Thinking about development of multi-channel surveillance and multi-dimensional early warning system of emerging respiratory communicable diseases / 中华流行病学杂志

The world has paid a heavy price for the pandemic of the emerging respiratory communicable disease, so more concern about communicable disease surveillance and early warning has been aroused. This paper briefly reviews the establishment of the surveillance and early warning system of respiratory communicable diseases in China, discusses its future development and introduces the novel surveillance methods and early warning models for the purpose of establishment of a multi-channel surveillance and multi-dimensional early warning system of communicable diseases in the future and the improvement of the prevention and control of emerging respiratory communicable diseases in China.

Global Epidemic of Ebola Virus Disease and the Importation Risk into China: An Assessment Based on the Risk Matrix Method / 生物医学与环境科学（英文）

OBJECTIVE@#To analyze the global epidemic status of the Ebola virus disease (EVD) and assess the importation risk into China.@*METHODS@#Data from World Health Organization reports were used. We described the global epidemic status of EVD from 1976-2021, and assessed and ranked the importation risk of EVD from the disease-outbreaking countries into China using the risk matrix and Borda count methods, respectively.@*RESULTS@#From 1976-2021, EVD mainly occurred in western and central Africa, with the highest cumulative number of cases (14,124 cases) in Sierra Leone, and the highest cumulative fatality rate (85%) in the Congo. Outbreaks of EVD have occurred in the Democratic Republic of the Congo and Guinea since 2018. The importation risk into China varies across countries with outbreaks of disease. The Democratic Republic of the Congo had an extremely high risk (23 Borda points), followed by Guinea and Liberia. Countries with a moderate importation risk were Nigeria, Uganda, Congo, Sierra Leone, Mali, and Gabon, while countries with a low importation risk included Sudan, Senegal, and Co

Host protection against Omicron BA.2.2 sublineages by prior vaccination in spring 2022 COVID-19 outbreak in Shanghai / 医学前沿

The Omicron family of SARS-CoV-2 variants are currently driving the COVID-19 pandemic. Here we analyzed the clinical laboratory test results of 9911 Omicron BA.2.2 sublineages-infected symptomatic patients without earlier infection histories during a SARS-CoV-2 outbreak in Shanghai in spring 2022. Compared to an earlier patient cohort infected by SARS-CoV-2 prototype strains in 2020, BA.2.2 infection led to distinct fluctuations of pathophysiological markers in the peripheral blood. In particular, severe/critical cases of COVID-19 post BA.2.2 infection were associated with less pro-inflammatory macrophage activation and stronger interferon alpha response in the bronchoalveolar microenvironment. Importantly, the abnormal biomarkers were significantly subdued in individuals who had been immunized by 2 or 3 doses of SARS-CoV-2 prototype-inactivated vaccines, supporting the estimation of an overall 96.02% of protection rate against severe/critical disease in the 4854 cases in our BA.2.2 patient cohort with traceable vaccination records. Furthermore, even though age was a critical risk factor of the severity of COVID-19 post BA.2.2 infection, vaccination-elicited protection against severe/critical COVID-19 reached 90.15% in patients aged ≽ 60 years old. Together, our study delineates the pathophysiological features of Omicron BA.2.2 sublineages and demonstrates significant protection conferred by prior prototype-based inactivated vaccines.

Guideline for the investigation of viral hepatitis A outbreak (version 2021) / 中华预防医学杂志

In China, the incidence rate of Hepatitis A has decreased from 56/100 000 in 1991 to 1.05/100 000 in 2020. The number of Hepatitis A outbreaks in China has decreased significantly, however, it has also happened in the last 5 years, and the risk still remains. In order to strengthen the technical guidance for the investigation and control of Hepatitis A outbreak, the Chinese Center for Disease Control and Prevention (China CDC) organized experts in related fields to compile this guideline. The main contents included outbreak definition, outbreak detecting and reporting, outbreak investigation and response, making conclusion and communication. This guideline is intended for use by staff at public health administrative departments, medical and health institutions, centers for disease control and prevention, health supervision agencies at different levels, and other relevant institutions, units and individuals. China CDC will update this guideline periodically based on the progress in this field and feedbacks during the implementation of this guideline.

