Remote Sensing and Ecological Variables Related to Influenza A Prevalence and Subtype Diversity in Wild Birds in the Lluta Wetland of Northern Chile.

The Lluta River is the northernmost coastal wetland in Chile, representing a unique ecosystem and an important source of water in the extremely arid Atacama Desert. During peak season, the wetland is home to more than 150 species of wild birds and is the first stopover point for many migratory species that arrive in the country along the Pacific migratory route, thereby representing a priority site for avian influenza virus (AIV) surveillance in Chile. The aim of this study was to determine the prevalence of influenza A virus (IAV) in the Lluta River wetland, identify subtype diversity, and evaluate ecological and environmental factors that drive the prevalence at the study site. The wetland was studied and sampled from September 2015 to October 2020. In each visit, fresh fecal samples of wild birds were collected for IAV detection by real-time RT-PCR. Furthermore, a count of wild birds present at the site was performed and environmental variables, such as temperature, rainfall, vegetation coverage (Normalized Difference Vegetation Index-NDVI), and water body size were determined. A generalized linear mixed model (GLMM) was built to assess the association between AIV prevalence and explanatory variables. Influenza positive samples were sequenced, and the host species was determined by barcoding. Of the 4349 samples screened during the study period, overall prevalence in the wetland was 2.07% (95% CI: 1.68 to 2.55) and monthly prevalence of AIV ranged widely from 0% to 8.6%. Several hemagglutinin (HA) and neuraminidase (NA) subtypes were identified, and 10 viruses were isolated and sequenced, including low pathogenic H5, H7, and H9 strains. In addition, several reservoir species were recognized (both migratory and resident birds), including the newly identified host Chilean flamingo (Phoenicopterus chilensis). Regarding environmental variables, prevalence of AIV was positively associated with NDVI (OR = 3.65, p < 0.05) and with the abundance of migratory birds (OR = 3.57, p < 0.05). These results emphasize the importance of the Lluta wetland as a gateway to Chile for viruses that come from the Northern Hemisphere and contribute to the understanding of AIV ecological drivers.

Detection and phylogenetic analysis of highly pathogenic A/H5N1 avian influenza clade 2.3.4.4b virus in Chile, 2022.

Highly pathogenic avian influenza (HPAI) A/H5N1 viruses continue to pose a significant threat to animal and human health worldwide. In late 2022, the first confirmed case of HPAI A/H5N1 infection in wild birds in Chile near the Chilean-Peruvian border was reported. Active surveillance by our group in the adyacent Lluta river estuary revealed an increase in A/H5N1 prevalence coinciding with the arrival of migratory birds from the Northern Hemisphere. Genomic analysis of A/H5N1-positive samples demonstrated a close genetic relationship to strains detected in Peru during the same period, which originated from A/H5N1 viruses causing outbreaks in North America. Notably, we identified genetic mutations that did not correlate with known enhanced transmission or binding traits to mammalian receptors. In summary, this study provides valuable genomic insights into the A/H5N1 Clade 2.3.4.4b viruses in wild birds in Chile, emphasizing the need for enhanced surveillance and response strategies to mitigate the threat posed by these highly pathogenic avian influenza viruses in South America.

Distribución geográfica y tipo de infección del virus linfotrópico T humano en pacientes peruanos 2019-2021

En el presente estudio describimos y caracterizamos la distribución geográfica de los casos positivos confirmados a HTLV-1 y 2 de pacientes peruanos con diagnóstico presuntivo entre 2019 y 2021. De un total de 555 muestras positivas confirmadas, 546 (98,4%) fueron HTLV-1 y 9 (1,6%) HTLV-2. Además, 22 de 24 departamentos del Perú presentaron casos de HTLV-1, siendo los principales motivos de solicitud de confirmación diagnóstica: aspirante a donar sangre con prueba de tamizaje reactivo, sospecha de leucemia/linfoma y paraparesia espástica tropical. Los resultados reflejan que la identificación de los puntos críticos constituye una brecha persistente respecto al diagnóstico, siendo cruciales para reducir el número de nuevos casos en Perú.

In the present study we describe and characterize the geographic distribution of HTLV-1 and 2 positive cases from Peruvian patients with presumptive diagnosis 2019 - 2021. Of a total of 555 confirmed positive samples, 546 (98.4%) were HTLV-1 and 9 (1.6%) HTLV-2. In addition, 22 of 24 departments of Peru presented cases of HTLV-1. The main reasons for requesting a confirmatory diagnosis being: aspiring to donate blood with a reactive screening test, suspicion of leukemia/ lymphoma and tropical spastic paraparesis. The results reflect that the identification of critical points constitutes a persistent gap regarding the diagnosis, being crucial to reduce the number of new cases in Peru.

