الملخص
Resumen Se revisa brevemente el concepto de inmunidad de grupo, poblacional o efecto "rebaño", mostrando que algunas ideas popularizadas no corresponden al concepto original. Se establece la relación con los números reproductivo básico y efectivo, enfatizándose que el umbral para el efecto rebaño no indica el número de individuos que se contagiarán en una epidemia. Se establece la relación con el umbral de vacunación efectiva y su relación con la efectividad de la vacuna. Se analiza el efecto reductor del umbral de inmunidad de rebaño producido por la heterogeneidad de transmisión y mezcla en la población y la existencia de subpoblaciones aisladas lo que podría llegar a ser importante y que podría explicar los bajos niveles de seroprevalencia post-epidemia de algunos lugares, ayudando a mitigar nuevos brotes.
Abstract The concept of herd immunity is briefly reviewed, showing that some popularized ideas do not correspond to the original concept. The relationship with the basic and effective reproductive numbers is established. It is pointed out that the threshold for the herd effect does not indicate the number of individuals that will be infected in an epidemic. The relationship with the effective vaccination threshold and its relationship with the effectiveness of the vaccine are established. The reducing effect of the herd immunity threshold produced by the heterogeneity of transmission and mixing in the population and the existence of isolated subpopulations are analyzed, which could be important and could explain the low levels of post-epidemic seroprevalence in some places helping to mitigate new outbreaks.
الموضوعات
Humans , Vaccines , Communicable Diseases/immunology , Epidemics , COVID-19/immunology , Seroepidemiologic Studies , Communicable Disease Control , Vaccination , Immunity, Herd , SARS-CoV-2 , COVID-19/prevention & controlالملخص
The COVID-19 pandemic that began in early 2020 is currently the subject of thousands of articles on the various aspects of its epidemiology. One recurrent theme is the phenomenon of herd immunity or herd effect. In this article, I present a short history of the concept, the arguments around its nomenclature, and the ecologist's view of the herd effect, using the case history of the sleeping sickness control in Africa.
الموضوعات
Humans , Trypanosomiasis, African , Immunity, Herd , Ecology , COVID-19الملخص
Mutations of SARS-CoV-2 have been associated with increased transmissibility and occasionally reduced sensitivity to neutralising antibody activity induced by past ancestry virus infection or current COVID-19 vaccines. Nevertheless, COVID-19 vaccines have consistently demonstrated high efficacy and effectiveness against COVID-19 severe disease, hospitalisation and death, including disease caused by designated variants of concern. In contrast, COVID-19 vaccines are more heterogeneous in reducing the risk of infection and mild COVID19, and are modestly effective in interrupting virus transmission. Ongoing mutations of SARS-CoV-2 resulting in increased transmissibility and relative evasion of neutralising antibody activity induced by past virus infection or COVID-19 vaccines are likely. The duration of protection induced by COVID-19 vaccines is modelled to be relatively short in protecting against infection and mild COVID-19, but is likely to be 2 - 3 years against severe disease. Current experience from the UK and Israel demonstrates that even with high levels of COVID19 vaccine coverage (>85% of the adult population), resurgences with new variants of concern remain a strong probability. Nevertheless, such resurgences are not mirrored by high rates of hospitalisation and death compared with what was experienced in relatively COVID-19 vaccine-naive populations. Even though COVID-19 vaccines are unlikely to result in a herd immunity state, their ability to protect against severe COVID-19 and death could allow for a return to normalcy once a large enough proportion of the adult population in a country has been vaccinated
الموضوعات
Immunity, Herd , Vaccination Coverage , SARS-CoV-2 , COVID-19الملخص
Introducción: el camino equitativo para disponer de vacunas seguras y efectivas es primordial para poner fin a la pandemia de COVID-19, por lo que es confortante que haya tantas vacunas en prueba y en desarrollo. La OMS (Organización Mundial de la Salud) trabaja ardua con sus socios para desarrollar, fabricar y distribuir vacunas seguras y eficaces. Metodología: la presente investigación es un estudio transversal, como fuente de información se obtuvo del plan mundial de vacunación contra el COVID-19 de la página web de nuestro mundo en datos. Resultados: se estableció que al 6 de agosto 2021 los países con mayores proporciones de vacunas con esquemas completos fueron: Emiratos Árabes Unidos (72), Uruguay (66), Chile (65), Baréin (62) e Israel (62). Aquellos con mayor porcentaje de vacunación son: Argentina (39), Brasil (31), Arabia Saudita (29), Corea del Sur (25,5) y Malasia (22). Conclusión: es imperioso continuar aumentado la asignación de dosis contra SARS-COV-2 en los diferentes países del mundo y a su vez que cada uno aumente su capacidad de aplicaciones de dosis de la vacuna y de manera específica en lo relacionado con los esquemas completos, que permitan lograr a corto plazo obtener la inmunidad de rebaño a nivel mundial.
