emerging foodborne pathogens

Emerging foodborne pathogens

黃顯宗

History

1970-1979

• A new and unfamiliar agent, Escherichia coli O27:H20, which caused outbreak of gastroenteritis in 1971.

• Disease outbreaks caused by Yersinia enterocolitica and Campylobacter jejuni were heard of near the end of the decade, but received little attention except from specialists in foodborne disease control.

1980-1989

• C. jejuni emerged as the leading cause of gastroenteritis in U.S.

• Y. enterocolitica was also identified in several outbreaks of gastroenteritis, most of them from dairy products.

• E. coli O157:H7 first appeared in 1982 and caused serious outbreaks.

• Aeromonas hydrophila also was recognized in the early part of the decade as a possible cause of foodborne disease.

• Beside the conventional V. cholerae and V. parahaemolyticus, other Vibrio species also attrached attention. L. monocytogenes also re-emerged as an important foodborne disease.

1990-

• Emerging of V. cholerae O139 in 1992

• Emerging of V. parahaemolyticus O3:K6 in 1996

• Cronobacter spp. (Enterobacter sakazakii )

全球性問題

• 縱然衛生情況，消費者知識，食品的加工處理等方面的進步，不可避免微生物所導致的食品致病在全球的公共衛生上仍然重要因子

• 全球而言， WHO 估計每年仍有約 15 億件下痢，三百萬五歲以下人口死亡，其中很顯著地因為食物中污染了動物來源的病菌或微生物毒素。

人畜共同 Zoonotic Diseases

• 人類病菌中， 60 % 是人畜共同疾病• 新生疾病中， 75 % 是人畜共同疾病

新生食品病原菌定義

• 最近才發生和認定者• 本來是已經確認的病原菌，不過近期在許

多地區快速地增加病例• 延伸至其他傳播的載體（媒介）• 近期在許多地區快速地增加病例• 多年來廣泛分布，不過，透過新方法的發

展，最近才被認定

• 造成許多人口的威脅，無論年齡、性別、生活或社經地位等

• 造成傷痛和死亡• 經濟的衝擊

新生食品病原菌影響

• 環境的變遷，氣候，科技等• 大量生產，全球供應• 經濟的發展• 國際旅遊與貿易• 人口特性的轉變• 公共衛生敗壞• 生活型態改變• 微生物的適應 adaptation

新生食品病原菌趨勢

全球食品病原普遍的原因 Poor sanitary conditions Malnutrition Changing demographics (increasing population of infants, elderly) Inadequate public health infrastructure Inadequate hygienic and technological conditions of food production Inadequate cooking, reheating and storage conditions Increasing tourism and international trade Increasing animal movement and insufficient control of borders Increasing international trade of animal and food Inadequate legislation and official control system Emerging/reemerging foodborne pathogens Acquisition of virulence and antibiotic genes by nonpathogenic

bacteria Adaptation and enhanced survival of pathogens in food Inadequate consumer education

Rapid changes

• Escherichia coli O157:H7 and the epidemic strain of Salmonella serotype Typhimurium Definitive Type 104 (which is resistant to at least five antimicrobial drugs), have become important public health problems.

• Well-recognized pathogens, such as Salmonella serotype Enteritidis, have increased in prevalence or become associated with new vehicles.

Altekruse SF, Cohen ML and Swerdlow DL. Emerging Foodborne Diseases. Emerg Infect Dis [serial on the Internet]. 1997, Sep [date cited]. Available from http://wwwnc.cdc.gov/eid/article/3/3/97-0304.htm

http://wwwnc.cdc.gov/eid/article/3/3/97-0304.htm

Rapid changes• Emergence in foodborne diseases is driven by the

same forces as emergence in other infectious diseases: changes in demographic ( 人口統計） characteristics, human behavior, industry, and technology; the shift toward a global economy; microbial adaptation; and the breakdown in the public health infrastructure.

• Addressing emerging foodborne diseases will require more sensitive and rapid surveillance, enhanced methods of laboratory identification and subtyping, and effective prevention and control.


http://wwwnc.cdc.gov/eid/article/3/3/97-0304.htm

Demographic changes• Because of in industrialized nations, the proportion of

the population with heightened susceptibility to severe foodborne infections has increased. In the US, a growing segment of the population is immunocompromised as a consequence of infection with human immunodeficiency virus (HIV), advancing age, or underlying chronic disease.

