overview of high consequence livestock pathogens for veterinarians

Overview of High Consequence Livestock Pathogens

For veterinarians

Center for Food Security and Public Health Iowa State University 2004

USDA High Consequence

Livestock Pathogens and Toxins

USDA High Consequence

Livestock Pathogens and Toxins


Disease AwarenessDisease Awareness• Veterinarians recognize animal

diseases at the local level• Prepare by knowing

−Typical signs of diseases−Basic disease etiology−Economic and trade impact−How to report suspected cases

• Disseminate knowledge


OverviewOverview

• Importance of agriculture and livestock to U.S. economy

• High consequence livestock pathogens−CDC’s Category A, B, C Bioterrorism

Agent List−Additional diseases

• Veterinarian’s responsibilities

Importance of Agriculture & Livestock


U.S. AgricultureU.S. Agriculture

• Exports are our lifeblood−2003, $56.2 billion exported in

agricultural commodities $12.2 billion from animal/animal

products

• Some diseases reportable to the OIE−Trade could be halted

• Negative effect on economy, livestock/grain producers, and employment rate


U.S. Animal Data, 2003U.S. Animal Data, 2003

Animal Number Value

Cattle 94.9 million ~$70.5 billion

Pigs 60 million ~$4.5 billion

Poultry (non-broiler)

338 million ~$1 billion

Sheep 6.1 million ~$600 million


Some Agents are ZoonoticSome Agents are Zoonotic

• Disease may be seen in animals before humans

• Animals are sentinels−Pets, livestock, wildlife

• Protect yourself • Educate your clients about the risks


Biosecurity: VeterinariansBiosecurity: Veterinarians• Disinfect your clothes, boots, equipment

between farms• Avoid vehicle contamination• Follow biosecurity guidelines set forth by

species-specific associations

CDC Category ABC Agent Overview


ClassificationClassification

• Prepared by the CDC’s Bioterrorism Preparedness and Response Office

• Category A: Highest priority• Category B: Second highest priority• Category C: Third highest priority


CDC Category ABC AgentsCDC Category ABC Agents

Category A• Anthrax• Botulism• Tularemia

Category C• Nipah

Category B• Brucellosis• Glanders• Melioidosis • Q Fever• Viral

encephalitis• Toxins


“Weaponization” of Agents“Weaponization” of Agents

• Alter characteristics of a pathogen to make it a more effective weapon−Enhance transmission− Increase virulence−Resistant to antibiotics−Evade vaccine protection −Alter clinical signs


Note to presenterNote to presenter

• As time allows select diseases you would like to review.

• The CDC Category A,B,C diseases are listed first, and then you will see the additional High Consequence Livestock Pathogens.

• The disease coverage is brief. If you would like more information on a disease, refer to the fact sheet or to the disease specific presentation.

CDC Category A

AnthraxBotulismTularemia


Anthrax: The AgentAnthrax: The Agent

• Bacillus anthracis – Gram positive spore-forming bacteria

• Forms spores• Human disease

−Skin− Intestinal−Pulmonary

• Animal disease−Septicemia and rapid death


Anthrax: The BioweaponAnthrax: The Bioweapon

• History• Available & easily

produced• Spores infective• Aerosolization• Low lethal dose• High mortality• Person-to-person transmission rare


