Vaccination impact: mortality and time shift to COVID-19 maximum severity in hospitalized patients. An Argentine multicenter registry.

INTRODUCTION: The COVID-19 vaccine became an effective instrument to prevent severe SARS-CoV-2 infections. However, 5% of vaccinated patients will have moderate or severe disease. OBJECTIVE: to compare mortality and days between the symptom onset to the peak disease severity, in vaccinated vs. unvaccinated COVID-19 hospitalized patients. METHODS: Retrospective observational study in 36 hospitals in Argentina. COVID-19 adults admitted to general wards between January 1, 2021, and May 31, 2022 were included. Days between symptoms onset to peak of severity were compared between vaccinated vs. unvaccinated patients with Cox regression, adjusted by Propensity Score Matching (PSM). Results in patients with one and two doses were also compared. RESULTS: A total of 3663 patients were included (3001 [81.9%] unvaccinated and 662 [18%] vaccinated). Time from symptom onset to peak severity was 7 days (IQR 4-12) vs. 7 days (IQR 4-11) in unvaccinated and vaccinated. In crude Cox regression analysis and matched population, no significant differences were observed. Regarding mortality, a Risk Ratio (RR) of 1.51 (IC95% 1.29-1.77) was observed in vaccinated patients, but in the PSM cohort, the RR was 0.73 (IC95% 0.60-0.88). RR in patients with one COVID-19 vaccine dose in PSM adjusted population was 0.7 (IC95% 0.45-1.03), and with two doses 0.6 (IC95% 0.46-0.79). DISCUSSION: The time elapsed between the onset of COVID-19 symptoms to the highest severity was similar in vaccinated and unvaccinated patients. However, hospitalized vaccinated patients had a lower risk of mortality than unvaccinated patients.

Introducción: A pesar de la eficacia de la vacuna contra el COVID-19 el 5% de los pacientes vacunados presentaran una enfermedad moderada o grave. El objetivo del presente estudio fue comparar los días entre el inicio de los síntomas y la gravedad máxima de la enfermedad, en pacientes con COVID-19 vacunados vs. no vacunados. Métodos: Estudio observacional retrospectivo en 36 hospitales de Argentina. Se incluyeron adultos con COVID-19 hospitalizados entre el 1/01/2021 y 31/5/2022. Se recolectaron datos demográficos, comorbilidades y progresión clínica de la enfermedad. Se compararon los días entre el inicio de los síntomas y el pico de gravedad entre vacunados y no vacunados mediante regresión de Cox, ajustada por emparejamiento por Propensity Score Matching (PSM). En un análisis de subgrupos, se compararon los resultados en pacientes con una y dos dosis de vacuna. Resultados: Se incluyeron 3663 pacientes (3001 [81.9%] no vacunados y 662 [18%] vacunados). El tiempo transcurrido desde el inicio de los síntomas hasta el pico de gravedad fue de 7 días (IQR 4 - 12) en no vacunados, y de 7 días (IQR 4-11) en vacunados. Tanto en el análisis de regresión de Cox crudo como en el ajustado, no se observaron diferencias significativas entre ambos grupos (HR ajustado 1.08 [IC 95% 0.82-1.4; p = 0.56]). En cuanto a la mortalidad, el Riesgo Relativo (RR) fue 1.51 (IC95% 1.29-1.77) en los pacientes vacunados, pero en la cohorte ajustada por Propensity Score, el RR fue de 0.73 (IC95% 0.60-0.88). El RR en el grupo con una dosis de vacuna COVID-19 en el análisis PSM fue 0.7 (IC95% 0.45-1.03), y con dos dosis 0.6 (IC95% 0.46-0.79). Discusión: El tiempo entre el inicio de los síntomas de COVID-19 y el pico de severidad fue igual en vacunados y no vacunados. Sin embargo, los pacientes vacunados hospitalizados presentaron menor mortalidad tras el ajuste por confundidores.

Temporal trends in hematopoietic stem cell transplantation in Argentina between 2009 and 2018: A collaborative study by GATMO-TC and INCUCAI.

