Pretreatment HIV-1 Resistance in Argentina: Results from the Second Surveillance Study Following World Health Organization Guidelines (2019).

More than 62,000 individuals are currently on antiretroviral treatment within the public health system in Argentina. In 2019, more than 50% of people on ART received non-nucleoside reverse transcriptase inhibitors (NNRTIs). In this context, the second nationwide HIV-1 pretreatment drug resistance surveillance study was carried out between April and December 2019 to assess the prevalence of HIV-1 drug resistance in Argentina using the World Health Organization guidelines. This was a nationwide cross-sectional study enrolling consecutive 18-year-old and older individuals starting ARVs at 19 ART-dispensing centers. This allowed us to estimate a point prevalence rate of resistance-associated mutations (RAMs) with a confidence interval (CI) of 5% (for the total population and for those without antiretroviral exposure). Four-hundred forty-seven individuals were included in the study. The prevalence of mutations associated with resistance was detected in 27.7% (95% CI 25.6-34.9%) of the population. For NNRTI, it was 19.6% (95% CI 16.3-24.5%), for integrase strand transfer inhibitor (INSTI) 6.1% (95% CI 6.1-11.9%), for nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) 3% (95% CI 1.9-5.9%), and for protease inhibitors 1.5% (95% CI 0.7-3.6%). Naive individuals had variants of resistance to NRTIs in 16.8% (95% CI 12.8-21.4) and 5.7% (95% CI 2.9-15.9) to INSTI. For experienced individuals, the prevalence of variants associated with resistance was 30.38% (95% CI 20.8-42.2) for NRTIs and 7.7% (95% CI 2.9-15.9) for INSTI. This study shows an increase in the frequency of nonpolymorphic RAMs associated with resistance to NNRTI. This study generates the framework of evidence that supports the use of schemes based on high genetic barrier integrase inhibitors as the first line of treatment and the need for the use of resistance test before prescribing schemes based on NNRTI. We report for the first time the presence of a natural polymorphism associated with the most prevalent recombinant viral form in Argentina and the presence of a mutation linked to first-line integrase inhibitors such as raltegravir.

Colorimetric RT-LAMP Detection of Multiple SARS-CoV-2 Variants and Lineages of Concern Direct from Nasopharyngeal Swab Samples without RNA Isolation.

Since, during the Coronavirus disease 19 (COVID-19) pandemic, a large part of the human population has become infected, a rapid and simple diagnostic method has been necessary to detect its causative agent, the Severe Acute Respiratory Syndrome-related Coronavirus-2 (SARS-CoV-2), and control its spread. Thus, in the present study, we developed a colorimetric reverse transcription-loop-mediated isothermal amplification (RT-LAMP) kit that allows the detection of SARS-CoV-2 from nasopharyngeal swab samples without the need for RNA extraction. The kit utilizes three sets of LAMP primers targeting two regions of ORF1ab and one region in the E gene. The results are based on the colorimetric change of hydroxynaphthol blue, which allows visual interpretation without needing an expensive instrument. The kit demonstrated sensitivity to detect between 50 and 100 copies of the viral genome per reaction. The kit was authorized by the National Administration of Drugs, Food and Technology (ANMAT) of Argentina after validation using samples previously analyzed by the gold standard RT-qPCR. The results showed a sensitivity of 90.6% and specificity of 100%, consistent with conventional RT-qPCR. In silico analysis confirmed the recognition of SARS-CoV-2 variants of concern (B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.427, and B.1.429), and lineages of the Omicron variant (B.1.1.529) with 100% homology. This rapid, simple, and sensitive RT-LAMP method paves the way for a large screening strategy to be carried out at locations lacking sophisticated instrumental and trained staff, as it particularly happens in regional hospitals and medical centers from rural areas.

Immunogenicity induced by the use of alternative vaccine platforms to deal with vaccine shortages in a low- to middle-income country: Results of two randomized clinical trials.

