Emergency Preparedness for School to Manage Large Outbreak of Influenza 學校面對大型流感爆發的緊急應變措施

1. Emergency Preparedness for School to Manage Large Outbreak of Influenza學校面對大型流感爆發的緊急應變措施 Centre for Health Education and Health Promotion, CUHK December 2005

3. Current WHO phase of pandemic alert Source: WHO

4. Will pandemic of influenza occur?流感大爆發將會發生嗎？ • If one has a crystal ball to view the future, this question would be answered. • 若果有一個水晶球，我們就會有答案了！

5. We would make some prediction based on the epidemiological triangle recognizing the three main factors-agent, environment and host in the pathogenesis of disease. 建基於流行病學三角圖的三個主要因素－宿主、感染原和環境，預計流感/禽流感病毒的爆發。 If we can control any two of the main factors, one would prevent the occurrence of a communicable diseases.　假如我們能控制任何兩個主要因素，我們便能預防傳染病的爆發。 宿主 HOST Vector 媒體 環境 感染原 AGENT ENVIRONMENT

6. For an influenza pandemic to occur, there should be three pre-requisites: 流感大爆發的三個基本誘因： • Novel influenza virus subtype emerge for an old subtype re-emerges to which there is no herb immunity;新亞型流感病毒出現或舊流感亞型病毒重現， 而在人羣中普遍的抵抗力有限， 甚至根本沒有抵抗力； • The new virus must be able to replicate in humans and cause serious illness; and 新病毒必須能夠在人體內複製並引起嚴重病況； 以及 • The new virus must be able to transmit from human to human.新病毒必須能夠容易在人與人之間有效傳播。

7. Three pandemics occurred in last century 近一世紀爆發過的三種流感 • 1918/19 (‘Spanish Flu’) causing death of 20 to 40 million people worldwide （西班牙型流感）引致全球死亡人數達 20 至 40 萬 • 1957/58 (‘Asian Flu’)（亞洲型流感） • 1968/69 (‘Hong Kong Flu’)（香港型流感） At present, there is no place with influenza pandemic yet.　目前暫未有其他流感大爆發。

8. What is avian influenza?甚麼是禽流感？ • Avian influenza, or “bird flu”, is a contagious disease of animals caused by viruses that normally infect only birds and, less commonly, pigs. • 禽流感由流感病毒引起，一般只影響鳥類，但豬隻也偶然會受感染。 • Avian influenza viruses are highly species-specific, but have, on rare occasions, crossed the species barrier to infect humans. • 大部份禽流感病毒只會在同一類動物身上流傳，只有個很少情況會交叉傳染到人類。

9. What is avian influenza?甚麼是禽流感？ • In domestic poultry, infection with avian influenza viruses causes two main forms of disease, distinguished by low and high extremes of virulence.若家禽感染禽流感，通常會產生兩種極端疾病：低毒性或高毒性。 • “Low pathogenic” form commonly causes only mild symptoms.低毒性的通常會引致較輕微的症狀。 • The highly pathogenic form spreads very rapidly through poultry flocks, causes disease affecting multiple internal organs, and has a mortality that can approach 100%, often within 48 hours. 高毒性的會在廣泛傳染家禽中，在 48 小時內引致達 100％的死亡率。

