Persistence of SARS-CoV-2 RNA shedding and infectivity in immunized population: Prospective study along different epidemiological periods in Argentina.

During the pandemic of COVID-19, numerous waves of infections affected the two hemispheres with different impacts on each country. Throughout these waves, and with the emergence of new variants, health systems and scientists have tried to provide real-time responses to the complex biology of SARS-CoV-2, dealing with different clinical presentations, biological characteristics, and clinical impact of these variants. In this context, knowing the extent period in which an infected individual releases infectious viral particles has important implications for public health. This work aimed to investigate viral RNA shedding and infectivity of SARS-CoV-2 beyond 10 days after symptom onset (SO). A prospective multicenter study was performed between July/2021 and February/2022 on 116 immunized strategic personnel with COVID-19 diagnosed by RT-qPCR, with asymptomatic (7%), mild (91%) or moderate disease (2%). At the time of diagnosis, 70% had 2 doses of vaccines, 26% had 2 plus a booster, and 4% had one dose. After day 10 from SO, sequential nasopharyngeal swabs were taken to perform RT-qPCR, viral isolation, and S gene sequencing when possible. Viral sequences were obtained in 98 samples: 43% were Delta, 16% Lambda, 15% Gamma, 25% Omicron (BA.1) and 1% Non-VOC/VOI, in accordance with the main circulating variants at each moment. SARS-CoV-2 RNA was detected 10 days post SO in 57% of the subjects. Omicron was significantly less persistent. Noteworthy, infective viruses could not be isolated in any of the samples. In conclusion, a 10-days isolation period was useful to prevent further infections, and proved valid for the variants studied. Recently, even shorter periods have been applied, as the Omicron variant is prevalent, and worldwide population is largely vaccinated. In the future, facing the possible emergence of new variants and considering immunological status, a return to 10 days may be necessary.

Longitudinal Follow-Up of the Immunity to SARS-CoV-2 in Health Care Workers in Argentina: Persistence of Humoral Response and Neutralizing Capacity after Sputnik V Vaccination.

SARS-CoV-2 vaccine protection has encountered waning of immune response and breakthrough infections. The hybrid immune response generated by the combination of vaccination and infection was shown to offer higher and broader protection. Here, we present a seroprevalence study of anti-SARS-CoV-2 spike/RBD IgG in 1,121 health care workers immunized with Sputnik V and a follow-up of humoral response at 2 and 24 weeks postvaccination (wpv), including neutralizing antibody response (NAT) against ancestral, Gamma, and Delta variants. The first seroprevalence study showed that among 122 individuals with one dose, 90.2% were seropositive versus 99.7% seropositivity among volunteers with the complete two-dose regimen. At 24 wpv, 98.7% of the volunteers remained seropositive, although antibody levels decreased. IgG levels and NAT were higher in individuals that had acquired COVID-19 previous to vaccination than in naive individuals at 2 and 24 wpv. Antibody levels dropped over time in both groups. In contrast, IgG levels and NAT increased after vaccine breakthrough infection. At 2 wpv, 35/40 naive individuals had detectable NAT against SARS-CoV-2 Gamma and 6/40 against Delta. In turn, 8/9 previously infected individuals developed a neutralizing response against SARS-CoV-2 Gamma and 4/9 against Delta variants. NAT against variants followed a trajectory similar to NAT against ancestral SARS-CoV-2, and breakthrough infection led to an increase in NAT and complete seroconversion against variants. In conclusion, Sputnik V-induced humoral response persisted at 6 months postvaccination, and hybrid immunity induced higher levels of anti-S/RBD antibodies and NAT in previously exposed individuals, boosted the response after vaccination, and conferred wider breadth of protection. IMPORTANCE Since December 2020, Argentina has begun a mass vaccination program. The first vaccine available in our country was Sputnik V, which has been approved for use in 71 countries with a total population of 4 billion people. Despite all the available information, there are fewer published studies on the response induced by Sputnik V vaccination compared to that of other vaccines. Although the global political context has paralyzed the verification by the WHO of the efficacy of this vaccine, our work aims to add new clear and necessary evidence to Sputnik V performance. Our results contribute to general knowledge of the humoral immune response developed by vaccines based on viral vector technology, highlighting the higher immune protection conferred by hybrid immunity and reinforcing the importance of completing vaccination schedules and booster doses to maintain adequate antibody levels.