INTRODUCTION: Hematopoietic stem cell transplantation is the only curative treatment for many disorders and international data shows a growing trend. METHOD: We aimed to evaluate the temporal trends in HSCT transplant rates in Argentina. A time-series analysis was performed for the period 2009 to 2018 using the national database from the National Central Coordinating Institute for Ablations and Implants. Crude and standardized transplant rates were calculated. A permutation joinpoint regression model analysis was used to identify significant changes over time. RESULTS: Altogether, 8,474 transplants were reported to INCUCAI by 28 centers (autologous 67.5%); the main indication was multiple myeloma (30%). The WHO age-sex standardized HSCT rates for the entire country were 153.3 HSCT/10 million inhabitants (95% CI 141.7-165.8) in 2009 and 260.1 HSCT/10 million inhabitants (95% CI 245.5-275.5) in 2018. There was a large gap in HSCT rates among the states and regions. The transplant rate was higher for autologous transplants throughout the years. Within the allogeneic group, the related donor transplant rate was higher than the unrelated donor transplant rate. The joinpoint regression analysis of HSCT rates for the whole country over time showed an observed annual percentage change of 6.3% (95% CI 5.4-7.3; p < 0.01). No changes were observed for unrelated donors during the study period. CONCLUSIONS: Age-sex standardized HSCT rates in Argentina are increasing, mainly due to autologous and family donor allogeneic transplants. A wide variation across the country was found, demonstrating differences in the access to transplantation among Argentine regions.

Temporal trends in hematopoietic stem cell transplantation in Argentina between 2009 and 2018: A collaborative study by GATMO-TC and INCUCAI

Special Article Introduction Hematopoietic stem cell transplantation is the only curative treatment for many disorders and international data shows a growing trend. Method We aimed to evaluate the temporal trends in HSCT transplant rates in Argentina. A time-series analysis was performed for the period 2009 to 2018 using the national database from the National Central Coordinating Institute for Ablations and Implants. Crude and standardized transplant rates were calculated. A permutation joinpoint regression model analysis was used to identify significant changes over time. Results Altogether, 8,474 transplants were reported to INCUCAI by 28 centers (autologous 67.5%); the main indication was multiple myeloma (30%). The WHO age-sex standardized HSCT rates for the entire country were 153.3 HSCT/10 million inhabitants (95% CI 141.7-165.8) in 2009 and 260.1 HSCT/10 million inhabitants (95% CI 245.5-275.5) in 2018. There was a large gap in HSCT rates among the states and regions. The transplant rate was higher for autologous transplants throughout the years. Within the allogeneic group, the related donor transplant rate was higher than the unrelated donor transplant rate. The joinpoint regression analysis of HSCT rates for the whole country over time showed an observed annual percentage change of 6.3% (95% CI 5.4-7.3; p< 0.01). No changes were observed for unrelated donors during the study period. Conclusions Age-sex standardized HSCT rates in Argentina are increasing, mainly due to autologous and family donor allogeneic transplants. A wide variation across the country was found, demonstrating differences in the access to transplantation among Argentine regions.

Monitoreo serológico y psicológico en personal de salud durante el comienzo de la pandemia COVID-19 / Serological and psychological monitoring of healthcare workers during the start of the COVID-19 pandemic

