Approximately 75% of recently emerging infectious diseases affecting humans are diseases of animal origin; approximately 60% of all human pathogens are zoonotic.

Zoonoses and Veterinary Public Health

DVM, PHD, OKAMOTO KarokuProf. Veterinary Public Health, Dep. Veterinary Medicine,

Fac. Agriculture, Kagoshima University

Quoted from CDC, USA

SARS2003

palm civet et.al

HPAI H5N11997/2003Water birdBSE

1986/1993Cow

West Nile1999

Bird/Mosquito

H1N1 Pandemic2009

Swine/Bird

Nipah virus1998

Megabat/Swine

Ebola1976

Monkey

HPS1993

Rodentia

Hendra virus1994

Megabat/Horse

Lassa1969

Rodentia BzHF1994

RodentiaVzHF1991

Rodentia

E. Coli O1571982

Cow/Food

Examples of emerging infectious disease(Pathogen, Year, Natural reservoir)

HPS: Hantavirus Pulmonary SyndromeSARS: Severe Acute Respiratory Syndrome

Venezuelan & Brazilian Hemorrhagic Fever

Annex 2 Decision instrument for the assessment and notification of eventsInternational Health Regulations(2005): IHR 2005

Event detected by national surveillance systemNational IHR Focal Point

Event shall be notified to WHO under the International Health Regulations

● Small pox● Poliomyelitis(wild type)● Influenza(new subtype)● Severe acute respiratory syndrome (SARS)

● Cholera● Plague● Yellow fever● Viral haemorrhagic fevers(Ebola, Lassa, Marburg)● West Nile fever● Others(Dengue fever, Rift Valley fever)

DOES THE EVENT MEET AT LEAST TWO OF THE FOLLOWING CRITERIA?I. Is the public health impact of the event serious?II. Is the event unusual or unexpected?III. Is there a significant risk of international spread?IV. Is there a significant risk of international travel or trade restrictions?

Each State Party shall notify WHO within 24 hours of assessment.

Diseases in the red are zoonoses.

Many of zoonoses have the potential to spread through various means over long distances and to become global problems. Calvin W. Schwabe(1927 – 2006)

Veterinary Epidemiology, UC Davis

Classification of ZoonosesDr. Schwabe provided the following classification system of

zoonoses based on the type of life cycle of the pathogen.

Direct zoonoses are transmitted from an infected vertebrate host to another host by direct contact, fomite or mechanical vector. The pathogen does not undergo developmental change or propagation during the transmission.

Cyclozoonosis requires more than one vertebrate host but no invertebrate host is needed. An example is echinococcosis.

Metazoonoses does require an invertebrate host where the pathogen multiples or develops before it can infect a vertebrate host.

Saprozoonoses are diseases transferred through a non-animal reservoir, such as a plant, or through the abiotic environment, such as through water or soil.

Cyclozoonosis

Metazoonoses

Direct zoonoses

Saprozoonoses

an vertebrate host

Avian influenza, Rabies, Hantavirus, Psittacosis, Bovine tuberculosis, Brucellosis, E. coli O157, Anthrax

an invertebrate host

West Nile fever, Yｅｌｌｏｗ　ｆｅｖｅｒ , Ｒｉｆｔ　Ｖａｌｌｅｙ　ｆｅｖｅｒ , Plague, Aｎｉｓａｋｉａｓｉｓ

more than one vertebrate host

Echinococcosis, Cｙｓｔｉｃｅｒｃｏｓｉｓ , Toxoplasmosis, Tｒｉｃｈｉｎｉａｓｉｓ

non-animal reservoir

Tetanus, Bｏｔｕｌｉｓｍ , Aｓｐｅｒｇｉｌｌｏｓｉｓ , Hｉｓｔｏｐｌａｓｍｏｓｉｓ , Tｏｘｏｃａｒｉａｓｉｓ , Fascioliasis, Anthrax

Calvin Schwabe One Health ProjectA CENTER OF EXCELLENCE AT THE INTERSECTION OF HUMAN,

ANIMAL, AND ENVIRONMENTAL HEALTH

Our MissionTo strengthen the UC Davis School of Veterinary Medicine's commitment to the One World-One Health movement by educating veterinarians of the future to integrate human, animal, and ecosystem protection into their professional lives.

