Reemergencia de la encefalitis equina del oeste (WEEV) en la Argentina: una revisión de aspectos epidemiológicos, virológicos y clínicos de relevancia / Reemergence of western equine encephalitis in Argentina

La encefalitis equina del oeste (WEEV, por su sigla en inglés, Western Equine Encephalitis) es una enfermedad reemergente en Argentina a partir del año 2023. La co-municación inicial fue en 1933, las últimas epizootias ocurrieron en 1983 y el último caso humano se registró en 1996. Se revisan las características del agente causal, la ecología con especial referencia a los vectores iden-tificados en el país, su competencia en la transmisión y el ciclo así como los factores de riesgo para adquirir la enfermedad. La situación epidemiológica en equinos y humanos desde noviembre 2023 hasta marzo 2024 es analizada. Se describen las formas clínicas de presen-tación de la enfermedad humana, las posibilidades evo-lutivas, los datos disponibles en los casos confirmados y el tratamiento. La metodología y algoritmo empleados para el diagnóstico etiológico en el Centro Nacional de Referencia son detallados. Las estrategias para la pre-vención y el control se basan en la vacunación de los equinos, el saneamiento ambiental y el control del foco ante la presentación de la enfermedad animal (vigilancia epidemiológica activa)

Western equine encephalitis (WEE) is a re-emerging dis-ease in Argentina starting in 2023. Since the initial notifi-cation in 1933, the last epizootics occurred in 1983, and the last human case was recorded in 1996.The charac-teristics of the causative agent, the ecology with special reference to vectors identified in the country, their compe-tence in transmission, and the cycle as well as the risks factors for acquiring the disease, are reviewed.The epidemiological situation in horses and humans from November 2023 to March 2024 is analyzed. The clinical presentation of the human disease, its evolutionary po-tential, available data in confirmed cases, and the treat-ment are described.The methodology and algorithm used for the etiological diagnosis at the National Reference Center are detailed. Strategies for prevention and control are based on vaccination of horses, environmental sani-tation and outbreak control in the presence of the animal disease (active epidemiological surveillance)

Leptospiral infection: a serosurvey in urban and rural communities in Olavarría county, Argentina.

INTRODUCTION: Leptospirosis is a neglected zoonotic disease, affecting mainly poor and vulnerable populations. METHODOLOGY: A cross sectional-study was carried out in 557 subjects from Olavarría county (Argentina) to estimate the seroprevalence of leptospirosis and the factors associated with seropositivity. A survey was carried out to obtain clinical and epidemiological data. Serum was tested for anti-leptospiral antibodies by Microscopic Agglutination Test (MAT). Chi-square or Fisher Exact tests were used to assess association between the MAT results and the exploratory variables. For the variables statistically associated, odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated. Individuals from Olavarría city were georeferenced to describe the spatial distribution and to detect clusters of seropositivity for leptospiral antibodies. RESULTS: The overall prevalence of leptospirosis infection was 7.00%, higher in rural (19.66%) than in urban populations (3.64%) (p < 0.001). Sejroe was the most predominant serogroup in rural communities while Icterohaemorrhagiae was the most prevalent in urban populations. The factors associated with Leptospira infection were the presence of rodents inside households (OR = 3.9) in rural populations, while contact with cats (OR = 4.97) and male gender (OR = 7.75) represented higher risk of infection for the urban ones. Cases with positive serology have been found near Tapalqué stream or in the peripheral areas of Olavarría city. CONCLUSIONS: The results from data obtained during the study period were similar to other reports and demonstrate the importance of continuous epidemiological surveillance system and specific community educational campaigns to prevent the leptospirosis infection in Olavarría county and other communities with similar characteristics especially in rural areas.