BACKGROUND: Shortages of component two of Sputnik V vaccine (rAd5) are delaying the possibility of achieving full immunisation. The immunogenic response associated with the use of alternative schemes to complete the scheme was not explored. METHODS: We did two non-inferiority randomized clinical trials with outcomes measures blinded to investigators on adults aged 21-65 years, vaccinated with a single dose of rAd26 ≥ 30 days before screening and no history of SARS-CoV-2. Participants were assigned (1:1:1:1:1) to receive either rAd5; ChAdOx1; rAd26; mRNA-1273 or BBIBP-CorV. The primary endpoint was the geometric mean ratio (GMR) of SARS-CoV-2 anti-spike IgG concentration at 28 days after the second dose, when comparing rAd26/rAd5 with rAd26/ChAdOx1, rAd26/rAd26, rAd26/mRNAmRNA-1273 and rAd26/BBIBP-CorV. Serum neutralizing capacity was evaluated using wild type SARS-CoV-2 reference strain 2019 B.1. The safety outcome was 28-day rate of serious adverse. The primary analysis included all participants who received ≥ 1 dose. The studies were registered with NCT04962906 and NCT05027672. Both trials were conducted in Buenos Aires, Argentina. FINDINGS: Between July 6 and August 3, 2021, 540 individuals (age 56·7 [SD 7·3]; 243 (45%) women) were randomly assigned to received rAd5 (n=150); ChAdOx1 (n=150); rAd26 (N=87); mRNAmRNA-1273 (n=87) or BBIBP-CorV (n=65). 524 participants completed the study. As compared with rAd26/rAd5 (1·00), the GMR (95%CI) at day 28 was 0·65 (0·51-0·84) among those who received ChAdOx1; 0·47 (0·34-0·66) in rAd5; 3·53 (2·68-4·65) in mRNA-1273 and 0·23 (0·16-0·33) in BBIBP-CorV. The geometric mean (IU/ml) from baseline to day 28 within each group increased significantly with ChAdOx1 (4·08 (3·07-5·43)); rAd26 (2·69 (1·76-4·11)); mRNA-1273 (21·98 (15·45-31·08)) but not in BBIBP-CorV (1·22 (0·80-1·87)). INTERPRETATION: Except for mRNA-1273 which proved superior, in all other alternatives non-inferiority was rejected. Antibody concentration increased in all non-replicating viral vector and RNA platforms. FUNDING: The trials were supported (including funding, material support in the form of vaccines and testing supplies) by the Buenos Aires City Government.

Genetic diversity and phylogeographic analysis of human herpesvirus type 8 (HHV-8) in two distant regions of Argentina: Association with the genetic ancestry of the population.

BACKGROUND: The genetic diversity of persistent infectious agents, such as HHV-8, correlates closely with the migration of modern humans out of East Africa which makes them useful to trace human migrations. However, there is scarce data about the evolutionary history of HHV-8 particularly in multiethnic Latin American populations. OBJECTIVES: The aims of this study were to characterize the genetic diversity and the phylogeography of HHV-8 in two distant geographic regions of Argentina, and to establish potential associations with pathogenic conditions and the genetic ancestry of the population. STUDY DESIGN: A total of 101 HIV-1 infected subjects, 93 Kaposi's Sarcoma (KS) patients and 411 blood donors were recruited in the metropolitan (MET) and north-western regions of Argentina (NWA). HHV-8 DNA was detected by ORF-26 PCR in whole blood, saliva and FFPE tissues. Then, ORF-26 and ORF-K1 were analyzed for subtype assignment. Mitochondrial DNA and Y chromosome haplogroups, as well as autosomal ancestry markers were evaluated in samples in which subtypes could be assigned. Phylogeographic analysis was performed in the ORF-K1 sequences from this study combined with 388 GenBank sequences. RESULTS: HHV-8 was detected in 50.7%, 59.2% and 8% of samples from HIV-1 infected subjects, KS patients and blood donors, respectively. ORF-K1 phylogenetic analyses showed that subtypes A (A1-A5), B1, C (C1-C3) and F were present in 46.9%, 6.25%, 43.75% and 3.1% of cases, respectively. Analyses of ORF-26 fragment revealed that 81.95% of strains were subtypes A/C followed by J, B2, R, and K. The prevalence of subtype J was more commonly observed among KS patients when compared to the other groups. Among KS patients, subtype A/C was more commonly detected in MET whereas subtype J was the most frequent in NWA. Subtypes A/C was significantly associated with Native American maternal haplogroups (p = 0.004), whereas subtype J was related to non-Native American haplogroups (p < 0.0001). Sub-Saharan Africa, Europe and Latin America were the most probable locations from where HHV-8 was introduced to Argentina. CONCLUSIONS: These results give evidence of the geographic circulation of HHV-8 in Argentina, suggest the association of ORF-26 subtype J with KS development and provide new insights about its relationship with ancient and modern human migrations and identify the possible origins of this virus in Argentina.