Introduction: the equitable path to safe and effective vaccines is paramount to bring the COVID-19 pandemic to an end. Thus, it is reassuring that so many vaccines are being tested and developed. The WHO (World Health Organization), together with its partners, is working hard to develop, manufacture and distribute safe and effective vaccines. Methodology: the present research is a cross-sectional study. Data was taken from the Our World in Data website, based on the global vaccination plan against COVID-19. Results: it was established that as of August 6 2021, the countries with the highest share of allocated vaccines and fully vaccinated people were: the United Arab Emirates (72), Uruguay (66), Chile (65), Bahrain (62) and Israel (62). Those with the highest percentage of applied vaccination doses were: Argentina (39), Brazil (31), Saudi Arabia (29), South Korea (25.5) and Malasya (22). Conclusion: it is imperative that both the allocation of doses of vaccines against SARS-COV-2 and the vaccine application capacity continue to be increased in all countries of the world, underlining the importance of completing the recommended vaccination protocols, in order to achieve herd immunity worldwide in the short term.
الموضوعات
Humans , Male , Female , Vaccination , SARS-CoV-2 , COVID-19 , Immunity, Herd , Pandemicsالملخص
Introducción: la humanidad enfrenta la mayor campaña de vacunación de la historia. El proceso de inmunización contra el COVID-19 que comenzó a principios de diciembre 2020 en Estados Unidos, Reino Unido, Rusia y China, está en marcha en todo el mundo y se destaca en la mayoría de los países más ricos. Objetivo: calcular el tiempo para alcanzar la inmunidad de rebaño para COVID-19 a nivel mundial, a partir de la información de vacunación de Johns Hopkins University. Metodología: la información sobre vacunación diaria a nivel mundial se obtuvo de Johns Hopkins University. Se tomó el período hasta el 30 de junio 2021. Resultados: se determinó que para el 19 de enero 2022 se logrará obtener la inmunidad de rebaño, para esta fecha se habrán aplicado 11.034.357.235 dosis para inmunizar a la población mundial. Conclusión: se infiere el significativo papel que logran los modelos matemáticos a la hora de representar los procesos de vacunación y de esta manera se trazarán en el futuro vías de investigación en la modelización matemática para lograr la inmunidad de rebaño de cualquier proceso infeccioso.
Introduction: humanity faces the greatest vaccination campaign in history. The immunization process against COVID-19, which started in early December 2020 in the United States, United Kingdom, Russia and China, is underway worldwide and is emphasized in most of the wealthiest countries. Objective: to estimate the time to reach global herd immunity against COVID-19, relying on the vaccination data released by Johns Hopkins University. Methodology: global daily vaccination data was obtained from Johns Hopkins University. The period as to June 30 2021 was reviewed. Results: it was determined that herd immunity will be achieved by January 19 2022. As of this date 11.034.357.235 doses will have been administered to immunize the world Ìs population. Conclusion: from this research we infer the significant role that mathematical models play when simulating vaccination processes, thus, future research avenues based on mathematical modeling to achieve herd immunity for any infectious process, will be designed.