Consenso Argentino de toxoplasmosis congénita 2020 / Argentine Consensus of congenital toxoplasmosis

Resumen La transmisión vertical de la infección por Toxoplasma gondii ocurre cuando la madre se infecta por primera vez en el transcurso del embarazo. El diagnóstico de la infección materna y la del re cién nacido se logra con el conjunto de pruebas serológicas, hallazgos clínicos y ecográficos. El reconocimiento temprano de la infección materna permite un tratamiento que reduce la tasa de transmisión y el riesgo de daño en el producto de la concepción. El objetivo de este consenso de expertos fue revisar la literatura científica para actualizar las recomendaciones de práctica clínica respecto de la prevención, el diagnóstico y el tratamiento de la toxoplasmosis congénita en nuestro país.

Abstract Mother-to-child transmission in Toxoplasma gondii infection occurs only when the infection is acquired for the first time during pregnancy. Diag nosis of maternal infection and the newborn is achieved by a combination of serological tests, clinical features and ultrasound images. An early diagnosis of maternal infection allows treatment that offers a reduction both in transmission rate and risk of congenital damage. The aim of this expert consensus was to review the scientific literature which would enable an update of the clinical practice guideline of prevention, diagnosis and treatment of congenital toxoplasmosis in our country.

[Argentine consensus of congenital toxoplasmosis]. / Consenso argentino de toxoplasmosis congénita 2020.

Mother-to-child transmission in Toxoplasma gondii infection occurs only when the infection is acquired for the first time during pregnancy. Diagnosis of maternal infection and the newborn is achieved by a combination of serological tests, clinical features and ultrasound images. An early diagnosis of maternal infection allows treatment that offers a reduction both in transmission rate and risk of congenital damage. The aim of this expert consensus was to review the scientific literature which would enable an update of the clinical practice guideline of prevention, diagnosis and treatment of congenital toxoplasmosis in our country.

La transmisión vertical de la infección por Toxoplasma gondii ocurre cuando la madre se infecta por primera vez en el transcurso del embarazo. El diagnóstico de la infección materna y la del recién nacido se logra con el conjunto de pruebas serológicas, hallazgos clínicos y ecográficos. El reconocimiento temprano de la infección materna permite un tratamiento que reduce la tasa de transmisión y el riesgo de daño en el producto de la concepción. El objetivo de este consenso de expertos fue revisar la literatura científica para actualizar las recomendaciones de práctica clínica respecto de la prevención, el diagnóstico y el tratamiento de la toxoplasmosis congénita en nuestro país.

Análisis de los trabajos de investigación bibliográfica elaborados en la Facultad de Ciencias Médicas / Analysis of the bibliographic research works elaborated in the Faculty of Medicine

OBJETIVO: comparar la calidad de la presentación escrita del Trabajo de Investigación Bibliográfica (TIBI) de las cohortes 2010 (c10) y 2013 (c13). MATERIAL Y MÉTODO: Estudio retrospectivo. Se analizó: ortografía, nomenclatura microbiológica (NM) sintaxis y léxico; número de citas bibliográficas, presentación según Vancouver (NV), adecuación entre número de citas, publicaciones periódicas y libros respecto de la guía (GR). Se resumió en media, y porcentaje; chi2e IC 95%, p <0,05. RESULTADOS: n: 107 planillas. En ortografía, NM, sintaxis y léxico se evidenció diferencia favorable a la c10. Promedio de citas en c10: 25,74, en c13: 28,61, p<0,05. El 27% y el 72,7% de cada cohorte cumplió con el número de publicaciones. El 84,1% y 90,9% de cada cohorte cumplió con los libros. El 15,9% y el 25% cumplieron con la presentación según NV. CONCLUSIONES: Se observa empeoramiento en la c13, por una disminución en el seguimiento de la GR.