Impact of genotypic diversity on selection of subtype-specific drug resistance profiles during raltegravir-based therapy in individuals infected with B and BF recombinant HIV-1 strains.

BACKGROUND: Current knowledge on HIV-1 resistance to integrase inhibitors (INIs) is based mostly on subtype B strains. This contrasts with the increasing use of INIs in low- and middle-income countries, where non-B subtypes predominate. MATERIALS AND METHODS: HIV-1 drug resistance genotyping was performed in 30 HIV-1-infected individuals undergoing virological failure to raltegravir. Drug resistance mutations (DRMs) and HIV-1 subtype were characterized using Stanford HIVdb and phylogenetic analyses. RESULTS: Of the 30 integrase (IN) sequences, 14 were characterized as subtype F (47%), 8 as subtype B (27%), 7 as BF recombinants (23%) and 1 as a putative CRF05_DF (3%). In 25 cases (83%), protease and reverse transcriptase (PR-RT) sequences from the same individuals confirmed the presence of different BF recombinants. Stanford HIVdb genotyping was concordant with phylogenetic inference in 70% of IN and 60% of PR-RT sequences. INI DRMs differed between B and F IN subtypes, with Q148K/R/H, G140S and E138K/A being more prevalent in subtype B (63% versus 0%, P = 0.0021; 50% versus 0%, P = 0.0096; and 50% versus 0%, P = 0.0096, respectively). These differences were independent of the time on raltegravir therapy or viral load at the time of genotyping. INI DRMs in subtype F IN genomes predicted a lower level of resistance to raltegravir and no cross-resistance to second-generation INIs. CONCLUSIONS: Alternative resistance pathways to raltegravir develop in subtypes B and F IN genomes, with implications for clinical practice. Evaluating the role of HIV-1 subtype in development and persistence of mutations that confer resistance to INIs will be important to improve algorithms for resistance testing and optimize the use of INIs.

Implementación del test rápido para VIH en la ciudad autónoma de Buenos Aires una estrategia para facilitar el acceso al diagnostico oportuno / Implementation of Rapid Test for HIV in Buenos Aires City: A Strategy to Facilitate Access to Timely Diagnosis

INTRODUCCIÓN: El diagnóstico oportuno de la infección por VIH es una estrategia clave en el control de la epidemia. El uso de las pruebas rápidas facilita el acceso al diagnóstico en el primer nivel de atención y en espacios por fuera del sistema de salud. MÉTODOS: Se describió el proceso de implementación del test rápido para VIH en la Ciudad Autónoma de Buenos Aires (CABA), analizando indicadores epidemiológicos para evaluar el impacto sanitario. RESULTADOS: Desde el inicio de esta estrategia en 2012 y hasta 2018, el test rápido se implementó en 36 centros de la ciudad, tanto en el sistema de salud como en organizaciones de la sociedad civil. En 2014 se inició una campaña de promoción con testeos mensuales en el espacio público de distintos barrios. El número de personas sometidas a la prueba se duplicó en los centros de testeo y aumentó progresivamente en los laboratorios de los hospitales públicos, con un descenso en la proporción de diagnósticos en estadios sintomáticos. CONCLUSIONES: La implementación de la prueba rápida para el diagnóstico de VIH en CABA muestra un modelo exitoso de oferta de prestación en los puntos de atención, que facilita el acceso al tamizaje y que puede extenderse para el diagnóstico y tratamiento de otras infecciones de transmisión sexual.

Pre-treatment drug resistance and HIV-1 subtypes in infants from Argentina with and without exposure to antiretroviral drugs for prevention of mother-to-child transmission.

