ASSESSING THE OUTBREAK RESPONSE AND IMPROVING …

1 ASSESSING THE OUTBREAK RESPONSEAND IMPROVING PREPAREDNESSGLOBAL TASK FORCE ON CHOLERA CONTROLCHOLERA OUTBREAKW orld health OrganizationWorld health OrganizationFor more information, please contact:CDS Information Resource CentreWorld health OrganizationCH 1211 Geneva 27 Fax: (+41) 22 791 4285 Email: THE OUTBREAK RESPONSEAND IMPROVING PREPAREDNESSGLOBAL TASK FORCE ON CHOLERA CONTROLCHOLERA OUTBREAKW orld health organization , Geneva 2004 WHO/CDS/CPE/ world health organization , 2004 All rights designations employed and the presentation of the material in thispublication do not imply the expression of any opinion whatsoever on thepart of the world health organization concerning the legal status of anycountry, territory, city or area or of its authorities, or concerning the delimitationof its frontiers or boundaries. Dotted lines on maps represent approximateborder lines for which there may not yet be full mention of specific companies or of certain manufacturers productsdoes not imply that they are endorsed or recommended by the world HealthOrganization in preference to others of a similar nature that are notmentioned.

2 Errors and omissions excepted, the names of proprietary productsare distinguished by initial capital world health organization does not warrant that the informationcontained in this publication is complete and correct and shall not be liablefor any damages incurred as a result of its 5 Cholera 10 Keywords: early detection rapid verification and 14 Keywords: case definition laboratory of the 18 Keywords: cholera coordination committee plan of of the 23 Keywords: clarifying rumours partnership with management: 26 Keywords: assessment of the patient rehydration of 31 Keywords: cholera treatment units supplies training of measures in health care 36 Keywords: isolation of patients disinfection of the community to limit the spread of the disease .. 40 Keywords: health education appropriate messages of the environment: safe 44 Keywords: chlorination water quality testing boiling water4 CHOLERA OUTBREAK of the environment: safe 48 Keywords: preparation of food hygiene in marketplaces cooked of the environment: 51 Keywords: improved sanitation education on practices.

3 54 Keywords: hygienic handling of corpses restrictions on .. 57 Keywords: information for action descriptive of international 62 Keywords: project proposals coordination of international for evaluation .. of the assessment rules in a cholera treatment dilution according to use .. for household water messages for health and use of the 1% chlorine stock solutionto disinfect water .. for safe preparation of food to prevent for coordination of cholera control OUTBREAK RESPONSEI ntroductionOBJECTIVESC holera OUTBREAK RESPONSE generally focuses on medicalaspects that are important for lowering mortality. However, amore comprehensive RESPONSE is needed to limit the spread ofthe disease. As the OUTBREAK RESPONSE is often led by medicalprofessionals, other aspects, such as environmental or com-munication issues, might tend to be document offers a framework for the assessment of acholera OUTBREAK RESPONSE , which will help to: provide a comprehensive overview of the OUTBREAK RESPONSE ; pinpoint the main strengths and weaknesses of the RESPONSE ; improve preparedness for and RESPONSE to future outbreaks; provide accurate recommendations based on WHO is intended primarily for: technical staff of ministries of health ; health professionals in WHO country offices; consultants responsible for undertaking a cholera OUTBREAK RESPONSEWHEN CAN IT BE USED?

4 This document can be used at the end of the OUTBREAK , forretrospective evaluation which is essential to plan for improvedprevention and RESPONSE in the future. Additional tools are givenin Appendices 1 and 2 to help with the evaluation document can also be used during an OUTBREAK to checkwhether any of the aspects of cholera control has OF THE DOCUMENTThe document contains a general section on cholera, plus 14technical sections, each with the following format: Keywords reflecting the principal topic(s) covered. Assessment of the OUTBREAK listing the questions that shouldbe addressed during the evaluation. Useful comments for improved preparedness particularlyuseful if there are recurrent outbreaks of cholera on aseasonal basis (usually in the rainy season). Tips highlighting the main issues relating to Detection2. Confirmation3. Response4. Information5. Treatment6.

5 Mortality7. Hygiene8. Community9. Water10. Food11. Sanitation12. Funeral13. Surveillance14. PartnersA-1A-2A-3A-4A-5A-6A-7A-8A-97 CHOLERA OUTBREAK RESPONSEC holera generalCholera is a diarrhoeal disease caused by infection of theintestine with the bacterium Vibrio cholerae, either type O1or O139. Both children and adults can be 20% of those who are infected develop acute, waterydiarrhoea 10 20% of these individuals develop severe waterydiarrhoea with vomiting. If these patients are not promptly andadequately treated, the loss of such large amounts of fluid andsalts can lead to severe dehydration and death within case-fatality rate in untreated cases may reach 30 50%.Treatment is straightforward (basically rehydration) and, ifapplied appropriately, should keep case-fatality rate below 1%.Cholera is usually transmitted through faecally contaminatedwater or food and remains an ever-present risk in many coun-tries.