Introducción: el personal de salud (PdS) es esencial en la lucha contra el COVID-19. Al inicio de la pandemia, el riesgo de adquirir la enfermedad en este grupo era desconocido. Buscamos estimar incidencia y prevalencia de anticuerpos anti-SARS-CoV-2, y prevalencia de burnout en una cohorte de PdS durante la pandemia COVID-19, así como valorar la prevalencia de burnout y depresión en la cohorte. Materiales y métodos: cohorte prospectiva conformada por médicos que atendían pacientes COVID-19 desde marzo de 2020 hasta enero de 2021, en un hospital de alta complejidad de la ciudad de Buenos Aires. Se evaluó IgM e IgG anti-SARS-CoV-2 quincenalmente durante 3 meses, así como la presencia de síntomas compatibles y factores asociados a la exposición. Se remitió a participantes con alteraciones de la esfera psíquica a contacto con el equipo de salud mental del hospital. Resultados: se incluyeron 52 participantes; de ellos, 31 eran mujeres; mediana de edad 32 años (rango 25-58). La mediana de horas semanales de trabajo autoinformadas fue 48 (IIC [intervalo intercuartil] 40-69,5). Inicialmente todos fueron PCR SARS-CoV-2 negativos en hisopado nasal; 11 (21,50% IC 95%; 9,62-32,53%) tuvieron COVID-19 sintomático con anticuerpos positivos. Los factores con mayor asociación a riesgo de COVID-19 fueron anosmia/disgeusia OR 403,33 (IC 95%; 47,60-3417,02), fiebre OR 172,53 (IC 95%; 28,82-1032,65), mialgias OR 41,97 (IC 95%; 8,08-217,84), conviviente con COVID-19 OR 28,17 (IC 95%; 5,67-179,97). Cerca del 40% presentaba alteraciones en las escalas de medición de burnout o depresión. Discusión: la incidencia hallada coincide con las cifras informadas acerca de personal de salud en la etapa inicial de la pandemia en la Argentina. Otro aspecto similar fue una mayoría de infecciones de curso leve, sin ningún paciente hospitalizado. No obstante, se halló una elevada incidencia de alteraciones de la esfera psíquica, tanto al comienzo como al final del seguimiento. Conclusiones: la incidencia de positivización de anticuerpos anti-SARS-CoV-2 fue cercana al 20%. No evidenciamos infecciones presintomáticas o asintomáticas. En cambio, la prevalencia de burnout y depresión fue elevada. La salud mental es un componente del personal de salud que debe ser priorizado en situaciones futuras de impacto similar. (AU)

Introduction: healthcare personnel are essential in the response against COVID-19. At the beginning of the pandemic the risk of acquiring the disease in this group was unknown. We sought to estimate incidence and prevalence of anti SARS-CoV-2 antibodies, as well as burnout prevalence in a cohort of healthcare staff during the pandemic, as well as assessing the prevalence of burnout and depression in this group. Materials and methods: prospective cohort formed by physicians tending to COVID-19 patients from march 2020 to january 2021 in a high-complexity hospital in the city of Buenos Aires. We evaluated anti SARS-CoV-2 IgM and IgG each 15 days for 3 months as well as the presence of compatible symptoms and factors associated to exposition to the virus. Patients showing signs of burnout and/or depression were referred to proper care by the mental health team in the hospital. Results: we included 52 patients, 31 women, median age was 32 years (range 25 - 58). Median amount of self-reported hours worked each week was 48 (IQR 40 - 69.5). Initially all participants had a negative COVID-19 PCR nasopharyngeal swab; 11 (21.50% CI95% 9.62 - 32.53%) had symptomatic COVID-19 with positive antibodies. Factors showing stronger association with testing positive were anosmia/dysgeusia OR 403.33 (CI95% 47.60-3417.02), fever OR 172.53 (CI95% 28.82 - 1032.65), myalgia OR 41.97 (CI95% 8.08 - 217.84), cohabitation with confirmed COVID-19 case OR 28.17 (CI95% 5.67 - 179.97). Near 40% showed alterations in burnout or depression scales. Discussion: the incidence rate we found was like reported values in the initial stages of the pandemic in Argentina. Another similarity was that all cases were mild; no hospitalization was required for any participant. We found an elevated incidence of alterations in the psychic sphere, both at the beginning and end of the follow up period. Conclusions:the incidence of positive SARS-CoV-2 antibodies was around 20%. No pre or asymptomatic cases were identified. Burnout and depression incidence was high. Mental health is a component that should never be overlooked in similar situations to come. (AU)

Low Incidence of Symptomatic Thrombotic Events in Adult Patients Hospitalized with Coronavirus 19: A Retrospective Cohort Study.