OBJECTIVES: To assess the prevalence and patterns of pre-treatment HIV drug resistance (PDR) and HIV-1 subtype in infants from Argentina with exposure to different antiretroviral drugs (ARVs) for the prevention of mother-to-child transmission (PMTCT). PATIENTS AND METHODS: HIV-1 genotyping was performed in 115 infants (median age = 2.3 months) born between 2007 and 2014 to screen for drug resistance mutations (DRMs) before starting first-line ART. HIV-1 subtype was characterized by phylogenetic and recombination analysis. RESULTS: Overall, DRMs were found in 34 of 115 infants (PDR level 30% to any ARV, 3.5% to PIs, 12% to NRTIs and 22% to NNRTIs). Of the 115 infants, 22 (19.1%) were ARV-unexposed. Another 93 were ARV-exposed: 28 (24.3%) to short-course zidovudine monotherapy ARV prophylaxis; 25 (21.7%) to nevirapine-based ARV prophylaxis; 12 (10.4%) to perinatal infant zidovudine prophylaxis + maternal combination ART with NNRTIs; and 28 (24.3%) to perinatal infant zidovudine prophylaxis+maternal combination ART with PIs. Transmitted drug resistance among ARV-unexposed infants was 32% (5% to PIs, 9% to NRTIs and 18% to NNRTIs). ART-exposed infants showed multi-class ARV resistance. Importantly, vertical transmission of a triple-class-resistant virus was confirmed in one case. Patterns of DRMs predicted high-level resistance to NNRTIs in a similar and high proportion (>50%) of infants with at least one DRM independently of ARV exposure. BF recombinants were found in 74%, subtype B in 20%, subtype C in 3% and novel AG and AB recombinants in 3%. CONCLUSIONS: PDR in HIV-1-infected children from Argentina is among the highest reported, jeopardizing successful lifelong suppressive ART as well as the efficacy of current PMTCT regimens.

[HIV-1 resistance to antiretroviral drugs in pregnant women from Buenos Aires metropolitan area]. / Resistencia de HIV-1 a drogas antirretrovirales en gestantes del área Metropolitana de Buenos Aires.

The study aimed to determine the prevalence of antiretroviral resistance associated mutations in HIV-1 infected pregnant woman treated in Buenos Aires metropolitan area (period 2008-2014). A total of 136 women with viral load = 500 copies/ml were included: 77 (56.6%) were treatment-naïve and 59 (43.4%) were antiretroviral-experienced patients either with current (n: 24) or previous (n = 35) antiretroviral therapy. Genotypic baseline resistance was investigated in plasma of antiretroviral-naïve patients and antiretroviral-experienced patients. The resistance mutations were identified according to the lists of the World Health Organization and the International Antiviral Society, respectively. Frequencies of resistance associated mutations detected in 2008-2011 and 2012-2014 were compared. A total of 37 (27.2%) women presented at least one resistance associated mutation: 25/94 (26.5%) in 2008-2011 and 12/42 (28.5%) in 2012-2014 (p > 0.05). Among naïves, 15 (19.5%) had at least one mutation: 10/49 (20.4%) in the period 2008-2011 and 5/28 (17.8%) in 2012-2014 (p > 0.05). The resistance mutations detected in naïves were associated with non nucleoside reverse transcriptase inhibitors, being K103N the most common mutation in both periods. In antiretroviral experienced patients, 22/59 (37.3%) had at least one resistance mutation. This study demonstrates a high frequency of resistance associated mutations which remained stable in the period analyzed. These levels suggest an increased circulation of HIV-1 antiretroviral resistant strains in our setting compared to previous reports from Argentina.

Resistencia de HIV-1 a drogas antirretrovirales en gestantes del área metropolitana de Buenos Aires / HIV-1 resistance to antiretroviral drugs in pregnant women from Buenos Aires metropolitan area

Se determinó la frecuencia de mutaciones asociadas a resistencia de HIV-1 a antirretrovirales en embarazadas del área metropolitana de Buenos Aires, 2008-2014. Se incluyeron 136 mujeres con carga viral ≥ 500 copias/ml: 77 (56.6%) eran naïve; las otras 59 (43.4%) eran expuestas, ya sea con tratamiento en curso (n: 24) o previo (n: 35). Se realizó análisis de resistencia genotípica basal en plasma de pacientes naïve y con experiencia de tratamiento antirretroviral. Las mutaciones se identificaron según las listas de la Organización Mundial de la Salud y la International Antiviral Society, respectivamente. Se comparó la frecuencia de mutaciones detectadas en los subperíodos 2008-2011 vs. 2012-2014. Un total de 37 (27.2%) mujeres presentaron ≥ 1 mutación asociada a resistencia: 25/94 (26.5%) en 2008-2011 y 12/42 (28.5%) en 2012-2014 (p > 0.05). Entre las naïve, 15 (19.5%) tenían ≥ 1 mutación: 10/49 (20.4%) en el subperíodo 2008-2011 y 5/28 (17.8%) en 2012-2014 (p > 0.05). Las mutaciones encontradas en pacientes naïve estuvieron asociadas a inhibidores no nucleosídicos de la transcriptasa reversa, y, como en estudios anteriores, K103N fue la más frecuente a lo largo de todo el período. Entre las pacientes expuestas, 22/59 (37.3%) presentaron ≥ 1 mutación asociada a resistencia. Este estudio demuestra una alta frecuencia de mutaciones asociadas a resistencia que se mantuvo estable a lo largo del período. Los niveles detectados sugieren una mayor circulación en nuestro medio de cepas de HIV-1 resistentes a antirretrovirales con respecto a los niveles previamente observados en Argentina.