الموضوعات
Vaccination , SARS-CoV-2 , Immunity, Herd , Mathematicsالملخص
Resumen Introducción: Los casos de sarampión están resurgiendo en muchos países del mundo. Hubo un brote de sarampión importado entre noviembre de 2018 y febrero de 2019 en Chile, lo que generó preocupación entre el público y las autoridades sanitarias. Muchos se preocuparon por la tasa de inmunización contra el sarampión de la población, un factor que se relaciona con la capacidad reproductiva del virus (medida de transmisibilidad de un patógeno). Objetivo: Aquí estimamos el número reproductivo efectivo (Re) de este brote de sarampión. Resultados: Aunque la estimación tiene mucha incertidumbre por el bajo número de casos y la ausencia de mezcla homogénea de la población, encontramos que Re fue aproximadamente 1,5. Discusión y Conclusiones: En consecuencia estimamos que aproximadamente 90,3% de la población tiene inmunidad al sarampión, lo que coincide con las estimaciones del Ministerio de Salud. Estos resultados sugieren que la población chilena ha establecido la inmunidad colectiva contra la introducción de casos importados de sarampión, lo que refleja un manejo preventivo adecuado de esta enfermedad.
Abstract Background: Measles cases are reemerging in many countries across the globe. There was an outbreak of imported measles between November 2018 and February 2019 in Chile, raising concern among the public and health authorities. Many were worried about the Chilean measles herd immunity, a factor that relates to the reproductive capacity of the virus (measure of transmissibility of a pathogen). Aim: Here we estimate the effective reproductive number (Re) of this measles outbreak. Results: Although the estimate is highly uncertain due to the low number of cases and the absence of homogeneous mixing of the population, we found Re was approximately 1.5. Discussion and Conclusions: Consequently we estimated about 90,3 % had measles immunity, consistent with administrative estimates from the Ministry of Health. These results suggest the Chilean population has established herd immunity against the introduction of imported measles cases, reflecting adequate preventive management of this disease.
الموضوعات
Humans , Vaccination , Measles , Measles Vaccine , Chile , Disease Outbreaks , Immunity, Herdالملخص
ABSTRACT OBJECTIVE: To estimate the seroprevalence of SARS-CoV-2 in the state of Maranhão, Brazil. METHODS: A population-based household survey was performed, from July 27, 2020 to August 8, 2020. The estimates considered clustering, stratification and non-response. Qualitative detection of IgM and IgG antibodies was performed in a fully-automated Elecsys® Anti-SARS-CoV-2 electrochemiluminescence immunoassay on the Cobas® e601 analyzer (Roche Diagnostics). RESULTS: In total, 3,156 individuals were interviewed. Seroprevalence of total antibodies against SARS-CoV-2 was 40.4% (95%CI 35.6-45.3). Population adherence to non-pharmaceutical interventions was higher at the beginning of the pandemic than in the last month. SARS-CoV-2 infection rates were significantly lower among mask wearers and among those who maintained social and physical distancing in the last month compared to their counterparts. Among the infected, 26.0% were asymptomatic. The infection fatality rate (IFR) was 0.14%, higher for men and older adults. The IFR based on excess deaths was 0.28%. The ratio of estimated infections to reported cases was 22.2. CONCLUSIONS: To the best of our knowledge, the seroprevalence of SARS-CoV-2 estimated in this population-based survey is one of the highest reported. The local herd immunity threshold may have been reached or might be reached soon.
الموضوعات
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Aged , Young Adult , Seroepidemiologic Studies , Immunity, Herd , COVID-19/immunology , Antibodies, Viral/blood , Brazil/epidemiology , Pandemics , SARS-CoV-2 , Middle Agedالملخص
Abstract INTRODUCTION: Estimates of the number of individuals infected by severe acute respiratory syndrome coronavirus 2 are important for health planning and establishment of expectations regarding herd immunity. METHODS: Seven testing rounds of a serological survey were conducted at 1-week intervals between April 19 and May 31, 2020 in Teresina municipality. RESULTS Over the 7 weeks, serological positivity increased from 0.56% (95% confidence interval [CI]: 0.18%-1.30%) to 8.33% (95% CI: 6.61%-10.33%), representing 33-53 persons infected for each reported case. CONCLUSIONS: Serological screening may be an important tool for understanding the immunity of a population and planning community interventions.
