Disease Early Warning System ( DEWos ) Idris Al Abaidani

1. Disease Early Warning System(DEWos)Idris Al Abaidani First National Course on Public Health Emergency Management 12 – 23 March 2011. Muscat, Oman

2. Objectives & expectations Outline of the presentation Case Study

3. Communicable disease (CDs) accounts for 51-95% of all reported deaths in refuge camps. CDs Alone or in combination with malnutrition, are major killers in conflict-affected settings Death rates among refugees and displaced persons significantly above the baseline have been recorded in many conflicts and over three quarters of these deaths may be due to CDs

4. Basic Principles A communicable disease may be defined as an illness that arises from transmission of an infectious agent or its toxic product from an infected person, animal, or reservoir to a susceptible host, either directly or indirectly through an intermediate plant or animal host, vector, or environment. Infectious Agent: Bacteria, viruses, fungi or parasites or their products that can cause disease. Susceptible Host: Person or animal not possessing sufficient resistance against a particular infectious agent to prevent contracting infection or disease when exposed to it.

5. Equilibrium between the Population, Infectious agent and the environment

6. A disease epidemic or outbreak:is the occurrence of cases of a particular disease in excess of the expected, therefore, demanding that emergency control measures be implemented.

7. The Communicable Disease Cycle Likelihood for transmitting disease Risk of dying or becoming ill within population

8. Major Disease Threats in Emergencies • Anytime among displace populations • Main cause during emergencies are: • Acute respiratory infections (ARI) • Measles • Diarrheal diseases • Malaria (endemic areas)

10. Risk factors for CDs Environment: • Loss of shelter • Location of temporary housing / overcrowding / poor ventilation • Lack of water (or contaminated water) • Inadequate sanitation • Disruption of public utilities (e.g. electricity, water and sewage treatment) • Increased exposure to disease vectors (e.g. mosquitoes, fleas, lice) • Population displacement from low to high endemic area (e.g., malaria) • Lack of access to health services • Poor surveillance/response systems • Ongoing conflict preventing control

11. Risk factors for CDs Host: • Low immunity • High proportion of vulnerable: young children/ pregnant women / elderly • High levels under-nutrition / malnutrition • Low levels vaccination coverage • HIV seroprevalence • Underlying chronic diseases, co-morbidities

12. What threat is posed by CDs in conflict situations Increased incidence of endemic diseases - high morbidity and mortality e.g. malaria, ARI, diarrhoeal diseases, TB and HIV/AIDS. Increased risk of epidemics- over 65% of outbreaks of international importance occur in conflict-affected settings – population displacement, overcrowding, malnutrition, poor water/sanitation. e.g. cholera, bacillary dysentery, measles. Increased duration of epidemics - delays in detection, poor access to health care, lack of drugs/vaccines, lack of expertise

13. What threat is posed by CDs in conflict situations Drugresistance can emerge rapidly eg TB, shigellosis • Inappropriate diagnosis • Use of outdated drugs/lack of quality control • Inappropriate drug regimens • Disruption of treatment/poor compliance due to • Purchasing inadequate quantities, selling drugs, saving drugs for future • interrupted treatment due to displacement Emerging diseases pose major threat – eg Monkey Pox, Ebola, Marburg. Eradication and elimination efforts threatened e.g. polio, Guinea Worm

14. CD threat after natural disasters? Type of disaster / Geographical area / Level of development of the disaster-affected region In the immediate aftermath of a disaster, most deaths are due to trauma and drowning. Communicable Diseases caused mostly by secondary effects and NOT by primary hazard. May be an increase in epidemic diseases such as cholera, bacillary dysentery or meningitis, or endemic diseases such as malaria, acute respiratory infections Natural disasters rarely cause large scale epidemics unless population displacement and overcrowding

15. CD risk factors post natural disasters Pathogens present in the area Environmental changes can increase vector breeding sites (rats, mosquitoes) Loss of water/sanitation/power supplies (waterborne diseases) Overcrowding Food shortages / malnutrition / health status Disruption / destruction of health services

16. Surveillence of CD • Ongoing systematic collection, analysis, and interpretation of data which is essential for planning, implementation and evaluation of public health practice. • Case definition • Epidemic thresholds: the minimum number of cases indicating the beginning of an outbreak of particular disease. • Weekly incident rate • AR: the proportion of those exposed to an infectious agent who become ill.