10. Influenza A viruses1 have 16 H subtypes and 9 N subtypes2. Only viruses of the H5 and H7 subtypes are known to cause the highly pathogenic form of the disease. However, not all subtypes will cause severe disease in poultry.甲型流感病毒分 16種 H 亞型及 9 種 N 亞型。並非所有亞型病毒都會令禽鳥產生嚴重疾病,只有 H5 及 H7 才會令禽鳥嚴重生病。 • H5 and H7 viruses are introduced to poultry flocks in their low pathogenic form. When allowed to circulate in poultry populations, the viruses can mutate, usually within a few months, into the highly pathogenic form. H5 及 H7病毒進入家禽體內時是低毒性的，但經變種後可在數月內轉化成高毒性的病毒。 • 1 Influenza viruses are grouped into 3 types, A, B, and C. A and B viruses are of concern for human health. Only A viruses can cause pandemics. • 流感病毒分甲、乙、丙型。甲型及乙型病毒影響人類健康。只有甲型會引致流感大爆發。 • 2 H subtypes are epidemiologically most important, as they govern the ability of the virus to bind to and enter cells, and multiplication of the virus then occurs. N subtypes govern the release of newly formed virus from the cells • 從流行病角度看，H 亞型較重要。 H 亞型能使病毒進入細胞，並進行分裂。N亞型則幫助新病毒從細胞中釋放出來‧

11. Common types of Flu 北京型 A/Beijing/262/95 (H1N1) 福建型 A/Fujian/411/2002 (H3N2) 莫斯科型 A/Moscow/10/99 (H3N2)

12. Do migratory birds spread highly pathogenic avian influenza viruses? 候鳥能傳播禽流感嗎？ • Considerable circumstantial evidence suggests that migratory birds can introduce low pathogenic H5 and H7 viruses to poultry flocks, which then mutate to the highly pathogenic form. • 資料顯示候鳥能把低毒性的 H5 及 H7 病毒帶到家禽，並在家禽群中變種成高毒性病毒。 • Recent events make it likely that some migratory birds are now directly spreading the H5N1 virus in its highly pathogenic form. Further spread to new areas is expected. • 近日更有證據顯示，候鳥直接帶有高毒性的 H5N1 病毒。預期病毒將會被帶到新地區。

13. What is special about the current outbreaks in poultry? 近日爆發的禽流感有何特別？ • The current outbreaks of highly pathogenic avian influenza, which began in SE Asia in mid-2003, are the largest and most severe on record. Never before in the history of this disease have so many countries been simultaneously affected.近日爆發高度傳染的禽流感，自2003 年中在東南亞爆發，是前所未有最大型及最嚴重的紀錄。以往從來沒有任何紀錄顯示如此多國家同時受這病毒所影響。 • Despite the death or destruction of an estimated 150 million birds, the virus is now considered endemic in many parts of Indonesia and Viet Nam and in some parts of Cambodia, China, Thailand, and possibly also the Lao People’s Democratic Republic. Control of the disease in poultry is expected to take several years. 雖然已有近 1 億 5 千萬隻家禽被銷毀，但病毒仍不斷在各地擴散，如泰國、印尼、中國等。若要控制病毒的擴散，預期需要花上多年時間。

14. What are the implications for human health? 禽流感對人類健康有何影響？ • The widespread persistence of H5N1 in poultry populations poses two main risks for human health.H5N1病毒在禽鳥中廣泛傳播將對人類健康產生兩種威脅： • The first is the risk of direct infection when the virus passes from poultry to humans, resulting in very severe disease. 首先，病毒可由禽鳥直接侵入人體產生嚴重疾病。 • Unlike normal seasonal influenza, where infection causes only mild respiratory symptoms in most people, H5N1 infection follows an unusually aggressive clinical course, with rapid deterioration and high fatality.與一般感冒不同，H5N1 不只會引致輕微的呼吸道感染徵狀，患者的病情更會迅速惡化，並且死亡率極高。

15. What are the implications for human health? 禽流感對人類健康有何影響？ • Primary viral pneumonia and multi-organ failure are common. In the present outbreak, more than half of those infected with the virus have died. 原發性病毒引致肺炎及多種器官衰竭是很普遍的情況。在今次的大爆發中，超過一半以上的感染人士不治。 • Most cases have occurred in previously healthy children and young adults.大部分感染者在病發前是健康的兒童和成年人。 • A second risk, of even greater concern, is that the virus – if given enough opportunities – will change into a form that is highly infectious for humans and spreads easily from person to person. Such a change could mark the start of a global outbreak (a pandemic).另外，更需要關注的另一個威脅是－－病毒變種成為人傳人的高度傳染性病毒。病毒變種將會代表全球禽流感爆發的一個開始。