The study aimed to determine the prevalence of antiretroviral resistance associated mutations in HIV-1 infected pregnant woman treated in Buenos Aires metropolitan area (period 2008-2014). A total of 136 women with viral load ≥ 500 copies/ml were included: 77 (56.6%) were treatment-naïve and 59 (43.4%) were antiretroviral-experienced patients either with current (n: 24) or previous (n = 35) antiretroviral therapy. Genotypic baseline resistance was investigated in plasma of antiretroviral-naïve patients and antiretroviral-experienced patients. The resistance mutations were identified according to the lists of the World Health Organization and the International Antiviral Society, respectively. Frequencies of resistance associated mutations detected in 2008-2011 and 2012-2014 were compared. A total of 37 (27.2%) women presented at least one resistance associated mutation: 25/94 (26.5%) in 2008-2011 and 12/42 (28.5%) in 2012-2014 (p > 0.05). Among naïves, 15 (19.5%) had at least one mutation: 10/49 (20.4%) in the period 2008-2011 and 5/28 (17.8%) in 2012-2014 (p > 0.05). The resistance mutations detected in naïves were associated with non nucleoside reverse transcriptase inhibitors, being K103N the most common mutation in both periods. In antiretroviral experienced patients, 22/59 (37.3%) had at least one resistance mutation. This study demonstrates a high frequency of resistance associated mutations which remained stable in the period analyzed. These levels suggest an increased circulation of HIV-1 antiretroviral resistant strains in our setting compared to previous reports from Argentina.

Score de sensibilidad genotípico de tratamientos antirretrovirales en embarazadas naïve infectadas por VIH-1 / Genotypic sensitivity score of antiretroviral therapies in naïve HIV-1 infected pregnant women

Introducción: el score de sensibilidad genotípica (GSS) es una herramienta para predecir el resultado virológico del TARV. El objetivo de este estudio es comparar el GSS de tres tratamientos an-tirretrovirales (TARVs) en una población de embarazadas infectadas por VIH (EIV) naïve en Buenos Aires, Argentina. Materiales y Métodos: se analizaron las pruebas de resistencia de 47 EIV naïve en la ciudad de Buenos Aires (período 2008-2011), utilizan-do el algoritmo de la Universidad de Stanford-HIVdb program (pre-valencia de resistencia primaria del 21,2 %). La eficacia predicha de cada fármaco se computó como 1,00-0,75-0,50-0,25 y 0,00 para las cinco categorías HIVdb: desde susceptible a resistencia de alto nivel. El GSS se obtuvo con la suma de las puntuaciones de los fármacos individuales incluidos (GSS = 3, significa tres medicamentos total-mente activos). Tres TARVs se compararon: zidovudina+lamivudina más nevirapina (ART1), nelfinavir (ART2) o lopinavir/ritonavir (ART3). Resultados: se obtuvo un GSS de 3 en el 80,9 % con ART1 y el 91,5 % con ART2 y ART3. No hubo diferencia estadísticamente significati-va en la posibilidad de lograr un GSS de 3 entre los TARVs evaluados. Conclusiones: no hubo diferencia estadística en la probabilidad de proporcionar un régimen comple-tamente activo con un inhibidor de la proteasa o nevirapina. En nuestra opinión, un TARV con una alta barrera genética sería preferible en el contex-to de la alta prevalencia de resistencia primaria ob-servada