OBJECTIVE: to compare the quality of the written presentation of the Bibliographic Research Work (TIBI) of the cohorts 2010 (c10) and 2013 (c13). METHODS: Retrospective study. We analyzed: spelling, microbiological nomenclature (NM), syntax and lexicon; number of bibliographic citations, presentation according to Vancouver (NV), adequacy between number of citations, periodical publications and books regarding the guide (GR). It was summarized in average, and percentage; chi2 and 95% CI, p <0.05. RESULTS: n: 107 forms. In spelling, SL, syntax and vocabulary, a favorable difference was evidenced with the c10. Average citations in c10: 25.74, in c13: 28.61, p <0.05. 27% and 72.7% of each cohort met the number of publications. 84.1% and 90.9% of each cohort complied with the books. 15.9% and 25% complied withthe presentation according to NV. CONCLUSIONS: We observed worsening in c13, due to a decrease in the follow-up of the GR.

Oportunidades ganadas en vacunación de los adultos. Implementación de una estrategia combinada para superar barreras / Gained opportunities in adult vaccination. Performing a combined strategy to overcome barriers

El Programa Nacional de Inmunizaciones en Argentina es-tablece la administración universal y obligatoria de las vacunas doble adultos (dT) y hepatitis B (HB) y las vacunas antigripal y antineumocó-cica para poblaciones especiales y mayores de 65 años. Son gratuitas y, excepto las vacunas antigripal y antineumocócica en personas en-tre 2-64 años, no requieren prescripción para su administración. Sin embargo, las tasas de vacunación en los adultos son bajas. Mejorar las coberturas vacunales en adultos es un desafío. Realizamos un estu-dio prospectivo de corte transversal para evaluar la implementación de una estrategia de vacunación combinada para aumentar la vacunación de los adultos de una institución. Esta se basó en el requerimiento obli-gatorio de dT en las cirugías programadas junto con el consejo médico en el vacunatorio y el acceso inmediato a la vacunación. Como resulta-do de esta estrategia se administraron 2.946 dosis extra que represen-tan un aumento de 312 % sobre las dosis sin intervención. Esta estrate-gia simple podría ser replicada fácilmente en otros centros

The National Immunization Program in Argentina recom-mends tetanus and diphtheria vaccine [Td] and hepatitis B for all healthy adults and influenza and pneumococcal vaccines for special populations. Despite the fact that these vaccines are free and without requirement for prescription, rates of vaccination remain low in adults.Improving vaccina-tion coverage among adults remains a major challenge. We performed a prospective cross-sectional study to assess a combined vaccination strat-egy in order to enhance compliance in a single institution. It was based on institutional requirement of Td vaccine for all elective surgery plus med-ical counseling provided by a trained physician at the Vaccination Room and immediate access to vaccination. As a result of this strategy, 2946 extra doses of vaccines were given. These doses represent an increase of 312% from the doses estimated without our intervention. This simple strategy may be easily replicated in other centers

Human rotavirus vaccine is highly efficacious when coadministered with routine expanded program of immunization vaccines including oral poliovirus vaccine in Latin America.

BACKGROUND: The efficacy of a rotavirus vaccine against severe rotavirus gastroenteritis when coadministered with routine Expanded Program on Immunization (EPI) vaccines including oral polio vaccine (OPV) was evaluated in this study. METHODS: Double-blind, randomized (2:1), placebo-controlled study conducted across 6 Latin American countries. Healthy infants (N = 6568) 6 to 12 weeks of age received 2 doses of RIX4414 vaccine or placebo following a 0, 1- to 2-month schedule. Routine vaccines including OPV were coadministered according to local EPI schedule. Vaccine efficacy (VE) against severe rotavirus gastroenteritis caused by circulating wild-type rotavirus from 2 weeks post-Dose 2 until 1 year of age was calculated with 95% confidence interval [CI]. Safety was assessed during the entire study period. Immunogenicity of RIX4414 and OPV was also assessed. RESULTS: During the efficacy follow-up period (mean duration = 7.4 months), 7 and 19 cases of severe rotavirus gastroenteritis were reported in the vaccine and placebo groups, respectively, with a VE of 81.6% (95% CI: 54.4-93.5). VE against severe rotavirus gastroenteritis caused by G1 type was 100% (95% CI: <0-100) and 80.6% (95% CI: 51.4-93.2) against the pooled non-G1 rotavirus types, respectively. There was no difference (P = 0.514) in the incidence of serious adverse events reported in the 2 groups. Antirotavirus IgA seropositivity rate at 1 to 2 months post-Dose 2 was 61.4% (95% CI: 53.7-68.6) in the RIX4414 group; similar seroprotection rates (≥96.0%) against the 3 antipoliovirus types was observed 1 month post-Dose 3 of OPV in both groups. CONCLUSION: RIX4414 was highly efficacious against severe rotavirus gastroenteritis caused by the circulating wild-type rotavirus (G1 and non-G1) when coadministered with routine EPI vaccines including OPV.