[Morbidity and mortality due to COVID-19 in latin america: study of three countries - february to july 2020]. / Morbilidad y mortalidad por COVID-19 en Latinoamérica: estudio en tres países - febrero a julio de 2020.

BACKGROUND: On March 11, 2020 the WHO declared the state of pandemic by COVID-19. As of July 29, 2020, 17 106 007 cases and 668 910 deaths have been reported globally. The region of the Americas has reported 9 152 173 cases (53%) and 351 121 deaths (52,2%), so the aggregate analysis of the data in countries in this region is of interest. Argentina, Chile and Colombia, due to their demographic and economic characteristics, are countries that can be studied. OBJETIVE: Analyze variables related to health systems and epidemiological data of SARS-CoV-2 virus disease in Argentina, Chile and Colombia. METHODS: A descriptive study of variables reported by the official organisms of each state was used. RESULTS: There is an important difference in active cases and mortality among the three countries; the Autonomous City of Buenos Aires has the highest number of active cases as of July 2020. Colombia has the highest numbers of deaths confirmed by COVID-19 in the months of February to July 2020. We suggest the unification of an information system for Latin America that allows a comprehensive monitoring of variables, improves the qua-lity of data and unifies the technical language.

Omicron Waves in Argentina: Dynamics of SARS-CoV-2 Lineages BA.1, BA.2 and the Emerging BA.2.12.1 and BA.4/BA.5.

The COVID-19 pandemic has lately been driven by Omicron. This work aimed to study the dynamics of SARS-CoV-2 Omicron lineages during the third and fourth waves of COVID-19 in Argentina. Molecular surveillance was performed on 3431 samples from Argentina, between EW44/2021 and EW31/2022. Sequencing, phylogenetic and phylodynamic analyses were performed. A differential dynamic between the Omicron waves was found. The third wave was associated with lineage BA.1, characterized by a high number of cases, very fast displacement of Delta, doubling times of 3.3 days and a low level of lineage diversity and clustering. In contrast, the fourth wave was longer but associated with a lower number of cases, initially caused by BA.2, and later by BA.4/BA.5, with doubling times of about 10 days. Several BA.2 and BA.4/BA.5 sublineages and introductions were detected, although very few clusters with a constrained geographical distribution were observed, suggesting limited transmission chains. The differential dynamic could be due to waning immunity and an increase in population gatherings in the BA.1 wave, and a boosted population (for vaccination or recent prior immunity for BA.1 infection) in the wave caused by BA2/BA.4/BA.5, which may have limited the establishment of the new lineages.

Prevalence and factors associated with self-reported anxiety in adults during the COVID-19 pandemic in Argentina, Brazil, Peru, Mexico, and Spain: A cross-sectional Ibero-American study.

The present study evaluated the factors associated with the perception of anxiety during the first wave of covid-19 in Ibero-American countries. This cross-sectional study was carried out with 5.845 participants of both sexes, over 18 years of age, and residents of four Latin American countries-Argentina (16.7%), Brazil (34.5%), Mexico (11.1%), and Peru (17.5%), and one European country-Spain (20.1%). Data were collected in 2020, between April 1st and June 30th in Spain and between July 13th and September 26th in the Latin American countries. We used an online questionnaire with sociodemographic, lifestyle, self-reported anxiety, and covid-19 related questions. The chi-square statistical test and Multivariate logistic regressions were performed to analyze the factors associated with self-reported anxiety. The presence of self-reported anxiety was found in 63.8% of the participants during the isolation period. The association occurred mainly in women (OR:1.52; CI: 1.3-1.7), those aged 18 to 29 years (OR: 1.51; CI: 1.2-1.9) and 30 to 49 years (OR: 1.56; CI: 1.3-1.9), residents of Argentina (OR: 1.55 CI: 1.2-1.9), Brazil (OR: 2.38; CI: 2.0-2.8) and Mexico (OR: 1.52; CI: 1.2-1.9), those who gained weight (OR:1.71 CI: 1.5-1.9) or lost weight (OR: 1.40; CI: 1.2-1.6), and those who reported having slept more (OR: 1.56; CI: 1.3-1.8) or less (OR: 2.89; CI: 2.5-3.4). We conclude that the prevalence of self-reported anxiety in Ibero-American countries was high during the period studied, highlighting a higher likelihood of its occurrence in Brazil, in those who began to sleep less and gained weight.