Evaluación de tres pruebas serológicas para la detección de anticuerpos contra el virus linfotrópico T humano tipo 1 (HTLV-1)

Introducción: El Perú es endémico al virus linfotrópico T humano tipo 1 (HTLV-1), por esas razones es importante conocer la fiabilidad de las pruebas diagnósticas que se usan en el país, con la finalidad de continuar o no su uso. El objetivo fue evaluar el rendimiento de tres pruebas serológicas ELISA Murex, ELISA Wantai e IFI INS-Perú para la detección de anticuerpos anti HTLV-1 frente a muestras peruanas. El estudio. Las tres pruebas fueron evaluadas frente a 382 sueros: 215 positivos y 167 negativos a HTLV-1 (Gold Standar: inmunoblot). Hallazgos. IFI no presentó falsos positivos, Wantai tuvo más falsos negativos (siete) y Murex más falsos positivos (ocho). Las tres pruebas mostraron resultados superiores a 95% para los parámetros estimados de exactitud diagnóstica. Conclusiones. IFI INS-Perú y ELISA Murex tuvieron buen rendimiento diagnóstico para la detección de anticuerpos contra HTLV-1 y son buenos candidatos para continuar siendo usados en Perú.

Background: Peru is endemic to the human T-lymphotropic virus type 1 (HTLV-1), for these reasons it is important to know the reliability of the diagnostic tests used in the country, in order to continue their use or not. The objective was to evaluate the performance of three serological tests ELISA Murex, ELISA Wantai and IFI INS-Peru for the detection of anti-HTLV-1 antibodies against Peruvian samples. The study. The three tests were evaluated against 382 sera: 215 positive and 167 negative for HTLV-1 (Gold Standard: immunoblot). Findings. IFI had no false positives, Wantai had more false negatives (seven) and Murex more false positives (eight). The three tests showed results above 95% for the estimated parameters of diagnostic accuracy. Conclusions. IIF INS-Perú and ELISA Murex had good diagnostic performance for the detection of antibodies against HTLV-1 and are good candidates to continue being used in Peru.

Clinical research focused in European adult women with minority diseases: Do we try hard enough?

We analyzed the European countries participation in clinical trials addressing to new drug development focused on rare diseases in women comparing to more prevalent diseases as breast cancer. Participation was not associated with type of healthcare system neither socio-economic features, but it was associated with population size. Protocol ratios focused on breast cancer vs. orphan drugs and rare diseases was 15:1 and 9:1, respectively, mainly focused on ovarian cancer. Protocol number was insufficient to evaluate the success of Regulation (EC) 141/2000, it is necessary to increase the scientific quality and the number of really new molecules.

Evaluación de una prueba de reacción en cadena de la polimerasa múltiplex anidada para la detección de HTLV-1

El Perú es un área endémica al virus linfotrópico T humano tipo 1 (HTLV-1) y para su confirmación diagnóstica se usa pruebas serológicas que pueden dar resultados no concluyentes. Objetivos: evaluar una prueba de PCR múltiplex anidada para diagnosticar el HTLV-1. Métodos: la validación de la PCR se realizó con primers dirigidos a las regiones Pol y LTR del HTLV-1. Se empleó el gen ß-globina como control endógeno interno y el límite de detección se evaluó con células MT2. Los parámetros de precisión diagnóstica se evaluaron frente a 95 muestras sanguíneas de Referencia. Resultados: la prueba evaluada obtuvo un límite de detección de 0,5 ng/µL de ADN sensibilidad diagnóstica=97,1%, especificidad diagnóstica y analítica=100%, vpn=97,2%, vpp, repetibilidad y reproducibilidad=100%; Kappa, Índice Youden=0,97. Conclusiones: la prueba evaluada presenta un alto rendimiento diagnóstico y debido a su bajo costo se recomienda su implementación en el algoritmo del diagnóstico de HTLV-1 en Perú.