The Calvin Schwabe One Health Project fosters a diverse and sustainable planet, with the goal of encouraging a new generation of veterinary expertise in the integration of better health for humans, animals, and their environment. To that end, One Health expands career pathways for veterinary students in disciplines such as public practice, wildlife and ecosystem health, food safety, herd health, disaster preparedness, rural health, and zoonotic disease threats.

The World Health Organization Expert Committee on Zoonoses came up with the classification system of zoonoses provided by Dr. Schwabe.

BirdMosquito

Other animals

Equine

Human

１．WNV is spread by the bite of an infected mosquito (vector). ２．Mosquitoes become infected when they feed on infected birds(Reservoir).３．WNV can cause most clinical cases in humans and horses that does generally not allow transmission to others(Dead-end host).

Metazoonoses West Nile fever

Life cycle of West Nile virus (WNV)

Dead-end host

Reservoir host

Vector

Many of zoonoses have the potential to spread through various means over long distances and to become global problems.

Endemic area of Japanese encephalitis and West Nile fever

West Nile fever suddenly occurred in the New York in 1999 .

A mosquito traveled by air?

★

WNV Positive mosquito

Human case

Spread of West Nile virus in New York City in 1999

WNV Positive ratio of dead birds

Kennedy International AirportA mosquito arrived at this terminal.

Newark Liberty International Airport

0

2000

4000

6000

8000

10000

19992000

20012002

20032004

20052006

20072008

No. of patients

fatality rate(%)

02468

101214161820

62 2166

Progression of West Nile fever in USA(1)

Initial high fatality rate may due to the following reasons. 1. Diagnostic and treatment system were not prepared.2. The number of patients in mild was increased with the progression of surveillance. 3. Acquisition of immunity.

WNV amplification between birds and mosquitoes took three years.

0

50

100

150

200

250

300

19992000

20012002

20032004

20052006

20072008

No. of death No. of State affected

0

10

20

30

40

50

60Why the number of death in 2002 was more than in 2003 when the number of patients peaked.

WNF occurred in almost all Sates in 2002, and many people acquired immunity.

Progression of West Nile fever in USA(2)

Small pox Smallpox is an infectious disease unique to humans(not zoonosis), caused by Variola virus. The fatality rate for flat-type is 90% or greater and nearly 100% is observed in cases of hemorrhagic smallpox.

Smallpox is believed to have emerged in human populations about 10,000 BC. In the early 1950s an estimated 50 million cases of smallpox occurred in the world each year.

To eradicate smallpox, each outbreak had to be stopped from spreading, by isolation of cases and vaccination of everyone who lived

close by. This process is known as "ring vaccination".

The global program on smallpox eradication initiated by WHO in 1958 and intensified since

1967. The global eradication of smallpox was certified by a commission of eminent scientists on December 1979.

Hemorrhagic-type smallpox.

Family: Poxviridae

Subfamily: ChordopoxvirinaeGenus: Orthopoxvirus

Camelpox virusCowpox virusEctromelia virus Monkeypox virusRaccoonpox virusTaterapox virusVaccinia virusVariola virusVolepox virus

Genus: ParapoxvirusBovine papular stomatitis virusOrf virusParapoxvirus of red deer in New ZealandPseudocowpox virus

Virus families not assigned to an order(65 Families)

Orthopoxvirus is a genus of poxviruses that includes many species isolated from mammals. Although Variola virus infects only human, some Orthopoxviruses have the ability to infect non-host species, such as monkeypox virus.

I now offer a few topics related with small pox eradication.

Monkeypox

Monkeypox was first found in 1958 in laboratory monkeys. African squirrels might be the common host for the disease. Rats, mice, and rabbits can get monkeypox, too.

