王仁水醫師

即將入冬,上下呼吸道疾病的診斷 與治療對策

• Ventilatory flow 換氣氣流

• Cough 咳嗽

• Mucociliary clearance

mechanisms 黏液纖毛清除功能

• Mucosal immune system 黏液免疫系統

Respiratory tract defences 天賜良能:呼吸道的防禦能力

Protective structures of the respiratory system

•Mucous membranes

•Hairs; ciliated epithelia

•Lymphoid tissues (tonsils)

•“Mucociliary escalator” keeps microbes out of

lower respiratory tract

•Alveolar macrophages; IgA

Respiratory system

environment is diverse

• Upper respiratory system

– Nose, pharynx, associated structures

– Purpose: to take in, warm and moisten

air

– Most common site of infections

• Lower respiratory system

– Larynx, trachea, bronchi, alveoli

– Purpose: ventilation, gas exchange

Geography of the respiratory

system (and sites of infection)

Most of the respiratory system is NOT colonized

by normal flora

Generally confined to nose, nasopharynx and

pharynx

• 急性呼吸道感染(acute respiratory tract infections; ARTIs)一直是人類罹病及致死的重要原因。在美國是十大死因的第六名，在台灣則是兒童十大死因的第四名。呼吸道感染的致病源通常是細菌或病毒，大部份的病源是不明的，文獻上社區性肺炎能確定病源的診斷率約40-80%。同時有兩種以上致病源的機率是十分普遍的，大約是30-40%[1,2]。

• 近年來由於分子生物學技術的進步，我們可以快速地診斷出許多新發現的呼吸道病源菌或病毒等，例如禽流感H5N1病毒、SARS冠狀病毒或人類間質肺炎病毒等。其中人類間質肺炎病毒被認為是呼吸道感染重要的病毒，可以侵犯任何年齡的人，侵犯的範圍包含上呼吸道和下呼吸道。

• Adults average ~2 to 4 colds1,2 and children average 3 to 8 colds3 per year

• In 1996, colds were associated with ~148 million days restricted activity, 20 million days missed work, 22 million days missed school, 45 million days bedridden4

• In 1998, 25 million office visits to primary care providers for upper respiratory infections (URIs)5

• Costs associated with VRIs estimated at ~$25 billion annually6

1. Turner RB. Pediatr Ann. 1998;27:790.

2. Monto AS et al. Clin Ther. 2001;23:1615.

3. Rosenstein N et al. Pediatrics. 1998;101:181

4. Adams PF et al. Vital Health Stat. 1999;10 (200).

5. Gonzales R et al. Clin Infect Dis. 2001;33:757.

6. Fendrick AM et al. Value in Health. 2001;4:412.

Economic and Societal Burden

of VirusRIs

Upper respiratory tract

infections(URI, 上呼吸道感染 ) • Rhinitis鼻炎

– Rhinovirus, coronavirus, influenza/parainfluenza 感染性

– Non-infective (allergic) rhinitis has 過敏性 similar symptoms (related to asthma)

• Sinusitis鼻竇炎

• Otitis media中耳炎

• Sinusitis/otitis media: risk of bacterial superinfection, mastoiditis,meningitis, brain abscess

Upper respiratory system

• Pharyngitis, laryngitis, tonsillitis, etc.

• by bacteria, viruses or both

• Usually self-limiting

• S pyogenes is an important pathogen

– Resistant to immune system

– Produces toxins (superantigens)

– Immune reaction (glomerulonephritis, rheumatic fever)

Sore throat

Cough

Activity restriction

Lower respiratory symptoms Headache

Coryza

Perc

en

t

RV RSV Parainfluenza

virus

Hemolytic

streptococci Influenza A Influenza B

0

20

40

60

80

100

Characteristics of VRIs of

Known Etiology

Reprinted from Br J Prev Soc Med, 1977;31:101-108, with permission from the BMJ Publishing Group.

Reprinted with permission from Monto AS et al. J Infect Dis. 1987;156:43.

© 1987 by The University of Chicago. All rights reserved.

