Accuracy of yellow fever case definition of epidemiologic surveillance, São Paulo, 2018

ABSTRACT OBJECTIVE To evaluate the accuracy of yellow fever (YF) suspected case definitions from the Brazilian Ministry of Health (BMH) and World Health Organization (WHO), as well as propose and evaluate new definitions of suspected cases, considering confirmed and discarded cases. METHODS The retrospective study was conducted at the Instituto de Infectologia Emílio Ribas (IIER), using the Epidemiologic Surveillance Form of YF cases. From the confirmed and discarded cases of YF, a logistic regression model was developed. The independent variables were used in a proposed definition of a suspected case of YF and its accuracy was evaluated. RESULTS In total, 113 YF suspect cases were reported, with 78 confirmed (69.0%). The definitions by BMH and WHO presented low sensitivity, 59% and 53.8%, and reduced accuracy, 53.1% and 47.8%, respectively. Predictive factors for YF were thrombocytopenia, leukopenia, and elevation of transaminases greater than twice normal. The definition including individual with acute onset of fever, followed by elevation of ALT or AST greater than twice the reference value AND leukopenia OR thrombocytopenia presented high sensitivity (88.3%), specificity (62.9%), and the best accuracy (80.4%), as proposed in the model. CONCLUSION The YF suspected case definitions of the BMH and the WHO have low sensitivity. The inclusion of nonspecific laboratory tests increases the accuracy of YF definition.

The effects of influenza-like illness definitions on influenza surveillance in hospitalized children / 中华疾病控制杂志

Objective To evaluate clinical factors associated with laboratory-confirmed influenza infection and probe into the effects of different influenza-like illness(ILI) definitions on influenza surveillance in hospitalized children. Methods The influenza surveillance on the hospitalized children with acute respiratory infection was carried out in Soochow university affiliated children’s hospital from October 2017 to May 2018. The definition of influenza-like illness(ILI), which proposed by world health organization (WHO), the European center for disease prevention and control (ECDC) and ministry of public health of China, was analyzed to determine the area under receiver operating characteristic curve (ROC), sensibility, specificity, and the positive and negative predictive values of the ILI definition using the laboratory evidence of influenza virus infection as golden criteria. Logistic regression model was employed to explore the risk factors of the laboratory confirmed influenza infection among the hospitalized children. Results Of the enrolled 1 459 hospitalized children, 204(14.0%) were lab-confirmed influenza cases. The ECDC definition had the highest sensitivity (91.7%, 95% CI: 87.9%-95.5%) but the lowest specificity (44.6%, 95% CI: 41.9%-47.4%). The WHO definition had the lowest specificity (70.6%, 95% CI: 64.3%-76.8%). China’s definition was the most discriminant definition with relatively high sensitivity (91.2%, 95% CI: 87.3%-95.1%) and specificity (51.5%, 95% CI: 48.8%-54.3%), and its positive area under curve value (71.2%, 95% CI: 67.9%-74.5%) was the highest. Multivariate analysis model showed that the detection rate of influenza virus in children with fever (≥38 ℃) was higher than that in children without fever (OR=7.03, 95% CI:3.89-12.70). Conclusions It is suggested to adopt China’s ILI definition to get better output during influenza surveillance among hospitalized children.

Características epidemiológica de la enfermedad de Chikungunya en Guazacapán, Santa Rosa en el período de marzo a diciembre 2015

Introducción. Esta enfermedad viral aguda transmitida por mosquitos Aedes y Albopictus que se puede manifestar desde formas de molestias leves hasta severas con fiebres altas y síntomas severos que afectan el sistema musculo esquelético con duración a veces por tiempos prolongados después del ataque agudo de la virosis. Objetivos. Describir las manifestaciones clínicas agudas y características epidemiológicas de pacientes sospechosos de Chikungunya, de acuerdo al Protocolo de Vigilancia Epidemiológica del Centro Nacional de Epidemiología (PVE), que fueron atendidos en el Centro de Salud del Distrito de Guazacapán (CSG), durante marzo a diciembre del 2015. Metodología. Estudio retrospectivo descriptivo. Se utilizó SIGSA 3 (sistema gerencial de salud) del CSG y Santa Rosa, Historias Clínicas de los pacientes y fichas del PVE. Estudio descriptivo con uso de proporciones y tabla de contingencia de 2x2 para obtención de sensibilidad y especificidad. Resultados. Se diagnosticaron 40% casos de Dengue y 60% de Chikungunya. Por Nexo epidemiológico (caso que cumple con los criterios de la definición clínica de caso y que está epidemiológicamente ligado en forma directa a un caso confirmado por laboratorio) 88% y 12% por pruebas confirmatorias para Chikungunya. Conclusión. La definición de caso establecida por el PVE tiene baja sensibilidad y una especificidad adecuada para el diagnóstico de la enfermedad de Chikungunya. La mayoría de diagnósticos de Chikungunya se hacen por Nexo Epidemiológico, los únicos con prueba confirmatoria son con fines de vigilancia epidemiológica. La fiebre está presente en todos los pacientes con Chikungunya. La Enfermedad de Chikungunya es más frecuente en mujeres dentro de la tercera década de la vida y está presente durante todo el año, en varios sectores y varía poco entre las semanas epidemiológicas. Palabras clave: Chikungunya, Ficha epidemiológica, Definición de caso, Diagnóstico, Nexo epidemiológico