Direct zoonoses

Seven years old girl in Republic of Zaire

Human monkeypox

Monkeypox is an exotic infectious disease caused by the monkeypox virus, and is usually transmitted to humans from rodents, pets, and primates through contact with the animal's blood or through a bite.

Human monkey pox can be difficult to distinguish clinically from smallpox. Case-fatality ratios in Africa have ranged from 1% to 10%.

It is assumed that vaccination against smallpox would provide protection against human monkeypox infection. Since the eradication of smallpox in 1979, human case increase gradually.

Six months later, she healed but many pockmark remained.

Distribution of 52 confirmed cases of human monkeypox.

Endemic Human Monkeypox, Democratic Republic of Congo, 2001–2004Emerg Infect Dis. 2007

Monkeypox positive/No. cases investigated

Age

<45–14

15–2425–34>35

Total

male

8/1212/225/172/91/6

28/66

female

7/219/198/130/81/7

24/68

Age and sex distribution of patients with monkeypox

Among 136 patients, 51 (37.5%) had laboratory-confirmed MPX infection, 61 (44.8%) had laboratory-confirmed chickenpox virus infection, and 1 (0.7%) had coinfection.

Movement of imported African rodents to pet shops and distribution of prairie dogs from a pet shop associated with

human cases of monkeypox, in 2003 USA.

All 35 human cases of monkeypox were associated with prairie dogs.

African rodents were resell to Japan, but 15 already dead before arrival and lived two rodents was not infected.

MMWR 2003Rodents and prairie dogs contacted with each other.

762 rodents

Cowpox and Pseudocowpox virusIn 1796, Dr Edward Jenner used “cowpox

virus” to inoculate a patient to prevent them from contracting smallpox. Discovery of virus is in 1892(tobacco mosaic disease), so it is not as clear what virus he used for vaccine 100 years ago. In fact, milker's nodule is usally caused by a parapox virus(Pseudocowpox), not by cowpox virus.

Milker's nodules

Nowadays, cowpox is a rare disease. It mostly occurs in Great Britain and some European countries. Cows are no longer the main carrier of the virus; instead woodland rodents are the natural hosts of the virus who then pass it on to domestic cats. Feline cowpox virus infection

What is cowpox?

Cowpox Virus Transmission from Pet Rats to Humans

16 years old boy

Germany: Outbreak including 5 patients caused by infected pet rats from the same litter in 2009. Human cowpox infections seem to be increasing. One obvious reason for an increase might be the fading cross-protective immunity to cowpox after the cessation of small pox vaccination.

Human cowpox is a disease of young people, with half of all cases occurring in individuals younger than 18 years, because of their not having been vaccinated for smallpox, which may confer some protection against cowpox.

VARV: Variola virus

VACV: vaccinia virus

CPXV: cowpox virus

VACV species imported to Brazil in 1804, when human vaccine arrived at a port on the arms of slaves returning from Portugal. The species was maintained in this manner(arm to arm) and in 1887 the first animal vaccine was produced in calves. In 1963, Brazilian VACVs(Group 1, 2) was isolated from the blood of a rice rat captured near the edge of Amazon rain forest. Since then, those virus were naturally isolated from a wild rodent. In 1999, exanthematous outbreaks affecting dairy cattle and their handlers were reported.

Brazilian VACVs existed before the beginning of the WHO smallpox eradication vaccination campaigns.

Original animal vaccine strein imported in 1887

Brazilian Vaccinia Viruses and Their Origins

The virus that Dr. Edward Jenner used for vaccination derived from milker's nodule in 1796 may be Brazilian VACVs.