Characteristics of RV-Associated

Illnesses

Illness with indicated syndrome (%) Percent with

Age group

(years)

No. of

isolates

Lower

respiratory

Upper

respiratory

Laryngo-

pharyngeal Other

Median

duration

(days) Activity

restriction

Physician

consultation

0–4 61 14.8 83.6 1.6 — 12 0 16.4

5–19 39 5.1 74.4 15.4 5.1 7 56.4 15.4

20–39 59 33.9 59.3 6.8 — 13 11.9 15.3

40 17 64.7 29.4 5.9 — 20 35.3 35.3

Total 176 23.8 68.2 6.8 1.2 12 19.9 17.6

Laryngitis

• Most commonly upper respiratory viruses

• Diphtheria

– C. diphtheriae produces a cytotoxic exotoxin causing tissue necrosis at site of infection with associated acute inflammation. Membrane may narrow airway and/or slough off (asphyxiation)

Acute epiglottitis

• H. influenza type B

• Another cause of

acute severe

airway

compromise in

childhood

Lower respiratory infections

• Usually stopped by

immune/mechanical means

– Pneumonia (inflammation of lung)

– Tuberculosis (chronic inflammation)

– Whooping cough (kills ciliated cells)

Pneumonia

• Infection of pulmonary parenchyma

with consolidation

Pneumonia

• Group “disease of the lungs”

• Infection involving the distal air

spaces usually with inflammatory

exudation (“localised oedema”).

• Fluid filled spaces lead to

consolidation

Classification of Pneumonia

• Clinical setting (e.g. community

acquired pneumonia) 臨床設備

• Organism (mycoplasma,

pneumococcal etc.) 病原菌

• Morphology (lobar pneumonia,

bronchopneumonia) 肺炎分佈形態

肺炎分類 by

Pathological description of pneumonia

肺炎的病理徵象

Organisms

• Viruses – influenza, parainfluenza,

measles, varicella-zoster, respiratory

syncytial virus (RSV). Common, often

self limiting but can be complicated

• Bacteria

• Chlamydia, mycoplasma

• Fungi

導致肺炎的病原菌

Many infectious agents cause

pneumonia

Bacterial

Legionella- spreads in ventilation systems

Mycoplasma (walking pneumonia)

very unusual microbes

“Pneumococcus” (S. pneumoniae)

– Encapsulated; causes inflammation

– Can spread and cause endocarditis, meningitis,

septicemia

Lobar Pneumonia

• Confluent consolidation involving a

complete lung lobe

• Most often due to Streptococcus pneumoniae (pneumococcus)

• Other organisms (Klebsiella, Legionella)

大葉性肺炎

Lobar Pneumonia

Clinical Setting

• Usually community acquired

• Classically in otherwise healthy

young adults

臨床特性

Lobar Pneumonia

Pathology

• A classical acute inflammatory response

– Exudation of fibrin-rich fluid

– Neutrophil infiltration

– Macrophage infiltration

– Resolution

• Immune system plays a part antibodies

lead to opsonisation, phagocytosis of

bacteria

免疫病理表徵

Lobar Pneumonia

Macroscopic pathology

• Heavy lung

– Congestion

– Red hepatisation

– Grey hepatisation

– Resolution

– The classical

pathway

目測病理表徵

Lobar pneumonia (upper lobe – grey

hepatisation), terminal meningitis

Lobar Pneumonia

Complications

• Organisation (fibrous scarring)纖維瘢痕

• Abscesss膿瘍

• Bronchiectasis支氣管擴張

• Empyema (pus in the pleural cavity)膿胸

併發症

Bronchopneumonia

• Infection starting in airways and

spreading to adjacent alveolar lung

• Most often seen in the context of pre-

existing disease

支氣管性肺炎

Bronchopneumonia

Bronchopneumonia

• The consolidation

is patchy and not

confined by lobar

architecture

Bronchopneumonia

Clinical Context

• Complication of viral infection

(influenza)

• Aspiration of gastric contents

• Cardiac failure

• COPD

Bronchopneumonia

Organisms

• More varied – Strep. Pneumoniae, Haemophilus influenza, Staphylococcus, anaerobes,

coliforms

• Clinical context may help.