BACKGROUND: Since the beginning of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) pandemic, there have been many reports of increased incidence of venous thromboembolism and arterial events as a complication. OBJECTIVE: To determine the incidence of symptomatic thrombotic events (TEs) in patients hospitalized for SARS-CoV2 disease (coronavirus 19 [Covid-19]). METHODS: A retrospective single-center cohort study with adult patients with a positive reverse transcriptase-polymerase chain reaction (rt-PCR) for SARS-CoV2, included from the date of diagnosis of Covid-19 and followed for 90 days or until death. RESULTS: A total of 1621 patients were included in this study. The median age was 73 years (interquartile range25th-75th [IQR] 53-87 years) and 57% (913) were female. Overall mortality was 21.6% (348). The overall incidence of symptomatic TEs within 90 days of diagnosis was 1.8% (30 of 1621) occurring in 28 patients, including an incidence of pulmonary embolism of 0.9% (15, 95% confidence interval [CI] 0.60%-1.6%), deep venous thrombosis of 0.61% (10, 95% CI 0.2%-1%), ischemic stroke of 0.25% (4, 95% CI 0.09%-0.65%), and ischemic arterial events of 0.06% (1, 95% CI 0.008%-0.43%). No acute coronary syndrome events were recorded. The incidence of symptomatic TEs was significantly lower in the general ward than in intensive care units (1.2% vs 5.7%; p < .001). The median time since positive rt-PCR for SARS-CoV2 to symptomatic TE was 22.5 days (IQR 19-43 days). There was no significant difference in the proportion of patients receiving (53.6%) and not receiving thromboprophylaxis (66.5%) and the development of TEs. CONCLUSION: The overall incidence of symptomatic TEs among these patients was lower than the incidence previously reported.

Impacto de la viremia de bajo grado en el riesgo de fallo virológico en pacientes con infección por VIH-1 / Impact of low-grade viremia on the risk of virological failure in patients with HIV-1 infection on antiretroviral therapy

Resumen Introducción: Cargas virales (CV) entre 20-200 copias/mL se consideran cargas virales de bajo grado (CVBG). Su implicancia clínica y manejo no han sido definidos. Objetivo: Evaluar el impacto de CVBG en el riesgo de desarrollo posterior de fallo virológico (FV). Pacientes y Métodos: Se incluyeron pacientes ≥ 18 años, desde enero de 2009 a diciembre de 2019, con infección por VIH-1 con CV< 20 copias/mL, por un mínimo de seis meses y/o en dos muestras consecutivas bajo tratamiento anti-retroviral . Se realizó seguimiento de las CV estrati ficándolas: CV < 20 copias/mL, CVBG (20-50 copias/mL y 51-200 copias/mL) y FV. Mediana de seguimiento 25 meses (IQR 15-31). Resultados: Fueron incluidos 1.416 pacientes con CV < 20 copias/ mL bajo TARV. De ellos, 797 permanecieron con CV< 20 copias/mL durante el seguimiento, 144 presentaron CV entre 20-50 copias/mL, 384 entre 51-200 copias/mL y 91 presentaron FV sin CVBG previa. De los 528 pacientes que tuvieron CVBG, 110 (20,1%) fallaron, riesgo 3,45 veces superior respecto a los que no tuvieron CVBG previa. El riesgo de FV fue 3,27 mayor para aquellos que tuvieron CVBG entre 51-200 copias/mL vs 20-50 copias/mL. Discusión: El estudio permite relacionar la CVBG con el FV posterior, siendo el mayor riesgo CVBG entre 51-200 copias/mL.

Abstract Background: Viral loads (VL) between 20-200 copies/mL are considered low-grade viral loads (LGVL). Its clinical implications and management have not been defined. Aim: To evaluate the impact of LGVL on the risk of subsequent development of virological failure (VF). Methods: Patients ≥ 18 years, with HIV-1 infection who had VL < 20 copies/mL for at least six months and/or in two consecutive samples under antiretroviral therapy (ART) were included, between January 1st, 2009 and December 31, 2019. Follow-up of the VLs was carried out stratifying them in VL < 20 copies/mL, LGVL (20-50 copies/mL and 51-200 copies/mL) and VF. Median follow-up 25 months (IQR 15-31). Results: 1,416 patients were included who reached VL < 20 copies/ml under ART, 797 patients remained with CV < 20 copies/mL during follow-up, 144 patients had VL between 21-50 copies/mL, 384 between 51-200 copies/mL and 91 had VF without previous LGVL. Out of 528 patients who had LGVL, 110 failed, risk 3.45 times higher than those who had no previous LGVL. Risk 3.27 times higher of VF for those who had LGVL between 51-200 copies/mL compared to 20-50 copies/mL. Discussion: The study allows to relate the LGVL with VF. This association was observed more frequently with LGVL between 51-200 copies/mL