COVID-19 prediction of tendency for 2021 in northwestern Argentina. / Pronóstico de la tendencia de COVID-19 para 2021 en el noroeste de Argentina.

Using a lagged polynomial regression model, which used COVID-19 data from 2020 with no vaccines, the prediction of COVID-19 was performed in a scenario with vaccine administration for Tucumán in 2021. The modeling included the identification of a contagion breaking point between both series with the best correlation. Previously, the lag that served to obtain the smallest error between the expected and observed values was indicated by means of cross correlation. The validation of the model was carried out with real data. In 21 days, 18,640 COVID-19 cases out of 20,400 reported cases were predicted. The maximum peak of COVID-19 was estimated 21 days in advance with the expected intensity.

Usando un modelo de regresión polinomial con retraso, que empleó datos de COVID-19 de 2020 con ausencia de vacunas, se realizó la predicción de COVID-19 en un escenario con administración de vacunas para Tucumán en 2021. La modelación incluyó la identificación de un punto de quiebre de contagios entre ambas series con la mejor correlación. Previamente, se indicó por medio de correlación cruzada el lag que sirvió para obtener el menor error entre los valores esperados y los observados. La validación del modelo fue realizada con datos reales. En 21 días fueron predichos 18.640 casos de COVID-19 de 20.400 casos informados. El pico máximo de COVID-19 fue estimado 21 días antes con la intensidad esperada.

Identification of coronaviruses in bats and rodents in northern and central Argentina.

Due to the present pandemic situation and the many animal species that are epidemiologically involved, there has been a surge of renewed interest in investigating the coronavirus (CoV) population circulating in wildlife, especially bats and rodents, which are potential reservoirs of new human pathogens. In Argentina, information about the viruses present in these mammals is very limited. To investigate the presence of coronaviruses in this country, we obtained 457 samples from hematophagous, insectivorous, and frugivorous bats and rodents from two regions of Argentina. We report here the detection of alphacoronavirus sequences in three groups of bats as well as in rodents. Phylogenetic analysis showed the closest relationships to alphacoronaviruses from Brazil.

Learning strategies of dental students in Buenos Aires, Argentina prior to and during the COVID-19 pandemic.

Various theories have endeavored to explain how knowledge is accessed. Students, in order to learn, need a good repertoire of appropriate metacognitive and self-regulating strategies and knowledge, which they use consciously or unconsciously. Teachers, in addition to knowing how to teach, need to be aware of students' learning strategies, metacognition, and self-regulation, and of the impact of changes associated with recent pandemic scenarios. AIM: The aim of this study was to identify the study strategies preferred by dental students in two different scenarios: prior to and during the pandemic. MATERIALS AND METHOD: The sample consisted of third-year dentistry students at Buenos Aires University (UBA) during 2019 (Group GP, 141 students, face-toface activity) and 2021 (Group GE, 60 students, e-learning during the pandemic). Participants were asked (a) to provide demographic information (sex and age) and (b) to answer the abridged ACRA scale. Statistical treatment included descriptive tests; Chi2, binomial exact and Student's t-test (p<0.05). RESULTS: The proportion of students who participated with respect to total students enrolled was 58.50% in 2019 and 26.20% in 2021, with female gender being significantly higher. There were significant differences in total number of participants during the different periods (p=0.001), and in gender distribution during the pandemic (p=0.007). Comparison between groups GP and GE showed no significant difference regarding preferences expressed in total values for the scale or for the domains. Analysis of preferences according to gender showed significant differences in total group (p=0.007) and the domains CLCS (Cognitive and Learning Control Strategies) (p= 0.008) and LSS (Learning Support Strategies) (p=0.002). The mean values of preferences selected by females were higher. Similar results were found upon analyzing preferences during the pandemic (n= 60) considering total score (p= 0.033) and the domains CLCS (p= 0.035) and LSS (p= 0.007). CONCLUSIONS: The study identified trends towards an increase in the score and consequently greater use of techniques included in the domains related to metacognition, especially among women. There is potential neutralization of the impact created by the methodological shift between the two periods (face-to-face and e-learning) probably as a result of the implicit adaptability, latent in students, regarding digital methodology, which enables them to adapt to learning in challenging situations.

