IDSR Notes-1.pdf

Unit Objectives 1.1 Define key concepts used in integrated disease surveillance and response (IDSR) 1.2 State objectives of IDSR 1.3 Describe IDSR and International Health Regulations 1.4 List priority diseases for IDSR 1.5 Des...

Unit Objectives 1.1 Define key concepts used in integrated disease surveillance and response (IDSR) 1.2 State objectives of IDSR 1.3 Describe IDSR and International Health Regulations 1.4 List priority diseases for IDSR 1.5 Describe types of epidemics 1.6 Explain common sources of epidemics 1.7 Discus epidemic preparedness 1.8 Identify cases of priority diseases, conditions, and events 1.9 Report priority diseases, conditions and events 1.10 Analyse disease surveillance data 1.11 Investigate suspected outbreaks and other public health events 1.12 Prepare to respond to outbreaks and other public health events 1.13 Describe organizational framework of epidemic preparedness 1.14 Explain how to respond to outbreaks and other public health events 1.15 Describe how to Communicate information during IDSR 1.16 Monitor, evaluate and improve disease surveillance and response 1.3 Definitions of Key concepts used in integrated Disease surveillance and Response. The following the concepts used in integrated disease surveillance and response: 1.1.1 Disease Surveillance. Surveillance is the on-going systematic collection, analysis, and interpretation of health data. It includes the timely dissemination of the resulting information to those who need them for action. Surveillance is also essential for planning, implementation, and evaluation of public health practice. Several types of surveillance are used in national programs. The choice of method depends on the purpose of the surveillance action. In general, types of surveillance methods describe: a focused location for surveillance (such as health facility-based surveillance or community- based surveillance). a designated or representative health facility or reporting site for early warning of epidemic or pandemic events (sentinel surveillance). surveillance conducted at laboratories for detecting events or trends not necessarily evident at other sites. disease- specific surveillance involving activities aimed at targeted health data for a specific disease. 1.1.3 Integrated Disease Surveillance and Response Integrated Disease Surveillance and Response (IDSR) is a strategy of the World Health Organization Regional Office for Africa for improving epidemiologic surveillance and response in the African region. Surveillance is the on-going systematic collection, analysis, and interpretation of health data. It includes the timely dissemination and use of information for public health action. Integrated Disease Surveillance and Response (IDSR) is a strategy for coordinating and integrating surveillance activities by focusing on the surveillance, laboratory and response functions of the national disease surveillance system. Instead of using scarce resources to maintain separate vertical activities, resources are combined to share activities and processes an 1.4 Objectives of the IDSR The objectives of the integrated Disease Surveillance and Response are as follows: on for detecting, investigating and responding to public health threats In this course, you will have an opportunity to know and use skills that are relevant to carrying out surveillance and response actions especially at the district level. 1.5 IDSR and international Health Regulations The purpose of the International Health Regulations (IHR) is to prevent, protect against, control and provide public health response to the international spread of disease in ways that are relevant and restricted to public health risks, and which avoid unnecessary interference with international traffic and trade. IHR (2005) is a binding and legal instrument. Among the several requirements in the IHR (2005) is a call for strengthening of national capacity for surveillance and control of public health events of national and international concern. The IHR (2005) is not a separate surveillance system. Instead, it requires strengthening the existing surveillance capacities in countries so that they meet international standards. Member States in the African Region recommended that IHR (2005) be implemented within the IDSR framework. This means that 1.6 Priority diseases for integrated disease Surveillance Regulation Epidemic prone diseases Acute haemorrhagic fever syndrome* *Ebola, Marburg, Rift Valley, Lassa, Crimean Congo, or West Nile Fever **National programmes may wish to add Influenza-like illnesses to their priority disease list Diseases targeted for eradication or elimination Buruli ulcer culiasis Other major diseases events or condition of public health importance Acute viral hepatitis Diabetes mellitus tal health (consider epilepsy) Disease or events of international concern Human influenza due to a new subtype RS chemical, radio nuclear, or due to unknown condition. 1.7 Definition and types of epidemics Welcome to this section which deals with definitions and types of epidemics. There are three major types of epidemics as given below: 1.7.1 Progressive epidemic( propagate) Occurs when; - A case of disease serves as a source of information, - Subsequent cases, in serve as sources for later cases, - The shape of the curve usually contains a serious of successively larger peaks. Increasing in scope or severity, advancing going forward. In medicine a disease that is going from bad to worse. 1.7.2 Endemicity The continuing presence of a disease within a given geographic area or population group.Found in or continued to a particular location, region or people. e.g malaria is endemic to tropical regions. 1.7.3 pandemic Pandemic –from Greek pan ‘all’ + demos ‘people’ ( is an epidemic of infectious disease that has spread through human population across a large region; for instance multiple continents, or even worldwide. A widespread endemic disease that is stable in terms of how many people are getting sick from it is not pandemic. 1.7.4 sporadicity This refers to a disease that occurs infrequently and irregularly. 1.7.5 Hyperendemicity This refers to persistent, high levels of disease occurrence 1.7.6. secular: This is the world or geographical distribution of a disease. 