Background: The genotypic sensitivity score (GSS) is a tool to predict virological treatment outcome. The objective of this study is to compare the GSS of three antiretroviral treatment (ART) strategies in a population of naive pregnant women (NPW) in Buenos Aires city, Argentina. Methods: Resistance tests from 47 NPW were analyzed in the context of a sentinel resistance surveillance study in Buenos Aires city (period 2008-2011), considering the genotype interpretation system of the Stanford HIVdb program (prevalence of primary drug resistance of 21.2%). The predicted efficacy of each drug was scored either as 1.00-0.75-0.50-0.25 and 0.00 for the five HIVdb categories: from susceptible to high-level resistance. GSS was obtained with the sum of the scores for the individual drugs included in a regimen (GSS of 3 means three fully active drugs). GSS of three ARTs were compared: zidovudine+lamivudine plus either nevirapine (ART1), nelfinavir (ART2) or lopinavir/ritonavir (ART3). Results: A GSS of 3 was achieved in 80.9% with ART1 and 91.5% with both ART2 and ART3. There was no statistical difference in the possibility of achieving a GSS of 3 between the three ARTs evaluated. Conclusions: There was no statistical difference in the probability of providing a fully active regimen with either a protease inhibitor or nevirapine. In our opinion, an ART with a high genetic barrier backbone may be preferred in the context of the high prevalence of primary resistance observed

Transmitted drug resistance in women with intrapartum HIV-1 diagnosis: a pilot epidemiological survey in Buenos Aires, Argentina.

INTRODUCTION: Surveillance of primary resistance to antiretroviral drugs is particularly important in pregnant population, in which infection by drug-resistant HIV has not only implications for maternal treatment, but could also jeopardize the efficacy of neonatal prophylaxis. We aim to describe the prevalence of resistance associated mutations (RAMs) in pregnant women with intrapartum HIV diagnosis in a public hospital of Buenos Aires, Argentina. MATERIALS AND METHODS: Prospective pilot study (period from 2008 to October 2013). Plasma samples were tested for viral load by Versant HIV-1 RNA 3.0 (bDNA) and sequenced using HIV-1 TRUGENE™Genotyping Kit (Siemens). The prevalence of RAMs was analyzed according to World Health Organization (WHO) criteria. RESULTS: Of 231 HIV-infected pregnant women assisted, 6% (n=14) had intrapartum diagnosis of HIV infection. 12 patients (85.7%) had previous pregnancies, 10 (71.4%) had inadequate prenatal care and 3 (23.1%) seroconverted during pregnancy. Maternal characteristics (expressed medians and ranges) were: age 25.5 (16-35) years; gestational age at birth: 39 (30-42) weeks; CD4 count: 500 (132-925) cells/µL; viral load: 9418 (1800-55299) copies/mL. No one had hepatitis B virus (HBV) or hepatitis C virus (HCV) coinfection; four (33.3%) had syphilis. Eight patients (57.1%) had vaginal delivery and six emergency C-section (42.9%). In six cases (46.2%), membrane rupture was spontaneous; four patients (28.6%) failed to receive intrapartum zidovudine (ZDV) infusion. In 12 patients a genotypic resistance test was performed: two (16.7%) had WHO RAMs corresponding to K103N mutation in both cases, conferring high-level resistance to nevirapine (NVP) and efavirenz. Two newborns (14.3%) were preterm. All received neonatal prophylaxis: ZDV in 1 case and combined prophylaxis (ZDV/3TC/NVP) in the remaining 13 (92.9%). All newborns were formula-fed. Two (14.3%) had congenital syphilis, one of whom died. One newborn was HIV-infected (positive proviral DNA at 24 hours of life, wild-type HIV). CONCLUSIONS: This pilot study suggests that levels of transmitted resistance in this high-risk population of pregnant women could be moderate to high. We preliminarily observed high-level resistance to NVP: if this finding is confirmed with a larger sample, it could potentially jeopardize the utility of this drug in the combined neonatal prophylaxis recommended in the absence of maternal antiretroviral therapy.

Increasing trends in primary NNRTI resistance among newly HIV-1-diagnosed individuals in Buenos Aires, Argentina.