Varias teorías se han esforzado por explicar cómo se accede al conocimiento. Para aprender, los estudiantes necesitan tener un conjunto de estrategias y conocimientos apropiados, y utilizarlos consciente o inconscientemente. Los docentes deben conocer las estrategias de aprendizaje, la metacognición y la autorregulación de los estudiantes, así como el impacto de los cambios asociados con los escenarios pandémicos recientes sobre esas estrategias. OBJETIVO: El objetivo de este estudio fue identificar las estrategias de estudio preferidas por los estudiantes de odontología en diferentes escenarios: previo y durante la pandemia. Materiales y Método: La muestra estuvo conformada por estudiantes de tercer año de la carrera de odontología (UBA) durante el año 2019 (Grupo GP, 141 estudiantes, actividad presencial) y 2021 (Grupo GE, 60 estudiantes, e-learning durante la pandemia). Los participantes proporcionaron información demográfica (sexo y edad) y respondieron el cuestionario ACRA abreviado. El tratamiento estadístico incluyó medidas de tendencia central, dispersión y distribución de frecuencias, prueba Chi2, binomial exacta y prueba t de Student (p<0,05). RESULTADOS: La distribución de estudiantes que participaron con respecto al total de estudiantes matriculados fue de 58,50% en 2019 y 26,20% en 2021, siendo significativamente mayor el género femenino. Hubo diferencias significativas en el número total de participantes durante los diferentes períodos (p=0,001) y en la distribución por género durante la pandemia (p=0,007). La comparación entre los grupos GP y GE no mostró diferencia significativa en cuanto a las preferencias expresadas en valores totales para la escala o para los dominios. El análisis de preferencias según género mostró diferencias significativas en: grupo total (p=0,007) y los dominios ECCA (Estrategias de Control Cognitivo y de Aprendizaje) (p= 0,008) y EAA (Estrategias de Apoyo al Aprendizaje) (p=0,002). Los valores medios de las preferencias seleccionadas por las mujeres fueron más altos. Resultados similares se encontraron al analizar las preferencias durante la pandemia (n= 60) considerando la puntuación total (p= 0,033) y los dominios ECCA (p= 0,035) y EAA (p= 0,007). CONCLUSIONES: El estudio identificó un aumento en el puntaje y consecuentemente un mayor uso de técnicas incluidas en los dominios relacionados con la metacognición, especialmente entre las mujeres. Existe una potencial neutralización del impacto creado por el cambio metodológico entre los dos períodos (presencial y e-learning) probablemente como resultado de la adaptabilidad implícita, latente en los estudiantes, respecto a la metodología digital, que les permita adaptarse al aprendizaje en situaciones desafiantes.

Persistent symptoms after COVID-19 in children and adolescents from Argentina.