Staph/anaerobes/coliforms seen in

aspiration

Bronchopneumonia

Complications

• Organisation

• Abscess

• Bronchiectasis

• Empyema

Viral pneumonia

• Gives a pattern of acute injury similar to adult respiratory distress syndrome (ARDS)

• Acute inflammatory infiltration less obvious

• Viral inclusions sometimes seen in epithelial cells

Several viral pneumonias also

described

• Adenovirus

• complications of Influenza

– Affects many types of animals (wild and domesticated); source of genetic exchange

– Can frustrate immune system due to constant antigen change

• RSV (respiratory syncytial virus)

– Especially dangerous for infants

– Tends to recur

Mechanisms of viral respiratory

infections

• Influenza

– kills epithelial cells; spreads rapidly to

other cells

• RSV

– Kills epithelial cells which can block

respiratory passages

Hantavirus pulmonary syndrome

• Spread by inhalation

of dust contaminated

by mice

• High fatality rate (40%)

• No person-to-person

spread

• Infects capillary

epithelium; blood

vessel damage and

shock

漢他病毒肺症候群

The immunocompromised host

• Virulent infection with common

organism (e.g. TB) – the African

pattern

• Infection with opportunistic pathogen

– virus (cytomegalovirus - CMV)

– bacteria (Mycobacterium avium intracellulare)

– fungi (aspergillus, candida,

pneumocystis)

– protozoa (cryptosporidia, toxoplasma)

免疫不全宿主

Diagnosis

• High index of suspicion

• Teamwork (physician, microbiologist,

pathologist)

• Broncho-alveolar lavage

• Biopsy (with lots of special stains!)

診斷

Immunosuppressed patient – fatal

haemorrhage into Aspergillus-containing

cavity

Tuberculosis

• 22 million active cases in the world

• 1.7 million deaths each year (most

common fatal organism)

• Incidence has increased with HIV

pandemic

肺結核

Tuberculosis

• Mycobacterial infection

• Chronic infection described in many

body sites – lung, gut, kidneys, lymph

nodes, skin….

• Pathology characterised by delayed

(type IV) hypersensitivity (granulomas

with necrosis)

Tuberculosis (pathogenesis of

clinical disease)

• Virulence of organisms

• Hypersensitivity vs. immunity

• Tissue destruction and necrosis

Mycobacterial virulence

• Related to ability to resist

phagocytosis.

• Surface LAM antigen stimulates host

tumour necrosis factor (TNF) a

production (fever, constitutional

symptoms)

結核病菌毒性

Organisms

• M. tuberculosis/M.bovis main

pathogens in human being.

• Others cause atypical infection

especially in immunocompromised

host. Pathogenicity due to ability;

– to avoid phagocytosis

– to stimulate a host T-cell response

Immunity and Hypersensitivity

• T-cell response to organism enhances

macrophage ability to kill mycobacteria

– immunity

• T-cell response causes granulomatous

inflammation, tissue necrosis and scarring

– hypersensitivity (type IV)

• Commonly both processes occur together

免疫以及過敏反應

Pathology of Tuberculosis (1)

• Primary TB (1st exposure)

– inhaled organism phagocytosed and

carried to hilar lymph nodes. Immune

activation (few weeks) leads to a

granulomatous response in nodes (and

also in lung) usually with killing of

organism.

– in a few cases infection is overwhelming

and spreads

Pathology of Tuberculosis (2)

• Secondary TB

– reinfection or reactivation of disease in a

person with some immunity

– disease tends initially to remain

localized, often in apices of lung.

– can progress to spread by airways

and/or blood stream.

Tissue changes in TB

• Primary

– Small focus (Ghon focus) in periphery of

mid zone of lung

– Large hilar nodes (granulomatous)

• Secondary

– Fibrosing and cavitating apical lesion

(cancer, an important differential

diagnosis)

Primary and secondary TB

• In primary the site of infection shows non-specific inflammation with developing granulomas in nodes

• In secondary there are primed T cells which stimulate a localised granulomatous response

Primary TB – Ghon Focus

Secondary TB

• Necrosis

• Fibrosis

• Cavitation

• T cell response:

CD4 (helper)

enhance killing.