Anthrax: The ResponseAnthrax: The Response

• Vaccine−Humans−Animals

• Antibiotics−Treatment−Prophylaxis

• Disinfection −Sporicidal agents, sterilization


Botulism: The AgentBotulism: The Agent

• Clostridium botulinum – Gram positive, spore-forming bacteria

• 7 different neurotoxins −Types A-G

• Clinical signs−Flaccid paralysis−Pigs, dogs, and cats

fairly resistant


Botulism: The BioweaponBotulism: The Bioweapon

• Used by Aum Shinrikyo cult in Japan

• Aerosolized• Easy to produce and

transport• Potent and lethal• Most poisonous substance

known


Botulism: The ResponseBotulism: The Response

• Toxoids for high risk people• Antitoxin available

−Case-by-case basis

• Botulinum toxins are easily inactivated with many disinfectants and heat


Tularemia: The AgentTularemia: The Agent

• Francisella tularensis• Transmitted by ingestion,

inhalation, vectors, direct contact through skin

• Six clinical forms in humans

UlceroglandularGlandular


Tularemia: The AgentTularemia: The Agent

• Sheep, young pigs, horses, dogs, cats• Sudden fever, lethargy, stiffness,

prostration, and death

• Wildlife• Usually find dead• Rabbits behave strangely

• Cattle, older pigs resistant


Tularemia: The BioweaponTularemia: The Bioweapon

• Stable • Aerosolized• Low infective dose via inhalation• Case fatality: 30-60% (untreated)• WHO estimation: 1970

−50 kg agent: City population 5 million 250,000 ill 19,000 deaths


Tularemia: The ResponseTularemia: The Response

• Person-to-person transmission not documented

• Antibiotics effective, if early or prophylactic

• Vaccine−For high risk individuals−Unknown efficacy

against inhalational tularemia

CDC Category BBrucellosis Q FeverGlanders ToxinsMelioidosis Viral Encephalitis


Brucellosis: The AgentBrucellosis: The Agent

• Gram-negative bacteria• Ingestion, inhalation, or

direct contact• Clinical signs

−Humans: cyclic fever and flu-like symptoms

−Animals: reproductive signs


Brucellosis: The AgentBrucellosis: The Agent

Species Natural HostHuman

Pathogen

B. abortusCattle, bison, elk,

horsesYes

B.melitensis Goats, sheep, cattle Yes

B. suisSwine, hares, reindeer,

caribou, rodentsYes

B. canis Dogs, other canids Yes

B. ovis Sheep No


Brucellosis: The BioweaponBrucellosis: The Bioweapon

• History• Highly infectious• Easily aerosolized• Stable • Prolonged incubation period

−May make diagnosis difficult

• Person-to-person unlikely


Brucellosis: The ResponseBrucellosis: The Response

• Long term antibiotics generally effective

• Vaccinate calves, no human vaccine• Eliminate reservoir• Standard precaution to

avoid exposure• Thorough disinfection


Glanders: The AgentGlanders: The Agent• Burkholderia mallei: Gram-negative • Transmission by ingestion,

inhalation, or direct contact−Animal-to-human transmission

is inefficient

• Clinical signs−Humans & horses: cutaneous &

pulmonary lesions, rapidly fatal illness


Glanders: The BioweaponGlanders: The Bioweapon

• History−WWI Russian horses−WWII Chinese civilians, horses, POW’s

• Easy to produce• Aerosolized, highly infectious• Mortality high in chronic form

−50-70%

• Person to person transmission: Rare


Glanders: The ResponseGlanders: The Response

• No vaccine • Antibiotic therapy likely effective• Destroyed by various chemicals


Melioidosis: The AgentMelioidosis: The Agent

• Burkholderia pseudomallei: Gram-negative

• Transmission: Contact, ingestion, inhalation

• Clinical signs: Humans, sheep, goats, and pigs−Asymptomatic to

pneumonia, lung and wound abscesses


Melioidosis: The Bioweapon Melioidosis: The Bioweapon

• Easy to produce • Available• Aerosolization• High mortality: 90%• Person-to-person (rare)• Animal-to-person (rare)


Melioidosis: The ResponseMelioidosis: The Response

• Long-term, multiple antibiotics effective

• Vaccines available: not in U.S.

• Easily destroyed by disinfectants


Toxins: The AgentsToxins: The Agents

• Staphylococcal enterotoxin B (SEB)

• Ricin toxin from castor plant

• Clostridium perfringens epsilon toxin


SEB: The AgentSEB: The Agent

• Staphylococcal enterotoxin B (SEB)• A common cause of food poisoning • Clinical signs: Humans

−Fever, chills, headache, myalgia−Non-productive cough if inhaled−GI signs if swallowed