Strategy and measures in response to highly uncertain emerging infectious disease / 中华流行病学杂志

The incidence and spread of emerging infectious diseases are highly uncertain. This paper summarizes the uncertainty and complexity of emerging infectious disease, and suggests that for the response to the varied emerging infectious diseases in the future, it is still necessary for human to take the strategy of constantly strengthening the prevention and control capability and improving various preparedness protocols. For the better response to emerging infectious diseases and protection of people's health and life, the following measures can be taken, paying more attention to the layout of the infectious disease surveillance network, establishing and maintaining the laboratory surveillance network of infectious diseases, establishing and improving a "wartime-peacetime" transition mechanism or system of medical treatment and response, developing and improving the prevention and control plan for emerging infectious diseases, strengthening the training and rehearsal of emerging infectious disease treatment and response, establishing and improving the system for the grading, classification and stockpile of medical supplies for public health emergency response and establishing and maintaining the system of early warning of emerging infectious diseases and technical platform regulations.

Progress in the practice of surveillance and early warning of infectious diseases in major countries and regions / 中华流行病学杂志

The COVID-19 pandemic is yet another reminder that the threat of infectious disease has never really gone away. As the cornerstone of preventing and controlling infectious diseases, effective surveillance and early warning are of great significance in understanding the outbreak and epidemic of specific infectious diseases and putting forward effective prevention and control measures. Therefore, we must continue strengthening the construction of infectious disease surveillance and early warning system. We reviewed the surveillance and early warning practices of infectious diseases in major countries and regions, then discussed the development direction in the field of surveillance and early warning of infectious diseases to provide the reference for strengthening the construction and capacity of infectious disease surveillance and early warning system in China.

Advance on research and application of laboratory pathogen monitoring and early warning technology of bacterial infectious diseases / 中华预防医学杂志

Human beings are still facing the public health challenges from bacterial infectious diseases. Carrying out systematic infectious disease monitoring and early warning is the most direct solution to prevent and control infectious diseases. Etiology is an important part of infectious disease monitoring and early warning. Effective pathogen monitoring can identify pathogens, outbreaks and sources at the first time. In this study, we have reviewed the research and application of etiology monitoring and early warning technology of bacterial infectious diseases and summarized the importance and application scenarios of etiology in infectious disease monitoring and early warning, as well as the research progress of etiology monitoring and early warning technology. Based on the work of existing laboratory monitoring networks, such as Chinese Pathogen Identification Network, the development trend and prospect of infectious disease laboratory network monitoring are put forward to provide a reference for establishing and perfecting the infectious disease monitoring and early warning system.

Application and reflection of laboratory-based monitoring in early warning of infectious diseases / 中华预防医学杂志

Despite the fact that our cognition towards infectious disease prevention, the advanced technology and the economic status of the whole society has made a great progress in the last decade, the outbreak of COVID-19 pneumonia has again enabled the public to acquire more about super-challenges of infectious diseases, epidemics and the relevant preventive measurements. In order to identify the epidemic signals in early stage or even before the onset of epidemic, the data research and utilization of a series of factors related to the occurrence and transmission of infectious diseases have played a significant role in research of prevention and control during the whole period of surveillance and early warning. Laboratory-based monitoring for the etiology has always been an important part of infectious disease warning system due to pathogens as the direct cause of such diseases. China has initially established a laboratory-based monitoring and early warning system for bacterial infectious diseases based on the Chinese Pathogen Identification Network with an aim to identify pathogens, outbreaks and sources. This network has played an essential role in early detection, tracking and precise prevention and control of bacterial infectious diseases, such as plague, cholera, and epidemic cerebrospinal meningitis. This issue focuses on the function of laboratory-based monitoring during the period of early warning, prevention, and control of bacterial infectious diseases, and conducted a wide range of researches based on the analysis of the epidemic and outbreak isolates, together with field epidemiological studies and normal monitoring systems. All of these could illustrate the effect of laboratory surveillance in the infectious disease risk assessment and epidemic investigation. At the same time, we have put forward our review and expectation of scenarios about laboratory-based monitoring and early warning technologies to provide innovative thoughts for promoting a leapfrog development of infectious disease monitoring and early warning system in China.