16. How do people become infected? 人類怎樣受感染？ • Main route of human infection- direct contact with infected poultry, or surfaces and objects contaminated by their faeces.直接接觸受感染禽鳥或受其糞便污染的物品是人類感染的主要途徑。 • Most human cases have occurred in rural or periurban areas where many households keep small poultry flocks, roaming freely, sometimes entering homes or sharing outdoor areas where children play.大部分人類感染的個案都發生在飼養家禽的郊區地方，居民讓家禽隨處走動，有些更讓家禽進入家裡或小孩玩耍的露天地方。

17. How do people become infected? 人類怎樣受感染？ • As infected birds shed large quantities of virus in their faeces, opportunities for exposure to infected droppings or to environments contaminated by the virus are abundant under such conditions. 由於受感染禽鳥的糞便都包含大量病毒，足以讓病毒曝露在空氣當中。 • Exposure is considered most likelyduring slaughter, defeathering, butchering, and preparation of poultry for cooking. 宰殺或烹調受感染的家禽。

18. Is it safe to eat poultry and poultry products? 進食家禽及家禽產品安全嗎？ • Yes, though certain precautions should be followed in countries currently experiencing outbreaks. In areas free of the disease, poultry and poultry products can be prepared and consumed as with no fear of acquiring infection. 在禽流感爆發的疫區，只要遵守處理家禽的正確方法，也可以安心進食家禽及家禽產品。在沒有受到疫情影響的地區，則可免於憂慮食物受病毒感染，可以放心進食家禽及其製品。

19. Is it safe to eat poultry and poultry products? 進食家禽及家禽產品安全嗎？ • In areas experiencing outbreaks, poultry and poultry products can also be safely consumed provided these items are properly cooked and properly handled during food preparation. 在禽流感爆發的疫區，只要處理及預備食物合乎衞生標準，並經過徹底煮熟，也可以放心食用家禽及其製品。 • The H5N1 virus is sensitive to heat. Normal temperatures for cooking (70oC in all parts of the food) will kill the virus.高温能有效殺死H5N1病毒。家禽必須徹底煮熟才可食用（食物內部要達攝氏70度）。

20. Is it safe to eat poultry and poultry products? 進食家禽及家禽產品安全嗎？ • Consumers need to be sure that all parts of the poultry are fully cooked (no “pink” parts) and that eggs, too, are properly cooked (no “runny” yolks). 必須確保家禽經已徹底煮熟才可食用（沒有任何部分呈粉紅色）。禽鳥蛋也要徹底煮熟才可食用（直至蛋黃及蛋白都凝固才可進食）。

21. Is it safe to eat poultry and poultry products? 進食家禽及家禽產品安全嗎？ • One should be aware of the risk of cross-contamination. Juices from raw poultry and poultry products should never be allowed, during food preparation, to touch or mix with items eaten raw. 必須避免食物交叉污染。在預備食物的過程中，不應讓未經煮熟的家禽及禽鳥蛋的汁液流出，更不可讓未經煮熟的家禽及家禽產品接觸或與其他生食食物混合處理。

22. Is it safe to eat poultry and poultry products? 進食家禽及家禽產品安全嗎？ • When handling raw poultry or raw poultry products, persons involved should wash their hands thoroughly and clean and disinfect surfaces in contact with the poultry products. Soap and hot water are sufficient for this purpose. 在處理未經煮熟的家禽及其製品之後，應徹底清潔雙手，並應用梘液及熱水徹底清洗曾處理未經煮熟的家禽及家禽產品的地方。