OBJECTIVES: Although long COVID-19 is widely recognized in adults, less information is available about this condition in children, especially in developing countries. Here, we studied the long-term symptoms of SARS-CoV-2 infection beyond 3 months and the associated risk factors in a pediatric population. METHODS: This observational study included 639 Argentinian children and adolescents with previously confirmed COVID-19 from June 2020-June 2021 and 577 children without previous COVID-19. Parents completed a survey about symptoms that their child had for >3 months after the diagnosis of SARS-CoV-2 infection. RESULTS: At least one persistent symptom was observed more frequently in children with previous COVID-19 than in the non-COVID-19 group (34% vs 13%, P <0.0001). SARS-CoV-2 infection increased the risk of headache, dizziness, loss of taste, dyspnea, cough, fatigue, muscle pain, and loss of weight by three- to seven-fold. The loss of smell was only reported in infected children. After controlling for the other variables, older age, symptomatic COVID-19, and comorbidities were independent predictors of long-term symptoms. CONCLUSIONS: One-third of children experienced persistent symptoms after COVID-19. Older age, symptomatic infection, and comorbidities were shown to be risk factors for long COVID-19. Pediatric long COVID-19 is a new condition that requires further investigation.

'Now you will understand what it is like to be confined': Did COVID-19 lockdowns affect perceptions about long-term psychiatric hospitalizations? A report from Argentina.

BACKGROUND: Lockdowns have been one of the government's primary measures to control COVID-19, especially during the initial waves of the pandemic, but there is concern on the impact of lockdowns on people's mental health. Confinement is still today the reality of many people with severe mental illness in many places of the world. OBJECTIVE: Given that the general population experienced confinement during the COVID-19 pandemic, we sought to explore if that affected perceptions about long-term psychiatric hospitalizations. METHODS: About 134 residents from middle-class neighborhoods in urban settings in the Province of Buenos Aires, Argentina, were surveyed. Participants were asked if they felt emotionally affected by the pandemic and lockdown, and about their perceptions of long-term psychiatric hospitalizations. Association between personal emotional impact by the pandemic or lockdown with perceptions about long-term psychiatric hospitalization were analyzed using chi-square test. Qualitative analysis of pandemic and lockdown effects was held. RESULTS: Respondents tended to overlap the emotional effects of the pandemic and the lockdown. Some responses explicitly referred to confinement. No association was observed between emotional impact by the pandemic or lockdown and perceptions about long-term psychiatric hospitalization among the sample. The general population's perceptions of long-term psychiatric hospitalization do not appear to be affected by the first-hand experience of confinement, which suggest persistence of stigma, and the need to reconsider public policies and actions that attempt to impact on it.

Comparison of Epidemiologic and Clinical COVID-19 Profiles in Children in Argentina, During Circulation of Original and Variant (Alpha, Gamma and Lambda) Strains.

BACKGROUND: Information on the impact of the different variants in children in Latin America is scarce. The objective of this study was to describe epidemiologic and clinical features of COVID-19 infection in children under 18 years of age in Argentina, comparing the periods before and after the circulation of new variants. METHODS: Observational, cross-sectional, multicentric, analytical study. All patients under 18 years of age with confirmed SARS-CoV-2 infection admitted at 22 healthcare centers were included. Two study periods were established: Period 1 (EW10-2020 to EW12-2021) for the Wuhan strain; Period 2 (EW13 to EW35 2021) for Alpha, Gamma, Delta and Lambda variants. FINDINGS: A total of 6330 confirmed cases were included. Period 1: 3575 (56.5%), period 2: 2755 (43.5%). During period 2, a lower number of asymptomatic cases was observed, while general, respiratory and neurologic signs and symptoms increased in all age groups. Oxygen therapy requirement was higher during the first period (36.7% vs 19.1%; P < 0.001). No significant differences were observed in the rates of severe or critical cases (6.3% vs 5,4%; P = 0.102), intensive care admission (2.1% vs 2%; P < 0.656) or case fatality (0.3% vs 0.5 %; P < 0.229). MIS-C cases occurred more frequently during the first period (1.9% vs 1.1%; P = 0.009). INTERPRETATION: The clinical spectrum of COVID-19 in Argentina has evolved. With the emergence of new variants, although the number of asymptomatic cases declined, numbers of severe and critical cases, as well as case fatality rates in children, remained unchanged.