• Animals: Likely similar to human


Ricin: The AgentRicin: The Agent

• Ricin toxin from bean of castor plant • Available worldwide• Clinical signs

−Acute onset of fever,chest tightness, cough,

dyspnea, nausea


Epsilon Toxin: The AgentEpsilon Toxin: The Agent

• Clostridium perfringens type B and D• Increases intestinal and vascular

permeability, liver and neurological damage

• Clinical signs−Calves: Diarrhea, abdominal pain,

listlessness, neurologic−Sheep, goats: Watery to bloody

diarrhea, neurologic−Humans: Little information


Toxins: The BioweaponToxins: The Bioweapon

• History• Aerosolized: SEB, ricin • Available worldwide• Easy to produce, stable• Many species affected• No person-to-person transmission


Toxins: The ResponseToxins: The Response

• Supportive care• No vaccines currently available for

SEB or ricin• Vaccines for animals for clostridial

disease• Toxins are inactivated with common

disinfectants


Viral Encephalitis: The AgentViral Encephalitis: The Agent

• The Alphaviruses: EEE, WEE, and VEE• Transmitted via mosquito• Clinical signs

−Humans, horses, donkeys,mules: Often asymptomatic to flu-like

−Encephalitis in small proportions

• Birds are asymptomatic carriers, act as sentinels


Viral Encephalitis:The Bioweapon

Viral Encephalitis:The Bioweapon

• Easy to produce• Aerosolization• High rate of infection• Person-to-person transmission

possible


Viral Encephalitis:The Response

Viral Encephalitis:The Response

• Supportive care• Vaccine

−Equine−Human: High risk

• Virus unstable in environment

CDC Category C

Nipah


Nipah Virus: The AgentNipah Virus: The Agent

• Paramyxovirus• Fruit bat reservoir• Clinical signs

−Humans: Encephalitis−Pigs: Respiratory, neurological−Dogs and cats: “Distemper”


Nipah Virus: The BioweaponNipah Virus: The Bioweapon

• Aerosolization potential

• Wide host range• No person-to-person

transmission expected

• High morbidity and mortality


Nipah Virus: The ResponseNipah Virus: The Response

• Avoid contact with all infected animals and fluids

• Vaccine being researched• Call authorities

immediately


Other Important Diseases

Other Important Diseases

• Rift Valley Fever• Hendra Virus


Rift Valley Fever: The AgentRift Valley Fever: The Agent

• Phlebovirus in family Bunyaviridae• Transmission: Mosquito, inhalation,

contact with infected body fluids• Clinical signs

−Humans: Flu-like, fever, headache Severe disease: Retinitis, hemorrhagic

fever

−Animals: Abortions, death in neonates


Rift Valley Fever: The Bioweapon

Rift Valley Fever: The Bioweapon

• WHO estimate: 1970−50 kg of virus aerosolized−35,000 incapacitated−400 deaths (1% mortality)

• Stable at most temperatures• Inactivated by various chemicals


Rift Valley Fever: The Response

Rift Valley Fever: The Response

• Vaccinate ruminants in endemic areas

• Control mosquitoes• Avoid contact with

infected tissues & blood−Wear protective clothing

• No person-to-person transmission


Hendra Virus: The AgentHendra Virus: The Agent

• Newly discovered−Australia

• Fruit bats• Transmission: Urine, body fluids• Humans

−Flu-like illness, respiratory failure• Horses, cats

−Acute respiratory signs, nasal discharge, fever, encephalitis, sudden death


Hendra Virus: The ResponseHendra Virus: The Response

• Little is known about disease• Highest level of security to work with

the agent• Potentially serious consequences

−High mortality rate−Lack of treatment

Additional High Consequence Livestock Pathogens




• African horse sickness• African swine fever• Akabane• Avian influenza (HP)• Bluetongue• BSE• Classical swine fever• Coccidioidomycosis• Contagious bovine

pleuropneumonia• Contagious caprine

pleuropneumonia• Foot and mouth disease

• Heartwater• Japanese encephalitis• Lumpy skin disease• Malignant catarrhal fever • Menangle• Newcastle disease• Peste des petit ruminants• Rinderpest• Screwworm myiasis• Sheep/goat pox• Swine vesicular disease• Vesicular stomatitis


World Organisation for Animal Health

World Organisation for Animal Health

• Early Warning System

• Disease reported within 24 hours

• Informs countries at risk

• Trade shut down until further notice


African Horse SicknessAfrican Horse Sickness

• Viral infection• Horses, mules, donkeys

−Lethal disease

• Arthropod-borne−Culicoides sp. (biting midges)