الموضوعات
Humans , Pneumonia, Viral/epidemiology , Coronavirus Infections/epidemiology , Betacoronavirus/immunology , Pneumonia, Viral/diagnosis , Pneumonia, Viral/immunology , Brazil/epidemiology , Confidence Intervals , Seroepidemiologic Studies , Sensitivity and Specificity , Coronavirus Infections , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Immunity, Herd , False Positive Reactions , Asymptomatic Diseases/epidemiology , Pandemics , Betacoronavirusالملخص
Resumen: A pesar del enorme impacto de las vacunas en la salud de la población, estas han sido y son objeto de cuestionamientos por grupos que las consideran innecesarias o inseguras y argumentan que las personas tienen el derecho a decidir sobre si estas deben ser administradas o no. Sin embargo el uso de vacunas tiene connotaciones distintas a otras decisiones en salud, ya que no vacunar impacta no solo al individuo, sino también a la comunidad que lo rodea. El inmunizar a un alto porcentaje de la población permite limitar la circulación de los agentes infecciosos, logrando la llamada inmunidad comunitaria que protege a los no vacunados por razones médicas o porque son muy pequeños. Por esta razón muchos países han definido las vacunas como obligatorias. Como Comité Consultivo de Inmunizaciones nos parece que esta estrategia es correcta sin embargo debe ser acompañada por una política de educación de la población y personal de salud sobre los beneficios y riesgos reales de las va cunas. Así mismo es necesario introducir mejoras en el sistema de notificación de reacciones adversas a vacunas haciéndolo más accesible. Adicionalmente se debe dar respuesta oportuna a los afectados por supuestas o reales reacciones a vacunas y en los casos de eventos adversos graves efectivamente asociados a vacunas. Entregar cobertura económica y acompañamiento. Finalmente es esencial la coordinación entre los diferentes actores y comunicadores para transmitir mensajes que generen confianza y respondan a las inquietudes de la población de hoy en día.
Abstract: Although vaccines have had a tremendous impact in public health they are questioned by certain groups that consider them unnecessary or unsafe and argue in favor of the right to decide to be vacci nated or not. However vaccines must have special considerations because unlike other medical deci sions, not vaccinating has consequences not only for the individual but also for other members of the community. Immunizing a high proportion of the population limits the circulation of an infectious agent attaining what is called community or herd immunity that protects the susceptible members of the group. For this reason many countries consider vaccination mandatory as a responsibility of every citizen. This committee agrees with this view but thinks other strategies should be implemented as well, such as special educational efforts for the public and parents addressing benefits and real risks of vaccinating. Also health care professionals should be trained in vaccines. The notification system for adverse events currently available should be improved and be more accessible. Persons truly affected by adverse events due to vaccination should receive on time responses and be offered psychological and financial support. Finally all stakeholders should make coordinated efforts to work together to deliver messages that answer concerns on vaccines and bring confidence back to the public.
الموضوعات
Humans , Vaccines/administration & dosage , Vaccination/statistics & numerical data , Vaccination Refusal/psychology , Health Policy , Parents/psychology , Chile , Public Health , Health Education/methods , Vaccination/legislation & jurisprudence , Health Personnel/organization & administration , Immunity, Herd , Vaccination Refusal/legislation & jurisprudenceالملخص
Abstract Introduction: Serological surveillance (serosurveillance) provides the most direct measure of herd immunity of vaccine-preventable diseases. Little is known about the opportunities and challenges of serosurveillance experiences, particularly pertussis. Objective: To describe the process of serosurveillance for vaccine-preventable diseases with an emphasis on the experience of pertussis in the metropolitan area of Antioquia (Valle de Aburrá) in 2015 and 2016 and analyze the contributions and challenges for its sustainability. Materials and methods: We described the planning and conduction of serosurveillance of pertussis antibodies of mothers and in the umbilical cord at the time of delivery in eight hospitals based on random sampling and their capacity to advance the serosurveillance periodically. We compared the contributions and the challenges of this experience with other probabilistic and non-probabilistic programs. Results: We achieved the participation of hospitals and mothers respecting the delivery care process. We established a serum bank following ethical and technical guidelines. This program based on the random selection of hospitals and mothers has enabled the estimation of antibodies prevalence in mothers and in the umbilical cord, which has been possible given the high coverage of hospital care during childbirth at a lower cost and fewer risks than a population-based survey in conflictive areas. The main challenges for the sustainability of this program are the creation of stable jobs and access to funding and legal and methodological long-term frameworks. Conclusions: Hospital serosurveillance as described is an option to monitor the impact of vaccination on the population. Our experience could be reproduced in other regions under similar conditions if the above-mentioned challenges are solved.