Hearing impairment in childhood bacterial meningitis is little relieved by dexamethasone or glycerol.

OBJECTIVE: Several studies have evaluated dexamethasone for prevention of hearing loss in childhood bacterial meningitis, but results have varied. We compared dexamethasone and/or glycerol recipients with placebo recipients, and measured hearing at 3 threshold levels. METHODS: Children aged 2 months to 16 years with meningitis were treated with ceftriaxone but were double-blindly randomly assigned to receive adjuvant dexamethasone intravenously, glycerol orally, both agents, or neither agent. We used the Glasgow coma scale to grade the presenting status. The end points were the better ear's ability to detect sounds of >40 dB, >or=60 dB, and >or=80 dB, with these thresholds indicating any, moderate-to-severe, or severe impairment, respectively. All tests were interpreted by an external audiologist. Influence of covariates in the treatment groups was examined by binary logistic regression. RESULTS: Of the 383 children, mostly with meningitis caused by Haemophilus influenzae type b or Streptococcus pneumoniae, 101 received dexamethasone, 95 received dexamethasone and glycerol, 92 received glycerol, and 95 received placebo. Only the presenting condition and young age predicted impairment independently through all threshold levels. Each lowering point in the Glasgow scale increased the risk by 15% to 21% (odds ratio: 1.20, 1.21, and 1.15 [95% confidence interval: 1.06-1.35, 1.07-1.37, and 1.01-1.31]; P = .005, .003, and .039) for any, moderate-to-severe, or severe impairment, respectively. Each increasing month of age decreased the risk by 2% to 6% (P = .0001, .0007, and .041, respectively). Neither dexamethasone nor glycerol prevented hearing loss at these levels regardless of the causative agent or timing of antimicrobial agent. CONCLUSIONS: With bacterial meningitis, the child's presenting status and young age are the most important predictors of hearing impairment. Little relief is obtained from current adjuvant medications.

Safety and pharmacokinetics of urtoxazumab, a humanized monoclonal antibody, against Shiga-like toxin 2 in healthy adults and in pediatric patients infected with Shiga-like toxin-producing Escherichia coli.

Shiga-like toxin-producing Escherichia coli (STEC) infection causes diarrhea, which is often bloody and which can result in potentially life-threatening hemolytic-uremic syndrome (HUS). Urtoxazumab, a humanized monoclonal antibody directed against the Shiga-like toxin 2 (Stx2) produced by STEC, has been developed as a promising agent for the prevention of HUS. Single randomized, intravenous, double-blind, placebo-controlled doses of urtoxazumab were administered to assess its safety and pharmacokinetics in healthy adults (0.1 to 3.0 mg/kg of body weight) and STEC-infected pediatric patients (1.0 and 3.0 mg/kg). No dose-related safety trends were noted, nor were antiurtoxazumab antibodies detected. The disposition of urtoxazumab showed a biexponential decline, regardless of the dose. In healthy adults, the mean terminal elimination half-life was consistent across the dose groups and ranged from 24.6 days (3.0-mg/kg dose group) to 28.9 days (0.3-mg/kg dose group). The mean maximum serum drug concentration (C(max)) ranged from 2.6 microg/ml at 0.1 mg/kg to 71.7 microg/ml at 3.0 mg/kg. The disposition of urtoxazumab following the administration of doses of 1.0 and 3.0 mg/kg in pediatric patients showed mean C(max)s of 19.6 and 56.1 microg/ml, respectively. Urtoxazumab was well tolerated, appears to be safe at doses of up to 3.0 mg/kg, and is a potential candidate for the prevention of HUS in pediatric patients.