Association between non-attendance to outpatient clinics and emergency department consultations, hospitalizations and mortality in a Health Maintenance Organization.

BACKGROUND: Non-attendance to scheduled medical appointments in outpatient clinics is a problem that affects patient health and health-care systems. OBJECTIVE: Evaluate association of non-attendance to scheduled appointments in outpatient clinics and Emergency Department (ED) visits, hospitalizations and mortality. METHODS: Retrospective cohort study of outpatients enrolled in 2015 to 2016 in the Hospital Italiano de Buenos Aires HMO with over five scheduled appointments. Individual non-attendance proportion was obtained by dividing missed over scheduled appointment numbers in the 365 days prior to index date. Outcomes were evaluated with a Cox proportional-hazards or Fine and Gray model for competing risks. We adjusted by several variables. RESULTS: Sixty-five thousand two hundred sixty-five adults were included. Mean age was 63.6 years (SD 18.16), 29.9% male. Outpatients had average 10.18 (SD 5.59) appointments. Non-attendance the year before the index appointment had a median of 20%. A 10% increase in non-attendance was significantly associated with ED visits (asHR 1.19; 95%CI 1.08-1.32, P < .001) and all-cause mortality (aHR 7.57; 95%CI 4.88-11.73, P < .001). In the matched subcohort analysis we observed a crude significant association of non-attendance with ED visits (P < .001) and all-cause mortality (P < .001). DISCUSSION: Our findings show non-attendance could be a marker of health events that lead to emergency department evaluations and/or death.

[Impact of low-grade viremia on the risk of virological failure in patients with HIV-1 infection on antiretroviral therapy]. / Impacto de la viremia de bajo grado en el riesgo de fallo virológico en pacientes con infección por VIH-1.

BACKGROUND: Viral loads (VL) between 20-200 copies/mL are considered low-grade viral loads (LGVL). Its clinical implications and management have not been defined. AIM: To evaluate the impact of LGVL on the risk of subsequent development of virological failure (VF). METHODS: Patients ≥ 18 years, with HIV-1 infection who had VL < 20 copies/mL for at least six months and/or in two consecutive samples under antiretroviral therapy (ART) were included, between January 1st, 2009 and December 31, 2019. Follow-up of the VLs was carried out stratifying them in VL < 20 copies/mL, LGVL (20-50 copies/mL and 51-200 copies/mL) and VF. Median follow-up 25 months (IQR 15-31). RESULTS: 1,416 patients were included who reached VL < 20 copies/ml under ART, 797 patients remained with CV < 20 copies/mL during follow-up, 144 patients had VL between 21-50 copies/mL, 384 between 51-200 copies/mL and 91 had VF without previous LGVL. Out of 528 patients who had LGVL, 110 failed, risk 3.45 times higher than those who had no previous LGVL. Risk 3.27 times higher of VF for those who had LGVL between 51-200 copies/mL compared to 20-50 copies/mL. DISCUSSION: The study allows to relate the LGVL with VF. This association was observed more frequently with LGVL between 51-200 copies/mL.