17. Early warning systems Early warning systems are in most instances, timely surveillance systems that collect information on epidemic-prone diseases in order to trigger prompt public health interventions. However, these systems rarely apply statistical methods to detect changes in trends, or sentinel events that would require intervention. In most cases they rely on an in-depth review done by epidemiologists of the data coming in, which is rarely done in a systematic way. WHO is strengthening the existing surveillance systems for infectious diseases developing early warning systems based on the new concepts and techniques Source: http://www.who.int/csr/labepidemiology/projects/earlywarnsystem/en/

18. Objective of Early Warning Surveillance To detect outbreaks / epidemic-prone diseases and implement early response To monitor diseases of high morbidity and mortality and define health priorities on the basis of health data To evaluate actions taken

19. To predict, detect and confirm outbreaks of public health importance in a timely fashion and to disseminate that information to those who need to know so that effective public heath action can be taken

20. Attributes of effective surveillance/early warning and response system • Close collaboration with authorities and partners from the start – create network • Small number of priority diseases • Syndromic reporting • Simple case definitions • Processes for dealing with alerts ("rumours") • Rapid case investigation and sampling • Rapid laboratory confirmation • Standard procedures for information sharing and initiation of response • Preparedness plans in place

24. Priority CD Interventions • Emergency medical and surgical care • Safe water and adequate sanitation/hygiene • Provision of safe food • Provision of shelter (site planning) • Immunization (measles = 1st priority, later restart routine EPI) • Access to 1° & 2° health services (case management) • Disease surveillance/outbreak preparedness & control • Vector control • Environmental sanitation / waste disposal • Health education

26. CDs during Phet & Guno

27. A circular were issued in this regards to all health care workers in order to raise their index of suspicious towards possible outbreaks as consequences of utilizing wadis waters

28. Zero reporting to be send form the health centers/polyclinics (sentinel sites)in the affected areas on daily bases to Dept.CDS&C in order to monitor trends of symptoms related to epidemic-prone diseases viz waterborne diseases.

32. Incidence of Influenza Like Illnesses (ILI) cases reported, Oman, 2006 - 2010

33. Case Study Communicable diseases surveillance in complex emergencies

34. Province X with total population of 2 million was affected by a major earthquake on 20 of Feb 2011 at 2 am. The epicentre of the earthquake was located near the capital city of the province (500,000 inhabitants). Extensive loss of life, property, and livelihood in 14 of the 21 districts of the province left a large segment of the population without basic needs and vulnerable to epidemic-prone diseases. As of 15 March 2011, Province X reported that 26,602 bodies had been buried; 13,638 people were missing; and 514,150 were displaced in 20 districts/cities in the capital city. In the public sector, 53 of 244 health facilities in the capital city were destroyed or severely incapacitated and 42 of 481 Provincial Health Office (PHO) staff died. This disaster occurred in the context of 30 years of civil unrest which had severe social and economical consequences for the province.

35. Questions Q1) What are the objectives of this surveillance / early warning system Q2)What are the basic data you want to get before implementing the surveillance system in complex situation? Q3)What specific data on the health events would you want collected? Q4) What sources of information would be useful in setting up this surveillance system?

36. Questions Q5) What health events would you want to monitor in the surveillance system? Q6) How frequently would you want the health data reported? Q7) How do you analyse the data?

37. Answers • Q1) What are the objectives of this surveillance / early warning system? • To detect outbreaks / epidemic-prone diseases and implement early response • To monitor diseases of high morbidity and mortality and define health priorities on the basis of health data • To evaluate actions taken

38. Q2) What are the basic data you want to get before implementing the surveillance system? • Population figures, and by: • Age • Sex • Location • Population movements • Specific groups at higher risk (orphans, single women)

39. Q3) What specific data on the health events would you want collected?  • Time, Place, Person   • Information should be tailored to the situation: Age (<5 years, >5 years), gender, location of residence, location of healthcare interaction, diagnosis and information sufficient to identify the reporter are commonly included.

40. Q4) What sources of information would be useful in setting up this surveillance system? • Health facilities:hospital admissions, OPD attendances,fixed/mobile clinics • Laboratory • Grave diggers, 24 hour graveyard watches, morgue, death registers • Community leaders • Traditional healers • Birth attendants • Home visitors, community health workers • Informal sources: e.g. telephone calls from reporters, media reports, reports from the public, etc.

41. Q5)What health events would you want to monitor in the surveillance system? • Total number of deaths. Ultimate criterion to judge gravity of a situation. • Deaths from diarrhoeal diseases, measles, pneumonia, fever/malaria, meningitis, anaemia, malnutrition, injuries • Cases of diarrhoeal diseases, measles, pneumonia, fever/malaria, meningitis, anaemia, malnutrition, injuries. • Syndrome-based rather than individual disease-based. • Limited number based on impact on morbidity and mortality, epidemic potential and existence of control measures

42. 6) How frequently would you want the health data reported? • Daily in the acute phase of an emergency. • Weekly once the CMR reduces to that of the surrounding population. The diagnosis of a case of a highly contagious diseases e.g., cholera, meningitis, measles, however should be urgently reported to the health co-ordinator. • Zero reporting • Feed back on the same basis. • Information to your hierarchy on the same basis.

43. Q7) How do you analyse the data? • Data treatment • Centralization of the data • Calculation of indices (rates, ratio, proportion…) • Data presentation according to place, time, people: tables, figures (templates) • Data Analysis • aggregated information • information per location, groups of people, and in the time

44. Q7) How do you analyse the data? (continue) • Mortality: • Rates (crude and rates per cause, age, gender, location) • CFR • Morbidity: • number of cases / diseases or syndromes • incidence / disease (age, gender and location) • Use of thresholds: • Severity of the situation (CMR; > 1/10000/day ; under 5 > 2/10000/day)