monitoring of post-vaccination humoral response and breakthrough infections including those in asymptomatic cases are warranted, especially in immunologically compromised individuals.

Field evaluation of COVID-19 antigen tests versus RNA based detection: Potential lower sensitivity compensated by immediate results, technical simplicity, and low cost.

One year into the coronavirus disease 2019 (COVID-19) pandemic, diagnostic strategies, although central for contact tracing and other preventive measures, are still limited. To meet the global demand, lower cost and faster antigen tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection are a convenient alternative to the gold standard reverse transcription-polymerase chain reaction (RT-PCR) assay. We tested laboratory-based RT-PCR RNA detection and two rapid antigen detection (RAD) tests, based on the immunochromatography test for nucleocapsid protein of SARS-CoV-2 (COVID-19 Ag ECO Test, ECO Diagnóstica, and Panbio COVID-19 Ag Rapid Test Abbott). Paired collection and testing were done in a small prospective open study in three clinical services in São Paulo, constituted of mostly symptomatic volunteers at collection (97%, 109/112) for a median of 4 days (interquartile range: 3-6), ranging from 1 to 30. Among the 108 paired RT-PCR/RAD tests, results were concordant in 96.4% (101/108). The test's performance was comparable, with an overall sensitivity of 87% and a specificity of 96%. These observations add to other data that suggest that antigen tests may provide reasonable sensitivity and specificity and deserve a role to improve testing strategies, especially in resource-limited settings.

Young age and sex work are associated with HIV seroconversion among transgender women in São Paulo, Brazil

Background: Transgender women worldwide have among the highest prevalence of HIV and the lowest access to prevention among groups at risk. However, few longitudinal studies have directly measured HIV incidence and identified predictors of HIV acquisition among transgender women. Setting: São Paulo, Latin America's largest city. Methods: We conducted a longitudinal study among transgender women in São Paulo. Participants were recruited by a long-chain peer referral process from May 2017 to July 2019. Those age 18 years and older and HIV-negative at baseline were retested every 6 months up to 18 months. HIV incidence was calculated by dividing the number of seroconversions by the person-years (py) of follow-up; 95% confidence intervals (CI) were constructed assuming a Poisson distribution. Conditional maximum likelihood ratios assessed differences in HIV incidence by risk factors. Results: A racial/ethnically diverse sample of 545 transgender women were enrolled. In 485.5 py of follow-up, 13 seroconversions were observed yielding an incidence of 2.68 per 100 py (95% CI 1.43­4.58). HIV incidence was significantly higher among transgender women age 18 to 24 years (rate ratio 3.85, 95% CI 1.24­12.93) and among those who engaged in sex work in the preceding month (rate ratio 5.90, 95% CI 1.71­26.62). Conclusion: HIV transmission continues at a high rate among transgender women in Brazil. Factors such as young age, lower level of education, and limited employment opportunities may lead to dependence upon sex work which in turn increase HIV risk. Transgender-friendly prevention services, particularly programs delivering pre-exposure prophylaxis (PrEP) are urgently needed.

Field evaluation of COVID­19 antigen tests versus RNA based detection: Potential lower sensitivity compensated by immediate results, technical simplicity, and low cost

One year into the coronavirus disease 2019 (COVID­19) pandemic, diagnosticstrategies, although central for contact tracing and other preventive measures, arestill limited. To meet the global demand, lower cost and faster antigen tests forsevere acute respiratory syndrome coronavirus 2 (SARS­CoV­2) detection are aconvenient alternative to the gold standard reverse transcription­polymerase chainreaction (RT­PCR) assay. We tested laboratory­based RT­PCR RNA detection andtwo rapid antigen detection (RAD) tests, based on the immunochromatography testfor nucleocapsid protein of SARS­CoV­2 (COVID­19 Ag ECO Test, ECO Diagnóstica,and Panbio COVID­19 Ag Rapid Test Abbott). Paired collection and testing weredone in a small prospective open study in three clinical services in São Paulo,constituted of mostly symptomatic volunteers at collection (97%, 109/112) for amedian of 4 days (interquartile range: 3­6), ranging from 1 to 30. Among the108 paired RT­PCR/RAD tests, results were concordant in 96.4% (101/108). Thetest's performance was comparable, with an overall sensitivity of 87% and aspecificity of 96%. These observations add to other data that suggest that antigentests may provide reasonable sensitivity and specificity and deserve a role toimprove testing strategies, especially in resource­limited settings.

Long-term virological effectiveness with darunavir/ritonavir-based salvage therapy in people living with HIV/AIDS from São Paulo, Brazil.

Even though darunavir/ritonavir (DRV/r) has high potency and a greater genetic barrier, there are few studies on the long-term effectiveness of DRV/r-based salvage therapy in people living with HIV (PLWH) in low and middle-income countries. This retrospective cohort study, from São Paulo, Brazil, included ART-experienced PLWH aged ≥18 years with virological failure (VF) who had started DRV/r plus an optimized background regimen (OBR) between 2008 and 2012. The proportion of patients with viral load (VL) <50 copies/mL, the improved mean CD4+ T cell count and the factors associated with VF during the 144-week follow-up were assessed. The study included 173 patients with the following characteristics [median (interquartile range)]: age 48 (42 -53) years; CD4+ T cell count, 229 (89 -376) cells/mm3; VL, 4.26 (3.70 -4.74) log10; 6 (4 -7) previous regimens; and 100 (38 -156) months of VF. After 144 weeks, 129 (75%) patients had VL< 50 copies/mL and a mean increase in the CD4+ T cell count of 190 cells/mm3. VL>100,000 copies/mL and poor adherence were associated with VF. DRV/r plus an OBR showed high long-term virological suppression and immunological recovery. VL>100,000 copies/mL and poor adherence were associated with VF at 144 weeks.

Prevalence of Antiretroviral Drug Resistance Mutations in HIV Seropositive Patients from an Outpatient Clinic of a Large University Hospital from São Paulo, Brazil.

Drug resistance mutations (DRMs) can affect the success of the therapy and compromise new prevention strategies. Increasing rates of resistance to antiretroviral (ARV) drugs have been reported in some areas. This study evaluated the DRMs prevalence among patients at Hospital das Clínicas (São Paulo). Among treatment-naive patients, the prevalence of transmitted DRMs (Stanford Calibrated Population Resistance) was 8.4% (21/249), with 69% (75/109) of acquired resistance among treatment-experienced patients. Rates of transmitted DRM showed an increase (6.6% in 2002-2009 vs. 15.1% in 2010-2015, p = .05), from the first to the second decade, mainly due to mutations to the NNRTI (non-nucleoside reverse transcriptase inhibitor) class. Among treatment-experienced cases, a nonsignificant decrease overall, significant for the protease inhibitors (PIs) class, was documented. Subtype B predominated in both groups (78%), followed by subtype F, BF recombinants, and subtype C. Our results add to the growing evidence of an increase in transmitted DRM, document extensive DRM among experienced patients, and a decrease in resistance to PIs class that may reflect the increased use of boosted PIs and newer ARV classes in more recent years.