CD8 (cytotoxic) kill

infected cells

giving necrosis

Complications

• Local spread

(pleura, lung)

• Blood spread.

Miliary TB or “end-

organ” disease

(kidney, adrenal

etc.)

• Swallowed -

intestines

The host-organism balance

• Not all infected get clinical disease

• Organisms frequently persist

following resolution of clinical disease

• Any diminished host resistance can

reactivate (thus 33% of HIV positive

are co-infected with TB)

宿主﹑病原間的槓桿

Secondary TB – rapid death due to

miliary disease

Why does disease reactivate?

• Decreased T-cell function

– age

– coincident disease (HIV)

– immunosuppressive therapy (steroids,

cancer chemotherapy)

• Reinfection at high dose or with more

virulent organism

Lung Abscess

• Localised collection of pus. Central

tissue destruction. Lined by

granulation tissue/fibrosis (attempted

healing)

• Tumour-like

• Chronic malaise and fever

肺膿瘍

Lung abscess

• Organisms: – Staphylococcus

– Anaerobes

– Gram negatives

• Clinical contexts: – Aspiration

– Following pneumonia

– Fungal infection

– Bronchiectasis

– Embolic

Bronchiectasis

• Abnormal fixed dilatation of the bronchi

• Usually due to fibrous scarring following

infection (pneumonia, tuberculosis, cystic

fibrosis)

• Also seen with chronic obstruction (tumor)

• Dilated airways accumulate purulent

secretions

支氣管擴張

Bronchiectasis

• Affects lower lobes preferentially

• Chronic recurring infection

sometimes leads to finger clubbing

Complications of bronchiectasis

• Pneumonia

• Abscess

• Septicaemia

• Empyema

• “Metastatic” abscess

• Amyloidosis

Fungal infections :

rare in healthy people

• Immune system usually controls growth

• Soil source is typical

• Can be accidental (after an earthquake,

e.g., Coccidioides immitis, “Valley fever”

黴菌感染

Role of VRIs in Asthma

Exacerbations

Data from Teichtahl H et al. Chest. 1997;112:591.

Viruses Detected in Adult Patients

Hospitalized with Asthma

54.5%

6.1%

27.3%

3% 3% Influenza A

Influenza B

RV

Adenovirus

RSV

Herpes

33 organisms isolated; 5 subjects had >1 virus detected and some viruses were

detected by >1 test.

6.1%

• 2 episodes of “common cold” before

age 1 yr decrease risk of asthma by age 7

by ~50%

• Other viral infections—eg, herpes, varicella,

measles—also protective

• Reported LRI with wheeze in the first 3 years

of life increases risk of asthma

Illi S et al. BMJ. 2001;322:390.

Respiratory Infections in Infancy May

Protect Against Development of Asthma

Children who had 2 older siblings or attended

day care during first 6 mo of life had increased

risk of wheeze early in life but decreased risk later.

Reprinted with permission from Ball TM et al. N Engl J Med. 2000;343:538. Copyright © 2000

Massachusetts Medical Society. All rights reserved.

P=0.01

P=0.03

P=0.001 P<0.001

P<0.001

2.7

1.0

0.4

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Ad

jus

ted

rela

tive r

isk

of

freq

uen

t w

heezin

g

Age (yr)

0.1

Effect of Day Care in Infancy and Number

of Older Siblings on Asthma Risk

• Viral infections (esp. RV) frequently cause exacerbations of asthma

• Possible mechanisms

– Extension into the lower airway1-3

– Inflammation2,3

Immunologic Mechanisms of VRI-

Induced Asthma Exacerbations

1. Gern JE et al. Am J Respir Crit Care Med. 1997;155:1159.

2. Gern JE, Busse WW. J Allergy Clin Immunol. 2000;106:201.

3. Fraenkel DJ et al. Am J Respir Crit Care Med. 1995;151:879.

Airway

Hyperresponsiveness

Plasma

leakage

Mucus

hypersecretion

Inflammatory

cell recruitment

and activation

Neural activation

Virus-infected

epithelium

Adapted from Gern JE, Busse WW. J Allergy Clin Immunol. 2000;106:201.