Introduction: This acute viral disease transmitted by Aedes and Albopictus mosquitoes can manifest from forms of mild to severe discomfort with high fevers and severe symptoms that affect the skeletal muscle system with a prolonged duration of time after the acute attack. Objective: To describe the acute clinical and epidemiological characteristics of patients suspected of Chikungunya, according to the Protocol of Epidemiological Surveillance of the National Epidemiology Center. Subjects treated at the Health Center District of Guazacapán from March to December 2015. Methodology: Retrospective, descriptive. It was used the SIGSA 3 of CSG and Santa Rosa, Medical Records and Epidemiological Surveillance Protocol. Descriptive study using proportions and 2x2 contingency table for obtaining sensitivity and specificity. Results: 40% Dengue and 60%Chikungunya. 88% was diagnosed epidemiologically linked and 12% for confirmatory tests for Chikungunya. Sensitivity and specificity of clinical conditions as Surveillance Protocol for diagnosis of Chikungunya: 55.33% and 92% respectively. Common symptoms: fever 100%, cutaneous manifestations 83%, arthralgia 74%, myalgia 67% and back pain 59%. Most frequent age range: 30-39 years. Gender 1.1: 1 F: M. Frequently epidemiological weeks 13 and 18. Residencies predisposition: La Poza de agua, El Astillero, San Pedro y Platanares. Conclusion: The case definition established by the Epidemiological Surveillance Protocol of the National Epidemiological Center of Guatemala has low sensitivity and adequate specificity for diagnosis of Chikungunya disease. Most Chikungunya diagnoses are made by epidemiological nexus, the confirmatory tests are done only to know the surveillance. Fever is present in all patients with Chikungunya. Chikungunya disease is more common in women in the third decade of life and is present throughout the year, in various sectors and varies by small amount between epidemiological weeks. Key Words: Chikungunya, Epidemiological record, Case definition, Diagnosis

Avaliação da validade do sistema nacional de vigilância da dengue / Assess the validity of the national system dengue surveillance

Introdução: O sistema de vigilância epidemiológica da dengue tem um papel primordial nas atividades de prevenção e controle da doença. Em 2014, o Ministério da Saúde do Brasil atualizou a definição de caso usada pela vigilância para notificação de pacientes suspeitos de dengue. Entretanto, o desempenho da nova definição de caso ainda não foi avaliado, tão pouco foi avaliado a validade do sistema nacional de informação no registro de casos de dengue. Objetivo: Avaliar a validade do registro de casos suspeitos da dengue pelo SINAN e a nova definição de caso suspeito de dengue. Metodologia: Entre 2009 e 2011, pacientes atendidos em um centro de emergência de Salvador por uma doença febril aguda (DFA) de duração ≤7 dias foram entrevistados para coleta de dados sobre a presença das manifestações clínicas usadas na definição de caso suspeito de dengue. A leucometria foi obtida dos prontuários. Amostras de sangue foram coletadas no dia do atendimento e após 14 dias, e testes de referência (ELISA-IgM, ELISA-NS1 e RT-PCR) foram usados para confirmação laboratorial da dengue. A base de dados do SINAN para 2009-2011 com o registro dos casos notificados de dengue no Distrito Sanitário para o nosso período de estudo foi obtida diretamente na coordenação de vigilancia epidemiológica da Secretaria Municipal de Saúde. A sensibilidade (SEN), a especificidade (ESP), os valores preditivos positivo e negativo (VVP e VPN) dos registros de dengue no SINAN bem como dos sintomas utilizados na definiçao de casos foram estimado. O intervalo de confiança de 95% foi utilizado para todas as análises. O projeto foi aprovado pelo CEP-CPqGM- e CONEP. Resultados: No período de 2009-2011, 3.864 pacientes com DFA foram incluídos no estudo, 997 (25,8%) foram laboratorialmente confirmados para dengue e 2.867 (74,2%)...