• Reported rates of salmonellosis, campylobacteriosis, and listeriosis were higher among HIV-infected persons than among those not infected with HIV. Salmonella (and possibly Campylobacter) infections are more likely to be severe, recurrent, or persistent


Human Behavior• Changes in food consumption have brought to light

unrecognized microbial foodborne hazards. • Fresh fruit and vegetable consumption, for example,

has increased nearly 50% from 1970 to 1994. • Fresh produce is susceptible to contamination during

growth, harvest, and distribution. • The surface of plants and fruits may be contaminated

by human or animal feces. Pathogens on the surface of produce (e.g., melons) can contaminate the inner surface during cutting and multiply if the fruit is held at room temperature.


Predicting the future

• They tend to cause infection at relatively low doses in humans, and to appear in food vehicles that are not subjected to cooking conditions that kill them.

• Many were first described in animals, so one place to look for new zoonotic public health threats would be in the index of a veterinary textbook of infectious diseases. 從畜產病去瞭解


• Another arena to search for foodborne pathogens is the unusual and exotic opportunistic pathogens that cause serious illness in the immunocompromised.


• New pathogens can arise because of new ecologies and technologies that bring existing pathogens into our food supply in new and surprising ways.

• For example, in 1996, 1465 persons in 20 states, the District of Columbia, and two Canadian provinces fell ill with a distinctive combination of recurrent diarrhea and extreme fatigue, caused by a recently recognized parasitic pathogen, Cyclospora cayetanensis （一種原生蟲） (Herwaldt, 2000). These illnesses were linked to eating fresh raspberries imported in the spring from Guatemala


• New pathogens can evolve when existing organisms acquire new virulence properties.

• Many enteric pathogens have virulence factors that are on mobile genetic elements, and appear to have acquired the critical pathogenic capacity as the result of horizontal evolution.

• For example, it has recently been shown that V. cholerae O1, the causative agent of cholera, harbors a filamentous phage that bears the cholera toxin genes

新生食品病原菌• 細菌• 病毒• 寄生蟲• 普恩蛋白 Prion

新生食品病原細菌• Salmonella (multidrug resistant strain)• Campylobacter jejuni• E. coli O157:H7• Listeria monocytogenes • S. aureus MRSA• Vibrios• Yersinia enterocolitica• Arcobacter spp. • Mycobacterium paratuberculosis

EMERGING OF NEW FOOD-BORNE PATHOGENIC BACTERIA

• Aeromonas species

• Edwardsiella tarda

• Enteric Viruses

• Plesiomonas shigelloides

• Vibrio species

• Cronobacter (Enterobacter) sakazakii

新生食品病原病毒

• Hepatit A and E

• Norovirus

• Avian influenza, AI

新生食品病原寄生蟲

• Cryptosporidium parvum 小隱孢子球菌• Cyclospora cayetanensis 環孢子蟲 • Anisakis spp. 異尖線蟲

全球食品中毒事件 1996 - 2006

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▼ Cryptosporidiosis, Leptospirosis, Lyme borreliosis

● Brucellosis, E. coli 0157, Salmonellosis

BSE

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Reference: WHO

美國情況Pathogen 每年新生食品中毒病例

預估 Cases No. of No. of

Ilnesses Deaths

每年經濟損失（ 10億元）

Campylobacter spp.

1,963,141 10,539 99 1.2

Salmonella non-typhoidal

1,341,873 15,608 553 2.4

E. coli O157:H7 62,458 1,843 52 .7

E. coli non-O157-STEC

31,229 921 26 .3

L. monocytogenes 2,493 2,298 499 2.3

Total 3,401,194 31,209 1,229 6.9

Reference: USDA’s Economic Research Service & CDC

世界部分 Campylobacter 中毒事件

年份國家中毒食品病人數 cases

2000 U.K & Wales Raw milk 333

2001-2002

Australia Chicken 601

2005 Denmark Chicken salad 4

2005 Scotland Chicken pate 82

2005-2006

U.S.A. Water 32

2007 U.S.A. Cheese (from unpasteurized milk)

67

2007 Denmark Water 16

Campylobacter jejuni

國家年份病人數複雜病情感染來源

Japan 1996 >5499 (students)