RV-Induced Airway Inflammation

• VRIs (especially RV infections in children >2 yr old)

and atopy synergistically enhance the risk of

wheezing1

– Antigen-specific IgE

– Eosinophilic inflammation

• Cytokine production pattern is related to outcomes of

experimental infection2

• High IFN-/IL-5 ratio=Th1-type (antiviral) response2

• Low IFN-/IL-5 ratio=Th2-type (allergic) response2

1. Rakes GP et al. Am J Respir Crit Care Med. 1999;159:785.

2. Gern JE et al. Am J Respir Crit Care Med. 2000;162:2226.

What Is Different About VRIs in

Asthma?

• PBMC IFN- secretion

– Reduced peak

viral shedding

• Sputum IFN-/IL-5

mRNA ratio correlates

with

– Lower symptom

scores

– More rapid viral

clearance

Parry DE et al. J Allergy Clin Immunol. 2000;105:692.

Reprinted from Gern JE et al. Am J Respir Crit Care Med. 2000;162:2226.

Immunologic Risk Factors for

More Severe VRIs

Virus detected at 14 days? No Yes

IFN/

IL-5

rati

o (

un

its)

100

101

102

103

104 Th1

Th2

• Viruses cause asthma exacerbations in adults

and children

• RVs cause ~60% of virus-induced

exacerbations of asthma

• RVs directly infect the bronchial airways

• The response to viral infection is shaped by

the host’s antiviral response

• VRIs in early childhood may protect against

the development of asthma

Summary

Influenza 流行性感冒

clinical presentation • Fever: high, abrupt

onset

• Malaise

• Myalgia

• Headache

• Cough

• Prostration

Prevention of “flu”

• Vaccine預防接種

– killed vaccine

– given annually to patients at risk of

complications

– given to health care workers

Antiviral as prophylaxis

• antivirals after a contact with ‘flu

– NICE guidelines

– rarely used

• During “containment phase” of first

wave of pandemic.

預防性投予抗流感病毒製劑

Other causes of Community

Acquired Pneumonia

• Microbiological causes (all bacteria)

– Mycoplasma pneumoniae黴漿菌肺炎

– Coxiella burnetii 貝氏柯克斯體

– Chlamydia 披衣桿菌

社區感染性肺炎

Coxiella burnetii 貝氏柯克斯體 Kingdom: Bacteria

Phylum: Proteobacteria

Class: Gammaproteobacteria

Order: Legionellales

Family: Coxiellaceae

Genus: Coxiella

Species: C. burnetii

Coxiella burnetii

(Derrick 1939)

Philip 1948

Gram(-)

Q fever

Chlamydia (genus)

C. trachomatis inclusion bodies (brown) in a McCoy cell culture.

Domain: Bacteria

Class: Chlamydiae

Order: Chlamydiales

Family: Chlamydiaceae

Genus: Chlamydia[]Jones et al. 1945 emend. Everett et al. 1999

Mycoplasma, coxiella and

Chlamydophila psittaci • Therapy治療

– all respond to tetracycline and

macrolides (eg clarithromycin,

azithromycin)

• Mortality死亡率

– varies with pathogen, but generally

lower than classical bacterial

pneumonia

• Known as “atypical pneumonia”非典型肺炎

– relates to presentation and response to

therapy in the pre-antibiotic era

Lab confirmation of mycoplasma,

coxiella and Chlamydophila psittaci

• By serology

– acute and convalescent bloods

– gold top vacutainer

實驗室檢查

Mycoplasma pneumoniae

• Common cause of community

acquired pneumonia

• Older children, young adults

• Person to person spread

黴漿菌肺炎

Coxiella burnetii (Q-fever)

• Diseases

– pneumonia

– pyrexia of unknown

origin (Q fever)