Voyages of Christopher Columbus(1492-1504)

Cyclozoonosis Echinococcosis(Hydatid Disease)

Skunk, liver. The inner surface of the cyst is lined by hydatid sand, and the cyst is surrounded by a thick capsule of fibrous connective tissue

Human, liver. Multiple thin-walled hydatid cysts project from the capsular surface of the liver.Iowa Sate Univ.: CFSPH

Humans are accidental intermediate hosts and are not able to transmit the disease. There are areas of high endemicity in southern South America, Mediterranean coast, southern part of Russia, Middle East, south-western Asia, northern Africa, Australia, Kenya, New Zealand and Uganda.

Relate to wool industry

WHO: Echinococcosis

Oral intake

Echinococcus granulosus

Echinococcus multilocularisDefinitive Host

Intermediate Host

Fox

Dog

E. multilocularis is found primarily in the northern hemisphere. It is widely distributed in continental Europe, and also occurs in much of northern and central Eurasia eastward to Japan (where it is found only on the island of Hokkaido), and in North America, where it primarily occurs in Canada, Alaska and the north central U.S. from Montana to central Ohio.

Cat

ingesting eggs shed in the

feces

Rodent

predatism

CFSPH: Echinococcosis

For the production of fur, red foxes were imported in Rebun island in 1924. First patient with hydatid cyst was detected in 1937, after a lapse of 2 years reaching 129 patients. Hokkaido authorities gave instructions to destroy all foxes and stray dogs.

Although the outbreak resolved, a hydatid patient was detected in east area of Hokkaido in 1965, and infection of Ezo red foxes were confirmed diffusely.

Nuber of points capturedNuber of foxes capturedNuber of positive foxesPositive rate(%)

Before1989-98

1995,157

3136.1

After2000-05

1483,840

180.5

Rebun island

Several monkeys, gorillas and orangutans died by hydatid desease in 2 zoological gardens in 1992 and 1994. By this circumstance, the Zoo were forced to shut.

in 1965

Since 1999, anthelmintic pellet including Praziquantel(Biltricide: effective against flatworms) were put in place widely where foxes are ranging.

Since then, about 10 patients each year continues to suffer the disease.

キツネの駆虫に関するガイドライン 参考資料

19661968

19701972

19741976

19781980

19821984

19861988

19901992

19941996

19982000

20022004

20062008

0

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30

40

50

60

70

80

Progression of prevalence of Echinococcosis in the foxes and dogs at Hokkaido through 1966-2008.

No. of foxes captured: 25,358No. of hydatid foxes: 5,174

Positive rate: 20.4%

北海道におけるエキノコックス症対策の経緯

No. of stray dogs : 9,945No. of hydatid dogs: 99

Positive rate: 1.0%

8

7

6

5

4

3

2

1

0

Dog

Fox

Echinococcus specific PCR using Cox1 primer

19831984

19851986

19871988

19891990

19911992

19931994

19951996

19971998

19992000

20012002

20032004

20052006

20072008

0

0.05

0.1

0.15

0.2

0.25

0.3

北海道におけるエキノコックス症対策の経緯

Number of pigs slaughtered: 27,321,373Number of hydatid pigs: 31,253

Positive rate: 0.11%

Progression of prevalence of Echinococcosis in the pig slaughtered at Hokkaido through 1983-2008.

Saprozoonoses Anthrax

Pasteur's Vaccine of Anthrax in Australia: as a preventative against Cumberland Disease in sheep, cattle and horses.

The trial was held under the supervision of two graziers and three government officials at Junee Junction in Australia during September and October 1888. The trial was undertaken on 39 sheep and 6 cattle. It was a complete success: all vaccinated animals remained in very good health, whereas all 19 unprotected sheep and one of the two non-vaccinated cows died within a few days.

In May 1881 Louis Pasteur performed a public experiment to demonstrate his concept of vaccination.

When conditions are not conducive to growth and multiplication of the vegetative bacilli, B. anthracis tends to form spores. These spores are extremely resistant to inactivation by heat or chemicals, and can survive in the environment for decades.

Rain and other agents can disperse the spores to other locations. Heavy rains, alternating with dry periods, may concentrate the spores and result in outbreaks among grazing animals.