Introduction: The epidemiological surveillance system dengue has a key role in the prevention and control of disease. In 2014, the Ministry of Health of Brazil updated the case definition used for surveillance for reporting suspected dengue patients. However, the performance of the new case definition has not yet been rated, so little was assessed the validity of the national system of information in the registry of dengue cases. Objective: Evaluate the validity of the registration of suspected cases of dengue by SINAN and the new definition of suspect dengue fever. Methods: Between 2009 and 2011, patients from an emergency center of Salvador by an acute febrile illness (DFA) ≤7 days were interviewed to collect data on the presence of clinical manifestations used in the definition of suspect dengue fever. The white blood cell count and the result of the tourniquet test were obtained from medical records. Blood samples were collected at treatment day and after 14 days, and reference tests (ELISA-IgM ELISA-NS1 and RT-PCR) were used for laboratory confirmation of dengue. The base SINAN data for 2009-2011 with registry of reported cases of dengue in the Sanitary District for our study period was obtained directly by coordinating epidemiological surveillance of the Municipal Health. The sensitivity (SEN), specificity ( ESP), positive and negative predictive values (PPV and NPV) of dengue records in SINAN and symptoms used to define cases were estimated. The 95% confidence interval was used for all analyzes. The project was approved by CEP-CPqGM- and CONEP. Results: In the period 2009-2011, 3,864 patients with DFA were included in the study, 997 (25.8%) were laboratory confirmed dengue and 2,867 (74.2%)...

Definition and management of the close contacts with Middle East respiratory syndrome cases: reflection and lessons in 2015 Korean outbreak

Middle East respiratory syndrome (MERS) is an emerging zoonosis caused by the novel MERS corona virus isolated in 2012. Most MERS cases have been reported from Arab countries of the Middle East, including Saudi Arabia, United Arab Emirates, Qatar, and Jordan. There have been a few imported cases in many countries, but the exception is Korea, which reported 186 confirmed cases originating from one imported case in a two-month outbreak in 2015. There are many lessons to be learned from the MERS outbreak in Korea, among them, management of contacts. The definition of "close contact" used by the Korean Centers for Disease Control and Prevention (KCDC) for MERS response was not clear and not compatible with the definition of the World Health Organization. This incorrect definition allowed the KCDC make serious mistakes in contact tracing and management in the early epidemic stage of MERS. After the rapid expansion of the outbreak, the KCDC redefined a "close contact" according to the definition of the US CDC. The total number of close contacts was 16,693 in this outbreak, and they were all forced to conduct a self-quarantine for 14 days after the last contact with a MERS patient. It was not clear whether self-quarantine of close contacts was effective to control the outbreak. Given the lack of prepared guidelines or a social support system for them, these measures for the massive number of asymptomatic contacts caused a great deal of confusion in the field A clear response guideline is needed for contact management based on robust evidence from this MERS epidemic in Korea.

Validation of a case definition for leptospirosis diagnosis in patients with acute severe febrile disease admitted in reference hospitals at the State of Pernambuco, Brazil / Validação de uma definição de caso para diagnóstico de leptospirose em pacientes com doença febril aguda grave, admitidos em hospitais de referência do Estado de Pernambuco, Brasil

