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4/14/2017 1 Infectious animal diseases Epidemiology and control measures Katsuaki Sugiura Global Animal Resource Science Nogaku Kokusai Tokuron 1 2017_0421 AGENDA : What are infectious diseases Interventions for the control of infectious animal disesases Foot and mouth disease Rabies African swine fever

Katsuaki Sugiura Global Animal Resource Science · Epidemiology and control measures Katsuaki Sugiura Global Animal Resource Science Nogaku Kokusai Tokuron 1 ... product Portugal,

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4/14/2017

1

Infectious animal diseases Epidemiology and control measures

Katsuaki Sugiura

Global Animal Resource Science

Nogaku Kokusai Tokuron 1 2017_0421

AGENDA :

• What are infectious diseases

• Interventions for the control of infectious

animal disesases

• Foot and mouth disease

• Rabies

• African swine fever

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What are infectious diseases

• Diseases caused by infection

• Infection is the invasion of the host animal by micro-organisms (viruses, bacteria, fungi and parasites) and their multiplication.

Disease cycle

Exposure

Incubation period

Latency period

Prodromal period

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Incubation period

Disease Incubation period

Influenza 1-3 days

HIV 2-3 months or longer

Measles 9-12 days

Rabies 1-3 months but varies from <1 weeks to >1 year

Foot and month disease 2-14 days

Rinderpest 3-15 days

African swine fever 3-15 days

BSE 2-9 years

Three factors involved in transmission of infectious diseases

Host (susceptible animals)

Pathogen (infected animals)

Environment (transmission media)

Direct transmission

Indirect transmission

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Transmissible diseases

Mode of transmission Examples

Direct contact Indirect contact Vector

Contagious ○ ○

African swine fever

FMD, Rinderpest

○ ○

Equine infectious anemia

○ Rabies

○ Strongylosis

Non-contagious

○ Arboviruses

Genetic defects

Epidemic patterns

8

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Basic reproduction number (Ro)

• Number of infections produced on average by an infected animal during its infectious period (generation time), when all contacts are susceptible.

• When Ro>1, epidemic occurs, and when Ro<1 epidemic does not occur.

• The value of Ro depends on the infectiousness of the disease, contact rate between animals, generation time.

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Basic reproduction number (Ro)

Human disease Transmission R0

Measles Airborne 12–18

Diphtheria Saliva 6–7

Smallpox Airborne droplet 5–7

Polio Fecal-oral route 5–7

Rubella Airborne droplet 5–7

Mumps Airborne droplet 4–7

HIV/AIDS Sexual contact 2–5

Pertussis Airborne droplet 5.5[2]

SARS Airborne droplet 2–5[3]

Influenza (1918 pandemic strain)

Airborne droplet 2–3[4]

Ebola (2014 Ebola outbreak)

Bodily fluids 1.5-2.5[5

Basic reproduction number (Ro)

Animal disease Transmission Ro

Foot-and-mouth disease

Air-borne 38.5

1964 UK epidemic

BSE Feed-born 400 1983-1988 UK epidemic

Rabies Saliva 1.05 1950 Tokyo epidemic

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Reproduction number changes

Impact by various diseases

Public health Spread Cost Trade

FMD - +++ +++ +++ Rabies +++ + + + BSE +++ + +++ +++ ASF - +++ +++ +++

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AGENDA :

• What are infectious diseases

• Interventions for the control of infectious

animal disesases

• Foot and mouth disease

• Rabies

• African swine fever

Possible interventions in free countries

• Import restriction policy for animals and animal products

• Disposal of waste food from international aircraft or ships

• Disinfection of international travelers' footwear

• Warning people • Early detection of infected

animals • Vaccination of susceptible

animals

Avoid pathogens and transmission

Immunize hosts

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Possible interventions in outbreaks

• Killing of infected animals • Cleaning and disinfection • Surveillance of infected area • Movement control of

susceptible animals • Avoid contact between

susceptible animals and vectors

• Vaccination • Treatment with

antimicrobials • ・・・

Combat pathogens

Avoid transmission

Immunize or treat hosts

Vaccination is not perfect

• Good vaccines provide long and strong protection.

• For diseases with a single antigenic type (e.g. rinderpest, rabies), vaccines produced with one simple strain of the pathogen is capable of conferring protection against any of the other strains of the same pathogen.

• Some vaccines only protect animals from the disease not from infection.