• Uncommon,

sporadic zoonosis

• Sheep and goats

• Complication

– culture negative

endocarditis

Chlamydia and respiratory

disease • Chlamydophila psittaci causes Psittacosis鸚鵡熱

– previously called Chlamydia psittaci

– uncommon, sporadic zoonosis

– caught from pet birds ,1879年首次於瑞士報告

• parrots, budgies, cockatiels

– psittacosis usually presents as pneumonia

Bronchiolitis

• Clinical presentation

– 1st or 2nd year of life

– Fever

– Coryza

– Cough

– Wheeze

• Severe cases

– grunting

– PaO2

– Intercostal / sternal indrawing

細支氣管炎

Bronchiolitis

• Aetiology

– >90% cases due to Respiratory Syncytial Virus (RSV)

• Lab confirmation

– By PCR on throat or pernasal swabs

– (direct IF on NPA in some labs)

• Therapy

– supportive

– nebulised ribavirin no longer used

Bronchiolitis

Epidemiology & Control

• Epidemics every winter

• Very common

• No vaccine

• Nosocomial spread in hospital wards

– cohort nursing

– handwashing, gowns, gloves

• Passive immunisation

– poor efficacy and cost-effectiveness

流行病學與疾病控管

Bronchiolitis

Complications

• Respiratory and cardiac failure

– prematurity

– pre-existing respiratory or cardiac

disease

• Scottish Intercollegiate Guidelines

Network

– SIGN guideline 91

Metapneumovirus

• First isolated 2001 children with

Acute Respiratory Tract Infection

– Nat Med 2001;7:719-24.

人類間質肺炎病毒

• 目前沒有任何抗人類間質肺炎病毒的藥物，僅以支持性療法進行治療。Ribavirin對呼吸道融合病毒有效，但是對人類間質肺炎病毒的效果不明。目前已有in vitro的實驗報告認為ribavirin或靜脈注射用的免疫球蛋白，會抑制人類間質肺炎病毒的複製。

治 療

Metapneumovirus

和氣喘的相關性

呼吸道感染在美國是5歲以下幼兒死亡原因的第二位，在台灣則是第四位。

並非所有的呼吸道感染性病毒都會誘發氣喘發作，暗示下呼吸道黏膜細胞可能有一些特殊受體，

被病毒結合後誘導不正常的免疫反應。

澳洲Rawlinson等研究179個確認有氣喘的病童，年齡均小於16歲。每次研究群中的孩童發生上呼吸道

感染時便採取鼻咽檢體檢測腺病毒、流感病毒、副流感病毒、人類間質肺炎病毒、呼吸道融合病毒，

並紀錄氣喘的發作情況，結果發現人類間質肺炎病毒和氣喘好像沒有關聯性。同樣北半球的

van den Hoogen在研究人類間質肺炎病毒時，也沒有觀察到和氣喘發作的關連性,其他的研究則顯示

不同的結果。芬蘭的研究顯示，在兩個連續的冬季，觀察132個病童，年齡4個月至13.5歲，當wheezing

發作時檢測其鼻咽檢體，結果有10人為人類間質肺炎病毒感染，其中又有7人為單純人類間質肺炎病毒感染。

香港中文大學的報告也指出，人類間質肺炎病毒感染導致的病人中，66.7%會造成氣喘急性發作，相對的

呼吸道融合病毒感染病人中僅有16.7%導致氣喘急性發作。以此來推測人類間質肺炎病毒是屬於比較容易

誘發氣喘發作的病毒。

林口長庚兒童醫院2001年8月至2002年7月期間在因社區性肺炎而住院之人，以reverse transcriptase

polymerase chain reaction (RT-PCR)方式檢測病人之鼻咽檢體是否有人類間質肺炎之感染。在收集116個社區性肺炎病人中，年齡分布3個月至18歲，平均4.52歲。共有95(81.9%)個人的致病原被確定。病毒感染有45人,細菌性感染有84(72.4%)人。其中人類間質肺炎病毒感染有6(5.2%)人。這6人中只有一位為2歲，其於為8-11歲之病童,男女各半。感染期間有4位在冬季(十月至次年一月)。他們均可發現混合感染的現象，細菌包括3位肺炎雙球菌，2位黴漿菌肺炎，及1位肺炎披衣菌。病毒有1位A型流感，1位副流感病毒第三型。胸部X光片檢查，4位為大葉性肺炎，2位為間質性浸潤增加。臨床表現包括發燒及咳嗽(100%)，流鼻水(83.3%)，肺部囉音(83.3%)，哮鳴(16.7%)。平均住院天數5.5±2.8天。這些病人在1至2星期後的門診追蹤皆全部康復而無其他併發症。混合其他呼吸道感染致病原是很常見的現象，包括細菌和病毒。