INTRODUCTION: Leptospirosis is often mistaken for other acute febrile illnesses because of its nonspecific presentation. Bacteriologic, serologic, and molecular methods have several limitations for early diagnosis: technical complexity, low availability, low sensitivity in early disease, or high cost. This study aimed to validate a case definition, based on simple clinical and laboratory tests, that is intended for bedside diagnosis of leptospirosis among hospitalized patients. METHODS: Adult patients, admitted to two reference hospitals in Recife, Brazil, with a febrile illness of less than 21 days and with a clinical suspicion of leptospirosis, were included to test a case definition comprising ten clinical and laboratory criteria. Leptospirosis was confirmed or excluded by a composite reference standard (microscopic agglutination test, ELISA, and blood culture). Test properties were determined for each cutoff number of the criteria from the case definition. RESULTS: Ninety seven patients were included; 75 had confirmed leptospirosis and 22 did not. Mean number of criteria from the case definition that were fulfilled was 7.8±1.2 for confirmed leptospirosis and 5.9±1.5 for non-leptospirosis patients (p<0.0001). Best sensitivity (85.3 percent) and specificity (68.2 percent) combination was found with a cutoff of 7 or more criteria, reaching positive and negative predictive values of 90.1 percent and 57.7 percent, respectively; accuracy was 81.4 percent. CONCLUSIONS: The case definition, for a cutoff of at least 7 criteria, reached average sensitivity and specificity, but with a high positive predictive value. Its simplicity and low cost make it useful for rapid bedside leptospirosis diagnosis in Brazilian hospitalized patients with acute severe febrile disease.

INTRODUÇÃO: Por sua apresentação clínica inespecífica, a leptospirose é frequentemente confundida com outras doenças febris agudas. Métodos bacteriológicos, sorológicos e moleculares apresentam limitações para o diagnóstico precoce: complexidade técnica, baixa disponibilidade, insensibilidade na doença precoce, ou alto custo. Este estudo objetivou validar uma definição de caso, baseada em dados clínicos e laboratoriais simples, destinada ao diagnóstico da leptospirose em pacientes hospitalizados. MÉTODOS: Foram incluídos pacientes adultos, admitidos em 2 hospitais de referência no Recife, com doença febril de até 21 dias e suspeita clínica de leptospirose, para testar uma definição de caso contendo 10 critérios clínico-laboratoriais. Leptospirose foi confirmada ou afastada por uma combinação de teste de aglutinação microscópica, ELISA e hemoculturas. Foram determinadas as propriedades do teste, para cada número de critérios da definição de caso preenchidos. RESULTADOS: Incluíram-se 97 pacientes, 75 com leptospirose e 22 negativos para a doença. O número médio de critérios da definição de caso preenchidos foi 7,8±1,2 e 5,9±1,5, respectivamente (p < 0,0001). A melhor combinação de sensibilidade (85,3 por cento) e especificifidade (68,2 por cento) foi obtida com a presença de 7 ou mais critérios, atingindo valores preditivos positivo de 90,1 por cento e negativo de 57,7 por cento, e acurácia 81,4 por cento. CONCLUSÕES: A definição de caso proposta, com um ponto de corte de pelo menos 7 critérios presentes, alcançou sensibilidade e especificidade moderadas, mas um elevado valor preditivo positivo. Sua simplicidade e o baixo custo tornam-na útil para o diagnóstico rápido da leptospirose à beira do leito, em pacientes brasileiros hospitalizados com doença aguda febril grave.

Measuring periodontitis in population studies: a literature review / Medição de periodontite em estudos populacionais: uma revisão de literatura

Case definitions used to identify periodontitis significantly affect the prevalence and risk estimates from population studies. A plethora of definitions has been employed by researchers since the 1940s. The variation in disease definitions affects the comparability and validity of the estimates. This study aimed to review case definitions of periodontitis in prevalence and risk population studies. PubMed and MedIine were searched for the following keywords: "Periodontitis" AND "cross sectional/case control/epidemiology". Studies were selected and reviewed. We found that there is a variety of case definitions being employed in prevalence and risk factor studies. Starting with the index systems, the definitions have been influenced by our understanding of the pathogenesis of the disease. There is a need for a uniform case definition for prevalence surveys and population-specific definitions for association studies.

A definição diagnóstica utilizada para identificar periodontite determina em grande parte a prevalência e as estimativas de risco a partir de estudos populacionais. Uma grande variedade de definições tem sido utilizada por pesquisadores desde a década de1940. Esta variabilidade de definição da doença afeta a comparação e a validade das estimativas. Este estudo teve por objetivo revisar as definições de periodontite em estudos populacionais de prevalência e de risco. Realizou-se uma busca eletrônica na base de dados PubMedMedIinecom as plavras-chave: "Periodontitis" AND "crosssectional/case control/epidemiology". Os artigos foram selecionados e analisados. Este trabalho de revisão encontrou grande variedade de definição de casos usada em estudos de prevalência e de fatores de risco.A partir dos sistemas de indexação, as definições foram influenciadas pelo então entendimento corrente da patogênese da doença. Há necessidade de uma definição de caso uniforme para inquéritos de prevalência e definições populacionais específicas para estudos de associação.