23. Is it safe to eat poultry and poultry products? 進食家禽及家禽產品安全嗎？ • Avian influenza is not transmitted through cooked food. To date, no evidence indicates that anyone has become infected following the consumption of properly cooked poultry or poultry products, even when these foods were contaminated with the H5N1 virus. 禽流感不會經徹底煮熟的食物傳播。直至現時為止，沒有資料顯示家禽及家禽產品，即使受H5N1病毒感染，經過徹底煮熟後，有人經過進食這些食物而感染禽流感。

24. Does the virus spread easily from birds to humans? 人類會否很容易經由禽鳥感染有關病毒？ • NO. Though more than 100 human cases have occurred in the current outbreak, this is a small number compared with the huge number of birds affected and the numerous associated opportunities for human exposure, especially in areas where backyard flocks are common. 不會。從禽流感爆發至今，只錄得100宗人類感染個案。有關情況與大量禽鳥受病毒感染及人類與禽鳥接觸的情況相比，尤以小型混合家禽飼養場普遍的地區為甚，人類感染個案並不普遍。

25. Does the virus spread easily from birds to humans? 人類會否很容易經由禽鳥感染有關病毒？ • It is not presently understood why some people, and not others, become infected following similar exposures. How do people become infected? 暫時還未清楚為何某些人會輕易地經過一般接觸而感染病毒。究竟人類如何感染病毒呢？

26. How serious is the current pandemic risk? 現時流感大流行疫情的情況嚴重嗎？ • The risk is serious. With the H5N1 virus now firmly entrenched in large parts of Asia, the risk that more human cases will occur will persist. 疫情嚴重。H5N1病毒已在亞洲大部分地區擴散，人類感染個案有上升的趨勢。 • Each additional human case gives the virus an opportunity to improve its transmissibility in humans, and thus develop into a pandemic strain.每個新錄得的人類感染個案，都有可能增加病毒傳染人類的風險，因而導致於人類社區爆發禽流感大流行。

27. How serious is the current pandemic risk? 現時流感大流行疫情的程況 • The recent spread of the virus to poultry and wild birds in new areas further broadens opportunities for human cases to occur. While neither the timing nor the severity of the next pandemic can be predicted, the probability that a pandemic, will occur has increased. 最近，新發現出現疫情的地區，病毒經由禽鳥傳播至野鳥，增添人類感染個案的可能。雖然未能估計出現流感大流行的時間及嚴重程度；然而，爆發流感大流行的可能性卻有上升的趨勢。

28. What are the most important warning signals that a pandemic is about to start? 流感大流行即將爆發時的警號是甚麼？ • When clusters of patients with clinical symptoms of influenza, closely related in time and place, are detected, this suggests human-to-human transmission is taking place. 當一群病患在相約時間及地點出現流感病徵，顯示有可能出現人傳人的情況。 • For similar reasons, the detection of cases in health workers caring for H5N1 patients would suggest human-to-human transmission. 要是一群醫護人員於照顧感染H5N1病患後出出現流感病徵，也顯示有可能出現人傳人的情況。

29. What are the most important warning signals that a pandemic is about to start? 流感大流行即將爆發時的警號是甚麼？ • Detection of such events should be followed by immediate field investigation of every possible case to confirm the diagnosis, identify the source, and determine whether human-to-human transmission is occurring. 當有關情況出現時，必須即時為每個確診個案展開全面調查，確定感染來源，並查明是否人傳人的感染個案。

30. What is the status of vaccine development and production? 抗禽流感病毒疫苗的發展及生產情況 • Vaccines are produced each year for seasonal influenza but will not protect against pandemic influenza. 疫苗為防備每年流感季節而生產，而不是為防禦流感大流行。 • Because the vaccine needs to closely match the pandemic virus, large-scale commercial production will not start until the new virus has emerged and a pandemic has been declared. 由於疫苗必須與流感大 流行之病毒相配，因此，必須待大流感 　　　爆發新病毒出現後才可大量生產疫苗。