The Pediatric Guideline Adherence and Outcomes (PEGASUS Argentina) program in severe traumatic brain injury: study protocol adaptations during the COVID-19 pandemic for a multisite implementation-effectiveness cluster randomized controlled trial.

BACKGROUND: The aim of this protocol is to describe the study protocol changes made and subsequently implemented to the Pediatric Guideline Adherence and Outcomes (PEGASUS) Argentina randomized controlled trial (RCT) for care of children with severe traumatic brain injuries (TBI) imposed by the COVID-19 pandemic. The PEGASUS study group met in spring 2020 to evaluate available literature review guidance and the study design change or pausing options due to the potential interruption of research. METHODS: As a parallel cluster RCT, pediatric patients with severe TBIs are admitted to 8 control (usual care) and 8 intervention (PEGASUS program) hospitals in Argentina, Chile, and Paraguay. PEGASUS is an intervention that aims to increase guideline adherence and best practice care for improving patient outcomes using multi-level implementation science-based approaches. Strengths and weaknesses of proposed options were assessed and resulted in a decision to revert from a stepped wedge to a parallel cluster RCT but to not delay planned implementation. DISCUSSION: The parallel cluster design was considered more robust and flexible to secular interruptions and acceptable and feasible to the local study sites in this situation. Due to the early stage of the study, the team had flexibility to redesign and implement a design more compatible with the conditions of the research landscape in 2020 while balancing analytical methods and power, logistical and implementation feasibility, and acceptability. As of fall 2022, the PEGASUS RCT has been active for nearly 2 years of implementation and data collection, scheduled to be completed in in fall 2023. The experience of navigating research during this period will influence decisions about future research design, strategies, and contingencies. TRIAL REGISTRATION: Pediatric Guideline Adherence and Outcomes-Argentina. Registered with ClinicalTrials.gov Identifier NCT03896789 on April 1, 2019.

Preceding anti-spike IgG levels predicted risk and severity of COVID-19 during the Omicron-dominant wave in Santa Fe city, Argentina.

The SARS-CoV-2 Omicron variant has increased infectivity and immune escape compared with previous variants, and caused the surge of massive COVID-19 waves globally. Despite a vast majority (~90%) of the population of Santa Fe city, Argentina had been vaccinated and/or had been infected by SARS-CoV-2 when Omicron emerged, the epidemic wave that followed its arrival was by far the largest one experienced in the city. A serosurvey conducted prior to the arrival of Omicron allowed to assess the acquired humoral defences preceding the wave and to conduct a longitudinal study to provide individual-level real-world data linking antibody levels and protection against COVID-19 during the wave. A very large proportion of 1455 sampled individuals had immunological memory against COVID-19 at the arrival of Omicron (almost 90%), and about half (48.9%) had high anti-spike immunoglobulin G levels (>200 UI/ml). However, the antibody titres varied greatly among the participants, and such variability depended mainly on the vaccine platform received, on having had COVID-19 previously and on the number of days elapsed since last antigen exposure (vaccine shot or natural infection). A follow-up of 514 participants provided real-world evidence of antibody-mediated protection against COVID-19 during a period of high risk of exposure to an immune-escaping highly transmissible variant. Pre-wave antibody titres were strongly negatively associated with COVID-19 incidence and severity of symptoms during the wave. Also, receiving a vaccine shot during the follow-up period reduced the COVID-19 risk drastically (15-fold). These results highlight the importance of maintaining high defences through vaccination at times of high risk of exposure to immune-escaping variants.

Effectiveness of mRNA-1273, BNT162b2, and BBIBP-CorV vaccines against infection and mortality in children in Argentina, during predominance of delta and omicron covid-19 variants: test negative, case-control study.

