Agro-Terrorism & Biosecurity

S. Christian Mariger Ph.D.

Biological Systems Engineering

BSE 2294 Animal Structures & Environments

Goals of Biosecurity

• Protect people and animals from dangerous microorganisms!

• Protect microorganisms and animals from dangerous people Bacillus Anthraces

Biological Challenges

• There are several unique challenges posed by microorganisms that differentiate biosecurity from other forms of high security.– First, although certain biological agents have the

potential to cause serious harm to the health and economy of a population if misused, all have legitimate uses for medical, commercial, and defensive application.

– Second, biological agents are widespread. They exist in nature and are globally distributed in research laboratories, collection centers, and clinical facilities.

Biosecurity in Agriculture

• Agriculture faces two threats to biosecurity:– Natural or unintentional transmission of

pathogens in livestock and crops.– Agro-terrorism, intentional introduction of

natural or modified pathogens, chemical or radiological toxins into our food production system

9-11-01’s Impact on Biosecurity

• The tragic events of September 2001 and the subsequent dissemination of Bacillus anthracis through the United States postal system underscored the dangers to national and international security posed by terrorist attacks, especially those involving pathogenic microorganisms and toxins.

The Threat of Agro-terrorism

• When a person, whether native or foreign, attempts to endanger the agricultural food system through:– spreading a disease– disrupting markets– or causing consumer fear for food safety.

Some threats to people and livestock

• Anthrax• Avian flu• Brucellosis• Bovine Spongiform Encephalitis (BSE-”Mad

Cow”)• Exotic Newcastle's disease• Foot and Mouth disease• Hog Cholera• Pseudo-rabies

Anthrax

• An acute infectious disease caused by the spore-forming bacterium Bacillus anthracis.

• Anthrax most commonly occurs in wild and domestic (cattle, sheep, goats, camels, antelopes, and other herbivores)

• Anthrax can also occur in humans when they are exposed to infected animals or tissue from infected animals.

Bacillus Anthraces

• Anthrax infection can occur in three forms:– cutaneous (skin)– inhalation – gastrointestinal.

• B. anthracis spores can live in the soil for many years, and humans can become infected with anthrax by handling products from infected animals or by inhaling anthrax spores from contaminated animal products. Anthrax can also be spread by eating undercooked meat from infected animals. It is rare to find infected animals in the United States.

Bacillus Anthraces

– Cutanious anthrax infection: note the characteristic black ulceration and swelling.

– This infection can be treated with gram negative and broad spectrum antibiotics

Bacillus Anthraces

– Inhalation anthrax infection: note the bleeding from the nose of this gazelle. This infection can be also treated with gram negative and broad spectrum antibiotics, but treatment must be prompt.

Avian Influenza

• In 1997, the first case of direct bird-to-human transmission of AI (H5N1) virus was documented in Hong Kong.

• Health officials throughout Asia have reported a total of 205 confirmed human cases, with 113 resulting in death.

• While evidence of human-to-human transmission is limited (one case was reported in Thailand and two possible cases in Vietnam), humans coinfected with avian influenza A and another strain could theoretically serve as hosts for a new strain.

• The result would be a flu to which no human is immune and no vaccine is available.

• Source Texas A&M Vet School

Avian Influenza

• The H5N1 virus presents a serious threat because wild birds could easily infect domestic flocks, this would be a disaster for poultry producers.

Brucellosis• Brucellosis, also known as Undulant Fever, is a highly contagious

zoonotic disease that primarily affects domestic livestock and many species of wildlife.

• Brucella is found worldwide; however, it is not very common in the U.S. In the U.S, most of these cases are reported in California, Florida, Texas, and Virginia.

• In animals, brucella is usually transmitted by contact with fluids and discharges from infected animals.

• In humans, Infection generally occurs in one of three ways: eating or drinking something that is contaminated with Brucella, inhalation, or having the bacteria enter the body through skin wounds.

• Brucella can also be spread during conditions of high humidity, low temperatures, and no sunlight; under these conditions, the bacteria can remain viable for several months in water, manure, wool, hay, equipment, and clothes

Bovine Spongiform Encephalitis

• BSE is caused by a prion (viral protein) that effects the central nervous system of infected animals.

• Transmission has been traced to animal feeds containing animal byproducts.

• The large epidemic of bovine spongiform encephalopathy (BSE) in the United Kingdom has been in decline since 1992, but has spread to other countries.

• Vigilance is required in all countries, especially in those in which there has been within-species recycling of ruminant feed.

BSE/CJD in humans is extremely rare

• Fewer than 150 people, globally, have been diagnosed with Creutzfeldt–Jakob Disease (CJD)

Exotic Newcastle's Disease (END)

• Exotic Newcastle Disease (END), also known as velogenic viscerotropic Newcastle disease, is a fatal, highly contagious viral disease that affects all species of birds.