SARS – infectious disease of 21st century.

Severe acute respiratory syndrome (SARS) is an emerging viral infectious disease. According to the World Health Organization, a suspected case of SARS is defined as documented fever (temperature >38°C), lower respiratory tract symptoms, and contact with a person believed to have had SARS or history of travel to an area of documented transmission. A probable case is a suspected case with chest radiographic findings of pneumonia, acute respiratory distress syndrome (ARDS), or an unexplained respiratory illness resulting in death, with autopsy findings of ARDS without identifiable cause. In this article some SARS epidemiological data in Indonesia will also presented. There are 7 SARS suspected cases and 2 probable cases were registered in Indonesia on the period of 1 March to 9 July 2003, and no more cases were reported after that time. How will be SARS progression in the future will be a subject of discussion among scientist, and we will have to wait and be prepared for any development might occur.

Evaluación del sistema de vigilancia epidemiológico del dengue utilizando como indicador la aplicación de la definición de caso sospechoso, Costa Rica 1998 / Evaluation of epidemiology system for dengue using as indicating the application of the definition of suspicious case, Costa Rica, 1998

Se analizó la sensibilidad del sistema de vigilancia para detectar casos de dengue, mediante la aplicación de la definición de caso en tres regiones de Costa Rica que durante el año 1998 presentaron diferente actividad de esta enfermedad. El propósito es fortalecer el sistema de notificación ogligatoria que permita la detección precoz de los casos sospechosos para lograr la intervención oportuna y eficaz en el control de esta enfermedad. Para ello, se realizó un estudio observacional de tipo analítico, enfocado desde la perspectiva de la demanda de los análisis del laboratorio. Los datos corresponden a 377 registros seleccionados aleatoriamente de la base de datos de 1998 del Centro de Referencia de Dengue (CDRD) del Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud (INCIENSA). Los resultados demostraron que el sistema basado en la vigilancia clínica de los casos sospechosos, no es sensible ni se relacionó con el comportamiento epidemiológico de la enfermedad. El mismo no detectó ni el 50 por ciento de los casos positivos, dejando gente infectada que mantiene el ciclo mientras existió entre un 16 y 46 por ciento de pacientes que desencadenaron acciones sin ameritarlas. Esto permite concluir que el personal médico que atiende al enfermo describe en el expediente el cuadro clínico y sospecha dengue porque indica pruebas para descartar esta patología, pero no lo anota como diagnóstico presuntivo. Por esta situacón no se genera la boleta de notificación obligatoria y, por lo tanto, no se activa oportunamente el sistema de vigilancia. Este es el primer estudio que analiza la sensibilidad del sistema de vigilancia de dengue y específicamente aplicado en relación con la activdad de la enfermedad.

The sensitivity of the National Surveillance Program to detect dengue cases was investigated in Costa Rica by evaluating the application of the case definition in three different health regions showing activity for dengue en 1998. The study was aimed to strengthen the Obligatory Notification System in order to achieve a timely detection of suspicious cases and an efficient outbreak control. The investigation corresponds to an observational analytical study from the perspective of the laboratory test demand. Data included 377 registers randomly selected from the data base of the National Reference Center for Dengue of the Costa Rican Institute for Investigation and Training in Nutrition and Health (INCIENSA). Data were processed in two stages: firstly, a descriptive statistics of the variables and, secondly, an univariate analysis of the results to define the sensitivity, specificity and predictive value of the case definition for dengue were carried out. Results showed that the system based on the clinical surveillance of the dengue suspicious cases is neither sensitive nor has connection with the epidemiological profile of the disease. The system showed to be unable to detect Iess than 50% of the positive cases causing that infected people maintain the cycle of the disease while between 16 and 46 % of patients receive the effects of control actions that are not required. Finally, data showed that clinicians attending the patients describe the clinical picture and guess about the possibility of dengue (even prescribing the necessity of serology test for dengue) but do not indicate it as the presumptive diagnose. As a consequence, the obligatory notification form is not filled out and the surveillance system does not receive a timely notification to activate the control actions. This is the first study aimed to analyze the national surveillance system for dengue in Costa Rica in association with the activity of the disease.

