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SARSSARS 与与 H1N1H1N1 的流行的流行概况概况余运贤余运贤

流行病学与卫生统计学教研组流行病学与卫生统计学教研组

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传染病和流行病学的概念传染病和流行病学的概念 传染病是由病原体（细菌、病毒和寄生传染病是由病原体（细菌、病毒和寄生

虫）引起的能在人与人或人与动物之间传虫）引起的能在人与人或人与动物之间传播的疾病。播的疾病。

流行病学是研究人群人群中疾病与健康状况的分布及其影响因素，并研究防制疾病及促进健康的策略和措施的科学。

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传染病流行的基本环节传染病流行的基本环节

传染源 ：传染源 ：散播病原体的人或动物散播病原体的人或动物

传播途径：传播途径：病原体离开传染源到达健病原体离开传染源到达健康人所经过的途径康人所经过的途径

易感人群：易感人群：对某种传染病缺乏免疫力对某种传染病缺乏免疫力而容易感染该病的人群而容易感染该病的人群

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传染病的预防措施：

1、控制传染源2、切断传播途径3、保护易感人群

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描述性研究描述性研究（（ descriptive studdescriptive studyy ））

通过描述疾病或健康状况的三间分布情况，找出某些因素通过描述疾病或健康状况的三间分布情况，找出某些因素与疾病或健康状况间的关系，提供病因线索。与疾病或健康状况间的关系，提供病因线索。

又称描述性流行病学。指根据日常记录资料或通过特殊调又称描述性流行病学。指根据日常记录资料或通过特殊调查所得的资料，包括实验室检查结果。按不同地区、不同查所得的资料，包括实验室检查结果。按不同地区、不同时间及不同人群特征分组，将一个社区人群疾病或健康状时间及不同人群特征分组，将一个社区人群疾病或健康状态分布情况进行简单描述，常常是流行病学调查的第一步，态分布情况进行简单描述，常常是流行病学调查的第一步，也是分析流行病学的基础。它主要描述分布的三大特征，也是分析流行病学的基础。它主要描述分布的三大特征，即：地区特征、时间特征和人群特征。即：地区特征、时间特征和人群特征。

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Severe Acute Respiratory SyndroSevere Acute Respiratory Syndrome (SARSme (SARS ））

The 2002-2003 SARS outbreak infected 8,422 indThe 2002-2003 SARS outbreak infected 8,422 individuals leading to 916 deaths in eight affected aividuals leading to 916 deaths in eight affected areasreas

The first case was identified on 16 November 20The first case was identified on 16 November 2002 in the southern Chinese city of Foshan. 02 in the southern Chinese city of Foshan.

The epidemic then spread within Guangdong prThe epidemic then spread within Guangdong province before a large superspreading event in Hovince before a large superspreading event in Hong Kong seeded the global outbreak.ong Kong seeded the global outbreak.

On 5 July 2003, the World Health Organization On 5 July 2003, the World Health Organization (WHO) announced the last affected area Taiwan (WHO) announced the last affected area Taiwan to be transmission free and declared the last huto be transmission free and declared the last human-to-human transmission chain successfully man-to-human transmission chain successfully interruptedinterrupted

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SARS SARS 传染源传染源 SARS coronavirus (CoV), was identifieSARS coronavirus (CoV), was identifie

d as the infectious agent in the syndrod as the infectious agent in the syndrome. me.

The origin of this pandemic remains uThe origin of this pandemic remains unclear.nclear.

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SARS EpidemiologySARS Epidemiology

The first waveThe first wave a chef from Heyuan who worked at a restaurant a chef from Heyuan who worked at a restaurant

in Shenzhen was reported to have atypical pneuin Shenzhen was reported to have atypical pneumoniamonia ；；

His wife, two sisters, and seven medical staff weHis wife, two sisters, and seven medical staff were infectedre infected ；；

SARS was outbreak in Heyuen in early Dec, 2002;SARS was outbreak in Heyuen in early Dec, 2002; The outbreak happened in Zhongshan. 28 case The outbreak happened in Zhongshan. 28 case

were recognised. 13 of the 28 patients were healwere recognised. 13 of the 28 patients were health-care workers.th-care workers.