Peru is an endemic area for human T-lymphotropic virus type 1 (HTLV-1) and for its diagnostic confirmation serological tests are used, which can give inconclusive results. Objectives: to evaluate a nested multiplex PCR test to diagnose HTLV-1. Methods: PCR validation was performed with primers targeting the Pol and LTR regions of HTLV-1. The ß-globin gene was used as an internal endogenous control and the detection limit was evaluated with MT2 cells. Diagnostic accuracy parameters were evaluated against 95 Reference blood samples. Results: the evaluated test obtained a detection limit of 0.5 ng/µL of DNA; diagnostic sensitivity=97.1%, diagnostic and analytical specificity=100%, vpn=97.2%, vpp, repeatability and reproducibility=100%; Kappa, Youden Index=0.97. Conclusions: the evaluated test has a high diagnostic performance and due to its low cost, its implementation in the HTLV-1 diagnosis algorithm in Peru is recommended.

Long-Term Interactions of Salmonella Enteritidis With a Lytic Phage for 21 Days in High Nutrients Media.

Salmonella spp. is a relevant foodborne pathogen with worldwide distribution. To mitigate Salmonella infections, bacteriophages represent an alternative to antimicrobials and chemicals in food animals and food in general. Bacteriophages (phages) are viruses that infect bacteria, which interact constantly with their host. Importantly, the study of these interactions is crucial for the use of phages as a mitigation strategy. In this study, experimental coevolution of Salmonella Enteritidis (S. Enteritidis) and a lytic phage was conducted in tryptic soy broth for 21 days. Transfer to fresh media was conducted daily and every 24 hours, 2 mL of the sample was collected to quantify Salmonella OD600 and phage titter. Additionally, time-shift experiments were conducted on 20 colonies selected on days 1, 12, and 21 to evaluate the evolution of resistance to past (day 1), present (day 12), and future (day 21) phage populations. The behavior of the dynamics was modeled and simulated with mathematical mass-action models. Bacteria and phage from days 1 and 21 were sequenced to determine the emergence of mutations. We found that S. Enteritidis grew for 21 days in the presence and absence of the phage and developed resistance to the phage from day 1. Also, the phage was also able to survive in the media for 21 days, however, the phage titer decreased in approx. 3 logs PFU/mL. The stability of the lytic phage population was consistent with the leaky resistance model. The time-shift experiments showed resistance to phages from day 1 of at least 85% to the past, present, and future phages. Sequencing of S. Enteritidis showed mutations in genes involved in lipopolysaccharide biosynthesis genes rfbP and rfbN at day 21. The phage showed mutations in the tail phage proteins responsible for recognizing the cell surface receptors. These results suggest that interactions between bacteria and phage in a rich resource media generate a rapid resistance to the infective phage but a fraction of the population remains susceptible. Interactions between Salmonella and lytic phages are an important component for the rational use of phages to control this important foodborne pathogen.

Novel Low Pathogenic Avian Influenza H6N1 in Backyard Chicken in Easter Island (Rapa Nui), Chilean Polynesia.

Little is known about the prevalence of avian influenza viruses (AIV) in wildlife and domestic animals in Polynesia. Here, we present the results of active AIV surveillance performed during two sampling seasons in 2019 on Easter Island (Rapa Nui). Tracheal and cloacal swabs as well as sera samples were obtained from domestic backyard poultry, while fresh faeces were collected from wild birds. In addition to detecting antibodies against AIV in 46% of the domestic chickens in backyard production systems tested, we isolated a novel low pathogenic H6N1 virus from a chicken. Phylogenetic analysis of all genetic segments revealed that the virus was closely related to AIV's circulating in South America. Our analysis showed different geographical origins of the genetic segments, with the PA, HA, NA, NP, and MP gene segments coming from central Chile and the PB2, PB1, and NS being closely related to viruses isolated in Argentina. While the route of introduction can only be speculated, our analysis shows the persistence and independent evolution of this strain in the island since its putative introduction between 2015 and 2016. The results of this research are the first evidence of AIV circulation in domestic birds on a Polynesian island and increase our understanding of AIV ecology in region, warranting further surveillance on Rapa Nui and beyond.

Experiencia peruana sobre el flujograma de diagnóstico del virus de inmunodeficiencia humana / Peruvian experience on the human immunodeficiency virus diagnostic flowchart

Sr. Editor: El Programa Conjunto de las Naciones Unidas sobre el VIH/Sida (ONUSIDA) propuso como meta que los países alcancen para el año 2030 el 95-95-95, es decir que un 95% de personas viviendo con VIH (PVV) estén diagnosticadas y de éstas que el 95% reciban tratamiento antirretroviral (TAR) y al menos el 95% tengan carga viral indetectable o supresión viral.