• Endemic in sub-Saharan Africa• Peak: Late summer - early autumn

−Prevalence influenced by climate


AHS: The DiseaseAHS: The Disease

• Incubation period: 2-14 days−Clinical signs typically seen in 5-7 days

• Four forms of the disease−Pulmonary

Mortality 100%−Cardiac

Mortality 50-70%−Mixed-pulmonary and cardiac−Horsesickness fever

Rarely fatal


AHS: Impact & ResponseAHS: Impact & Response• 1989: Portugal outbreak

−Eradication cost $1.9 million • U.S. Horse Industry

− Inventory: 5.25 million horses−Value of sales: $1.75 billion

• Vaccine available in endemic areas• No natural human infection• Vector control imperative to disease

control


African Swine FeverAfrican Swine Fever• Viral infection • Swine

−Febrile, contagious, systemic disease

• Garbage feeding− Infected pork-scraps

• Tick-borne−Ornithodoros sp. (soft ticks)

• Endemic in sub-Saharan Africa


ASF: The DiseaseASF: The Disease• Incubation period: 48-72 hours• Chronic infection

−Low fever, multi-focal erythema (raised and necrotic), pneumonia, painless swelling of joints

• High virulence (100% mortality)−High fever, recumbency, erythema,

anorexia, death • Low virulence (seroconversion)


ASF: Impact and ResponseASF: Impact and Response

• Morbidity approaches 100%−Mortality varies with virulence (0-100%)

• Import/export ban of hogs− Isolation and slaughter required

for eradication−Huge economic impact

• No treatment or vaccine• Humans not susceptible to disease


AkabaneAkabane

• Viral infection• Cattle, sheep, goats

−Reproductive disorders−Asymptomatic dams

• Mosquitoes, biting midges• Tropics and subtropics

−Australia, Japan, Israel, Korea− Incidence related to climate, season


Akabane: The DiseaseAkabane: The Disease

• Viremia: 1-6 days post-infection

• Adults asymptomatic• Pregnant ruminants

−Abortion and stillbirths−Dystocia

• Congenital abnormalities−Varies with stage of gestation

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Akabane: Impact and Response

Akabane: Impact and Response

• 2002 U.S. livestock statistics−Calves: 38.2 million head−Lambs: 4.36 million head −U.S. livestock naïve

• No effective treatment• No natural human infection• Potential vectors found in U.S.

−Control vector to control disease• Vaccine used in Japan


Avian Influenza, Highly PathogenicAvian Influenza,

Highly Pathogenic• Type A virus• Domestic and wild birds• Humans• Reservoir: Migratory water fowl

−Aerosols, contaminated drinking water

• Infected flock- source of virus for life• Worldwide distribution


HPAI: The DiseaseHPAI: The Disease

• Incubation period: 3-14 days • Birds

−Sudden death−Egg production drops−Neurological signs

• Humans−Conjunctivitis and

respiratory signs−Death possible


HPAI: Impact and ResponseHPAI: Impact and Response

• Direct losses− Depopulation and disposal− High morbidity and mortality− Quarantine and surveillance− Indemnities

• 2003: European outbreak (H7N7)−30 million birds destroyed−Estimated at $338 million USD

• 2004: Asian outbreak (H5N1)


HPAI: Impact and ResponseHPAI: Impact and Response

• Treatment−Poultry- none−Humans- antivirals

• Control outbreak through depopulation/disinfection

• Prompt response to MP AI outbreak• Vaccine

−Poultry: Expensive, no cross protection−Human: No cross protection


BluetongueBluetongue

• Viral disease• Ruminants: Primarily sheep • 24 serotypes worldwide

−5 isolated in the U.S.

