Epidemiological data analysis for the early warning alert and response network (EWARN) in humanitarian emergencies a quick reference handbook Epidemiological data analysis for the early warning alert and response network (EWARN) in humanitarian emergencies a quick reference handbook WHO Library Cataloguing in Publication Data World Health Organization. Regional Office for the Eastern Mediterranean Epidemiological data analysis for the early warning alert and response network (EWARN) in humanitarian emergencies: a quick reference handbook / World Health Organization. Regional Office for the Eastern Mediterranean p. ISBN: 978-92-9022-252-1 ISBN: 978-92-9022-253-8 (online) 1. Data Analysis 2. Disease Outbreaks - statistics & numerical data 3. Communicable Diseases – epidemiology 4. Disease Notification – standards 5. Disaster Planning 6. World Health Organization I. Title II. Regional Office for the Eastern Mediterranean (NLM Classification: WA 950) Acknowledgements The WHO Regional Office for the Eastern Mediterranean gratefully acknowledges the technical contribution of the following individuals of the Infectious Hazard Management Programme to the development of this publica- tion: Dr Peter Mala (Medical Officer), Dr Amgad Elkholy (Epidemiologist), Ms Akiko Takeuchi (Technical Officer) and Dr Muhammad Tayyab (Technical Officer). © World Health Organization 2019 Some rights reserved. This work is available under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 IGO licence (CC BY- NC-SA 3.0 IGO; https://creativecommons.org/licenses/by-nc-sa/3.0/igo). Under the terms of this licence, you may copy, redistribute and adapt the work for non-commercial purposes, provided the work is appropriately cited. In any use of this work, there should be no suggestion that WHO endorses any specific organization, products or services. 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Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters. Contents 1. Introduction ............................................................................................................. 5 2. Data collection ......................................................................................................... 7 Role of the surveillance team in data collection and management .................... 8 First surveillance level (reporting sources) ................................................................................. 8 Intermediate surveillance level ...................................................................................................... 8 Central surveillance level .................................................................................................................. 9 Types and sources of data ...................................................................................... 9 Alert signal data ................................................................................................................................... 9 Weekly aggregate data ....................................................................................................................11 Outbreak investigation data ..........................................................................................................11 3. Analysing EWARN epidemiological data ............................................................. 13 Objectives .............................................................................................................. 14 Analysis of the distribution of a disease or public health event .......................................14 Analysis of determinants .................................................................................................................14 Data analysis .......................................................................................................... 14 Data quality ..........................................................................................................................................15 Performance indicators ....................................................................................................................15 Recording/entering data .................................................................................................................15 Data compilation ................................................................................................................................16 Data cleaning and preparation for analysis ..............................................................................16 Analysis of weekly aggregate data ..............................................................................................16 Analysis of disease outbreak data ................................................................................................20 Summarizing data ..............................................................................................................................26 4. Data interpretation, feedback and information dissemination ........................ 27 Interpretation ........................................................................................................ 28 Feedback and information dissemination .......................................................... 28 Annex: Establishing a disease threshold ................................................................. 31 1. Introduction Background Humanitarian emergencies often increase the risk of transmission of communicable diseases, resulting in increased morbidity and mortality, particularly from outbreak-prone diseases. To address this increased risk, the World Health Organization (WHO) and its partners established the early warning alert and response network (EWARN), a simplified disease surveillance and response system that focuses on early detection of and rapid response to outbreaks or unusual health events. EWARN is implemented by the ministry of health of the affected country, or its equivalent, with support from WHO and other partner agencies. EWARN is implemented as an adjunct to the national surveillance system during the acute phase of an emergency, when existing communicable disease surveillance systems may be underperforming or disrupted. Since its introduction in 1999, EWARN has been implemented in response to emergencies in many countries in the WHO Eastern Mediterranean Region, including Sudan (1999, 2004), Pakistan (2005, 2009, 2010), Lebanon (2006), Somalia (2010), the Syrian Arab Republic (2012–2013) and Iraq (2013). It has been adapted to the various settings and has been given different names (e.g. DEWS: Disease Early Warning System; CSR: Communicable Disease Surveillance and Response; EWARS: Early Warning Alert and Response System). However, all these systems are based on the same principles. Rationale This quick reference handbook is intended to guide surveillance staff on their duties and responsibilities in managing and analysing EWARN surveillance data. Skilled human resources are a critical requirement to ensure effective management of EWARN surveillance systems, including generation of reliable and timely data in humanitarian crises. Humanitarian emergency response agencies need timely and good-quality epidemiological information to guide their response activities in order to save lives. However, relevant epidemiological skills,