Mr Editor: The Joint United Nations Program on HIV/AIDS (UNAIDS) proposed as a goal that the countries reach 95-95-95 by the year 2030, in other words, that 95% of people living with HIV (PLH) are diagnosed and of these that 95% receive antiretroviral treatment (ART) and at least 95% have undetectable viral load or viral suppression.

[Big Data in health: a new paradigm to regulate, a challenge for social justice.] / Big Data en salud: Un nuevo paradigma para regular, un desafío para la justicia social.

In addition to the opportunities posed by the use of Big Data in health, it also generates important challenges in the field of research, especially from the point of view of its management and ethical considerations. The European Union has been promoting different initiatives that allow the exploitation of this data in the context of the knowledge economy. The UNESCO Ethics Committee has identified three ethical principles to take into account regarding the application of Big Data in Health: independence, privacy and justice. The protection of privacy and patient safety is questioned in a context where cybersecurity is far to be complete. In addition, an imbalance in the exploitation of these data by the public and private sectors could generate inequalities that would represent a significant problem of social justice. This article follows a qualitative methodology based on the documentary analysis of current legislative texts, especially the recently approved General Data Protection Regulation (GDPR), as well as non-legislative documents of projects and parliamentary communications throughout the last two legislatures, with the aim of analyzing them and evaluating how they conform to the principles outlined by UNESCO, especially with respect to the principle of social justice. The most representative national projects that have started to be adopted are also reviewed.

Además de las oportunidades que supone el uso de Big Data en salud, también genera desafíos importantes en el campo de la investigación, especialmente desde el punto de vista de su gestión y de las consideraciones éticas. La Unión Europea ha estado promoviendo diferentes iniciativas que permitan la explotación de estos datos en el contexto de la economía del conocimiento. El Comité de Ética de la UNESCO ha identificado tres principios éticos a tener en cuenta sobre la aplicación de Big Data en Salud: independencia, privacidad y justicia. La protección de la privacidad y la seguridad de los pacientes se cuestiona en un contexto en el que la ciberseguridad está lejos de ser completa. Además, un desequilibrio en la explotación de estos datos por parte de los sectores público y privado podría generar inequidades que significarían un problema importante de justicia social. Este artículo sigue una metodología cualitativa basada en el análisis documental de los textos legislativos vigentes, especialmente el recientemente aprobado reglamento general de protección de datos (RGPD), así como documentos no legislativos de proyectos y comunicaciones parlamentarias a lo largo de las dos últimas legislaturas, con el objetivo es analizarlas y evaluar cómo se ajustan a los principios esbozados por la UNESCO, especialmente con respecto al principio de justicia social. También se revisan los proyectos nacionales más representativos que han empezado a adoptarse.

Estandarización y validación de un western blot para el diagnóstico del virus de inmunodeficiencia humana / Standardization and validation of a western blot for the diagnosis of human immunodeficiency virus

Ojetivos: Estandarizar y validar una prueba de western blot para el diagnóstico del virus de inmunodeficiencia humana. Métodos: Se realizó un estudio observacional prospectivo durante el 2017 y 2018. Se estandarizó la prueba de western blot, usando la técnica de electroforesis en gel de poliacrilamida con dodecil sulfato de sodio (SDS PAGE), siendo las tiras blot de nitrocelulosa preparadas con una concentración óptima de antígeno de VIH-1 de 2,71 µg/mm. Se validó el western blot en laboratorio, frente a 400 muestras referentes (300 sueros y 100 plasmas): 200 positivas y 200 negativas a anticuerpos contra VIH-1, siendo la prueba de referencia el Inmunoblot de la marca Fujirebio. Se estimaron los parámetros de rendimiento diagnóstico usando el programa Epidat v3.1 y Excel. Resultados: Se logró identificar ocho bandas importantes del antígeno de VIH-1: p17, p24, p31, p39, gp41, p55, p66 y gp120. De ellas, las que se tomaron como bandas diagnósticas específicas según el Consorcio de normalización de serología para los retrovirus, fueron: p24, p31, gp41 y gp120. La sensibilidad, especificidad, valor predictivo positivo y negativo e índice de validez frente a sueros fueron: 96,7%, 96,0%, 96,0%, 96,6%, 96,3%; y frente a plasmas: 98,0%, 100,0%, 100,0%, 98,0%, 99,0% respectivamente. No se encontraron falsos positivos y negativos, pero si algunos indeterminados. Conclusión: El desarrollo de esta prueba western blot con tecnología propia, presentó similar rendimiento diagnóstico a la prueba de referencia, sin mostrar reacciones cruzadas; siendo útil para la confirmación del VIH.