OBJECTIVE: To estimate the effectiveness of a two dose vaccine schedule (mRNA-1273, BNT162b2, and BBIBP-CorV) against SARS-CoV-2 infection and covid-19 related death and short term waning of immunity in children (3-11 years old) and adolescents (12-17 years old) during periods of delta and omicron variant predominance in Argentina. DESIGN: Test negative, case-control study. SETTING: Database of the National Surveillance System and the Nominalized Federal Vaccination Registry of Argentina. PARTICIPANTS: 844 460 children and adolescents without previous SARS-CoV-2 infection eligible to receive primary vaccination schedule who were tested for SARS-CoV-2 by polymerase chain reaction or rapid antigen test from September 2021 to April 2022. After matching with their corresponding controls, 139 321 (60.3%) of 231 181 cases remained for analysis. EXPOSURES: Two dose mRNA-1273, BNT162b2, and BBIBP-CorV vaccination schedule. MAIN OUTCOME MEASURES: SARS-CoV-2 infection and covid-19 related death. Conditional logistic regression was used to estimate the odds of SARS-CoV-2 infection among two dose vaccinated and unvaccinated participants. Vaccine effectiveness was estimated as (1-odds ratio)×100%. RESULTS: Estimated vaccine effectiveness against SARS-CoV-2 infection was 61.2% (95% confidence interval 56.4% to 65.5%) in children and 66.8% (63.9% to 69.5%) in adolescents during the delta dominant period and 15.9% (13.2% to 18.6%) and 26.0% (23.2% to 28.8%), respectively, when omicron was dominant. Vaccine effectiveness declined over time, especially during the omicron period, from 37.6% (34.2% to 40.8%) at 15-30 days after vaccination to 2.0% (1.8% to 5.6%) after ≥60 days in children and from 55.8% (52.4% to 59.0%) to 12.4% (8.6% to 16.1%) in adolescents.Vaccine effectiveness against death related to SARS-CoV-2 infection during omicron predominance was 66.9% (6.4% to 89.8%) in children and 97.6% (81.0% to 99.7%) in adolescents. CONCLUSIONS: Vaccine effectiveness in preventing mortality remained high in children and adolescents regardless of the circulating variant. Vaccine effectiveness in preventing SARS-CoV-2 infection in the short term after vaccination was lower during omicron predominance and decreasing sharply over time. TRIAL REGISTRATION: National Registry of Health Research IS003720.

Design and feasibility of an implementation strategy to address Chagas guidelines engagement focused on attending women of childbearing age and children at the primary healthcare level in Argentina: a pilot study.

BACKGROUND: Chagas is a public health problem, especially in Latin America, exacerbated by migratory movements and increasing urbanization. Argentina is among the countries with the highest estimated prevalence in the region, with 1,500,000 people infected, with mother to child as the main mode of transmission. Vertical transmission has been significantly reduced by treating women of childbearing age; several guidelines in the region recommend treatment as a primary prevention strategy for the child and a secondary prevention strategy for women and their families. Despite recommendations, women of childbearing age are not always treated, and children do not receive timely diagnosis and treatment. The objective of this research was to design an implementation strategy to improve using Chagas guidelines focused on attending women of childbearing age and children at the primary healthcare level and pilot it in three primary health care centers in Argentina. METHODS: We conducted a pilot feasibility study using the Consolidated Framework for Implementation Research. A qualitative process evaluation was conducted using semi-structured interviews with health care providers and observations in primary health care centers. RESULTS: We developed a multifaceted implementation strategy including training, flowcharts and reminders, a register of suspected and confirmed cases, and the selection of a management facilitator. The pilot study took place between September 2019 and May 2020. The implementation level was heterogeneous and varied depending on the components, being the facilitating factors, the simplicity of the intervention, professionals' willingness to expand the indication of serologic tests, and staff commitment to the adoption of intervention components. The main barriers found were the change of authorities at the local level, some professionals´ reluctance to administer etiological treatment, staff shortages, lack of diagnostic supplies, and the health emergency caused by the COVID-19 pandemic. CONCLUSIONS: Behavioral change strategies should be applied to improve implementation to address some of the main barriers, including support actions offered by opinion leaders, medical experts, and local health authorities. Rapid diagnostic tests should be readily available to maintain behavior changes. We suggest further refinement of the strategy and its implementation in more centers to assess outcomes prospectively with a hybrid implementation research design.