1.7.7 Surveillance: This is the systematic ongoing collection and analysis of data for public health purpose and the timely dissemination of public information for assessment and public health response as necessary. -Active: This is the collection of data about the occurrence of a disease by physically visiting the place and actively interviewing the people in that area -Passive: This is the collection of data about the occurrence of a disease through means that do not require the physical presence of the collector e.g by means of letters, reports, telephone, e- mail, fax etc. -sentinel: This is the collection of special data from a few selected qualified staff who have good knowledge of that disease or condition. 1.8. Common sources of epidemics A common –source outbreak is one in which a group of persons are all exposed to an infectious agent or toxin from the same source. These epidemics originate from a single source of infection of the disease –producing agent. Two types of common source epidemics 1.8.1point source or single exposure epidemic The exposure to the disease agent is brief and essentially simultaneous, the resultant, cases all develop within one incubation period of the disease, e.g (an epidemic of food poisoning). The curve has usually one peak. One point of interest is the median incubation period. It is the time required for 50% of the cases to occur following exposure. The main features of a point – source epidemic are; 1) the epidemic curve rises and falls rapidly with no secondary waves  2) the epidemic tends to be explosive and there is clustering o cases within a narrow interval of time. 3) More importantly , all the cases develop within one incubation period of disease Common- source epidemics are frequently, but not always, due to exposure to an infectious agent. They can result from contamination of the environment (air, water, food, soil) by industrial chemicals or pollutants. If the epidemic continues over more than, one incubation period, there is either a continuous or multiple exposures to a common source, or a propagated spread.. 1.8.2 Common –source, continuous Propagated or progressive epidemics occur when the infection spreads from person to person. The infectious agents causing the disease pass from one host to another either directly from person to person (e.g via hand shaking or kissing),or in directly via vectors (e.g mosquitoes in the case of malaria),or in water, food or another medium. The distribution of malaria cases is a good example of propagated epidemics because increased numbers of malaria cases occur again and again at different times. The propagated epidemic last longer than the common source outbreaks. This is because malaria will continue to spread in the community as long as mosquitoes are present in the environment, and there are is people who carry the parasite. 1.8. 3 Intermittent Common Source This is where the very often the often the epidemic curve has a pattern reflecting the intermittent nature of the exposure. 1.9 Epidemic preparedness: This should be done under the following headings: 1.9.1 Early Warning Early warning systems are in most instances, timely surveillance system that collect information on epidemic –prone diseases in order to trigger prompt public health interventions. However, these systems rarely, apply statistical method to detect changes in trends, or sentinel events that would require intervention. WHO is strengthening the exiting surveillance systems for infectious disease developing concepts and techniques. The system captures data on case counts of disease with epidemic potential. Improved surveillance in order to understand the changing epidemiology of the disease (changes in the distribution of cases, etc.) in order to identify population at high risk. It is possible to predict outbreaks and to prevent them by timely immunization of susceptible individuals in populations at high higher risk and by improving overall levels of vaccine coverage in the population. 1.9.2 Early detection Detection of an outbreak relies on the ability of the responsible authority to recognize an increase in number of cases of a particular disease significantly above the number normally expected. This recognition is simpler if a routine surveillance system collects either summary or case- based information on clinical and confirmed cases of the disease. The availability of such data allows for the establishment of background activity level and the establishment of a local outbreak ( or epidemic ) threshold. This threshold value is usually a number of cases in a defined period in excess of predetermined, expected number. In the absence of an effective surveillance system it may be difficult to detect small or limited outbreaks. However, large outbreaks may be detected by the existence of large numbers of cases, health clinic attendances, admissions to hospital, deaths or media reports. In all these situations it will be important to conform to outbreaks. 1.9.3 Notification A disease that, by statutory requirements must be reported to the public health authority. Notification systems are restricted to selected list of ‘important disease’ which may differ from one country to another. These are infectious diseases which require prompt action for control. Medical practitioners and other health personnel may have a special responsibility and may be legally required to provide such notifications. The health officer in charge of the district is usually responsible for receiving the notifications and taking the most appropriate action. of the district is usually responsible for receiving the notifications and taking the most appropriate action. Here is an Example of a form for notifiable disease: THE PUBLIC HEALTH (INFECTIOUS DISEASES) REGULATIONS No..........................................................19....... REPORT OF NOTIFIABLE INFECTIOUS DISEASES for the week ended..............................19....... Place Disease No. of cases previously reported No. of cases reported during week Deaths during week Total deaths................................................ Signature of medical officer. 