這些混合感染可能是先感染人類間質肺炎病毒感染，之後造成繼發性感染。其在肺炎病理機轉中所扮演的

角色仍不清楚。需進一步的研究。

Metapneumovirus

Metapneumovirus

Epidemiology

• Most children antibody(+) by age 5

• found in a wide range of ages

• Virus is newly discovered, not new

• World-wide distribution

• Highest incidence in winter

– 8% of samples in Canadian children’s

hospital

– J Clin Micro 2005;43:5520-5.

Metapneumovirus

Association with disease共同感染

• May be sole pathogen isolated

• Possibly second only to RSV in bronchiolitis

• Similar symptoms to RSV in both children and

adults

• Range of severity from mild to requiring ventilation

• Incidence of asymptomatic infection low (in

children at least)

– Williams JV et al. NEJM 2004;350:443-50 (and editorial)

• 2% of cases of influenza-like illness

– Emerging Infect Dis 2002;8:897-901

Laboratory confirmation

• PCR

Other recently discovered

respiratory viruses

• Bocavirus

• Various coronaviruses: SARS

Human bocavirus 人類博卡病毒 因為分子生物學發展的進步，近年來發現了許多新的呼吸道病毒。human bocavirus是最近兩年才被發現的DNA病毒，是其中一個最常被報告的呼吸道病毒，會造成呼吸道感染與急性腹瀉的症狀。最近，在日本和韓國均有研究報告，文獻上至今台灣尚無有關human bocavirus的報告。它是一種由PCR發現的病毒，造成的症狀與三年前流行的SARS-CoV病毒症狀類似。在2005年被學者Allander發現後，陸續在各個國家均有病例發生，均是造成兒童的下呼吸道感染，傳播途徑與潛伏期均未有明確之定論，它的角色可能與人類副肺炎病毒一樣，也是有可能會造成院內傳播，建議可以採行標準防護措施，以預防院內感染。希望國內能發展檢測此病毒的技術能力，建議可以針對疑似百日咳的病人做篩檢。

馬偕紀念醫院 紀鑫

Current Respiratory tests

• Samples for PCR: Throat swabs in viral

transport medium, bronchoalveolar lavage

(BAL), endotracheal aspirate etc

– Flu A, Flu B, parainfluenza 1-3, metapneumo,

adeno, RSV

Chlamydia trachomatis and

Chlamydophila pneumoniae and respiratory disease

• Chlamydia trachomatis

– STI which can cause infantile pneumonia

– diagnosed by PCR on urine of mother or pernasal

/ throat swabs of child

• Chlamydophila pneumoniae

– person to person (formerly Chlamydia pneumoniae)

– mostly mild respiratory infections

– may be picked up by test for Psittacosis

另類療法 : 花旗蔘與人蔘

Evidence-based Complementary and Alternative Medicine, Volume 2011, Article ID 282151,7 pages

North American (Panax

quinquefonius) and Asian

Ginseng (Panax ginseng)

Preparations for the Prevention

of Common cold in Healthy

Adults : A Systemic Reviews

Conclusions: there is insufficient

evidence that ginseng reduces the

incidence or severity of common colds

5 trials involving 747 participants

COLD-fx, the best-selling cold and flu

remedy in Canada & world-wide.

Summary

• Respiratory system can host a variety of

microbes. ECFA

• Normal flora in “restricted areas” 保護區

• Susceptibility depends on age, immune

system. 天助自助

• Some organisms are adept at evading

immune system. 魔高一丈

• Damage generally due to cytotoxicity and

inflammation. SARS

• Vaccines for some organisms. 洞燭先機