Prevenção e controle da febre amarela: avaliação de ações de vigilância em área indene no Brasil / Yellow fever prevention and control: assessment of surveillance activities in a previously unaffected area in Brazil / Prevención y control de la fiebre amarilla: evaluación de acciones de vigilancia en un área indemne de Brasil

A partir da reemergência da febre amarela em 2014/2015, o Brasil registrou nos anos sequentes sua maior epidemia de febre amarela das últimas décadas, atingindo principalmente a região sudeste. A febre amarela, doença viral hemorrágica, é causada por um flavivírus, transmitido por mosquitos silvestres (Haemagogus; Sabethes). Na ocorrência do ciclo urbano, erradicado no Brasil desde 1942, a transmissão se dá pelo Aedes aegypti. Primatas não humanos são os principais hospedeiros do vírus e constituem "sentinelas" na vigilância da febre amarela. Este artigo descreve as ações de controle e prevenção desencadeadas durante a epidemia de febre amarela no Estado do Espírito Santo, Brasil, e a implementação da vacinação por meio de um estudo ecológico com abordagem espacial. O estudo evidenciou a falha na detecção de epizootias em primatas não humanos pelos serviços de vigilância do Espírito Santo, sendo simultânea à detecção em humanos. Apresentou a evolução das ações de vacinação, com alcance de 85% de cobertura vacinal geral para o estado em seis meses, sendo heterogênea entre os municípios (de 59% a 122%). Destaca-se que 55% dos municípios com ações de imunização em tempo oportuno, considerando o intervalo adotado para este estudo, não apresentaram casos em humanos. A intensificação das ações de vigilância, interlocução entre as áreas e equipes multidisciplinares na condução da epidemia otimizou a detecção e o diagnóstico dos casos em humanos e viabilizou o controle da epidemia. Foi possível reconhecer avanços, apontar algumas medidas tardias e lacunas na vigilância que necessitam melhorias.

Following the reemergence of yellow fever in 2014/2015, Brazil recorded its largest yellow fever epidemic in recent decades, mainly affecting the country's Southeast region. Yellow fever is a hemorrhagic viral disease caused by a flavivirus transmitted by sylvatic mosquitos (Haemagogus; Sabethes). In the urban cycle, eradicated in Brazil since 1942, the virus is transmitted by Aedes aegypti. Nonhuman primates are the principal hosts of the virus and constitute "sentinels" in yellow fever surveillance. This article describes the control and prevention activities launched during the yellow fever epidemic in the State of Espírito Santo, Brazil, and the implementation of vaccination, through an ecological study with a spatial approach. The study revealed the lack of detection of epizootics in nonhuman primates by surveillance services in Espírito Santo, with simultaneous detection in humans. The study presented the evolution of vaccination activities, reaching 85% overall coverage for the state in six months, varying widely, from 59% to 122%, between municipalities (counties). Importantly, 55% of the municipalities with timely immunization, considering the interval adopted for this study, did not present human cases. The intensification of surveillance activities, communication between areas, and multidisciplinary teams in managing the epidemic optimized the detection and diagnosis of human cases and allowed control of the epidemic. The study identifies progress and points to some late measures and gaps in surveillance that require improvements.

A partir del resurgimiento de la fiebre amarilla en 2014/2015, Brasil registró los años siguientes su mayor epidemia de fiebre amarilla de las últimas décadas, alcanzando principalmente la región sudeste. La fiebre amarilla, enfermedad viral hemorrágica, es causada por un flavivirus, transmitido por mosquitos silvestres (Haemagogus; Sabethes). Respecto a la ocurrencia del ciclo urbano, erradicado en Brasil desde 1942, la transmisión se produce por el Aedes aegypti. Primates no humanos son los principales huéspedes del virus, y constituyen "centinelas" en la vigilancia de la fiebre amarilla. Este artículo describe las acciones de control y prevención desencadenadas durante la epidemia de fiebre amarilla en el Estado de Espírito Santo, Brasil, y la implementación de la vacunación mediante un estudio ecológico con abordaje espacial. El estudio evidenció el fallo en la detección de epizootias en primates no humanos por los servicios de vigilancia de Espírito Santo, siendo simultánea a la detección en humanos. Presentó la evolución de las acciones de vacunación, con alcance de un 85% de cobertura en la vacunación general para el estado en seis meses, siendo heterogénea entre los municipios (de 59% a 122%). Se destaca que un 55% de los municipios con acciones de inmunización en tiempo oportuno, considerando el intervalo adoptado para este estudio, no presentaron casos humanos. La intensificación de las acciones de vigilancia, interlocución entre las áreas y equipos multidisciplinarios en la gestión de la epidemia optimizó la detección y diagnóstico de los casos humanos y viabilizó el control de la epidemia. Fue posible reconocer avances, apuntar algunas medidas tardías y lagunas en la vigilancia que necesitan mejorías.