OBJECTIVE: Our objective was to estimate primary resistance in an urban setting in a developing country characterized by high antiretroviral (ARV) coverage over the diagnosed population and also by an important proportion of undiagnosed individuals, in order to determine whether any change in primary resistance occurred in the past five years. DESIGN: We carried out a multi-site resistance surveillance study according to WHO HIV resistance guidelines, using a weighted sampling technique based on annual HIV case reports per site. METHODS: Blood samples were collected from 197 drug-naive HIV-1-infected individuals diagnosed between March 2010 and August 2011 at 20 HIV voluntary counselling and testing centres in Buenos Aires. Clinical records of enrolled patients at the time of diagnosis were compiled. Viral load and CD4 counts were performed on all samples. The pol gene was sequenced and the resistance profile determined. Phylogenetic analysis was performed by neighbour-joining (NJ) trees and bootscanning analysis. RESULTS: We found that 12 (7.9%) of the 152 successfully sequenced samples harboured primary resistance mutations, of which K103N and G190A were the most prevalent. Non-nucleoside reverse transcriptase inhibitors (NNRTI) resistance mutations were largely the most prevalent (5.9%), accounting for 75% of all primary resistance and exhibiting a significant increase (p=0.0072) in prevalence during the past 10 years as compared to our previous study performed in 1997-2000 and in 2003-2005. Nucleoside reverse transcriptase inhibitor (NRTI) and protease inhibitor primary resistance were low and similar to the one previously reported. CONCLUSIONS: Levels of primary NNRTI resistance in Buenos Aires appear to be increasing in the context of a sustained ARV coverage and a high proportion of undiagnosed HIV-positive individuals.

Infecciones y otros problemas de salud en usuarios de pasta base de cocaina en un centro asistencial de Buenos Aires, Argentina / Infections and other health problems among coca paste users at a drug treatment center in Buenos Aires, Argentina

INTRODUCCIÓN: la pasta base de cocaína (PBC) es una forma fumable de cocaína de creciente utilización entre los jóvenes. OBJETIVO: describir el patrón de consumo de drogas, las seroprevalencias de VIH, hepatitis B (VHB), hepatitis C (VHC), sífilis y otrosproblemas de salud en usuarios de PBC en un centro asistencial de Argentina. MÉTODO: se incluyeron voluntarios mayores de 18 años, asistidos en el Centro Nacional de Reeducación Social (CENARESO)en el período 2006-2007, que consumieron PBC en los 6 meses anteriores a la entrevista y que nunca utilizaron drogas inyectables. Se aplicó un cuestionario estructurado, se tomó una muestra de sangre para serología de VIH, VHB, VHC y sífilis, y se analizó una sub-muestra de radiografías de tórax. RESULTADOS: más de la mitad de los 146 voluntarios manifestó haber fumado PBC varias veces por semana. Los participantes eran también consumidores frecuentes de cocaína en polvo (64%), cannabis (80,8%) y tranquilizantes (44,5%). Los principales problemas de salud auto-percibidos como consecuencia del consumo de PBC fueron las lesiones orales y la pérdida de peso. El 4,3% de los voluntarios resultó VIH-positivo. Las prevalencias de infección por sífilis, VHB y VHC fueron 2,7%, 5,5%, y 5,5%, respectivamente. El 16% estaba coinfectado con uno o más de los agentes estudiados. DISCUSIÓN: la prevalencia de infecciones, unida a otros problemas de salud de los usuarios de PBC, indica la necesidad de nuevas investigaciones a fin de diseñar intervenciones preventivas y terapéuticas apropiadas

INTRODUCTION: cocaine paste is a smokable form of cocaine increasingly used among young people. OBJECTIVE:to describe patterns of drugs, seroprevalences of HIV, hepatitis B (HBV), hepatitis C (HCV), syphilis and other health problems among coca paste users assisted at a drug treatment center in Argentina. METHOD: volunteers, eighteen-year-old and olderassisted at the National Center for Social Re-education (CENARESO)during 2006-2007, who had consumed coca paste over the past 6 months previous to the interview and had never injected drugs, were selected. A structured questionnaire wasused and blood was drawn to test HIV, HBV, HCV and syphilis. A sub-sample of thorax X-rays was analyzed. RESULTS: morethan half of the 146 volunteers had smoked coca paste severaltimes a week. The use of other drugs was frequently associated: sniffed cocaine 64%, cannabis 80,8%, and tranquilizers 44,5. Oral lesions and lost of weight were referred as health problems stemming from coca paste use. Out of the 146 volunteers, 4.3%resulted HIV-positive. Prevalences of infection for syphilis, HBV, and HCV were 2,7%, 5,5% and 5,5%, respectively. 16% wasco-infected with one or more infectious agents. DISCUSSION: the prevalence of infections detected, along with other clinical problems found among this coca paste users, show the need for further research, in order to design proper preventive and therapeutic interventions

Utilización del ensayo Cobas Amplicor Monitor HIV-1 en el diagnóstico temprano de la infección por HIV en pediatría / Utility of the Cobas Amplicor Monitor HIV-1 assay in the early diagnosis of HIV pediatric infection