31. What drugs are available for treatment?抗禽流感病毒藥物 • Two drugs (in the neuraminidase inhibitors class), oseltamivir (commercially known as Tamiflu) and zanamivir (commercially known as Relenza) can reduce the severity and duration of illness caused by seasonal influenza.現時只有兩隻較有效的抑制神經氨酸藥物特敏福/Relenza 能夠緩減季節性流感的病徵及縮短病情。 • The efficacy of the neuraminidase inhibitors depends on their administration within 48 hours after symptom onset.在流感病徵出現後48小時內可見抑制神經氨酸藥物的效用。

32. What drugs are available for treatment?抗禽流感病毒藥物 • For cases of human infection with H5N1, the drugs may improve prospects of survival, if administered early, but clinical data are limited. 就人類感染H5N1個案而言，若及早服用適當的藥物，可能提升病患的生存率。然而，有關臨床試驗數據仍然相當有限。 • The H5N1 virus is expected to be susceptible to the neuraminidase inhibitors. 抑制神經氨酸藥物似乎能夠控制H5N1病毒。

33. What drugs are available for treatment?抗禽流感病毒藥物 • An older class of antiviral drugs, the M2 inhibitors amantadine and rimantadine, could potentially be used against pandemic influenza, but resistance to these drugs can develop rapidly. 另一種抗病毒藥物 M2抑制劑，包括金剛胺及rimantadine，此些藥可能緩減大流感徵狀，但同樣病毒產生抗藥性也相當快。

34. Although Avian Flu has similar symptoms as seasonable influenza, Avian Flu is unlikely if one has not contacted infected poultry and/or birds. 雖然禽流感及季節性流感的病徵相約；然而，若不接觸禽鳥，感染禽流感的機會則不大。

35. If any students or staff has been to high risk area and/or in contact with poultry or birds, and develop flu like illness, they must consult doctors immediately. They must give an accurate account of history of traveling and history of contact. 若有學生或職員曾到禽流感爆發的高危地區，並出現感冒病徵，必須立即求診。病患必須詳細說明外遊的記錄及曾接觸人士的情況。

36. To prepare well to safeguard health of the community, the Government aims: 為保障巿民健康，政府必須： • Reduce risk of human infections 減低人類感染危險 • Early detection of influenza pandemic, and 及早發現流感大流行的爆發；及 • Enhance emergency preparedness and response for influenza pandemic 制定完善應變措施

37. Basic measures for keeping school premises hygienic and healthy to prevent pandemic influenza保持校園健康衛生以預測流感大爆發的基本措施

38. For parents/students/staff:家長/學生/教職員： • Parents should check the temperature of their children daily before school with proper recording duly signed by parent家長應在子女每天上學前替他們量度體溫，並正式記錄下來。 • Stay at home and consult doctor with fever or feeling unwell.若有發燒或感冒徵狀，請求醫並留在家中休息。 • School staff and students should wear face masks when they have respiratory tract inflection symptoms若學校職員及學生有呼吸道感染徵狀，必須配戴口罩。

39. Students should wash hands before meals and after sneezing, coughing or cleaning the nose. They should not share towels or utensils.學生在進食前或咳嗽及觸碰鼻子後必須洗手。不可共用手巾或用具。 • Consult doctor promptly in case of fever and/or respiratory symptoms.若有發燒或呼吸道感染徵狀，必須立刻求醫。 • School bus drivers and the assistants should not drive/get on the bus if they have fever. They should wear mask if they have respiratory tract infection.若校巴司機及其助理有發燒徵狀，便不該接觸校巴。若他們有呼吸道感染徵狀，便必須配戴口罩。

40. Schools should:學校應該： • Clean and disinfect school premises and facilities at least daily with diluted household bleach with disinfectant mats at school entrance.至少每天以稀釋家用消毒藥水清潔及消毒校內設施一次，並在學校入口放置消毒地毯。 • Provide adequate facilities and cleaning material for hand-washing.提供足夠的洗手設計及配套。 • Maintain good indoor ventilation and wash dust filters of air conditioners frequently.保持室內空氣流通，及經常清洗冷氣機隔塵網。