12 deaths Alfalfa

U.S.A 1999 321 - Beef

Canada 2000 27 5 deaths Water

Sweden 2002 39 - Fermented sausage

U.S.A 2002 34 5 HUS Ground beef

Netherlands 2005 32 - Steak tartare

U.S.A 2006 376 3 deaths Fresh spinach

世界部分 E. coli O157:H7 中毒事件

本國資訊• 腸病毒屬於小 RNA 病毒科（ Picornaviridae ），為一群病毒的總稱，在 1997 年

以前，已知而被分類的腸病毒共有小兒麻痺病毒（ Poliovirus ）共 3 型（ 1 至 3型）、克沙奇病毒（ Coxsackievirus ），含 23 種 A 型（ A1 至 A22 型， A24型）及 6 種 B 型（ B1-B6 型）、伊科病毒（ Echovirus ）共 30 型（ 1 至 33 型，但 8 、 10 及 28 型除外）及腸病毒（ Enterovirus ）（ 68 型～）等 60 餘型

• 近年來又陸續發現多種型別，依據基因序列分析結果將之重新歸類，分為人類腸病毒 A 、 B 、 C 、 D （ Human enterovirus A 、 B 、 C 、 D ）型，其中腸病毒71 型被歸類於人類腸病毒 A 型。

• 除了小兒麻痺病毒之外，以腸病毒 71 型（ Enterovirus Type 71 ）最容易引起神經系統的併發症，此病毒是在 1969 年美國加州的一次流行中首次被分離出來，當時引起很多無菌性腦膜炎與腦炎的病例。此後包括澳洲、日本、瑞典、保加利亞、匈牙利、法國、香港、馬來西亞等地都有流行的報告，台灣在十幾年前也曾經流行過，可見此型腸病毒的分布是全世界性的。

• 感染腸病毒 71 型後，發生神經系統併發症的比率特別高，但是嚴重程度各有不同，有的只出現腦膜炎、輕微腦炎、肢體麻痺等非致命性的併發症，有的則像1998 年台灣的流行一樣出現死亡病例，包括保加利亞、匈牙利、馬來西亞、日本都有過類似的情形，其可能的危險因子尚待進一步的探討與研究。

Vibrio species

Vibrio species

• Since 1992, a new pandemic strain of V.

cholerae O139 occurred and rapidly spread over

many countries (Faruque et al., 2003; Wong et

al., 2002).

• Occurrence of O3:K6 strains of V.

parahaemolyticus widely spread all over the

world and are recognized as the first pandemic

strain of this species (Chiou et al., 2000; Wong

et al., 2000).

Cronobacter (Enterobacter) sakazakii

• The severe consequences of infection in some cases may be linked to the production of enterotoxin by E. sakazakii.

• More than 20% of the 18 tested strains produced enterotoxin.

• When infection does not result in death, the affected infant may have permanent neurological or developmental deficiencies.

• Infants may be colonized with E. sakazakii without developing symptoms (Gurtler et al., 2005).

ANTIMICROBIAL RESISTANCE

如何控制食源性疾病

• 從農場至餐桌全程作業控管• 衛生品質保證制度的落實， GMP 和

HACCP

公共衛生的努力• Public health system

• Surveillance

• Epidemiology for earlier diagnosis

• Early response to outbreaks

• Provide to disease patterns changing

• Public health lab. support for rapid and accurate diagnosis

• Rapid communication links

• Communication to public

• Education on prevention and/or detection

參考文獻

Tauxe RV. 2002. Emerging foodborne pathogens. Int.J.Food Microbiol. 78:31-41.

http://bvs.panalimentos.org/local/file/inclusiones2008/7GSS_PULSENET_AVAN%C7ADO2008/II%20Curso%20Avanz%20WGSS-Taller%20WGSS-PulseNet/Resources%20for%20CD/Articles/tauxe.pdf

參考文獻

Newell DG, Koopmans M, Verhoef L, Duizer E, Aidara-Kane A, Sprong H, Opsteegh M, Langelaar M, Threfall J, Scheutz F, van der Giessen J, Kruse H. 2010. Food-borne diseases - the challenges of 20 years ago still persist while new ones continue to emerge. Int.J.Food Microbiol. 139 Suppl 1:S3-15. http://uesc.br/cursos/pos_graduacao/mestrado/animal/bibliografia2013/bianca_art1_newell.pdf

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