• Vector-borne−Culicoides (biting midge)

• Worldwide distribution−Mediterranean outbreak, 1997-2002


Bluetongue: The DiseaseBluetongue: The Disease• Incubation period: 5-20 days• Sheep

−Salivation, facial swelling, nasal discharge

−Cyanotic (blue) tongue−Reproductive disorders

• Cattle, goats−Subclinical; possible mild hyperemia

• Wildlife−Hemorrhages, sudden death


Bluetongue: Impact and Response

Bluetongue: Impact and Response

• Affects cattle industry−$125 million per year in lost trade and

animal testing• No treatment; supportive care• Vector control• Vaccine available

−Serotype specific, adverse effects• Humans: Low risk of infection


Bovine Spongiform Encephalopathy

Bovine Spongiform Encephalopathy

• Prions• Cattle and humans

−Progressively fatal neurologic disease

• Transmission−Consumption of scrapie-

infected feed−Spontaneous mutation

• Worldwide distribution


BSE: The DiseaseBSE: The Disease

• Cattle (BSE)− Incubation period: 2-8 yrs− Initial signs subtle−Final stages

Excitable, hypermetria, ataxic, tremors, loss of condition, death

• Humans (vCJD)− Incubation unknown−Neurological signs progressing to death−28 years old (mean age at death)


BSE: Impact and ResponseBSE: Impact and Response

• United Kingdom−£3.7 billion by end of 2001/02 financial

year• No effective treatment or

vaccine • Surveillance program• Restrictions in place

− Import, animal feeds, slaughter, mammalian products

• Very resistant


Classical Swine FeverClassical Swine Fever

• Viral infection• Pigs and wild boars

−Highly contagious reservoir

• Transmission−Oral (contaminated garbage), direct

contact, aerosol, vertical, insects, fomites

• Worldwide distribution


CSF: The DiseaseCSF: The Disease

• Incubation period: 2-14 days• Variable clinical signs

−Acute to asymptomatic Fever, weakness, anorexia, purplish

discoloration of ears/thighs Chronic infection fatal

−Strain of virus−Susceptibility of pigs− Indistinguishable from ASF


CSF: Impact and ResponseCSF: Impact and Response

• Mortality approaches 100% in acute/chronic infections

• Ban on import/export of pigs/products− Huge economic impact

• No treatment• Control through quarantine, slaughter• Vaccine in endemic countries• Humans not susceptible to disease


CoccidioidomycosisCoccidioidomycosis

• Dimorphic fungus−Saprophytic and parasitic

phase• Dogs, cats, horses, humans• From soil or dust

−Arthroconidia become airborne, inhaled

• Endemic in southwest U.S., northern Mexico, Argentina


Coccidioidomycosis: The Disease

Coccidioidomycosis: The Disease

• Incubation period: 1-3 weeks• Disease varies in severity and species

affected• Asymptomatic to disseminated• Primary form

−Fever, lethargy, dry/harsh cough

• Disseminate form−Lameness, joint swelling, abscesses and

draining skin lesions


Coccidioidomycosis: Impactand Response

Coccidioidomycosis: Impactand Response

• Infection is costly−1990: Kern County, CA

Cost more than $66 million−Can be widespread in livestock

• Not communicable or zoonotic• Anti-fungal treatment• No vaccine• Prevent exposure to dust in

endemic areas


Contagious Bovine Pleuropneumonia (CBPP)

Contagious Bovine Pleuropneumonia (CBPP)

• Bacteria−Mycoplasma mycoides mycoides−Small colony type

• Bovine and zebu• Transmission via close contact

(inhalation); transplacental• Endemic in Africa

−Eradicated in Western Hemisphere


CBPP: The DiseaseCBPP: The Disease

• Incubation period: 20-123 days• Respiratory signs

−Cough, broad stance• Chronic infections

−Depressed, thin, polyarthritis−25% Subclinical carriers

• Morbidity ~100%• Mortality 10-70%


CBPP: Impact and ResponseCBPP: Impact and Response

• High economic, social impact− Zambia, Tanzania, Botswana− Drought leading to spread of

disease

• Treatment not always effective− Organism sequestered

• Vaccine available in endemic areas− Not always economically feasible

• Humans not susceptible


Contagious Caprine Pleuropneumonia (CCPP)

Contagious Caprine Pleuropneumonia (CCPP)

• Bacteria−Mycoplasma capricolum −Mycoplasma mycoides capri

• Goats• Transmission by direct contact

− inhalation

• Africa, Middle East, Eastern Europe, Soviet Union, Far East


CCPP: The DiseaseCCPP: The Disease• Incubation period: 6-28 days• Mycoplasma F38 strain