1.9.4. Verification As soon as an outbreak has been report, it is important to take action so that the disease does not spread. in this regard , it is necessary to verify the outbreak. When WHO receives information of an event that may constitute a public health emergency of international concern, it shall offer to collaborate with the State Party concerned in assessing the potential for international disease spread, possible interference with international traffic and the adequacy of control measures. Such activities may include collaboration with other standard- setting organizations and the offer to mobilize international assistance in order to support the national authorities in conducting and coordinating on-site assessments. When requested by the State Party, WHO shall provide information supporting such an offer. 1.9.5 Early response As soon as an outbreak has been report, it is important to take action so that the disease does not spread. in this regard , it is necessary to verify the outbreak. 1.9.6 post epidemic assessment Various aspect of epidemic after it is over need to be assessed. The aim of post –e epidemic assessment is to learn lessons that may strengthen your preparedness ,detection, prevention and control methods in case of future epidemics. Assess adequacy of epidemic detection and response; ask question such as- 1. Did you use an epidemic monitoring chart? if yes 2. How effective was in detecting the epidemic early 3. How adequate were you contingency stocks 4. How speedy were your actions for vector control 5. How successful were your case management activities. Careful post-epidemic assessment will show the strengths and weaknesses of the system in place at your Health post level and of your action in tackling the epidemic. The investigation should focus on how efficient the system was in confirming the epidemic, the status of preparedness (drugs, insecticides, logistics etc.), timing and impact of intervention measures, and the participation of the community and other partners. Identify both the strengths and weakness of the response to the epidemic. Your report or assessment will help you and your supervisors to improve the epidemic response system. 1.9.7 Preparedness plan of Action The preparation plan of action should be put in place depending on the information available. The information will under normal circumstances be consolidate after any previous epidemic and from the data obtained from the post epidemic assessment. Various committees should be formed; transport, funds, and all other requirements made easily available. Most important is the aspect of sensitizing the communities and the involve partners and the political leadership. The 4 Ps: The 4 Ps the preparedness plan of Action include: - Plan -prepare -practice -protect/ prevent 1.10. Identification of cases of priority diseases, conditions and events This section describes how to: - Use standard case definition for reporting suspected priority diseases - Update district procedures for surveillances - Update description and listing of catchment areas, including distribution of collection form. - Reporting tools and guidelines - Use of laboratory network and produces to improve capacity for surveillance and response. Health staff conduct surveillance activities at all level of health systems that they detect public health problems of concern to their community. An essential function of public system is to be vigilant in its capacity to detect not only know public health threats with established case definition and formal reporting channels but also events of or hazards that are not clusters of disease pattern or rumours of unexplained deaths. 1.11 Reporting priority Diseases, conditions and events For each priority event, disease or condition, review the minimum data element that health facilities and other sources should report. State the information that should be reported from in – patient and outpatient sources. - State the disease or conditions that require immediate reporting and communicate the list to health facilities in the district. - Define the means for reporting to the district ( by Phone, by form,, by voice. - Define how often the required data should bereported 1.12 Analysis of disease surveillance data Define the data management requirement for each reporting site. For example develop and disseminate the procedures including deadlines so that reporting sites know that they must report each reporting period. a. Tally , compile and report summary totals b. Check data quality and eventually clean them c. Analyse data: produce. weekly, monthly quarterly d. Provide some interpretation to the next high level e. Submit data to the next level f. Provide feedback to the community and relevant Reporting site. 1.13 Investigation of suspected outbreaks and other public health events. 1.Prepare for Field work -investigation -Administration.consultation 2. Establishing the Existence of an Outbreak -is this an epidemic or cluster of cases - Does the observed number exceed the expected number of cases 3. Verify the diagnosis - to ensure that the problem has been properly diagnosed - to rule out laboratory error as the basis for the increase in diagnosed cases -summarize the clinical findings with frequency distribution 4. Define and identify cases 4a. Establishing a case Definition - A case definition is a standard set of criteria for deciding whether an individual should be classified as having health condition of interest - A case definition includes clinical criteria and particularly in the setting of an outbreak investigation -restrictions by time, place and person. - Apply them consistently and without bias to all persons under investigation. - To be classified as confirmed, a case usually must have laboratory verification. - A case classified as probable usually has typical clinical features of the disease without laboratory confirmation. A case classified as possible usually has fewer of the typical clinical features, 4b. identifying and counting Cases - In some outbreaks , public health officials may decide to alert the public directly , usually through the local media - Identifying contacts to case –patients - Conduct a survey of the entire population. 