Objectives: To standardize and validate a western blot test for the diagnosis of human immunodeficiency virus. Methods: A prospective observational study was carried out during 2017 and 2018. The western blot test was standardized, using the polyacrylamide gel electrophoresis technique with sodium dodecyl sulfate (SDS PAGE), being the nitrocellulose blot strips prepared with an Optimal HIV-1 antigen concentration of 2.71 µg / mm. The western blot was validated in the laboratory against 400 reference samples (300 sera and 100 plasmas): 200 positive and 200 negatives for antibodies against HIV-1, being the reference test the Immunoblot of the Fujirebio brand. Diagnostic performance parameters were estimated using Epidat v3.1 and Excel. Results: Eight important bands of the HIV-1 antigen were identified: p17, p24, p31, p39, gp41, p55, p66, and gp120. According to the Consortium for the normalization of serology for retroviruse, those that were taken as specific diagnostic bands were: p24, p31, gp41, and gp120. The sensitivity, specificity, positive and negative predictive value and validity index against sera were: 96.7%, 96.0%, 96.0%, 96.6%, 96.3%; and against plasmas: 98.0%, 100.0%, 100.0%, 98.0%, 99.0% respectively. No false positives and negatives were found, but some were undetermined. Conclusions: The development of this western blot test with proprietary technology presented similar diagnostic performance to the reference test, without showing cross-reactions, being useful for confirming HIV.

Evaluación de tres marcas de pruebas rápidas frente a muestras de sangre para la detección de anticuerpos contra VIH / Evaluation of three brands of rapid tests against blood samples for the detection of antibodies against HIV

Uno de los factores importantes para disminuir la propagación del virus de inmunodeficiencia humana (VIH) en el Perú, es la accesibilidad del diagnóstico a través de pruebas rápidas (PR), las cuales son aplicadas hasta en las comunidades más alejadas, sin embargo, en el quinquenio 2011 - 2015 los establecimientos de salud adquirieron y usaron más de 10 diferentes marcas, generando confusión en la aplicación de la metodología descrita en los insertos y en consecuencia resultados erróneos (falsos positivos y falsos negativos).

One of the important factors to reduce the spread of the human immunodeficiency virus (HIV) in Peru is the accessibility of diagnosis through rapid tests (RP), which are applied even in the most remote communities. However, during the five years 2011 - 2015, health establishments acquired and used more than 10 different brands, generating confusion in applying the methodology described in the inserts and consequently erroneous results (false positives and false negatives).

Evidence of influenza infection in dogs and cats in central Chile.

As companion animals, dogs and cats live in close contact with humans, generating the possibility of interspecies pathogen transmission events. Equine origin H3N8 and avian origin H5N1 influenza virus have been reported in dogs and cats respectively since 2004 with outbreaks associated with different strains recorded for both species in Asia and North America. To date, there have been no reports of influenza viruses from companion animals in South America. To fill this gap in knowledge, we performed active epidemiological surveillance in shelters that received abandoned animals, backyard production systems and veterinary clinics between May 2017 and January 2019 to estimate the burden of influenza infection in cats and dogs in the central region of Chile. Blood samples, oropharyngeal swabs or both were collected for influenza A virus detection by RT-qPCR, NP-ELISA, and hemagglutination inhibition assay. Logistic regression models were performed to assess the association between NP-ELISA-positivity and variables including sex and animal origin. The percentage of ELISA-positive samples was 43.5 % (95 % CI: 37.0-50.1) and 23.3 % (95 % CI: 10.6-42.7) for dogs and cats, respectively. No association was found between NP-ELISA results and sex or animal origin for either dogs or cats. Two ELISA positive samples showed hemagglutination inhibition titers against pandemic H1N1 influenza. One dog sample tested positive by RT-qPCR, indicating an overall RT-qPCR positivity in dogs of 1.1 % (95 % CI: 0.05-6.7). None of the tested cat samples were positive by this assay.

Temporal dynamics and the influence of environmental variables on the prevalence of avian influenza virus in main wetlands in central Chile.