COVID-19 among Chronic Dialysis Patients after First Year of Pandemic, Argentina.

We performed a descriptive study to characterize effects from COVID-19 among chronic dialysis patients compared with the general population in Argentina during March 2020-February 2021. COVID-19 case-fatality rate of chronic dialysis patients was 10 times the national rate; the age-standardized mortality ratio was 6.8 (95% CI 6.3-7.3).

[Impact of COVID-19 related lockdown on the metabolic profile of people with HIV infection in Argentina]. / Impacto de la cuarentena por COVID-19 en el perfil metabólico de personas con infección por VIH en Argentina.

BACKGROUND: The spread of SARS-CoV-2 required widespread lockdown to mitigate the pandemic. Argentine authorities imposed preventive social isolation for 234 days (March 20th to November 9th 2020). This measure led to major changes in the population's lifestyle. AIM: To examine the influence of COVID-19 lockdown measures on the metabolic profile of HIV-infected patients in Argentina. METHODS: Retrospective cohort study of 10,239 HIV-infected patients under follow up in a private clinic for HIV care. Adult patients with ongoing antiretroviral therapy (ART) and a baseline determination of blood glucose, total cholesterol, HDL-cholesterol and triglycerides done before lockdown (BL: second semester of 2019) and a second determination during lockdown (DL: May 2020) were included. Patients with recent changes in ART that may have metabolic impact, those starting lipid/glucose lowering agents and pregnant women were excluded. Categorical variables were compared using the χ2 test or Fisher's exact test, and continuous variables using the t-test or the Mann-Whitney test. A two-tailed value of p < 0.05 was considered significant. RESULTS: 540 individuals were included, median of age was 47 years and 74.6% were male. Median body mass index was 26.1 and 94.6% had low cardiovascular risk. There was a significant increase in the percentage of patients that met criteria for hyperglycemia (BL 4.8% and DL 8.5%, p < 0.001). We also observed significant (p < 0.001) increase in median (IQR) BL vs DL values in LDL-cholesterol [109 (90-128) vs 118 (97-139) mg/dL]; and triglycerides [120 (87-172) vs. 132 mg/dL (96-184)]. The proportion of patients with hyper-LDL cholesterolemia according to individual cardiovascular risk increased from 12.6 to 17.2% (p = 0.04). CONCLUSION: Our results suggest that quarantine, at least in its initial phases, may have a negative impact on the metabolic profile of this population.

An epidemic model for COVID-19 transmission in Argentina: Exploration of the alternating quarantine and massive testing strategies.

The COVID-19 pandemic has challenged authorities at different levels of government administration around the globe. When faced with diseases of this severity, it is useful for the authorities to have prediction tools to estimate in advance the impact on the health system as well as the human, material, and economic resources that will be necessary. In this paper, we construct an extended Susceptible-Exposed-Infected-Recovered model that incorporates the social structure of Mar del Plata, the 4°most inhabited city in Argentina and head of the Municipality of General Pueyrredón. Moreover, we consider detailed partitions of infected individuals according to the illness severity, as well as data of local health resources, to bring predictions closer to the local reality. Tuning the corresponding epidemic parameters for COVID-19, we study an alternating quarantine strategy: a part of the population can circulate without restrictions at any time, while the rest is equally divided into two groups and goes on successive periods of normal activity and lockdown, each one with a duration of τ days. We also implement a random testing strategy with a threshold over the population. We found that τ=7 is a good choice for the quarantine strategy since it reduces the infected population and, conveniently, it suits a weekly schedule. Focusing on the health system, projecting from the situation as of September 30, we foresee a difficulty to avoid saturation of the available ICU, given the extremely low levels of mobility that would be required. In the worst case, our model estimates that four thousand deaths would occur, of which 30% could be avoided with proper medical attention. Nonetheless, we found that aggressive testing would allow an increase in the percentage of people that can circulate without restrictions, and the medical facilities to deal with the additional critical patients would be relatively low.