Análisis de mutaciones primarias asociadas a resistencia a los antirretrovirales en niños con diagnóstico reciente de HIV-1 / Analysis of antiretroviral resistance-associated primary mutations in recently HIV-1 diagnosed children

El objetivo de este estudio fue analizar prospectivamente los niveles de resistencia a las drogas antirretrovirales y el progreso de la carga viral plasmática (CV) en niños infectados verticalmente por HIV-1 antes y durante el tratamiento antirretroviral (TARV).

The aim of this study was to prospectively analyze antiretroviral drug resistance and plasma viral load in HIV-1 vertically-infected children beforme and during antiretroviral therapy (ART).

Análisis de mutaciones primarias asociadas a resistencia a los antirretrovirales en niños con diagnóstico reciente de HIV-1 / Analysis of antiretroviral resistance-associated primary mutations in recently HIV-1 diagnosed children

El objetivo de este estudio fue analizar prospectivamente los niveles de resistencia a las drogas antirretrovirales y el progreso de la carga viral plasmática (CV) en niños infectados verticalmente por HIV-1 antes y durante el tratamiento antirretroviral (TARV).(AU)

The aim of this study was to prospectively analyze antiretroviral drug resistance and plasma viral load in HIV-1 vertically-infected children beforme and during antiretroviral therapy (ART).(AU)

Influence of admission findings on death and neurological outcome from childhood bacterial meningitis.

A post hoc analysis of 654 children with bacterial meningitis showed that the level of consciousness is the most important predictor of death and/or neurological sequelae, more than is etiology per se. This finding emphasizes the need of including a measurement of the presenting status in all studies examining treatment efficacy.

[Argentine Consensus of Congenital Toxoplasmosis]. / Consenso Argentino de Toxoplasmosis Congénita.

The mother-to-child transmission in Toxoplasma gondii infection occurs only when the infection is acquired for the first time during pregnancy. The prenatal and early postnatal diagnosis can only be achieved by serological testing. Serologic tests have different sensitivities, specificities and complexities, so that different tests in more than one blood sample are necessary for the diagnosis. Serological follow-up of the infants should be conducted during the first year of life or until the diagnosis of congenital toxoplasmosis can be ruled out. Treatment recommendations try to reduce the transmission rate and the risk of congenital damage. Congenital toxoplasmosis incidence rate is approximately 5 per 1000 births, but can be reduced to 0.5 per 1000 with an active screening program. The aim of this consensus group was to review the scientific literature on congenital toxoplasmosis and prepare a statement on prevention, diagnosis and treatment that should be implemented in our country.

Consenso argentino de toxoplasmosis congénita / Argentine Consensus of Congenital Toxoplasmosis

La transmisión de la infección por Toxoplasma gondii de la madre al hijo ocurre cuando la madre se infecta por primera vez en el transcurso del embarazo. Tanto el diagnóstico prenatal, como el del primer año de vida se basa en pruebas serológicas; y la mayoría de las veces es necesario realizar más de una de estas pruebas ya que tienen distintos porcentajes de sensibilidad y/o especificidad así como distintos niveles de complejidad. El recién nacido requiere seguimiento serológico en el primer año de vida o hasta que se descarte el diagnóstico de toxoplasmosis congénita. El diagnóstico temprano de la infección, en la mujer embarazada, permite un tratamiento oportuno y se indica con el propósito de reducir la tasa de transmisión y el daño congénito. Es posible que con un programa activo, de prevención y tratamiento temprano, se pueda reducir la tasa de incidencia de la toxoplasmosis congénita de alrededor del 5 por mil nacimientos a 0.5 por mil. El objetivo de este consenso fue revisar la literatura científica para la prevención, el diagnóstico y el tratamiento de la toxoplasmosis congénita, para que se pueda implementar en nuestro país.