Vigilância epidemiológica das doenças de transmissão hídrica e alimentar: manual de treinamento / Epidemiological surveillance of water and foodborne diseases: training manual

Este Manual é um instrumento que subsidia o treinamento em vigilância epidemiológica das doenças de transmissão hídrica e alimentar (VE-DTHA), direcionado para profissionais de saúde que atuam na investigação de surtos ou de casos de doenças de notificação compulsória relacionadas à transmissão hídrica e alimentar.

Living with COVID-19: The road ahead

INTRODUCTION@#The COVID-19 pandemic has affected the world for more than a year, with multiple waves of infections resulting in morbidity, mortality and disruption to the economy and society. Response measures employed to control it have generally been effective but are unlikely to be sustainable over the long term.@*METHODS@#We examined the evidence for a vaccine-driven COVID-19 exit strategy including academic papers, governmental reports and epidemiological data, and discuss the shift from the current pandemic footing to an endemic approach similar to influenza and other respiratory infectious diseases.@*RESULTS@#A desired endemic state is characterised by a baseline prevalence of infections with a generally mild disease profile that can be sustainably managed by the healthcare system, together with the resumption of near normalcy in human activities. Such an endemic state is attainable for COVID-19 given the promising data around vaccine efficacy, although uncertainty remains around vaccine immunity escape in emergent variants of concern. Maintenance of non-pharmaceutical interventions remains crucial until high vaccination coverage is attained to avoid runaway outbreaks. It may also be worthwhile to de-escalate measures in phases, before standing down most measures for an endemic state. If a variant that substantially evades immunity emerges, it will need to be managed akin to a new disease threat, with pandemic preparedness and response plans.@*CONCLUSION@#An endemic state for COVID-19, characterised by sustainable disease control measures, is likely attainable through vaccination.

Análisis de Modelo Matemático con percepción de riesgo para la CoVid19. Resultados para Cuba / Analysis of Mathematical Model with risk perception for the CoVid19. Results for Cuba

En Epidemiología, han jugado un importante papel los Modelos Poblacionales que dividen a la población de estudio en subpoblaciones según los atributos que las distinguen, lo que permite representar la dinámica de contagio social de una determinada enfermedad, especialmente en momentos de brote epidémico. En el presente trabajo se explica cómo se representa la transmisión de enfermedades a través de modelos matemáticos definidos por ecuaciones diferenciales. En esta propuesta se formula un modelo matemático definido por ecuaciones diferenciales para representar la transmisión del SarsCov2 distinguiendo entre las poblaciones de infectados sintomáticos y asintomáticos de la CoVid19, con funciones que simulan las acciones gubernamentales e individuales ante la percepción de riesgo. También se presenta un análisis de los resultados obtenidos en Cuba(AU)

In Epidemiology, Population Models have played an important role, dividing the study population into subpopulations according to the attributes that distinguish them, allowing the dynamics of social contagion of a given disease to be represented, especially at times of epidemic outbreak. This work explains how the transmission of diseases is represented through mathematical models defined by differential equations. In this proposal, a mathematical model defined by differential equations is formulated to represent the transmission of SarsCov2, distinguishing between symptomatic and asymptomatic infected populations of CoVid19, with functions that simulate government and individual actions in the face of risk perception. An analysis of the results obtained in Cuba is also presented(AU)

Esclerosis múltiple en el contexto de la pandemia de COVID-19 / Multiple sclerosis in the context of pandemic COVID-19

En la esclerosis múltiple se pierde la tolerancia inmunológica a las vainas de mielina. Los virus pueden intervenir en su etiopatogenia. La actual pandemia de COVID-19 puede incrementar los casos y exacerbar los brotes de esclerosis múltiple(AU)

Multiple sclerosis causes the loss of immune tolerance to myelin sheaths. Viruses may be involved in its pathogenesis. The current COVID-19 pandemic may increase the number of cases and exacerbate the outbreaks of this disease(AU)

Un comentario sobre el artículo: Brotes, epidemias, eventos y otros términos epidemiológicos de uso cotidiano / A comment about the article: Brotes [outbreaks], epidemias [epidemics], eventos [events], and other Epidemiological Terms of Daily Usage

Con regocijo leí el artículo de los autores Otto Peláez y Pedro Más, publicado en el reciente número de la revista, titulado "Brotes, epidemias, eventos y otros términos epidemiológicos de uso cotidiano"1, que consideré muy oportuno para esclarecer conceptos y definiciones epidemiológicas en estos tiempos de pandemias y, particularmente, de la epidemia nacional de la COVID-19. Según la opinión de los propios autores, este artículo se elaboró por la necesidad especial de actualizar conceptos, relacionados con la vigilancia y el control epidemiológico, que están siendo utilizados por técnicos e instituciones oficiales y organismos internacionales de forma inexacta por su sinonimia.1) En ese sentido, lo califico como un documento básicamente didáctico, que deberá estimular algunos comentarios de los especialistas y los profesionales de las diferentes disciplinas que estudian los problemas de salud de...(AU)