• END is probably one of the most infectious and fatal diseases of poultry in the world with many birds dieing before showing any clinical signs of illness and death rates approaching 100 percent

• Transmission occurs through direct contact between healthy birds and the bodily discharges of infected birds, specifically feces and secretions from the nose, mouth, and eyes. Newcastle Disease can also be spread by mechanical means, including contaminated shoes, clothing, implements, and premises

• (Note: END is often spread by vaccination and debeaking crews, manure haulers, rendering-truck drivers, feed-delivery personnel, poultry buyers, egg-service workers, and poultry farm owners and employees)

Exotic Newcastle's Disease (END)

• Due to the close confinement of commercially raised birds, the disease is able to spread rapidly.

• The most common source of exposure for humans in contact with contaminated animals or animal products.

Foot and Mouth Disease • Foot-and-Mouth Disease (FMD) is a severe, highly contagious

infectious viral disease of cloven-hoofed domestic and wild animals, such as cattle, pigs, sheep, goats, and water buffalo.

• This disease spreads widely and rapidly and is widely believed to be the most economically devastating livestock disease.

• Transmission occurs through a variety of mechanisms: – Inhalation or ingestion (from infected source to susceptible animals) – Direct contact with infected animals – Mechanical fomites (e.g., vehicles, instruments, feed, etc.) – Airborne (up to 60 km overland and 300 km by sea) in temperate zones

under proper conditions (these include a high viral load, stable atmospheric conditions, and a susceptible population downwind)

– Virus is shed in saliva, feces, urine, milk, semen, and breath for up to four days before clinical signs appear in acutely infected animals

Foot and Mouth Disease

• Symptoms of foot and mouth disease

Hog Cholera

• Hog cholera is a highly infectious viral disease of swine manifested by septicemia and generalized hemorrhage.

• Transmission : Direct contact with infected pigs and ingestion of uncooked contaminated food wastes containing infected pork scraps.

Pseudorabies

• Is totally unrelated to rabies. Nevertheless, pseudorabies (PR) is the name most commonly used in North America and other parts of the world.

• Aujeszky's disease (AD) virus is primarily an infection of pigs which represent its only known reservoir host. It is sometimes transmitted naturally from pigs to individual cattle, horses, dogs and cats which develop nervous signs and rapidly die. These animals are end hosts and do not usually spread it. It has never been known to cause disease in people.

Pseudorabies

• Pseudorabies describes the clinical signs of aujeszky's in dogs. Another early name was 'mad itch' reflecting the most striking clinical sign in cattle.

Biosecurity

• Biosecurity for people:– Personal hygiene (wash hands and clothing) – Limit visitors to the farm– Have a central point to meet others– Insist visitors wear clean clothes/shoes– Use footbaths around confined animals– Know workers background– Use caution with visitors that have recently

been to foreign countries

Biosecurity

• Biosecurity for animals:– Routine Vaccination– Isolate new animals– Veterinarian-Client relationship with local

practitioner

Biosecurity

• Biosecurity for feed:– Do not contaminate feed with manure– Be aware of feeding ruminant protein products

to sheep, goats, and cattle– Poultry litter/urea products may also pose a

threat consult VCE agent and suppliers for more information

– Limit visitor access to feeds and feeding areas

Biosecurity

• Biosecurity for public events:– Isolate show animals before re-entry to herd– Clean trucks and trailers of mud and manure– Have valid health certificates for out of state

travel

Biosecurity

• Good records are essential:– Individual animal ID– Treatment and vaccination records– Keep record of feed purchases and sources– Back up computer sources with a hard copy

Biosecurity

• Surveillance:– Check on herds/flocks regularly– Central meeting point for visitors– Contact law enforcement in the event of

vandalism or suspicious persons– Contact veterinarian for unusual deaths or

problems

If you get sick!

• Help your medical professional, let them know: – Types of animals you have been exposed to. – What pests (insects, mice/rats, birds,

raccoons etc.) have been identified at your farm.

– Do you work in a dusty environment. – Have you traveled, tell them where.– What agricultural chemicals have you been

exposed to.

References

• Center for Disease Control (CDC): http://www.cdc.gov/ncidod/diseases/index.htm

• National Agricultural Biosecurity Center (NABC): http://nabc.ksu.edu

• Solarno, R & Estes, D. (2003) Biosecurity: Protecting High Consequence Pathogens and Toxins Against Theft and Diversion Available online: www.mipt.org/pdf/Biosecurity-Protecting-High-Consequence-Pathogens.pdf