Although wild birds are considered the main reservoir of the influenza A virus (IAV) in nature, empirical investigations exploring the interaction between the IAV prevalence in these populations and environmental drivers remain scarce. Chile has a coastline of more than 4000 kilometres with hundreds of wetlands, which are important habitats for both resident and inter-hemispheric migratory species. The aim of this study was to characterize the temporal dynamics of IAV in main wetlands in central Chile and to assess the influence of environmental variables on AIV prevalence. For that purpose, four wetlands were studied from September 2015 to June 2018. Fresh faecal samples of wild birds were collected for IAV detection by real-time RT-PCR. Furthermore, a count of wild birds present at the site was performed and environmental variables, such as temperature, rainfall, vegetation coverage (Normalized Difference Vegetation Index (NDVI)) and water body size, were determined. A generalized linear mixed model was built to assess the association between IAV prevalence and explanatory variables. An overall prevalence of 4.28% ± 0.28% was detected with important fluctuations among seasons, being greater during summer (OR = 4.87, 95% CI 2.11 to 11.21) and fall (OR = 2.59, 95% CI 1.12 to 5.97). Prevalence was positively associated with minimum temperature for the month of sampling and negatively associated with water body size measured two months before sampling, and NDVI measured three months before sampling. These results contribute to the understanding of IAV ecological drivers in Chilean wetlands providing important considerations for the global surveillance of IAV.

Evaluación de dos marcas comerciales de pruebas de ELISA para el diagnóstico de HTLV-1 frente a muestras peruanas

Resumen Por ser el Perú un país endémico de HTLV-1, es importante conocer la confiabilidad de las marcas comerciales para el diagnóstico más usadas en nuestro país. En el presente estudio, evaluamos dos marcas comerciales de pruebas de ELISA (Biokit y Wantai) para la detección de anticuerpos contra HTLV-1 frente a muestras peruanas. Ambas marcas comerciales fueron evaluadas frente a 242 sueros: 123 positivos a HTLV-1 y 119 negativos a HTLV-1 (referencia: inmunoblot). Se estimaron los parámetros de precisión diagnóstica. La sensibilidad, especificidad, VPP, VPN e índice de validez de Biokit fueron: 100%, 93,2%, 93,8%, 100%, 96,6%; respectivamente y de Wantai fue de 99,1% para todos los parámetros. Concluimos, que la marca Biokit fue la más adecuada para ser usada en el Laboratorio de Referencia Nacional de Virus de Transmisión Sexual, VIH/SIDA de Perú.

Abstract As Peru is endemic to HTLV-1, it is important to know the reliability of the most used screening trademarks in our country. In the present study, we evaluated two brands of ELISA (Biokit and Wantai) for the detection of antibodies against HTLV-1/2 against Peruvian samples. Both brands were evaluated against 242 sera: 123 positive for HTLV-1 and 119 negative for HTLV-1 (Reference: Immunoblot). We estimated diagnostic accuracy parameters. The sensitivity, specificity, PPV, NPV and validity index of Biokit were: 100%, 93.2%, 93.8%, 100%, 96.6%; respectively and Wantai were 99.1% for all parameters. We conclude that the Biokit brand is the most suitable for use in the National Reference Laboratory of Sexually Transmitted Viruses HIV/AIDS, Peru.

Pathophysiology of Alloimmunization.

INTRODUCTION: Alloimmunization is caused by exposure to erythrocytes from a donor that expresses blood group antigens other than those of the recipient and is related to processes that alter the balance of the immune system. Knowing the pathophysiology of alloimmunization process is essential to understand clinical complications associated with this process. PATIENTS AND METHODS: From October 2016 to April 2017, irregular antibody screening was performed in 1,434 polytransfused (compatible with the ABO and D system) patients by means of agglutination techniques using erythrocytes of a known phenotype of 44 patients with a positive alloantibody screening. Non-alloimmunized (control) subjects were matched for age, gender, pathology, and treatment group with alloimmunized patients. The subsets of B, T, and Treg lymphocytes were determined by flow cytometry. RESULTS: The results of screening for alloantibodies in patients by specificity of antibodies were as follows: nonspecific (30%), followed by anti-Dia (13%), anti-e (9%), anti-S (9%), anti-I (7%), anti-K (7%), and anti-P (7%). A lower percentage of CD4+ T lymphocytes and an increase of CD8+ T lymphocytes were observed in alloimmunized patients, as well as a low CD4/CD8 ratio (0.7 vs. 1.6, p = 0.003), a higher percentage of B lymphocytes versus the control group (30 vs. 20%, p = 0.003), and a decrease of Treg CD4+ lymphocytes versus the control group (3 vs. 12 cells/µL, p = 0.043). These observations suggest that alloimmunized patients have important alterations in the number of some lymphocyte subsets that can be translated into clinical immune dysregulation. CONCLUSION: A decreased CD4/CD8 ratio, increased B lymphocytes, and Treg lymphocyte deficiency are the most significant changes observed in alloimmunized patients.