−Respiratory symptoms Coughing, labored respiration, nasal

discharge,

−Chronic cases: Carriers

• M. mycoides capri−Septicemia, reproductive, GI, respiratory

symptoms

• Morbidity 100%; Mortality 60-100%


CCPP: Impact and ResponseCCPP: Impact and Response

• Africa and Asia−Goats essential to economics

Meat, milk, hides

• Treatment with antibiotics possible early−Newly infected countries: Slaughter

recommended

• Vaccine available in some countries• Humans not susceptible


Foot and Mouth Disease: FMDFoot and Mouth Disease: FMD

• Viral infection−Highly contagious

• Cloven-hooved animals −Not horses

• Transmission: Direct contact, aerosol, fomites

• Worldwide distribution−Eradicated from U.S. in 1929


Present

Recent Activity

Free

(Rev. 3-25-01)

Foot-and-Mouth DiseaseDistribution and Recent Activity

Foot-and-Mouth DiseaseDistribution and Recent Activity


FMD: The DiseaseFMD: The Disease

• Incubation period: 2-12 days• Cattle

− Indicator host− Fever, vesicles, salivation,

lameness• Sheep and goats

− Maintenance hosts− Mild clinical signs

• Pigs: Amplifying host− Lameness predominant sign


FMD: Impact and ResponseFMD: Impact and Response

• 2001, U.K. Outbreak−Total costs over $18 billion

USD

• 6 million animals slaughtered−FMD free in less than 1 year

• Public perception−Animal welfare−Smoke pollution


FMD: Impact and ResponseFMD: Impact and Response

• Most important livestock disease in the world

• USDA upgrading safeguarding measures

• Quarantine, depopulation, disinfection• Vaccination – complex decision• Extremely rare, mild symptoms in

people


HeartwaterHeartwater

• Rickettsial bacterium• Cattle, sheep, goats, and water

buffalo−Severe disease

• Arthropod-borne−Amblyomma sp.

• Endemic in Africa and Caribbean islands


Heartwater: The DiseaseHeartwater: The Disease

• Incubation period: 14-18 days• Four forms of the disease

−Peracute (rare) Sudden death

−Acute (most common) High fever, respiratory distress,

nervous signs−Subacute (rare)

Prolonged fever and pulmonary edema−Mild or subclinical

Transient fever


Heartwater: Impact and Response

Heartwater: Impact and Response

• Zimbabwe national losses−$56 million

• Potential outbreak in U.S.−Estimated 40–100% mortality

• Treat with tetracycline• Vaccine is available• Vector control


Japanese EncephalitisJapanese Encephalitis

• Viral infection• Humans, pigs, and

other domestic species• Arthropod-borne

−Culex sp.

• Endemic in temperate and tropical Asia


JE: The DiseaseJE: The Disease

• Incubation period: 6-10 days• Horses

−Fever and neurologic signs

• Swine−Stillbirths

• Humans−Fever, headache−Fatal encephalitis possible


JE: Impact and ResponseJE: Impact and Response

• High financial loss in pigs• No effective treatment

−Supportive care

• Vector control measures• Vaccine

−Horses and swine−Humans


Lumpy Skin DiseaseLumpy Skin Disease

• Viral infection• Cattle• Arthropod vector

−Mosquitoes and biting flies

• Endemic in sub-Saharan Africa

• Peak: Rainy season


Lumpy Skin Disease:The Disease

Lumpy Skin Disease:The Disease

• Incubation period: 2-5 weeks

• Fever, abortions, decreased milk production−Nodules typically appear

10 days later

• Mortality rates vary− 2-85%


Lumpy Skin Disease: Impact and ResponseLumpy Skin Disease: Impact and Response

• Severe economic losses due to decreased animal production

• Control secondary infections

• Attenuated LSD vaccine−South Africa

• Sheep and goat pox vaccine−Kenya, Egypt


Malignant Catarrhal FeverMalignant Catarrhal Fever

• Viral infection• Wildebeest- Africa• Sheep/goats- N. America• Susceptible species:

Cattle, bison, other wild ruminants−Dead-end hosts

• Aerosol or mechanical transmission


MCF: The DiseaseMCF: The Disease

• Incubation period: 9-77 days• Four clinical forms

−Acute Sudden death

−Head and eye Fever, necrotic lesions

− Intestinal Severe diarrhea

−Mild


MCF: Impact and ResponseMCF: Impact and Response

• High economic losses in exotics• Mortality near 100% in clinically ill

animals• No effective treatment

−Supportive therapy

• No current vaccine• Human disease not

documented


Menangle virusMenangle virus

• Viral infection−Recently discovered

• Swine reproductive disease• Humans infected• Not highly contagious• Fruit bat reservoir

−Fecal-oral or urinary-oral • Single outbreak

−New South Wales, Australia


Menangle: The DiseaseMenangle: The Disease

• Incubation period: Unknown−Pigs seroconvert in 10-14 days

• Disease in developing fetuses−Mummification −Stillbirth−Deformities

• Decreased farrowing rate• No signs in postnatal pigs


Menangle: Impact and Response

Menangle: Impact and Response

• Great economic impact in naïve swine populations

• 1977 outbreak−Farrowing rate decreased 44%−Decreased litter size −Strong immunity after infection

• No vaccine• Humans

−Malaise, fever, chills−Full recovery


Exotic Newcastle Disease (END)

Exotic Newcastle Disease (END)

• Virus affecting poultry−Four pathotypes

• Migratory birds−Secondary human spread

• Feral pigeons• Psittacines shed virus for >1 year• vND endemic in Asia, Middle East,

Africa, Central/ South America


END: The DiseaseEND: The Disease

• Incubation period: 2-15 days• Drop in egg production,

neurological damage, GI signs, respiratory distress

• Numerous deaths within 24-48 hours

• Deaths continue for 7-10 days• Morbidity 100%, mortality 90%


END: Impact and ResponseEND: Impact and Response

• Most costly poultry disease worldwide• 2002-2003: California outbreak

−$160 million impact• Developing countries

−Affects quality and quantity of dietary protein

• Vaccine available• Human’s can acquire eye infections

from contact with virus


Peste des Petits RuminantsPeste des Petits Ruminants

• Viral infection• Goats and sheep• Close contact

−Aerosol, fomites?

• Morbidity and mortality up to 100%

• Africa, the Middle East, India


Peste des Petits Ruminants:The Disease

Peste des Petits Ruminants:The Disease

• Incubation period: 3-10 days• Sudden onset

−Fever, erosive stomatitis, conjunctivitis, pneumonia

−More severe in young−Abortions−Diarrhea, dehydration and death

• Prognosis correlated with extent of mouth lesions


Peste des Petits Ruminants: Impact and Response

Peste des Petits Ruminants: Impact and Response

• Ecomonic losses−Loss of production, death, abortion−Limit trade, export −Constraints on availability of

protein for human consumption

• No specific treatment• Rinderpest vaccine

−Protects for 12 months−Hinders rinderpest campaign in Africa


RinderpestRinderpest

• Viral infection• Highly contagious• Cattle, domestic buffalo

−Other ungulates can carry disease

• Direct or close contact−Also contaminated food,

water, fomites

• East Africa, possibly Asia


Rinderpest: The DiseaseRinderpest: The Disease

• Incubation period−3-15 days

• Four forms−Classical: Fever, diarrhea, nasal/ocular

discharge, oral erosions−Peracute: Young animals, rapidly fatal−Subacute: Mild signs, low mortality−Atypical: Irregular fever, mild diarrhea


Rinderpest:Impact and Response

Rinderpest:Impact and Response

• Africa: 1982-84 outbreak cost $500 million

• $100 million spent annually on vaccination world-wide

• Diagnosis usually means slaughter• Vaccine offers life-long immunity• Humans not susceptible to disease


Screwworm MyiasisScrewworm Myiasis

• Larvae of the Family Calliphoridae• All warm-blooded animals• Humans and animals infected

when female fly deposits eggs into wound

• Morbidity variable, can reach 100%• Tropical regions


Screwworm Myiasis: The Disease

Screwworm Myiasis: The Disease

• Larvae−Emerge in 8-12 hours−Visible within 3 days

• Wounds−Bloody discharge−Foul odor−Secondary infection

• Depression, off feed, rubbing• Signs similar in humans


Screwworm Myiasis:Impact and ResponseScrewworm Myiasis:

Impact and Response• Estimated losses if reintroduced

−$540 million annually−$1.27 billion for eradication

• Treatment−Removal of larvae−Topical larvicide 2-3 days

• Sterile fly technique−U.S. free in 1966−Mexico free in 1991

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Sheep and Goat PoxSheep and Goat Pox

• Viral infection−Capripoxvirus−Contagious

• Most important pox disease of domestic animals

• Direct contact− Inhalation, insects?

• Parts of Africa, Asia, India, and the Middle East


Sheep and Goat Pox: The Disease

Sheep and Goat Pox: The Disease

• Incubation period: 4-13 days• Clinical signs include

−Fever, conjunctivitis, dyspnea−Skin lesions take up to 6

weeks to heal• Mortality

−50% in susceptible flock−100% in young

• No chronic carriers


Sheep and Goat Pox: Impact and ResponseSheep and Goat Pox: Impact and Response

• Infection can limit trade of live animals and product

• Treat secondary infections• Vaccination

−Endemic areas with attenuated virus

• Slaughter should be considered• Humans not susceptible


Swine Vesicular DiseaseSwine Vesicular Disease

• Viral infection−Resistant to heat, pH, curing−Moderately contagious

• Swine and humans• Ingestion or close contact • Previously Europe and Hong Kong

−Only in Italy as of 2002


SVD: The DiseaseSVD: The Disease

• Incubation period:− Ingestion: 2-5 days−Direct contact: 2-7 days

• Clinically resembles FMD • Fever, salivation, lameness• Vesicles

−Snout, mammary gland, coronary band

• Mortality low


SVD: Impact and ResponseSVD: Impact and Response

• Control measures costly• Export restrictions• Supportive care• Vaccine not commercially available• Human infection not common

− Incubation period: 1-5 weeks−Mild influenza-like symptoms−Vesicular lesions not seen


Vesicular Stomatitis Vesicular Stomatitis

• Viral infection• Horses, donkeys, cattle, swine,

South American camelids• Arthropod-borne, direct contact,

aerosol• Morbidity 90%, mortality low• Southwest United States


VSV: The DiseaseVSV: The Disease• Animals

− Incubation period 3-5 days−Oral/mammary/coronary band

lesions, salivation, lameness Resembles FMD

−Recovery in 2 weeks• Humans

− Incubation period 1-6 days− Influenza-like symptoms, rarely oral

vesicles−Self limiting


VSV: Impact and ResponseVSV: Impact and Response

• Outbreaks every 10 years in the U.S• 1982 and 1995: $53-$202 per head

lost on cattle• 1998: Equine outbreak• Supportive treatment • Vaccines available during

an outbreak

The Veterinarian’s Responsibility




• Guardian of animal and public health• Sharpen awareness of disease

agents• Alert officials early• Be involved with emergency

response plans at all levels• You are the expert

−Provide leadership and input to clients and community


ContactsContacts

• Phone numbers to know−State Veterinarian−State Public Health

Veterinarian−APHIS- Area Veterinarian

in Charge−Public Health Officials

Conclusion


SummarySummary

• Importance of agriculture and livestock

• Specific disease agents on high consequence livestock pathogen list−Zoonotic potential

• Veterinarian’s responsibilities• Awareness education imperative


ConclusionConclusion

“The best prescription,is knowledge.”

Dr. C. Everett KoopFormer U.S. Surgeon General


AcknowledgmentsAcknowledgments

Development of this presentation was funded by a grant from the Centers for Disease Control and Prevention to the Center for Food Security and Public Health at Iowa State University.


AcknowledgmentsAcknowledgments

Author:

Co-author:

Reviewer:

Danelle Bickett-Weddle, DVM, MPH

Katie Steneroden, DVM, MPHStacy Holzbauer, DVM

James Roth, DVM, PhDGlenda Dvorak, DVM, MS, MPH

overview of high consequence livestock pathogens for veterinarians

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