Dado que en Argentina el ensayo de HIV RNA cualitativo (QL) ha sido discontinuado, el objetivo del presente trabajo fue evaluar el ensayo de RNA cuantitativo (CV) COBAS AMPLICOR Monitor HIV-1 para su posible incorporación en el diagnóstico pediátrico de infección por HIV en niños expuestos perinatalmente y estimar la concordancia con QL. Fueron incluidas 214 muestras (134 pacientes), 174 muestras de 113 pacientes negativos y 40 correspondientes a 21 pacientes positivos con diagnóstico definitivo. Todas las muestras fueron estudiadas para CV usando el procedimiento estándar (ST, rango 400-750.000 copias/ml) y aquellas por debajo del rango lineal se procesaron por el método ultrasensible (US, rango 50-100.000 copias/ml). El ensayo de CV fue comparado con el de QL en un subgrupo de 93 muestras (78 negativas y 15 positivas). Las 174 muestras pertenecientes a niños HIV negativos tuvieron CV indetectables y entre las 40 muestras pertenecientes a niños HIV positivos, 37 evidenciaron CV detectables (2-5,88 log 10). En 4/37 muestras se detectaron CV entre 165-575 copias/ml, que en muestras posteriores evidenciaron altos valores de CV. El 83,7 % de las muestras resultaron con CV> a 4 log 10. La sensibilidad de la CV según grupo etario fue de 77,7 % < 15 días, 93,3 % entre 15-45 días y la especificidad general del 100 %. La concordancia global entre QL y CV fue del 97,8 %, siendo el ensayo de CV más sensible. Nuestros resultados sugieren la inclusión del ensayo COBAS AMPLICOR en el algoritmo diagnóstico, no presentando resultados falsos positivos.

Since in Argentina qualitative dHIV RNA (QL) test, has been discontinued, the objective of this study was to evaluate the quantitative RNA (VL) COBAS AMPLICOR monitor HIV-1, for its possible inclusion in the paediatric diagnosis of HIV infection and to evaluate the concordance between both assays. In this study 214 samples corresponding to 134 patients were included, 174 and 40 specimens from 113 HIV-negative and 21 HIV-positive patients respectively. All samples were studied for VL using the standard procedure (ST, range 400-750.000 copies/mal), and those below the linear range were further tested by the ultrasensitive method (US, range 50-100.000 copies/ml) QL and VL assays were compared among a subgroup of 93 samples (78 negative and 15 positive). All 174 samples from HIV negative children had undetectable VL. 37/40 samples from HIV-positive had detectable VL (2-5,88 log 10) 4/37 specimens had VL between 165-575 copies/ml, later samples from the corresponding patients showed high VL. 83,7 % of the samples had VL> 4 log 10. The sensitivities found were 77,7 % and 93,3 % among infants < 15 days and between 15-45 days of aged respectively. The general specificity of the COBAS AMPLICOR was 100 %. The concordance between QL and VL eas 97,8 %, showing the later one better sensitivity. Our results support the inclusion of COBAS AMPLICOR in the diagnosis algorithm, not showing false positive results.

Update on primary HIV-1 resistance in Argentina: emergence of mutations conferring high-level resistance to nonnucleoside reverse transcriptase inhibitors in drug-naive patients.

Here we present a survey including 52 drug-naive recently HIV-1-infected subjects from Buenos Aires City and province (79%) and 3 other regions in Argentina (21%). Recent infections were established from previous negative serology (32/52), indeterminate Western blot (12/52), or acute retroviral syndrome after high-risk HIV exposure (8/52) within 9 months before genotyping (median time, 4.2 months). Genotyping was performed from plasma by sequencing both protease and reverse transcriptase. Phylogenetic analysis combined with bootscanning resulted in 21 subtype B sequences and 31 B/F recombinants (RecBF). On protease, minor resistance-related mutations were found in both subtype B and RecBF with low frequencies. The substitution L89M, recently suggested as a resistance-related mutation in some subtype F viruses, was observed in 1 RecBF. On reverse transcriptase, major resistance-related mutations were found in 4 of 52 (7.7%) patients from different health centers: M41L (subtype B) and K103N+/-P225H (1 RecBF and 2 subtype B). The greater than 5% resistance threshold found indicates a need for sentinel resistance surveillances calling for an update in the current resistance testing guidelines in Argentina.