[Evaluation of two brands of test of ELISA for the diagnosis of HTLV-1 against Peruvian samples]. / Evaluación de dos marcas comerciales de pruebas de ELISA para el diagnóstico de HTLV-1 frente a muestras peruanas.

As Peru is endemic to HTLV-1, it is important to know the reliability of the most used screening trademarks in our country. In the present study, we evaluated two brands of ELISA (Biokit and Wantai) for the detection of antibodies against HTLV-1/2 against Peruvian samples. Both brands were evaluated against 242 sera: 123 positive for HTLV-1 and 119 negative for HTLV-1 (Reference: Immunoblot). We estimated diagnostic accuracy parameters. The sensitivity, specificity, PPV, NPV and validity index of Biokit were: 100%, 93.2%, 93.8%, 100%, 96.6%; respectively and Wantai were 99.1% for all parameters. We conclude that the Biokit brand is the most suitable for use in the National Reference Laboratory of Sexually Transmitted Viruses HIV/AIDS, Peru.

Mid-term outcome of severe tricuspid regurgitation: are there any differences according to mechanism and severity?

AIMS: Patients with significant tricuspid regurgitation (TR) addressed according the new classification in torrential TR may have different prognosis compared with just severe TR patients. We sought to determine distribution and mechanism of consecutive severe TR patients, in accordance with aetiology and severity by applying the new proposed classification scheme and their long-term outcomes. METHODS AND RESULTS: Between January and December 2013, 249 patients with significant TR referred to the cardiac imaging unit (mean age 79.9 ± 10.2 years; 29.8% female) were included. Patients were divided according to aetiology in six groups, and TR severity was reclassified into severe, massive, and torrential TR. The follow-up period was of 313 ± 103 days. When considering cardiovascular mortality, patients in the massive/torrential group showed the highest number of events (P < 0.007). Patients with TR due to pulmonary diseases had the worst prognosis according to different aetiology. Noteworthy, the best predictors for the combined endpoint [cardiovascular mortality and readmission admission for heart failure (HF)] were TR severity according to the new classification [hazard ratio (HR) 2.48, 95% confidence interval (CI) 1.25-4.93] and clinical scores such as New York Heart Association classification and congestive status (HR 1.78, 95% CI 1.28-2.49; HR 2.08, 95% CI 1.06-4.06, respectively). CONCLUSION: Patients with massive/torrential TR and patients with comorbidities, especially pulmonary disease, were identified as populations at higher risk of death and readmission for HF. New classification scheme and clinical assessment may establish who may benefit the most of intensive therapeutic treatments and intervention on the tricuspid valve.

Duración de la supresión viral en pacientes con VIH en terapia antiretroviral en Perú: análisis de sobrevida acumulada 2004-2012 / Duration of viral suppression in HIV patients on antiretroviral therapy in Peru: cumulative survival analysis 2004 - 2012

Introducción. El objetivo primordial de los programas nacionales es la supresión de la replicación viral hasta niveles indetectables y el sostenimiento de esta respuesta virológica a lo largo del tiempo. El objetivo del estudio fue analizar la duración de la supresión viral en pacientes adultos con VIH que iniciaron tratamiento antiretroviral en el Perú durante el periodo 2004-2006 con seguimiento hasta el 2012 mediante análisis de sobrevida acumulada. Métodos. Se realizó un estudio observacional retrospectivo realizado en base a la cohorte histórica de pacientes que accedieron al programa nacional de tratamiento antirretroviral durante el periodo 2004 al 2006 en el Perú y que tuvo seguimiento hasta el 31 de diciembre del 2012. Resultados. Del total de 6289 pacientes, 5142(81,7%) iniciaron algún esquema de tratamiento y 4530(72%) alcanzaron supresión viral, la cual se sostuvo por tiempo variable durante el periodo de observación. Según la tasa de sobrevida acumulada el 91,1% mantuvieron supresión viral hasta 1 año, 84,6% hasta 2 años, 80,2% hasta 3 años, 77,1% hasta 4 años, 74,1% hasta 5 años y 70,1% hasta 6 años. Conclusiones. La cohorte peruana que empezó el tratamiento antirretroviral en la etapa inicial de implementación del programa nacional, presentó duración de supresión viral sostenida con tasas comparables o por encima a otros países latinoamericanos. La duración de la supresión viral es indicador longitudinal del desempeño de los programas nacionales y locales, que puede contribuir a estimar la duración del uso de un solo tipo de esquema de terapia antiretroviral y validar adherencia.

