INVESTIGASI OUTBREAK
Outbreak adalah peningkatan insidensi kasus yang melebihi ekspektasi normal secara mendadak pada suatu komunitas, di suatu tempat terbatas, misalnya desa, kecamatan, kota, atau institusi yang tertutup (misalnya sekolah, tempat kerja, atau pesantren) pada suatu periode waktu tertentu (Gerst- man, 1998; Last, 2001; Barreto et al., 2006). Hakikatnya outbreak sama dengan epidemi (wabah). Hanya saja terma kata outbreak biasanya digunakan untuk suatu keadaan epidemik yang terjadi pada populasi dan area geografis yang relatif terbatas. Area terbatas yang merupakan tempat terjadinya outbreak disebut fokus epidemik. Alasan lain penggunaan terma outbreak sebagai pengganti epidemi karena kata epidemi atau wabah berkonotasi gawat sehingga dapat menimbulkan kepanikan pada masyarakat (Tomes, 2000). Kata epidemi tidak disukai oleh para pejabat sebab kejadian epidemi di suatu wilayah dapat menampar muka pejabat yang bertanggungjawab di wilayah tersebut. Karena itu biasanya terma epidemi atau wabah diganti dengan terma yang lebih halus, yaitu “outbreak” atau “kejadian luar biasa” (extra-ordinary events), disingkat KLB. Bahkan dalam bahasa Inggris juga dikenal kata yang lebih eufemistik (halus) daripada outbreak, yaitu “upsurge” yang berarti peningkatan suatu kejadian peristiwa secara tiba-tiba.
Adapun outline investigasi dapat digunakan panduan adalah sebagai berikut: Outline for an outbreak investigation Title: What & Where
Introduction Background of outbreak
Information on disease Relevance for country setting
Outbreak notification and verification: • When: Date/time How first identified: surveillance system, increase in hospital cases, etc. What happened: Signs
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Symptoms Deaths…of who/which population
• Where Who responded: Investigation team members…give credit to all who participate in the investigation….define the “we” Hypothesis In a preliminary report, the hypothesis probably has not been generated yet In a final report, this could be included here (as in an abstract) •
Objectives: To identify case patients To describe the outbreak area To identify the aetiology To collect biological and/or environmental samples To describe clinical illness and presentation Differential diagnosis To generate the hypothesis To document exposure To identify risk factors To suggest measures for control (short-term) To suggest measures for prevention (long-term)
Methodology: Descriptive Study •
Identification of case patients: Case definition Time, person, place Probable, suspected, confirmed How identified: line list, snowball sampling, household survey Exposure history Medical history Samples: Individual and cluster including blood, throat swabs, CSF, etc. How processed & where
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Anthropological Study •
Community and individual understanding: to tell the story, identify social and cultural practices and to find the index case Observations Relationships Timelines Social Mapping Relationships Group discussions (informal/formal) Causal explanations Informal interviews In-depth interviews Case studies •
Environmental Study Observation of immediate area and surroundings Samples: water, soil, etc. PCR swabs
Veterinarian Study Observation of species present and affected Breed, age, sex Samples: Blood, urine, faeces Feed supply
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Results: •
Descriptive findings: leads to differential diagnosis…a clinical hypothesis How many case patients, from where with individual notes…Patient A, links to Patient B & C, etc., how it subsequently spread Add figure to show distribution of cases by date of onset of illness (Epi-curve) Clinical profile of case patients: Mean age, gender, clinical onset, symptoms, duration and long term sequelae Add table to show characteristics of case-patients
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Anthropological Findings Emerging themes on knowledge, attitudes, relationships and practices Add quotations to let the people affected speak for themselves and in their own words Add social map of community
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Environmental findings Profile of affected population: SES, religious practices, occupational exposure Geography, vegetation; water sources, weather patterns Add map to show relationships between source and exposure Specific location variation; travel history related to affected area
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Veterinary Findings Profile of herd or flock health Number of healthy, exposed, sick Respiratory disease Abortion storm
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Laboratory investigation
Number of samples collected Tests performed Diagnostic imaging tests: ultrasound, X-ray, magnetic resonance imaging (MRI), etc. Autopsy/Biopsy (brain, heart, lung) Necropsy
To conduct an analytical study: Generate null hypothesis for an epidemiological study: Study design: Cohort study: with large populations exposed during short time Case control: to compare two groups in terms of exposure to risk factors Calculate sample size: 80% power, 95% CI Find cases and/or proxies Find controls: randomly select, or purposively match 3:1 standard Develop standardized questionnaire: systematic questioning Develop data analysis plan: OR; P value; 95% CI; chi-square; logistical regression Present the results
If not possible to conduct an analytical study, continue with the Discussion Section Discussion: •
Description of suspected disease and/or environmental risk Build links between disease and this outbreak
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Cause of disease and/or environmental risk Build links between cause and this outbreak If links to human involvement document quality/reliability of interviews
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Generalizability Is this risk isolated or linked to wider problem How many outbreaks of this kind reported: first, many…similarities and differences Red Herrings: explanation
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Conclusion: Epidemiological evidence
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Lessons learned: What we did right What we did wrong
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Recommendations: Short term: control Medium term: limit transmission Long term: prevention Dari template laporan diatas : mana yang bisa dikerjakan saja tidak harus semua dan jika mungkin membuat kerangka waktu dan peta partisipatif sederhana (seperti dibawah ini) Contoh rekaman kejadian Avian Influenza: 4
Peta Partisipatif jika mungkin:
Dari berbagai sumber: By Team Epidemiologi Bvet Lampung
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