41. Flexible break time and lunch time to avoid over crowding彈性小休及午膳以避免校園太過擠迫。 • Notify the Department of Health and EMB of unusual symptoms of infection are noted or large number of students on sick leave.若有一批學生同時因不尋常感染徵狀而請假，通知衛生署及教育統籌局。 • Encourage students/staff to increase body immunity by eating a balanced diet, taking regular exercise, adequate rest鼓勵學生及職員均衡飲食、進行適量運動及保持足夠休息以增強身體抵抗力。

42. Strongly advise students and staff not to attend schools when they have fever.強烈建議發燒之學生及學校職員不要上學。 • Advice them to consult doctors.建議有感染徵狀人士求醫。 • Provide adequate and proper face masks, gloves and other appropriate protective equipment.提供足夠的口罩、手套等保護裝備。 • Develop contingency plan.預備緊急應變措施。

43. All organisation should have its own practical contingency plan.所有機構都應該有個別的實用緊急應變措施。

44. Points for consideration in planning:-設計措施時要注意的事項： • Identify personnel for designated jobs, i.e., infection control, liaison persons etc.確定每人負責的工作，如傳染病控制、統籌人員等。 • Split into smaller working groups using different access points and reduce number of meetings with greater use of telephone conference.以不同切入點將同工分為較小的工作小組，減少會議的次數轉而以進行電話會議。

45. Stock pile personal protective equipment (PPE) such as masks, disinfectants.存放一定份量的個人防護裝備，如口罩及消毒劑。 • To provide training and briefing for staff on general measures and also specific measures such as use of PPE.為職員提供有關一般措施以及專有措施（如個人防護裝備）的培訓及簡報。 • Test and review contingency.測試及檢討緊急應變措施的內容。 • Designate deputies of management if become ill.若管理人員染病，委派管理層的副手負責。 • Specify responsibilities of key individual team.具體指定個別工作小組之職務。 • Establish inflection control procedures.

46. SARS prevention also applicable. Take reference from EMB handbookwww.emb.gov.hk 建立傳染病控制程序。預防沙士的措施同樣適用。可參考教育統籌局手冊www.emb.gov.hk • Spandemic preparedness can be accessed at the Centre for Health Protection website via the Influenza Page. English version http://www.chp.gov.hk/view_content.asp?lang=en&info_id=590 • Chinese version http://www.chp.gov.hk/view_content.asp?lang=tc&info_id=590 • School against SARS 健康校園齊抗炎http://www.hkedcity.net/project/cuhk_sars/index_e.phtmlHygiene Charter 衛生約章http://www.hygienecharter.org.hk/eng/index.php

47. Hygiene Charter衛生約章 • http://www.hygienecharter.org.hk/eng/index.php

48. Hygiene Charter 衞生約章 As a continuing effort in the fight against SARS, Operation UNITE (community initiated movement comprising community leaders from all sectors to help the community in fighting against SARS) has conceived a Hygiene Charter with the academic and professional advice by the Chinese University of Hong Kong, which aims at encouraging individuals, as well as business and industry sectors, to pledge their commitment to improve hygiene practices for the good of all. 「衛生約章」是「心連心 - 全城抗炎大行動」團結社會各界力量抗禦非典型肺炎的重要項目之一。得到香港中文大學多位專家及顧問的協助，提供專業知識及意見，合力制訂有關建議，為社會提供有效可行並容易遵守的疾病預防措施，藉以凝聚廣大市民及多個業界，共同肩負提升衛生水平的責任。

49. ‘Schools Against SARS’ campaign「健康校園齊抗炎」行動

50. “Schools Against SARS” Campaign 「健康校園齊抗炎」行動 • http://www.hkedcity.net/project/cuhk_sars/index_e.phtml