Una consideración sobre el artículo: Brotes, epidemias, eventos y otros términos epidemiológicos de uso cotidiano / Considerations on the article: Outbreaks, epidemics, events and other epidemiological terms of frequent use

Hemos leído con sumo interés el trabajo de Peláez y Más1 publicado recientemente en su revista. A raíz de los datos expuestos en su contenido, quisiéramos, primeramente, puntualizar la importancia de tener en cuenta el marco legal de la Organización Mundial de la Salud (OMS), como lo es el Reglamento Sanitario Internacional (RSI).2 El RSI es un instrumento jurídico internacional de carácter vinculante para 194 países, entre ellos todos los Estados Miembros de la OMS. Tiene el objetivo de ayudar a la comunidad a prevenir y afrontar riesgos agudos de salud pública, susceptibles de atravesar fronteras y amenazar a poblaciones de todo el mundo. Actualmente el RSI vigente tiene el objetivo de ayudar...(AU)

Dispersion of a new coronavirus SARS-COV-2 by airlines in 2020: temporal estimates of the outbreak in Mexico

ABSTRACT Background: On January 23, 2020, China imposed a quarantine on the city of Wuhan to contain the SARS-CoV-2 outbreak. Regardless of this measure, the new infection has spread to several countries around the world. Objective: We developed a method to study the dissemination of this infection by airline routes and provide estimations of the time of arrival of the outbreak to different cities. Methods: Using the Kermack and McKendrick model complemented with diffusion on a graph composed of nodes and edges, we made an analysis of COVID-19 dispersion to other cities by air travel. Results: The estimation was accurate in that it was possible to predict in the middle of February 2020 the arrival of the first outbreak in Mexico, which eventually occurred between March 20 and 30. This estimation was robust with respect to small changes in epidemiological parameters at the other nodes. Conclusions: The estimation of the time of arrival of the outbreak from its epicenter, allows for a time period to implement and strengthen preventive measures aimed at the general population as well as to strengthen hospital infrastructure and training of human resources. In the present study, this estimation was accurate, as observed from the real data of the beginning of the outbreak in Mexico City up to April 6, 2020.

Condiciones estimadas para controlar la pandemia de COVID-19 en escenarios de pre y poscuarentena en el Perú / Estimated conditions to control the covid-19 pandemic in peruvian pre- and post-quarantine scenarios

RESUMEN Objetivos: Determinar la probabilidad de control del brote de la COVID-19 en el Perú, en un escenario pre y poscuarentena en modelos de simulaciones matemáticas. Materiales y métodos: Se realizan simu laciones de brotes para la pandemia de COVID-19, usando ecuaciones estocásticas bajo los siguientes supuestos: un R0 poblacional precuarentena de 2,7 o 3,5, y un R0 poscuarentena de 1,5, 2 o 2,7, positivos asintomáticos del 18% o 40%, y una capacidad resolutiva máxima de 50 o 150 pacientes en las unidades de cuidados intensivos. Se evalúa el éxito del aislamiento y rastreo de contactos, no se incluyen otras medidas de mitigación. Resultados: En la etapa precuarentena, el éxito en el control de más del 80% de las simulaciones se daba solo si el aislamiento de casos positivos se implantaba desde el primer caso, luego se tenía menos de un 40% de probabilidad de éxito. En la poscuarentena, con 60 casos positivos es necesario aislarlos precozmente, rastrear al 100% sus contactos y disminuir el R0 a 1,5 para que el control del brote tenga éxito en más del 80% de los casos. Otros escenarios tienen baja probabilidad de éxito. Conclusiones: El control del brote en el Perú en la etapa precuarentena demandaba requisitos de difícil cumplimiento, por ello la cuarentena era necesaria; para suspenderla con éxito se requeriría una impor tante reducción de la dinámica de propagación de la enfermedad, el aislamiento precoz de los positivos y el seguimiento de todos los contactos.