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The second waveThe second wave —since Jan 12, 2003—since Jan 12, 2003 A 46-year-old male seafood merchant who was admitted to the Second AffiA 46-year-old male seafood merchant who was admitted to the Second Affi

liated Hospital of Zhongshan University on Jan 31, 2003.liated Hospital of Zhongshan University on Jan 31, 2003. The patient stayed in the hospital for only 18 h, but caused more than 30 hThe patient stayed in the hospital for only 18 h, but caused more than 30 h

ospital staff to become infected. ospital staff to become infected. During transfer, ambulance driver, two doctors, and two nurses were infeDuring transfer, ambulance driver, two doctors, and two nurses were infe

cted.cted. Within the next 8 days, 20 more medical staff and 19 family members who Within the next 8 days, 20 more medical staff and 19 family members who

had been in contact with the patient became infected.had been in contact with the patient became infected. And then resulted in outbreak in Guangzhou.And then resulted in outbreak in Guangzhou. In mid-February, one doctor working at the Second Affiliated Hospital of In mid-February, one doctor working at the Second Affiliated Hospital of

Zhongshan travelled to Hong Kong, and became the major source of the SZhongshan travelled to Hong Kong, and became the major source of the SARS ARS

The outbreak was characterised by infection within hospitals and family clusters, suggesting that transmission arises through close contact with infected patients.

SARS EpidemiologySARS Epidemiology

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Characteristics of SARS patients in Hong

Kong, Beijing and Taiwan. Hong Kong (n=1755) Beijing (n=917) Taiwan (n=664)‡

Characteristic No. of

patients (%)*

CFR

(%) AOR† (95% CI)

No. of

patients

(%)

CFR

(%) AOR (95% CI)

No. of

patients

(%)

CFR

(%) AOR (95% CI)

Sex

Female 978 (56) 13.2 1 405 (44) 3.0 1 341 (52) 22.6 1

Male 777 (44) 22.3 1.40 (1.01-1.94) 512 (56) 3.5 0.85 (0.38-1.87) 311 (48) 33.1 1.17 (0.79-1.74)

Age group (years)

0-30 515 (29) 0.6 0.05 (0.01-0.18) 440 (48) 0.2 n/a‡ 170 (26) 13.5 0.74 (0.39-1.42)

31-40 379 (22) 7.1 0.68 (0.38-1.20) 193 (21) 1.0 n/a‡ 101 (15) 10.9 0.55 (0.25-1.22)

41-50 320 (18) 11.6 1 151 (17) 2.6 1 121 (19) 19.8 1

51-60 170 (10) 17.6 1.46 (0.83-2.60) 76 (8.3) 11.8 7.72 (2.37-25.2) 78 (12) 42.3 2.59 (1.33-5.04)

60+ 371 (21) 55.3 5.63 (3.52-9.01) 57 (6.2) 24.6 8.52 (2.36-30.8) 181 (28) 48.6 2.94 (1.66-5.21)

Preexisting comorbid conditions

No 1395 (80) 10.0 1 755 (96) 1.5 1 455 (70) 22.2 1

Yes 358 (20) 45.5 1.59 (1.09-2.31) 35 (4.4) 14.3 4.06 (1.62-10.19) 197 (30) 40.1 1.64 (1.09-2.46)

Admitted before symptom onset

No 1636 (93) 14.6 1 859 (94) 3.5 1 598 (92) 23.9 1

Yes 119 (6.8) 52.9 1.45 (0.88-2.38) 58 (6.3) 0.0 n/a§ 50 (7.7) 70.0 4.85 (2.46-9.53)

Lau et al. BMC Infectious Diseases 2010, 10:50

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Figure 2A shows the Figure 2A shows the epidemic curve in each epidemic curve in each

regionregion

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SARS IncubationSARS Incubation

The estimated means of the incubation The estimated means of the incubation distributions were 4.4 days in Hong Kodistributions were 4.4 days in Hong Kong, 5.7 days in Beijing and 6.9 in Taiwang, 5.7 days in Beijing and 6.9 in Taiwan.n.

The mean delay from onset to admissiThe mean delay from onset to admission were 3.6, 2.7 and 2.8 days respectivon were 3.6, 2.7 and 2.8 days respectively for Hong Kong, Beijing and Taiwan.ely for Hong Kong, Beijing and Taiwan.

