Epidemiology of Dengue in Argentina during the 2010/11 to 2019/20 Seasons: A Contribution to the Burden of Disease.

BACKGROUND: Dengue is an important public health problem in Argentina, as in many other countries. We reviewed and updated information on the dengue disease burden in Argentina over a 10-year period. METHODS: We conducted a retrospective descriptive study from 2010 to 2020 based on data from the National Health Surveillance System. The main outcomes included dengue cases, incidence rates, deaths, and serotype distribution by season, age group, and region. RESULTS: A total of 109,998 confirmed cases of dengue were reported. Seasonality stands out, prevailing during summer and autumn. Two main outbreaks (seasons 2015/16 and 2019/20), with increasing magnitude, were observed. The 2019/20 season showed the highest number of cases (58,731) and incidence rate (135/100,000). The Northeast region had the highest number of cases and incidence rate. In 2020, for the first time, autochthonous cases were registered in the Cuyo region. The only region with no autochthonous cases was the South. Adolescents and young adults showed the highest incidence rate. The case fatality rate for the period was 0.05%. Four serotypes circulated, but the predominant one was DEN-1 (78%). CONCLUSIONS: Dengue has been expanding temporally and spatially. Although the DEN-1 serotype widely predominated, the increasing circulation of other serotypes raises concerns regarding re-exposure and the severity of future cases. Understanding epidemiological trends is key to defining public prevention and control policies.

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.

Evaluación de la epidemia argentina de Dengue, 2015-2016 / Evaluation of the argentine Dengue epidemic, 2015-2016

El dengue es una de las principales enfermedades tropicales emergentes. Se estima que 3.900 millones de personas, de 128 países, están en riesgo de infección por los virus del dengue. En Argentina al mosquito Aedes aegypti, vector del virus del dengue, se lo consideró erradicado en 1963 y 1965. En nuestro país el dengue reemergió en el año 1998 ocasionando desde entonces brotes de distinta magnitud cada año (excepto 2001 y 2005 donde no hubo casos registrados). Con anterioridad a la temporada 2015-2016, el brote de mayor magnitud ocurrió en 2009 con más de 26.000 casos. La mayor parte de los brotes en Argentina comenzaron en localidades limítrofes con Bolivia, Paraguay y Brasil para luego extenderse a otras localidades más alejadas. Éste trabajo pretendió estudiar la dinámica espacio-temporal de la distribución de casos de dengue de la Argentina y los factores ambientales y sociodemográficos a los que estuvieron asociados en las epidemias de 2009 y 2015-2016. En esta investigación se trabajó con técnicas de reconocimiento de variables predictivas para la ocurrencia y dispersión de los brotes de dengue en el territorio. Como era esperable, el clima y las epidemias en países limítrofes fueron cruciales para pronosticar la transmisión en el país, que continúa mostrando un comportamiento epidémico respecto al dengue. Los modelos espacio-temporales de la distribución de casos entre 2009 y 2016 mostraron también relación al mismo tipo de variables, pero priorizando la situación de circulación de virus en países limítrofes

Utilización de métodos de captura y recaptura para la estimación del subregistro de notificación de Chagas Congénito en la Argentina em 2012 / Using capture-recapture methods for estimating the underreporting of notification of congenital Chagas in Argentina em 2012

A partir del éxito relativo del control de la transmisión vectorial y transfusional, el chagas congénito se ha establecido como un problema de salud pública, siendo una importante vía de transmisión en zonas endémicas y no endémicas de la Argentina. Se estima que el 5 por ciento de los hijos de madres positivas nacen con la infección. Hasta el momento no existe manera de prevenir la transmisión congénita de Chagas. El tratamiento en la embarazada está contraindicado, pero es efectivo y bien tolerado en niños y bebés en la fase aguda de la infección, con tasas de curación cercanas al 100 por ciento. Por ese motivo es de vital importancia garantizar el diagnóstico y tratamiento de todos los niños con riesgo de transmisión congénita. Con este objetivo, la Argentina ha adoptado el tamizaje prenatal para Chagas de todas las embarazadas y la notificación obligatoria a través del Sistema Nacional de Vigilancia de la Salud (SNVS) de todas las embarazadas con Chagas y de todos los niños hijos de madre positiva, para posibilitar las acciones de seguimiento. Otro sistema que recopila información sobre las embarazadas con Chagas es el Sistema Informático Perinatal (SIP). El objetivo de este trabajo fue analizar el subregistro de notificación de Chagas congénito en la Argentina, durante 2012, a través de métodos de captura y recaptura (MCR), a nivel nacional y regional. Para ello se utilizaron tres fuentes de datos: dos de ella provenientes del módulo de Vigilancia por laboratorio (SIVILA) del SNVS, la base de notificación de embarazadas positivas para Chagas y la base de recién nacidos de madres con Chagas y la tercera correspondiente a las mujeres con Chagas notificadas al SIP. Se realizó el relacionamiento probabilístico de los datos y luego se aplicaron MCR basados en el enfoque de cobertura de la muestra para la estimación del número de recién nacidos con riesgo de transmisión vertical (TV) de Chagas...