ABSTRACT Objectives: To determine the probability of controlling the outbreak of COVID-19 in Peru, in a pre- and post-quarantine scenario using mathematical simulation models. Materials and methods: Outbreak si mulations for the COVID-19 pandemic are performed, using stochastic equations under the following assumptions: a pre-quarantine population R0 of 2.7 or 3.5, a post-quarantine R0 of 1.5, 2 or 2.7, 18% or 40%, of asymptomatic positives and a maximum response capacity of 50 or 150 patients in the intensive care units. The success of isolation and contact tracing is evaluated, no other mitigation measures are included. Results: In the pre-quarantine stage, success in controlling more than 80% of the simulations occurred only if the isolation of positive cases was implemented from the first case, after which there was less than 40% probability of success. In post-quarantine, with 60 positive cases it is necessary to isolate them early, track all of their contacts and decrease the R0 to 1.5 for outbreak control to be successful in more than 80% of cases. Other scenarios have a low probability of success. Conclusions: The control of the outbreak in Peru during pre-quarantine stage demanded requirements that were difficult to comply with, therefore quarantine was necessary; to successfully suspend it would require a significant reduction in the spread of the disease, early isolation of positives and follow-up of all contacts of positive patients.

Influenza A (H1N1): outbreak management in a dialysis unit and clinical outcomes of infection in chronic hemodialysis patients / Influenza A (H1N1): controle de surto em unidade de diálise e desfechos clínicos da infecção em pacientes em hemodiálise crônica

ABSTRACT Introduction: Chronic hemodialysis (HD) patients are considered to be at high risk for infection. Here, we describe the clinical outcomes of chronic HD patients with influenza A (H1N1) infection and the strategies adopted to control an outbreak of influenza A in a dialysis unit. Methods: Among a total of 62 chronic HD patients, H1N1 infection was identified in 12 (19.4%). Of the 32 staff members, four (12.5%) were found to be infected with the H1N1 virus. Outcomes included symptoms at presentation, comorbidities, occurrence of hypoxemia, hospital admission, and clinical evaluation. Infection was confirmed by real-time reverse transcriptase polymerase chain reaction. Results: The 12 patients who had H1N1 infection did not differ significantly from the other 50 non-infected patients with respect to age, sex, dialysis vintage, dialysis modality, or proportion of comorbidities. Obesity was higher in the H1N1-infected group (41.5 vs. 4%, p<0.002). The most common symptoms were fever (92%), cough (92%), and rhinorrhea (83%). Early empirical antiviral treatment with oseltamivir was started in symptomatic patients and infection control measures, including the intensification of contact-reduction measures by the staff members, antiviral chemoprophylaxis to asymptomatic patients undergoing HD in the same shift of infected patients, and dismiss of staff members suspected of being infected, were implemented to control the spread of infection in the dialysis unit. Conclusion: The clinical course of infection with H1N1 in our patients was favorable. None of the patients developed severe disease and the strategies adopted to control the outbreak were successful.

RESUMO Introdução: Pacientes em hemodiálise (HD) crônica apresentam risco elevado para infecções. O presente estudo descreve os desfechos clínicos de pacientes em HD crônica com infecção pelo vírus influenza A (H1N1) e as estratégias adotadas para controlar um surto de influenza A numa unidade de diálise. Métodos: Doze (19,4%) de 62 pacientes em HD crônica e quatro (12,5%) de 32 funcionários desta unidade de diálise apresentaram infecção pelo vírus H1N1. Os desfechos incluíram sintomas à apresentação, comorbidades, ocorrência de hipoxemia, internação hospitalar e avaliação clínica. A presença de infecção foi confirmada por reação em cadeia da polimerase via transcriptase reversa (RT-PCR) em tempo real. Resultados: Os 12 pacientes com infecção por H1N1 não diferiram significativamente dos 50 pacientes sem infecção no tocante a idade, sexo, tempo em diálise, modalidade de diálise e percentual de comorbidades. O percentual de obesidade foi mais elevado no grupo com infecção por H1N1 (41,5% vs. 4%, p<0,002). Os sintomas mais comuns foram febre (92%), tosse (92%) e rinorreia (83%). Os pacientes foram submetidos a tratamento antiviral com oseltamivir e medidas de controle (intensificação das medidas de redução de contato pelos funcionários da clínica, quimioprofilaxia com antiviral para pacientes assintomáticos em HD na mesma sala dos pacientes com infecção e afastamento de funcionários da clínica com suspeita de infecção) para controlar a disseminação da infecção pela unidade de diálise. Conclusão: O curso clínico da infecção por H1N1 em nossos pacientes foi favorável. Nenhum evoluiu para doença grave e as estratégias adotadas foram efetivas no controle do surto.