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传播途径传播途径 water-bornewater-borne Food-borneFood-borne blood-borneblood-borne vector-bornevector-borne Air-borneAir-borne othersothers

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SARSSARS 病毒的传播 病毒的传播 主要经过紧密接触传主要经过紧密接触传播，以近距离飞沫传播播，以近距离飞沫传播为主，也可通过手接触为主，也可通过手接触呼吸道分泌物，经口鼻呼吸道分泌物，经口鼻眼传播，另有研究发现眼传播，另有研究发现存在粪存在粪 -- 口传播的可能。口传播的可能。

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密切接触

1、医务人员2 、家庭成员、共同生活者3 、关系密切的朋友4 、接触病人者

危险人群：危险人群：

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Nanshan Zhong.

BMJ 2006;333;389-391

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H1N1 EpidemicH1N1 Epidemic WHO declared a pandemic in June 2009, a total of 74 cWHO declared a pandemic in June 2009, a total of 74 c

ountries and territories had reported laboratory confirountries and territories had reported laboratory confirmed infections. med infections.

As of October 2009, worldwide H1N1 virus has As of October 2009, worldwide H1N1 virus has been implicated in overbeen implicated in over 318 925 laboratory-318 925 laboratory-confirmed human cases and 3917confirmed human cases and 3917 deathsdeaths..

As of 20 May 2009, 10 243 laboratory-confirmed cases of new influenza A (H1N1) virus infection, including 80 deaths, had been reported to WHO from 41 countries.

Most of these cases were from North America (USA, 5469; Mexico, 3734; Canada, 496).

The majority of fatal cases were reported from Mexico Approximately 2–5% of confirmed cases in the United

States and Canada, as well as 6% in Mexico, have been admitted to hospital.

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H1N1 distribution by ageH1N1 distribution by age

http://www.who.int/wer

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High risk for High risk for hospitalizationhospitalization

Almost one-half of the patients hospitalized in the United States, and 21 of 45 (46%) fatal cases in Mexico have had underlying conditions, including pregnancy, asthma, other lung diseases, diabetes, morbid obesity, autoimmune disorders and associated immunosuppressive therapies, neurological disorders and cardiovascular disease.

Among 20 pregnant women in the United States confirmed to have been infected with new influenza A (H1N1) virus, 3 required hospitalization, 1 of whom died.

Among 30 patients hospitalized in California, 64% had underlying conditions and 2 of 5 pregnant women developed complications, including spontaneous abortion and premature rupture of membranes.

http://www.who.int/wer

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Map: International Co-circulation of 2009 H1N1 and Map: International Co-circulation of 2009 H1N1 and Seasonal InfluenzaSeasonal Influenza

(As of October 2, 2009; posted October 2, 2009, 11:00 (As of October 2, 2009; posted October 2, 2009, 11:00 AM ET) AM ET)

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HINI IncubationHINI Incubation

The median incubation period of the The median incubation period of the virus was 2 days (range, 1 to 7).virus was 2 days (range, 1 to 7).

Cao et al. N Engl J Med 2009;361:2507-17.

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感谢 : L. Stammard, 1995

• 病毒家族 : 正黏液病毒科• 基因组为单股负链 RNA 病毒 • 呈球形，直径 8O 一 120 nm ，有囊膜• 根据外膜蛋白血凝素抗原 (HA) 和神经氨酸酶

(NA) ，甲型流感病毒可以分为 l5 个 H 亚型

甲型流感病毒

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传播途径 The pandemic H1N1 virus is spread from pThe pandemic H1N1 virus is spread from p

erson to person, similar to seasonal influenerson to person, similar to seasonal influenza viruses. It is transmitted as za viruses. It is transmitted as easily easily as the as the normal seasonal flu and can be passed to otnormal seasonal flu and can be passed to other people by exposure to her people by exposure to infected droplets infected droplets expelled by coughing or sneezingexpelled by coughing or sneezing that can b that can be inhaled, or that can contaminate e inhaled, or that can contaminate hands or hands or surfacessurfaces. .

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Population Population ImmunizatiImmunizati

ononin 2008in 2008

Miller et al. Lancet. 2010 Mar 27;375(9720):1100-8.

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Baseline immunization Baseline immunization in 2008in 2008

Miller et al. Lancet. 2010 Mar 27;375(9720):1100-8.

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The population The population immunization in 2009immunization in 2009

Miller et al. Lancet. 2010 Mar 27;375(9720):1100-8.

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Special example for Special example for influenzainfluenza

when an airplane that held 54 when an airplane that held 54 passengers, 1 of whom had passengers, 1 of whom had influenza, was grounded for three influenza, was grounded for three hours with a failed air-circulation hours with a failed air-circulation system, a clinical syndrome of system, a clinical syndrome of influenza developed in 72 percent of influenza developed in 72 percent of all passengers during the next three all passengers during the next three days.days.