Resumen Introducción. La vigilancia serológica es la forma más directa de medir la inmunidad de rebaño frente a las enfermedades prevenibles por vacunación. Poco se sabe acerca de las oportunidades y los desafíos de las experiencias de serovigilancia, en general y, específicamente, la de la tosferina. Objetivo. Describir el proceso de serovigilancia de enfermedades prevenibles por vacunación con énfasis en la experiencia en el caso de la tosferina en el área metropolitana de Antioquia (Valle de Aburrá) en el 2015 y el 2016 y analizar lo que dicha experiencia ha aportado y los desafíos que persisten para su sostenibilidad. Materiales y métodos. Se describió el proceso de planeación y el desarrollo de la serovigilancia de tosferina en el momento del parto en ocho hospitales seleccionados al azar, así como la capacidad para adelantar el programa de manera periódica. Se compararon los aportes y los desafíos en el curso de esta experiencia con los de otros programas poblacionales probabilistas e institucionales no probabilistas. Resultados. Se logró la participación de los hospitales y de las madres con pleno respeto del proceso de atención del parto, y se conformó un banco de sueros siguiendo lineamientos éticos y técnicos. El programa permitió estimar la prevalencia de anticuerpos en la madre y en el cordón umbilical, lo que se facilitó por la alta cobertura de atención hospitalaria del parto, a un menor costo y menos riesgos que los programas poblacionales en zonas conflictivas. Los principales desafíos para la sostenibilidad del programa son la estabilidad laboral del personal de salud, así como normas y una financiación de largo plazo. Conclusiones. La serovigilancia hospitalaria es una opción para monitorizar el impacto poblacional de la vacunación. Esta experiencia se podría extender a otras regiones en condiciones similares si se resuelven los retos mencionados.
الموضوعات
Female , Humans , Infant, Newborn , Pregnancy , Whooping Cough/epidemiology , Population Surveillance , Vaccine-Preventable Diseases/epidemiology , Pregnancy Complications, Infectious/immunology , Pregnancy Complications, Infectious/epidemiology , Urban Population , Bordetella pertussis/immunology , Seroepidemiologic Studies , Whooping Cough/blood , Whooping Cough/prevention & control , Sampling Studies , Models, Statistical , Colombia/epidemiology , Immunity, Herd , Vaccination Coverage , Fetal Blood/immunology , Vaccine-Preventable Diseases/blood , Vaccine-Preventable Diseases/prevention & control , Antibodies, Bacterial/bloodالملخص
PURPOSE: Neisseria meningitidis and Neisseria gonorrhoeae share between 80% and 90% of their genetic sequence. Meningococcal serogroup B vaccines based on outer membrane vesicles—such as VA-MENGOC-BC—could cross-protect against gonorrhea. The aim of this study was to analyze the incidence rates of gonorrhea and other sexually transmitted diseases with respect to the use of the VA-MENGOC-BC vaccine. MATERIALS AND METHODS: Health statistics between 1970 and 2017 were reviewed and the incidence of meningococcal disease and sexually transmitted diseases (gonorrhea, syphilis, condyloma acuminatum, hepatitis B and human immunodeficiency virus infection) were analyzed during the pre- and post-vaccination periods. Gonorrhea incidence was also analyzed by age groups. RESULTS: VA-MENGOC-BC was successfully used to control a meningococcal epidemic in Cuba. The strategy to combat the epidemic was carried out in two stages. The first one was a nationwide mass-vaccination campaign from 1989 to 1990, targeting the population at highest-risk aged 3 months to 24 years. During the second stage, begun in 1991, it was included in the Expanded Immunization Program. Gonorrhea incidence increased from 1970 to 1989. However, after the VA-MENGOC-BC massive vaccination campaign a sharp decrease of gonorrhea incidence was observed. It lasted between 1989 and 1993. A second incidence peak was detected in 1995, but it dropped again. Data clearly show a decline in the incidence of gonorrhea following massive vaccination, in contrast with other sexually transmitted diseases. Incidence rates in unvaccinated age groups also decreased, probably due to herd immunity. CONCLUSION: There is evidence that VA-MENGOC-BC could induce a moderate protection against gonorrhea.