Recomendación rápida sobre el uso de antihipertensivos IECA/ARA II en pacientes con riesgo o documentación de COVID-19 / Rapid recommendation on the use of ACEI/ARA antihypertensives in patients at risk or with documented COVID-19

Ciertos hallazgos preclínicos generaron preocupación en la comunidad científica y en la población general sobre el uso de inhibidores de la enzima convertidora de angiotensina (IECA) y los antagonistas del receptor de la angiotensina II (ARAII), y los posibles desenlaces adversos asociados con relación a la infección por el nuevo Coronavirus (SARS-Cov-2).Por este motivo, nos planteamos como objetivo proveer de recomendaciones dinámicas (living recommendations) para el tratamiento con fármacos IECA o ARA II en pacientes con riesgo o documentación de infección por SARS-CoV-2 (en todo su espectro de gravedad). Se utilizó como metodología la adaptación/adopción de guías de práctica clínica bajo el enfoque GRADE, actualizando la evidencia al 7 de abril de 2020 mediante búsquedas en múltiples bases de datos y consultando a un panel multidisciplinario libre de conflictos de interés. Como resultado de este proceso se arribó a la siguiente afirmación: se recomienda, en contexto de la pandemia de COVID-19, en personas que se encuentran en tratamiento con IECA/ARAII, mantener el tratamiento sin cambios por sobre suspenderlo o reemplazarlo por otros fármacos (Recomendación fuerte a favor - calidad de evidencia baja). (AU)

Certain preclinical findings raised concerns in the scientific community and in the general population about the use ofangiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor antagonists (ARA) and the possible adverse outcomes associated with the infection with the new Coronavirus (SARS-Cov-2). For this reason, our objective is to provide living recommendations for treatment with ACEI or ARA in patients with risk or documentation of SARS-CoV-2 infection (inall its severity spectrum). The adaptation/adoption of clinical practice guidelines under the GRADE approach was used as a methodology, updating the evidence as of April 7, 2020, by searching multiple databases and consulting a multidisciplinary panel free of conflicts of interest. As a result of this process, the following statement was reached: it is recommended, in the context of the COVID-19 pandemic, in people who are undergoing treatment with ACEI/ARA, to maintain the treatment unchanged instead of its suspension or replacement with other drugs (Strong recommendation in favor - low quality ofevidence). (AU)

[High prevalence of hypovitaminosis D in HIV-infected persons attending an outpatient clinic, Buenos Aires city]. / Alta prevalencia de hipovitaminosis D en personas infectadas con HIV atendidas en un centro ambulatorio de la ciudad de Buenos Aires.

Hypovitaminosis D is frequent worldwide. In Argentina, according to studies conducted between 1987 and 2015, prevalence was > 40% in the general population. In people living with HIV it may vary between 20 and 90%, but the prevalence in our environment is not known. Our objective was to determine the prevalence of hypovitaminosis D in a cohort of adults with HIV infection in the city of Buenos Aires. We analyzed retrospectively medical records of 814 HIV positive subjects older than 18 years with at least one determination of vitamin D. The median age was 44 years (interquartile range 21-80), 746 (91.6%) were men, and 813 (99.9%) were on antiretroviral treatment. Univariate and multivariate analyses were performed to determine the association of hypovitaminosis D with CD4 values, viral load for HIV, and antiretroviral therapy. The present study shows that, in our environment, hypovitaminosis D is very common in people with HIV infection. Although it does not reveal evidence of a relationship with viral load for HIV, immune status, or antiretroviral treatment, the systematic search for hypovitaminosis D is mandatory in this population, taking into account its high frequency and the increased risk of osteopenia, osteoporosis and fractures, as described in people with HIV.

La hipovitaminosis D es frecuente en el mundo. Según estudios realizados entre 1987 y 2015, en Argentina la prevalencia fue > 40%. En personas con infección por HIV variaría entre 20 y 90%, pero en nuestro medio no se conoce con precisión. Nuestro objetivo fue determinar la prevalencia de hipovitaminosis D en una cohorte de adultos con infección por HIV asistidos en forma ambulatoria en la ciudad de Buenos Aires. Se analizaron retrospectivamente las historias clínicas de 814 sujetos mayores de 18 años HIV positivos con al menos una determinación de vitamina D. La mediana de edad fue 44 años (rango intercuartílico 21-80), 746 (91.6%) eran hombres y 813 (99.9%) recibían tratamiento antirretroviral. Se realizó análisis uni y multivariado para determinar asociación entre hipovitaminosis D y valores de CD4, carga viral para HIV y terapia antirretroviral. La prevalencia de hipovitaminosis D fue 79.7% (insuficiencia 34.2%, deficiencia 45.5%). No se encontró asociación con el uso de efavirenz o inhibidores de la proteasa (p = 0.86 en ambos casos), con el recuento de linfocitos CD4, ni con la carga viral plasmática (p = 0.81 y 0.74, respectivamente). El presente estudio muestra que, en nuestro medio, la hipovitaminosis D es muy frecuente en personas con infección por HIV. Aun cuando no revela evidencia de relación con carga viral para HIV, estado inmune, ni tratamiento antirretroviral, es necesaria la búsqueda sistemática de hipovitaminosis D en esta población, en vista de la alta frecuencia de osteopenia y osteoporosis y el mayor riesgo de fracturas descripto en personas HIV positivas.