The mother-to-child transmission in Toxoplasma gondii infection occurs only when the infection is acquired for the first time during pregnancy. The prenatal and early postnatal diagnosis can only be achieved by serological testing. Serologic tests have different sensitivities, specificities and complexities, so that different tests in more than one blood sample are necessary for the diagnosis. Serological follow-up of the infants should be conducted during the first year of life or until the diagnosis of congenital toxoplasmosis can be ruled out. Treatment recommendations try to reduce the transmission rate and the risk of congenital damage. Congenital toxoplasmosis incidence rate is approximately 5 per 1000 births, but can be reduced to 0.5 per 1000 with an active screening program. The aim of this consensus group was to review the scientific literature on congenital toxoplasmosis and prepare a statement on prevention, diagnosis and treatment that should be implemented in our country.

Measles virus-specific antibody levels in individuals in Argentina who received a one-dose vaccine.

In spite of active measles virus (MV) vaccination strategies, reemergence continues to occur, impairing global eradication programs. The immune status against measles was evaluated in 350 vaccinated healthy Argentine children and teenagers who received a single dose of the MV Schwarz strain Lirugen vaccine (Aventis Pasteur). Sera were assessed for immunoglobulin G (IgG) antibodies by a commercial enzyme immunoassay (EIA) (Enzygnost; Behring), an in-house EIA, and neutralization EIA. Results obtained with these methods showed a marked decline in IgG level with increasing age. At 1 to 4 years of age, 84% of children had IgG antibodies above 200 mIU/ml, conventionally accepted as protective levels, whereas only 32% of older children and teenagers had antibody levels exceeding 200 mIU/ml. Moreover, the MV IgG content in the teenage group was significantly lower than the IgG antibody level of the group of younger children (P < 0.0001). In contrast, screening for IgG antibody levels to inactivated tetanus vaccine showed that, on average, 80% of this population was fully protected and that this high level of protection remained through the teenage years. This study suggests that within this population a considerable proportion of individuals had low measles antibody levels that may be insufficient to protect against reinfections or clinical disease.

Vacunación en huéspedes inmunocomprometidos / Vaccine in immunocompromiced host

Los lactantes, niños y adolescentes con inmunodeficiencia primaria o secundaria constituyen una población creciente. La adecuada utilización de las vacunas incluídas en el Calendario Nacional y otras son una valiosa herramienta para la calidad de vida. Debe considerarse simultáneamente la vacunación de los convivientes. La indicación de la vacuna es personalizada. Se revisan las indicaciones en los pacientes con tratamiento prolongado con corticoides; inmundeficiencia primaria (humoral, celular/combinada); inmunodeficiencia secundaria (cáncer, transplante médula ósea/órganos sólidos.)

Vacunación en huéspedes inmunocomprometidos / Vaccine in immunocompromiced host

Los lactantes, niños y adolescentes con inmunodeficiencia primaria o secundaria constituyen una población creciente. La adecuada utilización de las vacunas incluídas en el Calendario Nacional y otras son una valiosa herramienta para la calidad de vida. Debe considerarse simultáneamente la vacunación de los convivientes. La indicación de la vacuna es personalizada. Se revisan las indicaciones en los pacientes con tratamiento prolongado con corticoides; inmundeficiencia primaria (humoral, celular/combinada); inmunodeficiencia secundaria (cáncer, transplante médula ósea/órganos sólidos.)