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Pros and cons of vaccination

(Pros)

• Provide clinical protection;

• Reduce circulation of the pathogen;

(Cons)

• Induce incidents or accidents;

• Interfere with screening techniques;

• Costly

Epidemiological structures that influences the vaccination result

• Single domestic species with no wild species or vector

• Several domestic species with no wild species or vector

• Several domestic and wild species with no vector

• Several domestic and wild species with vector

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Epidemiological context of rabies in Europe

Cattle

Foxes

Dogs Cats Other

Humans

Vaccination of foxes

Vaccination of humans

Vaccination of domestic animals

Wildlife cycle

Spillover

Domestic relay

AGENDA :

• What are infectious diseases

• Interventions for the control of infectious

animal disesases

• Foot and mouth disease

• Rabies

• African swine fever

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What is FMD

• A viral disease

• 7 serotypes

• Cloven-hoofed animals (cattle, sheep, goats, pigs, etc.) are susceptible

• Highly contagious

• Vaccines available (protect animals from the disease but not from infection)

What is FMD

• A viral disease

• 7 serotypes

• Cloven-hoofed animals (cattle, sheep, goats, pigs, etc.) are susceptible

• Highly contagious

• Vaccines available (protect animals from the disease but not from infection)

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World beef trade

口蹄疫の空気伝播 (1981年、フランス→英国)

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Three factors involved in transmission of FMD

Host (susceptible animals)

Pathogen (infected animals)

Environment (transmission media)

Direct transmission

Indirect transmission

Contaminated hands, footwear, clothing, vehicles; Contaminated meat products, milk; Contaminated semen;

Contact between animals

Contaminated aerosols; Airborne; Humans.

Interventions taken in free countries without vaccination

• Import restriction policy for animals and animal products

• Disinfection of international travelers' footwear

• Warning people not to visit farms

• Maintenance of early detection capability

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Interventions taken in free countries and zones with vaccination

• Import restriction policy for animals and animal products

• Maintenance of early detection capability of infected animals

• Vaccination of pigs, cattle and sheep

Possible interventions taken in outbreaks

• Killing of infected and contact animals

• Destruction of contaminated goods

• Movement control of animals, animal products

• Disinfection of vehicles, equipment and people

• Vaccination of animals at risk

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AGENDA :

• What are infectious diseases

• Interventions for the control of infectious

animal disesases

• Foot and mouth disease

• Rabies

• African swine fever

What is rabies?

• A viral disease

• All mammals are susceptible

• Transmit by direct contact

• 100% lethal

• Vaccine available

• PEP available

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Rabies free countries/areas

Three factors involved in transmission of Rabies

Host (susceptible animals)

Pathogen (infected animals)

Environment (transmission media)

Direct transmission

Indirect transmission

Contact between animals

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Interventions taken in rabies free countries

• Import restriction policy for animals

• Capability maintenance of early detection of infected animals and surveillance

• Registration of dogs

• Vaccination or no vaccination but with vaccine reserve

Interventions taken in rabies infected countries

• Vaccination of dogs (and wild animals)

• Registration of dogs

• Capturing of wild and free roaming dogs

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AGENDA :

• What are infectious diseases

• Interventions for the control of infectious

animal disesases

• Foot and mouth disease

• Rabies

• African swine fever

What is African Swine Fever

• A viral disease

• Pigs, warthogs, wild boars and some ticks are susceptible

• Highly contagious

• High mortality in pigs

• Resistant pathogen

• No vaccine available

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Direct transmission

Indirect transmission

Sucking Sucking

Ticks

Pigs Wild boars

How is ASF transmitted

Warthogs

Sucking

Direct and indirect transmission

ASF is maintained in Africa

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Sources of ASF infection from African continent into free areas

Transmission route Location and date of occurrence

Raw pork waste at airport/port

Lisbon, 1957 Sao Tome, 1979 Madagascar, 1998 Georgia, 2007

Movement of pork or pig product

Portugal, 1960

Sources of ASF infection into other countries

Transmission route Location and date of occurrence

Raw pork waste at airport/port

Malta, 1978 Sardinia, 1978 Dominican Rep., 1978 Cuba, 1980

Movement of pork product

Spain, 1960* France, 1964* Italy, 1983 Belgium, 1985*

Natural ranging of infected wild boar

Russia, 2007 Lithuania, 2014 Poland, 2014 Latvia, 2014 Estonia, 2014

Movement of pigs Haiti, 1978

*Smuggling of pig products

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European situation

0

50

100

150

200

250

300

2007 2008 2009 2010 2011 2012 2013 2014 2015

1 7

18 22 14 9 13

261

166

18

39 35

54 50 58 57

75

13

of

anim

als

infe

cted

Wild boar

Domestic swine

Three factors involved in transmission of ASF

Host (susceptible animals)

Pathogen (infected animals)

Environment (transmission media)

Direct transmission

Indirect transmission

Infected pork products Ticks Premises, people and trucks

Contact between animals

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Interventions taken in countries free from ASF

• Import restriction policy for animals and animal products

• Disposal of waste food from international aircraft or ships

• Sterilization of garbage

• Maintenance of early detection capability

Possible interventions taken in outbreaks

• Killing of infected and contact animals

• Destruction of contaminated goods

• Movement control of animals, animal products

• Disinfection of vehicles, equipment and people

• Avoid contact between pigs and tick vectors (endemic African countries)