Spores and vegetative cells of B. anthracis

Capsulated B. anthracis in the blood of an animal that has died of anthrax.

Virtually all mammals and some birds can contract anthrax, but susceptibility varies widely and most clinical cases occur in wild and domesticated herbivores. Cattle, sheep, and goats are considered to be highly susceptible; horses somewhat less so. Pigs, other omnivores, and carnivores are more resistant to disease, but they may become ill if the dose is high. Birds are highly resistant.

Bloody discharges from the nose, mouth, and anus

Enlarged spleen has a ‘blackberry jam’ consistency.

20,000-100,000 cases estimated globally/year

Louisiana State Univ.: World Anthrax Site

Human case rates for anthrax are highest in Africa and central and southern Asia. Where the disease is infrequent or rare in livestock, it is rarely seen in humans.

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19081910

19121914

19161918

19201922

19241926

19281930

1932

Human

Equine

Cow

Occurrence of Anthrax in Kagoshima prefecture through 1908-1932

Nu

mb

er o

f ca

ses The bone meals imported from

China and Korea in Meiji period were contaminated with Anthrax spores.

It was revealed that the application of bone meal was very effective to crop growth in Kagoshima Prefecture consisting of volcanic ash soils in the middle of Edo period.

Numer of cattles with Anthrax in Japan, 1960-2000

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6019

60

1964

1968

1972

1976

1980

1984

1988

1992

1996

2000

Nu

mb

er o

f ca

ses

In Japan, only one animal-Anthrax case in several years was reported recently. The spores still may be distributed in the soil, the number of them do not reach the onset dose.By the oral route, minimum infectious dose for sheep was 3.5 x 10 4 spores and that the dose needed to ensure lethal infection in sheep, horses and cattle was 5 x 108 spores.

WHO: Anthrax in humans and animals

Wood bison is designated as the Status of Endangered Wildlife in Canada

Number of bisons died of anthrax in Canada

0

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350

400

1962

1963

1965

1967

1968

1971

1978

1991

1993

2000

2001

Nu

mb

er o

f d

eath

sDuring the first documented outbreak of anthrax, in the

summer of 1962, 281 bison died in the eastern Slave River Lowlands. Outbreaks soon became widespread,

extending during the course of the next few years to as far south as bison herds in the Sweet Grass area.

Wood Buffalo National ParkSlave River Lowlands Mackenzie BisonLiard River Valley (Nahanni)

450018001555

400

Number of Bisons in National Park

Wood Bison in the NWT

No cases of human anthrax have been diagnosed in the last two decades in Canada.

Distribution by decade of 75 cases of anthrax in humans in Texas, 1935 to 2001.

CDC: Epizootiology and Ecology of Anthrax

Cutaneous anthraxEarly 1900s: 200 cases annuallyLate 1900s: 6 cases annually

Inhalational anthrax20th century: 18 cases/16 fatal

Anthrax in U.S.

Outbreaks of anthrax in wild animals including bison were a public health threat in United States, formerly.

2001 Anthrax Letters

• 22 cases– 11 cutaneous– 11 inhalational

• 5 deaths (all inhalational)– Index case in Florida– 2 postal workers in Maryland– Hospital supply worker in New York City– Elderly farm woman in Connecticut

2001 anthrax attacks

Who did it for what purpose?The truth has not been revealed until now.

The second letter dated at 9 November

• Japanese religious cult• 1993

– Unsuccessful attempts at biological terrorism– Released anthrax from office building

• Vaccine strain used – not toxic– No human injuries

• Successful attempt in 1995– Sarin gas release in Tokyo subway– 1,000 injured – 12 deaths

Guru in the cult

Aum Shinrikyo

A group behaving fanatically would exist in any country. It is an unavoidable phenomenon resulting from the mentally suffering society.

The International Health Regulations (2005) provide not only the ability of the world community to cope with public health emergencies affecting more than one country, but they have important implications for biosecurity, including the response to transborder incidents involving the accidental or deliberate release of biological or chemical agents or radiological materials.