Alta prevalencia de hipovitaminosis D en personas infectadas con HIV atendidas en un centro ambulatorio de la ciudad de Buenos Aires / High prevalence of hypovitaminosis D in HIV-infected persons attending an outpatient clinic, Buenos Aires city

La hipovitaminosis D es frecuente en el mundo. Según estudios realizados entre 1987 y 2015, en Argentina la prevalencia fue > 40%. En personas con infección por HIV variaría entre 20 y 90%, pero en nuestro medio no se conoce con precisión. Nuestro objetivo fue determinar la prevalencia de hipovitaminosis D en una cohorte de adultos con infección por HIV asistidos en forma ambulatoria en la ciudad de Buenos Aires. Se analizaron retrospectivamente las historias clínicas de 814 sujetos mayores de 18 años HIV positivos con al menos una determinación de vitamina D. La mediana de edad fue 44 años (rango intercuartílico 21-80), 746 (91.6%) eran hombres y 813 (99.9%) recibían tratamiento antirretroviral. Se realizó análisis uni y multivariado para determinar asociación entre hipovitaminosis D y valores de CD4, carga viral para HIV y terapia antirretroviral. La prevalencia de hipovitaminosis D fue 79.7% (insuficiencia 34.2%, deficiencia 45.5%). No se encontró asociación con el uso de efavirenz o inhibidores de la proteasa (p = 0.86 en ambos casos), con el recuento de linfocitos CD4, ni con la carga viral plasmática (p = 0.81 y 0.74, respectivamente). El presente estudio muestra que, en nuestro medio, la hipovitaminosis D es muy frecuente en personas con infección por HIV. Aun cuando no revela evidencia de relación con carga viral para HIV, estado inmune, ni tratamiento antirretroviral, es necesaria la búsqueda sistemática de hipovitaminosis D en esta población, en vista de la alta frecuencia de osteopenia y osteoporosis y el mayor riesgo de fracturas descripto en personas HIV positivas.

Hypovitaminosis D is frequent worldwide. In Argentina, according to studies conducted between 1987 and 2015, prevalence was > 40% in the general population. In people living with HIV it may vary between 20 and 90%, but the prevalence in our environment is not known. Our objective was to determine the prevalence of hypovitaminosis D in a cohort of adults with HIV infection in the city of Buenos Aires. We analyzed retrospectively medical records of 814 HIV positive subjects older than 18 years with at least one determination of vitamin D. The median age was 44 years (interquartile range 21-80), 746 (91.6%) were men, and 813 (99.9%) were on antiretroviral treatment. Univariate and multivariate analyses were performed to determine the association of hypovitaminosis D with CD4 values, viral load for HIV, and antiretroviral therapy. The present study shows that, in our environment, hypovitaminosis D is very common in people with HIV infection. Although it does not reveal evidence of a relationship with viral load for HIV, immune status, or antiretroviral treatment, the systematic search for hypovitaminosis D is mandatory in this population, taking into account its high frequency and the increased risk of osteopenia, osteoporosis and fractures, as described in people with HIV.

Solving Monocular Visual Odometry Scale Factor with Adaptive Step Length Estimates for Pedestrians Using Handheld Devices.