Since the relative success of vector control and transfusional transmission, congenital Chagashas became a concerning public health problem, and is an important route of transmission inendemic and non-endemic areas of Argentina. It is estimated that 5 percent of newbons frominfected mothers are born infected. So far there is no way to prevent congenital transmissionof Chagas. The treatment is contraindicated in pregnant women, but it is effective and welltolerated in the acute phase of infection in children and infants, with cure rates approaching100 percent. Therefore it is very important to ensure the diagnosis and treatment of all children atrisk of congenital transmission. With this objective, Argentina has adopted the antenatal screening for Chagas of all pregnant women and mandatory report through the National System of Health Surveillance (SNVS) of all pregnant women with Chagas and all newbornsfrom positive mothers, to enable monitoring actions. Another system collecting informationon pregnant women with Chagas is the Perinatal Information System (SIP).The aim of this study was to analyze the under-reporting of congenital Chagas disease inArgentina, in 2012, by capture-recapture methods (MCR), at national and regional level. Thedata source were three lists: two from the laboratory monitoring module (SIVILA) of SNVS (reports of positive pregnant women and reports newborns from positive mothers) and thethird corresponding to positive pregnant women reported to SIP. The probabilistic linkaje ofthe data was performed and then MCR based on sample coverage approach were applied, inorder to estimate the number of infants at risk of vertical transmission (TV) Chagas...

Overcoming language and cultural barriers: a graphical communication tool to perform a parasitological screening in two vulnerable populations from Argentina.

This is an exploratory study of the application of a support tool for the detection of asymptomatic subjects carrying enteric parasites in two vulnerable populations in Argentina: a shantytown in the city of Buenos Aires and a rural Wichí indigenous community in the province of Chaco. The ethnic and cultural diversity, high illiteracy rate, and language barriers called for the development of an auxiliary resource to explain stool sample collection procedures. In individual interviews with each family, the authors used two instructional guidance leaflets in comic strip format depicting the procedures. They evaluated the acceptance of the graphical communication tool on the basis of the number of retrieved samples. Percentages of respondent families were 72.2% and 66.7%, respectively. Definitive validation of these instruments would allow their use in community studies, community service learning experiences, and research on aboriginal communities that would otherwise be excluded from studies on health status.

Incidence of influenza-associated mortality and hospitalizations in Argentina during 2002-2009.

BACKGROUND: We estimated rates of influenza-associated deaths and hospitalizations in Argentina, a country that recommends annual influenza vaccination for persons at high risk of complications from influenza illness. METHODS: We identified hospitalized persons and deaths in persons diagnosed with pneumonia and influenza (P&I, ICD-10 codes J10-J18) and respiratory and circulatory illness (R&C, codes I00-I99 and J00-J99). We defined the influenza season as the months when the proportion of samples that tested positive for influenza exceeded the annual median. We used hospitalizations and deaths during the influenza off-season to estimate, using linear regression, the number of excess deaths that occurred during the influenza season. To explore whether excess mortality varied by sex and whether people were age <65 or ≥ 65 years, we used Poisson regression of the influenza-associated rates. RESULTS: During 2002-2009, 2411 P&I and 8527 R&C mean excess deaths occurred annually from May to October. If all of these excess deaths were associated with influenza, the influenza-associated mortality rate was 6/100,000 person-years (95% CI 4-8/100,000 person-years for P&I and 21/100,000 person-years (95% CI 12-31/100,000 person-years) for R&C. During 2005-2008, we identified an average of 7868 P&I excess hospitalizations and 22,994 R&C hospitalizations per year, resulting in an influenza-associated hospitalization rate of 2/10,000 person-years (95% CI 1-3/10,000 person-years) for P&I and 6/10,000 person-years (95% CI 3-8/10,000 person-years) for R&C. CONCLUSION: Our findings suggest that annual rates of influenza-associated hospitalizations and death in Argentina were substantial and similar to neighboring Brazil.

Hepatitis virales / Viral hepatitis

Los virus que con mayor frecuencia producen hepatitis son los hepatotropos: virus de la hepatitisA (VHA), B (VHB), C (VHC), D (VHD), E (VHE). Otros virus como el citomegalovirus,Epstein Barr, herpes virus y varicela-zóster también pueden comprometer al hígado en forma aguda acompañando a la enfermedad sistémica producida por los mismos Los hepatotropos tienen distintas formas de transmisión y evolución clínica. Los virus de la hepatitis A y de la hepatitis E se transmiten por vía fecal-oral mientras que los de las hepatitis B y C se transmiten principalmente por vía parenteral. El modo de transmisión sexual es el más frecuente para virus B en zonas de baja endemia como la Argentina, mientras que las prácticas o derivados parenterales son el modo de transmisión más frecuente para el virus de la hepatitis C. Por su parte, el virus de la hepatitis D es un virus defectivo, ya que para resultar infectivo la persona debe portar el virus de la hepatitis B. El pronóstico y la gravedad de la hepatitis viral dependen de muchos factores, incluyendo la edad de la persona, el tipo de virus, el tipo de respuesta inmunológica que genera el huésped para controlar el virus, y la existencia de otros trastornos de salud que puedan influir en la evolución de la enfermedad hepática o su tratamiento.En la Argentina, la hepatitis A ha ocasionado brotes epidémicos cada tres a cuatro años hasta el año 2005, momento en el que se incorporó la vacuna al año de edad en el Calendario Nacional de Vacunación (Resolución Ministerial Nº653/05). Hasta entonces la hepatitis A era la causa principal de fallo hepático fulminante en la Argentina en niños menores de 10 años, llegando en algunos casos a la necesidad del trasplante hepático, con mayor frecuencia en niños de 5 años de edad. El último transplante realizado en la Argentina por FHF por VHA fue en el año 2006.