6 New outbreaks can occur sporadically in any part of theworld where water supply, sanitation, food safety, and hygieneare inadequate. The greatest risk occurs in over-populatedcommunities and refugee settings characterized by poorsanitation, unsafe drinking-water, and increased person-to-person transmission. Because the incubation period is veryshort (2 hours to 5 days), the number of cases can rise OUTBREAK RESPONSEIt is impossible to prevent cholera from being introduced intoan area but spread of the disease within an area can beprevented through early detection and confirmation of cases,followed by appropriate RESPONSE . Because cholera can be anacute public health problem with the potential to cause manydeaths, to spread quickly and eventually internationally, and toseriously affect travel and trade a well coordinated, timely,and effective RESPONSE to outbreaks is activities should always be followed by the planningand implementation of preparedness activities that will allowfuture cholera outbreaks to be dealt with more strong cholera preparedness plan and programme is the bestpreparation for outbreaks in countries at risk of cholera, whetheror not they have yet been affected, or countries in which seasonalrecurrence of the disease may be STRATEGIES: ORAL CHOLERA VACCINESIn the long term, improvements in water supply, sanitation, foodsafety and community awareness of preventive measures arethe best means of preventing cholera, as well as other diarrhoealdiseases.

7 However, WHO is currently evaluating the use of newertools to complement these traditional measures. Oral choleravaccines of demonstrated safety and effectiveness have recentlybecome available for use by individuals. Some countries havealready used oral vaccine to immunize populations consideredIntroduction1. Detection2. Confirmation3. Response4. Information5. Treatment6. Mortality7. Hygiene8. Community9. Water10. Food11. Sanitation12. Funeral13. Surveillance14. PartnersA-1A-2A-3A-4A-5A-6A-7A-8A-99 CHOLERA OUTBREAK RESPONSEto be at high risk for cholera outbreaks. Use of these vaccinesin both endemic and epidemic situations requires is under way to investigate the role of mass vaccination asa public health strategy for protecting at-risk populations againstcholera. Issues being addressed include logistics, cost, timing,vaccine production capacity, and criteria for the use of massvaccination to contain and prevent OUTBREAK RESPONSE1.

8 OUTBREAK detectionKEYWORDSEARLY DETECTION RAPID VERIFICATION AND RESPONSEASSESSMENT OF THE were the first cases notified to health authorities (throughsurveillance system, media release or radio announcements,informal sources, other)?Are the communication channels for reporting cases wellestablished in regions or municipalities? the beginning, what alerted people to the possibility of anoutbreak: a sudden occurrence of the disease? a persistent increase in reported cases(over a period of more than one week)? a sudden increase in the number of cases? an abnormal number of deaths? what basis was it decided that this was an OUTBREAK : a single case? a cluster of cases? case incidence greater than expected (compared withthe same period of time in previous years)?Introduction1. Detection2. Confirmation3. Response4. Information5. Treatment6. Mortality7. Hygiene8. Community9. Water10. Food11.

9 Sanitation12. Funeral13. Surveillance14. PartnersA-1A-2A-3A-4A-5A-6A-7A-8A-911 CHOLERA OUTBREAK long did the information take to reach decision-making levelfrom the area where the OUTBREAK occurred? (It should not be morethan one week.) were the first actions taken at the central level: telephone call to the affected areas to verify rumours? dispatch of a rapid- RESPONSE team (see tip )? other?USEFUL COMMENTS FOR IMPROVED PREPAREDNESSA ccording to the way in which health authorities were notifiedof the OUTBREAK , what conclusions can we draw about the healthsurveillance system? Is the surveillance system able to detect outbreaks?Is it important to improve detection capacity by including otherstakeholders ( private clinics, traditional healers) in the notificationprocess?Having a special form with key questions might help in quicklydifferentiating rumours from real sources of information can be used: Use journalists as a complementary source for of information onoutbreaks of cholera; any information collected through media needsto be confirmed (see section 2).

10 Set up a hot line with answering machine to encourage people toleave information or OUTBREAK RESPONSEI ntroduction1. Detection2. Confirmation3. Response4. Information5. Treatment6. Mortality7. Hygiene8. Community9. Water10. Food11. Sanitation12. Funeral13. Surveillance14. A RAPID VERIFICATION AND RESPONSE TEAMWhen an OUTBREAK is suspected, it might be important to send amultidisciplinary team to the field in order to confirm the outbreakand to take the first measures for controlling the spread of team might consist of: a physician who will both verify patients clinical symptomsand train health care workers in good case management; a microbiologist who will take stool samples (and environ-mental samples) for laboratory confirmation of cholera andtrain health care workers in correct sampling procedure; an expert in Information, Education and Communication (IEC)who will assess how the community reacts to cholera anddefine and disseminate key health education messages; an epidemiologist who will assess data collection andsurveillance procedures.