الموضوعات
Humans , Cuba , Gonorrhea , Hepatitis B , HIV , Immunity, Herd , Immunization Programs , Incidence , Membranes , Neisseria gonorrhoeae , Neisseria meningitidis , Serogroup , Sexually Transmitted Diseases , Syphilis , Vaccination , Vaccinesالملخص
Until 1995, the incidence of symptomatic acute hepatitis A was minimal and there were no cases of national outbreak in Korea. However, there was a nationwide outbreak of hepatitis A that peaked in 2009. In 2019, a total of 10,083 cases of acute hepatitis A were reported for seven months of the year according to the Korea Center for Disease Control and Prevention. This may be attributed to the proportion of susceptible subjects in the Korean population, as about 10 years have passed since herd immunity was induced by the epidemic occurring during the late 2000s. Recent studies have shown that the rate of seropositivity for anti-hepatitis A virus antibodies (anti-HAV) is the lowest in adults in their 20s and has not changed much over the past 10 years, and seropositivity of anti-HAV in adults in their 30s has continued to decline from 69.6% in 2005 to 32.4% in 2014. Most young adults who have not yet experienced hepatitis A and are not vaccinated are vulnerable to hepatitis A infection. This year's epidemic of hepatitis A is a predictable outcome for vulnerable populations. Therefore, effective acute hepatitis A control and prevention strategies are needed, particularly for those in their 20s and 30s.
الموضوعات
Adult , Humans , Young Adult , Antibodies , Hepatitis A Antibodies , Hepatitis A , Hepatitis , Immunity, Herd , Incidence , Korea , Prevalence , Vulnerable Populationsالملخص
The importance of vaccine on public health is related to the herd protection related to the levels of vaccine coverage, which directly influences the vaccinated individuals as well as the unvaccinated community. Reaching the level of herd protection by increasing vaccine coverage is the basic strategy to eradicate related infectious diseases. Again, herd protection has played an important role in public health practices. With the increasing interests in estimating the vaccine herd protection, we however, have seen only few relevant papers including observational population-based and cluster-randomized clinical trials reported in China. We hope to discuss the study designs for evaluating the vaccine herd protection in order to generate evidence-based related research in this field.
الموضوعات
Humans , China/epidemiology , Communicable Disease Control , Communicable Diseases/immunology , Immunity, Herd/immunology , Research Design , Vaccination/trends , Vaccines/immunologyالملخص
Outbreaks of porcine reproductive and respiratory syndrome virus (PRRSV) in vaccinated sow herds from occurrence to stabilization were monitored and analyzed in terms of serology and reproductive performance. Three different conventional pig farms experienced severe reproductive failures with the introduction of a type 1 PRRSV. These farms had adopted mass vaccination of sows using a type 2 PRRSV modified live vaccine (MLV). Therefore, to control the type 1 PRRSV, an alternative vaccination program utilizing both type 1 and type 2 MLV was undertaken. Following whole herd vaccinations with both types of MLV, successful stabilization of PRRS outbreaks was identified based on serological data (no viremia and downward trends in ELISA antibody titers in both sows and suckling piglets) and recovery of reproductive performance. Additionally, through comparison of the reproductive parameters between outbreak and non-outbreak periods, it was identified that PRRSV significantly affected the farrowing rate and the number of suckling piglets per litter at all three pig farms. Comparison of reproductive parameters between periods when the different vaccination strategies were applied revealed that the number of piglets born in total and born dead per litter were significantly increased after the introduction of the type 1 PRRS MLV.