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Daniel M. Musher

N Engl J Med 2003;348:1256-66.

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How to protect from How to protect from H1N1H1N1

Avoidance of infections that are spread by large Avoidance of infections that are spread by large droplets requires avoidance of close contact with ill droplets requires avoidance of close contact with ill persons.persons.

In the case of infections that are spread by droplet In the case of infections that are spread by droplet nuclei, shared space should also be avoided unless nuclei, shared space should also be avoided unless ventilation is extremely good: attending a Broadway ventilation is extremely good: attending a Broadway show during an outbreak of influenza is certainly not show during an outbreak of influenza is certainly not advisable for a person who has not been vaccinated. advisable for a person who has not been vaccinated.

Washing hands after greeting someone with a viral Washing hands after greeting someone with a viral infection may be appropriate, because viruses may infection may be appropriate, because viruses may be transmitted by direct contact,be transmitted by direct contact,

and self-inoculation is an important part of and self-inoculation is an important part of pathogenesis.pathogenesis.

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流感疫苗研究现状流感疫苗研究现状

66 月月 88 日，日，甲型甲型 H1N1H1N1流感疫苗生流感疫苗生产用毒株，产用毒株，从美国运抵从美国运抵北京，标志北京，标志着甲型着甲型 H1H1N1N1 流感疫流感疫苗的批量生苗的批量生产正式启动。产正式启动。

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Controlling communicable Controlling communicable diseases (1)diseases (1)

Preparedness and preventionPreparedness and prevention training health and outreach stafftraining health and outreach staff supplies and equipment for diagnosis, supplies and equipment for diagnosis,

treatment and environmental health treatment and environmental health measures;measures;

strengthening health surveillance systems strengthening health surveillance systems and practicing protocols for managing and practicing protocols for managing information on certain diseases;information on certain diseases;

raising awareness among the populationraising awareness among the population

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Health care worker infected Health care worker infected in SARS outbreakin SARS outbreak

From November 2002 to July 2003, severe respiratory distress syndrome (SARS) quickly spread from Foshan (Shunde district), Guangdong Province in the People’s Republic of China to 33 other countries or regions on 5 continents.

There were 8447 cases, 21% occurring in health care workers (HCWs), and 813 deaths (9.6% overall mortality) by the time of July 2003.

In the Hong Kong and Hanoi outbreaks, 46% and 63% of cases occurred in HCWs, respectively.

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Controlling communicable Controlling communicable diseases diseases (2)(2)

Public-health surveillancePublic-health surveillance Public-health surveillance is the collection, analysis Public-health surveillance is the collection, analysis

and dissemination of health information to enable and dissemination of health information to enable appropriate action to be taken.appropriate action to be taken.

Outbreak controlOutbreak control Suspected disease outbreaks, indicated by information Suspected disease outbreaks, indicated by information

from a health surveillance system, should be rapidly from a health surveillance system, should be rapidly investigated using standards protocols for assessmentinvestigated using standards protocols for assessment

The two main strategies for controlling outbreaks of The two main strategies for controlling outbreaks of communicable disease are to reduce the number of communicable disease are to reduce the number of cases through preventive activities and to reduce cases through preventive activities and to reduce mortality due to the disease through early case mortality due to the disease through early case detection and effective treatmentdetection and effective treatment

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Outbreak controlOutbreak control

Preventive and curative measures work togPreventive and curative measures work together ether to reduce the sources of infection by rapidly isoto reduce the sources of infection by rapidly iso

lating and treating patients and controlling anilating and treating patients and controlling animal reservoirs;mal reservoirs;

to protect susceptible groups through immunito protect susceptible groups through immunization, nutritional support and possibly chemozation, nutritional support and possibly chemoprophylaxisprophylaxis

to reduce transmission through improvements to reduce transmission through improvements in hygiene conditions and hygiene behaviour.in hygiene conditions and hygiene behaviour.

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医院是传染病管理的前哨医院是传染病管理的前哨

医院是传染病的集散地医院是传染病的集散地 医务人员是传染病的高暴露人群医务人员是传染病的高暴露人群 医务人员要承担传染病管理的任务医务人员要承担传染病管理的任务

传染病报告传染病报告 病人管理病人管理 疾病监测疾病监测

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