Introduction. The primary objective of national programs is the suppression of viral replication to undetectable levels and the sustaining of this virological response over time. The objective of the study was to analyze the duration of viral suppression in adult patients with HIV who started antiretroviral treatment in Peru during the period 2004-2006 with follow-up until 2012 using cumulative survival rate analysis. Methods. A retrospective observational study was conducted based on the historical cohort of patients who linked to the antiretroviral treatment national program during the period 2004 to 2006 in Peru with follow-up until December 31st, 2012. Results. Of the 6289 patients, 5142 (81.7%) initiated some treatment scheme and 4530 (72%) reached viral suppression which was sustained by variable time during the observation period. According to the cumulative survival rate 91.1% sustained viral suppression up to 1 year, 84.6% up to 2 years, 80.2% up to 3 years, 77.1% up to 4 years, 74.1% up to 5 years and 70.1% up to 6 years. Conclusions. The Peruvian cohort that began antiretroviral treatment in the initial phase of implementation of the national program, presented comparable results or above other Latin American countries in the duration of sustained viral suppression. The duration of viral suppression is a longitudinal indicator of the performance of national and local programs, which could also help to estimate the time of use of the therapeutic schemes of antiretrovirals and validate adherence.

[Diagnostic performance of the indirect immunofluorescence test for the detection of antibodies against HTLV-1]. / Rendimiento diagnóstico de la prueba de inmunofluorescencia indirecta para la detección de anticuerpos contra HTLV-1.

The objective of the study was to determine the diagnostic yield of the indirect immunofluorescence (IFI) test for the detection of antibodies against HTLV-1. A diagnostic test evaluation study was performed. HTLV-1-infected MT2 cells and HTLV-1-uninfected K-562 cells were cultured; then these cells were impregnated and fixed in sheets for immunofluorescence and faced to Peruvian sera. A total of 155 sera (80 HTLV-1-positive sera and 75 sera positive for other diseases) from the Peruvian Instituto Nacional de Salud were used. In addition, the parameters of repeatability (intra-laboratory) and reproducibility (in laboratories of the Peruvian coast, mountains and jungle) of the test were evaluated. The IFI test detected the presence of antibodies against HTLV-1 reaching a sensitivity of 98.75% (95% CI: 95.69 - 100.00%), a specificity of 98.67% (95% CI: 95.40 - 100.00%) and the Kappa index was 0.975. There were no false positives or false negatives; however, one undetermined result and one non-specific result were obtained. The test showed 100% qualitative agreement when performing the repeatability and reproducibility. The results obtained are comparable to the reference test. Therefore, the IFI test had a good diagnostic performance and would be useful for the confirmation of HTLV-1.

El objetivo del estudio fue determinar el rendimiento diagnóstico de la prueba de inmunofluorescencia indirecta (IFI) para la detección de anticuerpos contra HTLV-1. Se realizó un estudio de evaluación de prueba diagnóstica. Se usaron cultivos celulares MT2 infectados con HTLV-1 y K-562 sin infección, luego fueron sembrados, fijados en láminas para inmunofluorescencia y enfrentados a sueros. Se usaron 155 sueros (80 positivos para HTLV-1 y 75 positivos para otras enfermedades) procedentes de la seroteca del Instituto Nacional de Salud del Perú. Adicionalmente, se evaluó la repetibilidad (en el laboratorio) y reproducibilidad (en laboratorios de costa, sierra y selva) de la prueba. La prueba IFI para la detección de anticuerpos contra HTLV-1 tuvo una sensibilidad de 98,75% (IC 95%: 95,69-100%), una especificidad de 98,67% (IC 95%: 95,40-100%) y el índice de kappa de 0,975. No hubo falsos positivos ni falsos negativos; sin embargo, sí se obtuvo un resultado indeterminado y uno inespecífico. La prueba mostró 100% de concordancia en la repetibilidad y reproductibilidad. Concluimos que los resultados obtenidos son comparables a la prueba de referencia. La prueba de IFI presenta un buen rendimiento diagnóstico y sería de utilidad para la confirmación de HTLV-1.