الموضوعات
Agriculture , Disease Outbreaks , Enzyme-Linked Immunosorbent Assay , Immunity, Herd , Immunity, Heterologous , Mass Vaccination , Porcine Reproductive and Respiratory Syndrome , Porcine respiratory and reproductive syndrome virus , Vaccination , Viremiaالموضوعات
Humans , Antibody-Dependent Enhancement/immunology , Immunity, Herd/immunology , Viral Vaccines/immunology , Zika Virus/immunology , Brazil/epidemiology , Disease Outbreaks , Time Factors , Zika Virus Infection/epidemiology , Zika Virus Infection/prevention & control , Zika Virus Infection/virologyالملخص
Introdução: A Doença Meningocócica (DM) é uma infecção bacteriana aguda causada pela Neisseria meningitidis. Acomete principalmente crianças menores de cinco anos, sobretudo as menores de um ano. Suas manifestações clínicas variam desde doença leve até síndrome séptica e/ou meningite. Diante da letalidade da doença, o Ministério da Saúde incluiu no calendário vacinal, no segundo semestre de 2010, a vacina adsorvida meningocócica C (conjugada). Justificativa: Considerando a recente implementação da vacina no serviço público, é necessário avaliar o impacto desta na saúde da população. Este estudo tem como objetivo descrever a ocorrência de Meningite Meningocócica do tipo C em crianças menores de cinco anos na macrorregional Sul do Estado de Santa Catarina dois anos antes (2008 e 2009) e dois anos depois (2011-2012) após a campanha vacinal contra o meningococo C, realizada no ano de 2010. Métodos: Este é um estudo observacional do tipo transversal. Resultados/Discussão: No período estudado, houve apenas cinco casos confirmados de doença meningocócica. O baixo número de casos deve-se provavelmente à ampla utilização da vacina em clínicas particulares já em anos anteriores aos estudados. Nenhuma criança morreu devido à meningite meningocócica ou meningococcemia, sendo que estudos no Brasil em períodos anteriores à vacinação mostraram letalidade em torno de 20%. Conclusão: O menor número de casos e menor mortalidade pela DM demonstram maior efetividade da Vigilância Epidemiológica e efetividade do diagnóstico precoce (AU)
Introduction: Meningococcal disease (MD) is an acute bacterial infection caused by Neisseria meningitidis. It mainly affects children under five years of age, especially children under one year. Its clinical manifestations range from mild disease to septic syndrome and/or meningitis. Given the lethality of the disease, the Ministry of Health included the adsorbed meningococcal C vaccine (conjugated) in the vaccine calendar in the second half of 2010. Justification: Considering the recent implementation of the vaccine in the public service, it is necessary to evaluate its impact on the health of the population. This study aims to describe the occurrence of Meningococcal Meningitis type C in children under five years of age in the southern macro-region of the State of Santa Catarina two years before (2008-2009) and two years after (2011-2012) the vaccination campaign against meningococcus C carried out in 2010. Methods: This is an observational cross-sectional study. Results/Discussion: In the study period, there were only five confirmed cases of meningococcal disease. The low number of cases is likely due to the wide use of the vaccine in private clinics already years before those studied here. No child died due to meningococcal meningitis, and studies in Brazil prior to vaccination show lethality around 20%. Conclusion: The lower number of cases and lower mortality due to MD demonstrate greater effectiveness of the Epidemiological Surveillance and the effectiveness of early diagnosis (AU)
الموضوعات
Humans , Male , Female , Infant , Child, Preschool , Meningococcal Vaccines/immunology , Neisseria meningitidis, Serogroup C/immunology , Meningococcal Infections/prevention & control , Meningococcal Infections/epidemiology , Brazil/epidemiology , Cross-Sectional Studies , Treatment Outcome , Vaccines, Conjugate , Immunization Programs , Immunity, Herdالملخص
The epidemiology of human group A rotavirus was analyzed by examining genotypic data acquired from 1989 to 2009 in South Korea. This information was derived from all the available published articles on rotavirus studies in South Korea, retrieved from both the PubMed and KoreaMed databases. Four common G types (G1, G2, G3, and G4) and three common P types (P[8], P[4], and P[6]) accounted for approximately 93% and 99% of the rotavirus reports, respectively. The G9 type was frequently detected after 2000, and because of this prevalence, it is considered to be the fifth most important G type rotavirus after the G1.G4 genotypes. Less common G types of the virus such as G12, G11, and G10 were detected in some geographic settings, and it is important to consider the context of these subtypes and their epidemiological significance. The P[9] virus genotype was observed in the study and has been discussed in many other studies; however, the P[3], P[10] and P[25] genotypes were rarely detected in the epidemiological research. In general, the distributions of the G and P genotypes showed temporal and geographical fluctuations, and a nationwide rotavirus vaccine program that targeted these genotypes demonstrated effectiveness in protecting against the circulating rotavirus strains. However, further analysis is needed to determine the true long-term effectiveness of these vaccines; the analysis should also consider the unexpected effects of vaccinations, such as vaccine-induced diseases, herd immunity, and changes in host susceptibilities.