The urban environments represent challenging areas for handheld device pose estimation (i.e., 3D position and 3D orientation) in large displacements. It is even more challenging with low-cost sensors and computational resources that are available in pedestrian mobile devices (i.e., monocular camera and Inertial Measurement Unit). To address these challenges, we propose a continuous pose estimation based on monocular Visual Odometry. To solve the scale ambiguity and suppress the scale drift, an adaptive pedestrian step lengths estimation is used for the displacements on the horizontal plane. To complete the estimation, a handheld equipment height model, with respect to the Digital Terrain Model contained in Geographical Information Systems, is used for the displacement on the vertical axis. In addition, an accurate pose estimation based on the recognition of known objects is punctually used to correct the pose estimate and reset the monocular Visual Odometry. To validate the benefit of our framework, experimental data have been collected on a 0.7 km pedestrian path in an urban environment for various people. Thus, the proposed solution allows to achieve a positioning error of 1.6⁻7.5% of the walked distance, and confirms the benefit of the use of an adaptive step length compared to the use of a fixed-step length.

Incremental 3D Cuboid Modeling with Drift Compensation.

This paper presents a framework of incremental 3D cuboid modeling by using the mapping results of an RGB-D camera based simultaneous localization and mapping (SLAM) system. This framework is useful in accurately creating cuboid CAD models from a point cloud in an online manner. While performing the RGB-D SLAM, planes are incrementally reconstructed from a point cloud in each frame to create a plane map. Then, cuboids are detected in the plane map by analyzing the positional relationships between the planes, such as orthogonality, convexity, and proximity. Finally, the position, pose, and size of a cuboid are determined by computing the intersection of three perpendicular planes. To suppress the false detection of the cuboids, the cuboid shapes are incrementally updated with sequential measurements to check the uncertainty of the cuboids. In addition, the drift error of the SLAM is compensated by the registration of the cuboids. As an application of our framework, an augmented reality-based interactive cuboid modeling system was developed. In the evaluation at cluttered environments, the precision and recall of the cuboid detection were investigated, compared with a batch-based cuboid detection method, so that the advantages of our proposed method were clarified.

Indoor Positioning System Based on Chest-Mounted IMU.

Demand for indoor navigation systems has been rapidly increasing with regard to location-based services. As a cost-effective choice, inertial measurement unit (IMU)-based pedestrian dead reckoning (PDR) systems have been developed for years because they do not require external devices to be installed in the environment. In this paper, we propose a PDR system based on a chest-mounted IMU as a novel installation position for body-suit-type systems. Since the IMU is mounted on a part of the upper body, the framework of the zero-velocity update cannot be applied because there are no periodical moments of zero velocity. Therefore, we propose a novel regression model for estimating step lengths only with accelerations to correctly compute step displacement by using the IMU data acquired at the chest. In addition, we integrated the idea of an efficient map-matching algorithm based on particle filtering into our system to improve positioning and heading accuracy. Since our system was designed for 3D navigation, which can estimate position in a multifloor building, we used a barometer to update pedestrian altitude, and the components of our map are designed to explicitly represent building-floor information. With our complete PDR system, we were awarded second place in 10 teams for the IPIN 2018 Competition Track 2, achieving a mean error of 5.2 m after the 800 m walking event.

Range image registration using a photometric metric under unknown lighting.

Based on the spherical harmonics representation of image formation, we derive a new photometric metric for evaluating the correctness of a given rigid transformation aligning two overlapping range images captured under unknown, distant, and general illumination. We estimate the surrounding illumination and albedo values of points of the two range images from the point correspondences induced by the input transformation. We then synthesize the color of both range images using albedo values transferred using the point correspondences to compute the photometric reprojection error. This way allows us to accurately register two range images by finding the transformation that minimizes the photometric reprojection error. We also propose a practical method using the proposed photometric metric to register pairs of range images devoid of salient geometric features, captured under unknown lighting. Our method uses a hypothesize-and-test strategy to search for the transformation that minimizes our photometric metric. Transformation candidates are efficiently generated by employing the spherical representation of each range image. Experimental results using both synthetic and real data demonstrate the usefulness of the proposed metric.