5. Performing Descriptive Epidemiology -characterize an outbreak by time, place and person 6. Developing Hypotheses.- all aspects of the investigation should be addressed - The source of the agent,  - The mode of transmission ( Vehicle and Vector) - The exposures that caused the disease First consider what you know about the disease itself:. What is the agent’s usual reservoir?.How it is usually transmitted?.What vehicles are commonly implicated?.what is the known risk factors? 7.Evaluating Hypotheses -Either by comparing the hypotheses with the established facts or -By using analytic epidemiology to quantify relationships and explores the roles of change 8.Refining Hypotheses and Executing 9. implementing control and prevention measures - aim to apply control measures at the weak link or links in the chain of infection. 10. Communicating the Finding - An oral briefing for authorities - And written scientific report. The report should include; - The summary of relevant methods of collection, performed analysis and interpretations - Describe implemented preventive and control measures - Describe other impacts relative to prevention and control - Make recommendations regarding futures surveillance and control - Distribute report to others disease control program. 1.14 preparations for response to outbreaks and other public health events. Update the policies of the district rapid epidemic response team so that assessing preparedness is a routine agenda item of the team. Specify and disseminate schedules for: a. Meeting to routinely assess preparedness for response and discuss current problems or activities. b. Outbreak response meeting. 1.15 organisational Framework of epidemic preparedness -community or primary public health response level - Intermediate public response levels (Many countries have more than one intermediate level ; district, province, region ,state - National level ( National Anti- Epidemic Committee and Responsibilities) 1.15. 1 National Epidemic Preparedness and prevention committee and responsibilities The response at national level consists of two function- assessment and notification. a. assessment of all reports of urgent events within 48 hours ; and b. Notification to WHO immediately through the national IHR focal Point when the assessment indicates the event is notifiable under 1 of Articles of IHR At the National level , the public health response requires the capacity to: Determine rapidly the control measures required to prevent domestic and international spread. c. Provide support through specialised staff. d. Provide a direct operational link with senior health and other officials to approve rapidly and implement containment and control measures. e. Provide direct liaison with other relevant government ministries f. Provide, by the most efficient means of communication available, links with hospitals, clinics, airports, ports ground crossing , laboratories etc. g. Establish , operate and maintain a nation public health emergency response plan 1.15.2 Provincial Epidemic and Prevention Committee and responsibilities The core capacity requirements at intermediate levels are the following; - To confirm the status of reported events and to support or implement additional control - To assess reported events immediately and if found urgent, to report all essential information to the national level. 1.15.3 District Epidemic and prevention committee and responsibilities The core capacity requirements at intermediate levels are the following; - To confirm the status of reported events and to support or implement additional control - To assess reported events immediately and if found urgent, to report all essential information to the provincial level. 1.15.4 Satellite Epidemic and prevention Committee and responsibilities At the local community level and or - To detect events involving disease or death above expected levels for the particular time and place in all areas within the country. - To report all available essential information immediately to the appropriate level of health care response. 1.17 Responding to outbreaks and other public health and events  Coordinate and mobilise resources and personnel to implement the appropriate public health response. 1.18 Communicating information during IDSR Encourage future cooperation by communicating with levels that proved data , reported outbreaks , cases and events about investigation outcome and success of response efforts. 1.19 Monitoring , evaluating and improving disease surveillance and response - Decide if additional indicators will be evaluated and plan how to monitor and evaluate timeliness and completeness of reporting. - State objectives you would like to achieve for improving surveillance in your district over the next year. - Assess the effectiveness of the surveillance and response systems, - Take action to correct problems and make improvements. 1.20 Activity Is the outbreak from a single source or common source? Does the disease spread from to person? 1. The main features of a point- source is include the following except (a) The epidemic curve rises as falls, with secondary waves (b) Cases develop within one incubation period of disease (c) The epidemic curve rises rapidly and continues to rise (d) The epidemics tends to be effusive (e) The epidemics tends to be non-explosive 2. One of the aims of post- epidemic assessment is to learn a lesson that, in case of future epidemics may strengthen: (a) Treatment (b) Diagnosis (c) Preparedness (d) Isolation (e) Surveillance 3. The term “secular trend” implies: (a) Changes in the pattern settlements (b) Rural – urban variations (c) Changes in the occurrence of diseases (d) Geographic distribution of disease (e) None of the above 4. The occurrence of cases of particular disease in excess of the expected is called ; (a) Epidemic (b) Pandemic (c) Endemic (d) Sporadic (e) Seasonal trend 1.21 Summary The section looked at the key concepts, objectives, priority diseases and types of epidemics that are used in Integrated Disease Surveillance and response. It also looked at how to report priority diseases, and conditions and steps for investigation of suspected outbreak and other public health events.