الموضوعات
Humans , Epidemiology , Genotype , Immunity, Herd , Prevalence , Republic of Korea , Rotavirus , Vaccination , Vaccines , Virusesالملخص
Objetivo. Calcular la proporción crítica (Pc) para el logro de la inmunidad colectiva a partir de un estudio poblacional realizado en el 2009 en Medellín, Colombia, por edad, en forma global y desagregada por sexo, zona de procedencia y estrato socioeconómico. Métodos. Se realizó una encuesta de seroprevalencia poblacional, con una muestra aleatoria de 2 124 individuos de 6 a 64 años, representativa por edad, sexo y zona. Se estimó el número básico de reproducción utilizando una regresión cuadrática de los títulos promedio de IgG contra la rubéola por edad en los individuos no vacunados con títulos mayores o iguales a 15 UI/ml. Se calculó el número efectivo de reproducción (Re ) con los datos de la proporción ponderada de protección por edad, sexo, zona y estrato socioeconómico. Resultados. En forma global, la Pc fue de 90,0% (IC95% 88,695,2) y el Re de 0,95 (IC95% 0,81,8), para una proporción ponderada de protección de 89,4% (IC95% 86,891,6). La protección fue menor que la Pc esperada en ambos sexos, en los estratos socioeconómicos alto y bajo, y en la zona rural. En la zona urbana la protección fue mayor que la Pc (89,4%, IC95% 86,691,7 en comparación con 87,4%, IC95% 85,287,8). Conclusiones. En la zona urbana se ha avanzado hacia la inmunidad colectiva, pero se requiere aumentar la proporción de protección en forma global, en las mujeres, en la zona rural y en los individuos de estrato socioeconómico alto. El número efectivo puede tener un valor mayor de uno, lo que indica el potencial de propagación de la enfermedad.
Objective. Calculate the critical proportion (Pc ) for achieving herd immunity based on a 2009 population study conducted in Medellin, Colombia, by age, globally and disaggregated by sex, location, and socioeconomic stratum. Methods. A survey of seroprevalence in the population was conducted by means of a random sample of 2 124 individuals aged 6 to 64 that was representative of age, sex, and location. The basic reproduction number was estimated using a quadratic regression of the average IgG titers for rubella by age in unvaccinated individuals with titers greater than or equal to 15 IU/ml. The effective reproduction number (Re) was calculated with the data on the weighted proportion of protection by age, sex, location, and socioeconomic stratum. Results. Overall, the Pc was 90.0% (95% CI, 88.695.2%) and the Re was 0.95 (95% CI, 0.81.8), for a weighted proportion of protection of 89.4% (95% CI, 86.8 91.6%). Protection was lower than the expected Pc in both sexes, in high and low socioeconomic strata, and in the rural area. In the urban area, protection was greater than the Pc (89.4%, with a 95% CI, 86.691.7%, compared to 87.4% and a 95% CI, 85.287.8%). Conclusions. The urban area has made progress toward herd immunity, but the overall proportion of protection in women, the rural area, and the high socioeconomic strata must be increased. The effective number may be greater than one, indicating the potential for the spread of the disease.