Adecuación de la definición de caso sospechoso de dengue basado en la asociación de síntomas y signos según los registros médicos, Costa Rica, 1998 / Adjustment of definition of suspicious case of dengue based on the association of symptoms and signs according to the medical registries, Costa Rica, 1998

A partir de octubre de 1993, en Costa Rica se estableció una definición de caso sospechoso de dengue, basada en la presencia de fiebre y dos o más de los siguientes signos y síntomas: cefalea, mialgias, artralgias, dolor retroocular y exantema, la cual, aplicada al sistema de vigilancia, le confiere una sensibilidad general de 36%. Con el propósito de sugerir una definición de caso sospechoso de dengue que pueda mejorar la sensibilidad del sistema, se estudió la probabilidad de que el personal médico diagnostique a un paciente con dengue está o no relacionada con la presencia de ciertos síntomas y signos.Para ello, se realizó un estudio observacional de tipo analítico para someter a prueba, mediante una regresión logística, los diferentes síntomas y signos que podrían estar asociados a la infección por el virus dengue. Se consideraron los criterios clínicos anotados por el personal médico en el expediente y los resultados del análisis del laboratorio de referencia de dengue. La población en estudio correspondió a la totalidad de los expedientes incluidos en el estudio "Evaluación del Sistema de Vigilancia Epidemiológico del Dengue utilizando como indicador la aplicación de la definición de caso sospechoso, Costa Rica, 1998".El mejor modelo estructurado de la definición de caso sospechoso incluyó fiebre (OR=1,7 IC95% 0,7-3,9), mialgias (OR=1,7 IC95% 1-2,9), artralgias (OR=1,6 IC95% 0,8-2,9), exantema (OR=2,8 IC95% 1,3-5,9), dolor retroocular (OR=2,8 IC95% 1,5-5,3) y manifestaciones de sangrado (OR=6,4 IC95% 1,3-30) por ser síntomas y signos que al ser discriminantes, automáticamente desencadenaron un primer diagnóstico diferencial del dengue. Sin embargo, su aplicación al sistema de vigilancia del dengue, le confiere apenas una sensibilidad del 25%...

In October 1993, a case definition for dengue based on the presence of fever and two or more of the following symptoms: headache, mialgia, arthralgia, retroocular pain and exantema, was established in Costa Rica. When applied in the National Surveillance Program, this definition had showed a general sensitivity of 36%. In the present investigation, the probability for the health personnel to diagnose a case of dengue based on the presence of a combination of symptoms and signs, was evaluated. The study was intended to suggest a dengue case definition to improve the sensitivity of the surveillance system. The study population fully correspond to the clinical files included in a previous report ("Evaluación del Sistema de Vigilancia Epidemiológico del Dengue utilizando como indicador la aplicación de la definición de caso sospechoso, Costa Rica, 1998"). This research corresponds to an analytical observational study. The association of difterent symptoms and signs to the possibiíity of diagnosing a dengue virus infection was evaluated by using a logistic regression analysis. Data evaluated included the clinical criteria described by health personnel in the patient's clinical files and the results of the laboratory tests indicated for the confirmation of dengue infection. The results showed that the best structured model for the suspicious case definition included fever (OR=1,7 IC95% 0,7-3,9), myalgia (OR=1,7 IC95% 1-2,9), arthralgia (OR=1,6 IC95% 0,8-2,9), exanthema (OR=2,8 IC95% 1,3-5,9), retroocular pain (OR=2,8 1C95% 1,5-5,3) and bleeding manifestations (OR=6,4 IC95% 1,3-30). The combination of these symptoms and signs allow the discrimination of dengue cases in the first step of the differential diagnosis. However, the application of this combination gives the system a sensitivity of only 25 %...

Definição de caso e vigilância epidemiológica / Case definition and epidemiological surveillance

O objetivo desta nota técnica é apresentar a importância da definição de casos em vigilância epidemiológica, visando ao uso uniforme na prática dos serviços. A definição padronizada de caso é um dos requisitos para a notificação e investigação de doenças de notificação compulsória em um sistema de vigilância epidemiológica nacional. Isto garante que casos de determinada doença que estejam sendo investigados em diferentes lugares e períodos possam ser classificados adequadamente, permitindo comparações entre espaços geográficos, conjuntos populacionais distintos, entre outros.

The objective of this tecnical note is to present the importance of case definition in epidemiological surveillance, aiming its uniform use among health services. Standardized case definition is one of requirements for notification and investigation of mandatory reporting diseases in a national epidemiological surveillance system. It guarantees that cases of a disease being investigated in different place populations and time will be properly classified.