Preparing for Biological and Chemical Attacks - Protecting Animals And Plants

The Animal and Plant Health Inspection Service (APHIS)

Animals and plants, especially those that human beings depend on for food, are also subject to attack. On the front line of this problem is the Department of Homeland Security's Animal and Plant Health Inspection Service (APHIS). APHIS is a largely unknown agency but an important one. It monitors the nation's borders for foreign agricultural diseases and pests. It protects farm animals from disease and pests and provides a host of services to cattle ranchers, milk producers, turkey farmers, and other agrarian groups.

According to the Center for Nonproliferation Studies report Chronology of CBW Attacks Targeting Crops and Livestock, 1915–2000 (October 2001), bioterror attacks on a nation's animals and agriculture are not uncommon in times of war. The German secret service deployed anthrax against horses and mules slated for use by the Allied powers in World War I. In Afghanistan in the 1980s, the Russian military used toxins against the horses of the rebel mujaheddin. England suspected that Nazi Germany had dropped Colorado potato beetles on rural areas during World War II to destroy potato crops; in 1950, communist East Germany accused the United States of a similar attack.

One in eight American jobs and 13% of the U.S. gross national product (the value of all the goods and services produced in the country) are dependent on agriculture. The country's economic stability depends on a safe and readily available food supply. U.S. crops and livestock could be tempting targets to terrorists, especially because of the perceived ease of attacking such targets. (See Table 5.3.) Livestock and plant pathogens could threaten U.S. agricultural productivity and cause economic damage. Such factors as the resilience of the agent used, the density of the targeted animal population, and the susceptibility of targeted plants and animals to disease determine the level of vulnerability. (See Table 5.4.)

Potential threats to U.S. agricultural products and livestock come from a number of pathogens and agents. Animals could contract many types of disease, including anthrax, Q fever, brucellosis, foot-and-mouth disease (FMD), Venezuelan equine encephalitis, hog cholera, African swine fever, avian influenza, Newcastle disease, Rift Valley fever, rinderpest, and others. The Office International des Epizooties (OIE) is a 155-member organization that sets the animal health standards for international trade. They maintain two lists of diseases: List A includes diseases with the potential for very rapid spread across national borders and serious socio-economic or public health consequences. List B includes diseases that are considered dangerous within the individual country where an outbreak occurs. Table 5.5 shows the List A and many of the List B animal diseases. Many staple plants, such as corn, wheat, rice, and soybeans, are susceptible to disease. Soybean rust, for example, can be easily introduced and spreads quickly, which could cause U.S. soybean producers, processors, livestock producers (who feed soy products to their animals), and consumers to lose up to $8 billion annually, according to USDA estimates. Table 5.6 lists plant diseases of particular agriterrorism concern.

Some of these plant and animal agents can be found outside U.S. borders, and many can be readily transported, inadvertently or intentionally, into the United States, some with low risk of detection. APHIS is the agency

TABLE 5.4

TABLE 5.5

TABLE 5.6

responsible for diagnosing and managing all suspicious agricultural disease outbreaks. APHIS's authority, depending on the pathogen involved, extends as far as confiscating property and eradicating all plant and animal hosts within quarantine zones. Binding international agreements force countries to immediately disclose select plant and animal disease outbreaks, regardless of severity. Such disclosures can have an instant impact on export trade, as other countries prohibit potentially contaminated items from entering their borders. National security and public trust can both be threatened in such cases, depending on the extent of disease transmission, the success of the government's response, and the amount of time it takes to bring conditions back to normal.

Foot-and-Mouth Disease (FMD)

One example of how countries' livestock industries can be affected by disease has been the various outbreaks of foot-and-mouth (also called hoof-and-mouth) disease. During an outbreak in the United Kingdom in 1967 and 1968, for example, more than 430,000 animals were destroyed; an outbreak in 2000–01 in the United Kingdom and Ireland forced the destruction of more than eight million animals at over ten thousand locations. The out-break caused severe economic hardship throughout the United Kingdom and parts of Europe.

A member of the picornavirus family, FMD is endemic in many parts of the world, but the United States has not seen cases since the 1920s. Thus, few American veterinarians are familiar with the early stages of FMD infection. An animal becomes infected shortly after exposure but well before the onset of clinical symptoms. When symptoms do occur, they may include a sudden rise in temperature, followed by an eruption of blisters in the mouth, in the nostrils, on areas of tender skin, and on the feet. The blisters expand, then break, exposing raw, eroded skin surfaces. Eating becomes difficult and painful. Because the soft tissue under the hooves is swollen, the animal limps. Livestock raised for meat lose weight, and dairy cattle and goats give far less milk. FMD kills very young animals and causes pregnant females to abort.

Merely transporting infected tissue can start an epidemic—a single infected cow or pig can generate enough viral particles to communicate the disease over vast geographic areas in weeks. An outbreak of this disease could be easily introduced to the United States and might debilitate the U.S. livestock industry. According to the USDA, an outbreak could cost as much as $20 billion over fifteen years in increased consumer costs, reduced livestock productivity, and restricted trade.

APHIS does not permit imports of FMD-positive animals. While scientists appear close to developing an effective vaccine, vaccinating all susceptible animals would cost about $1 billion annually. In addition, the vaccine would not eradicate the disease. Currently the only effective countermeasure against FMD is slaughtering and incinerating all exposed and infected animals.