October 17, 2005	Monday	Ramzan 12, 1426

‘LIVESTOCK bio-terrorism’ is the intentional introduction of a disease agent, toxin, or disease vector into animal population to damage the food supply and disrupt the economy, or to meet an animal activist’s agenda.

There are numerous pathogens that are used or can be by bio-terrorists to threaten animal health or destroy their production. These are referred as ‘the poor man’s atomic bomb’.

The use of biological weapons against livestock has devastating effects on the livestock industries with disastrous effects on wildlife and endangered species. The currently available bio-weapons are broad-spectrum diseases capable of causing mass mortality among humans, domestic animals and wildlife.

Bio-terrorist use enzootic (encompassing a large population) livestock diseases and emerging diseases that may infect human and animal populations represent a serious threat to livestock and wildlife populations.

Bio-terrorist attacks do not require access to weaponized disease strains or laboratory cultures of disease organisms. Samples of infectious materials obtained or cultured from infected animals or carcasses are all that is required.

Natural highly virulent diseases, easily acquired and transported to cause catastrophic epidemics in countries with industrialised livestock production methods are common and widely distributed in many countries around the world. Virulent contagious diseases such as anthrax, rinderpest and foot-and-mouth (FMD) are enzootic and common within a number of countries. Pakistani livestock population also suffers from these diseases.

Epidemics not only affect farmers but also the industry. These days a debate is going on the health status of goats imported by Pakistan from India. There are many controversies that animals are suffering from infectious diseases.

The outbreak may result in costs and losses. Direct costs include mortality, morbidity, loss of production, treatment, depopulation, restrictions on breeding, emergency vaccination, tracing of potentially infected animals, diagnostic activities, and the establishment quarantines and movement restrictions.

Consequential losses include idle production (linked to stamping-out policy and long-term restriction on movements) and trade disruption. The foot-and-mouth disease (FMD) in 2001 in the UK inflicted a loss of about 3–4 billion Briish pounds.

The catastrophic impact resulting from the agricultural bio-weapon is high in the developing countries like Pakistan due to limitations on the availability of doctors, veterinarians, medicines, and medical facilities for treatment and quarantine. However, even countries with well-organized and efficient veterinary services are susceptible to deliberate or inadvertent introductions of highly infectious pathogenic disease agents into their livestock populations.

Many people wonder as to how a ‘poisonous powder’ could be harmful only for the bovine (cattle and buffalo) species, and how such a small amount could be so effective. The true nature of the ‘powder’ is not known but it could be small ground pieces of infected tissues taken from some animals dead from rinderpest (a viral disease of cattle and buffalo).

Perhaps the oldest application of bio-weapons was the contamination of water sources using animal carcasses, human cadavers, faeces or poisonous plants and their derivatives.

Many agents developed for use against animals and humans during the early decades of the 20th Century were not highly contagious. Biotechnology techniques and equipment permit large-scale production of bio-weapons in small-scale facilities at a low cost. The basic techniques are simple with microbrewery and pharmaceutical equipment easily adaptable for bio-weapons production.

Disease organisms are introduced effectively and clandestinely into a livestock population with little chance of detection through randomly or selectively introducing pre-infected animals or feeds into feedlot operations.

The best targets are intensive farming units or feedlots where a large number of animals may suffer from the disease and disseminate its agent. An effective alternative strategy is to contaminate a large number of small farms in a country which may result in an outbreak difficult to control. Infection of wildlife can also be extremely difficult to discover and control.

For livestock, the most feared is the introduction of rinderpest virus. A virulent strain of rinderpest can kill millions of heads of cattle. It is recently brought under control in Pakistan. A virulent strain of the FMD is equally dangerous. Some of the poultry viruses can cause immense economic damage. The African horse sickness virus can kill thousands of horses and mules of the Army.

The FMD is the most contagious disease of mammals in cloven-hoofed animals, particularly bovine and porcine species. Typical cases are characterized by vesicular lesions of feet, buccal mucosa and, in females, the mammary gland. Clinical signs can vary from mild to sever and fatalities may occur, especially in young animals.

Infection is readily spread by direct contact between animals but indirect transmission by means of fomites is also possible and, of course, by direct deposit of infectious material in the mouth. Windborne spread of infection over considerable distances may occur and a single outbreak can, therefore, be a threat to a whole territory.

The FMD virus is extremely contagious and infects most wild and domesticated ungulate species (sheep, goats, cattle, deer, pigs, etc.), but not humans. Although the FMD is typically a debilitating rather than a fatal disease among healthy adult animals, the disease is extremely damaging by causing severe losses in meat and dairy production due to mortality among new-born animals, and sickness and debility among the adults.

Rates of infection in the FMD reach 100 per cent within susceptible populations, and mortality ranges from five to 75 per cent among infected animals depending on species, age and condition. Eradication is extremely difficult as asymptomatic and recovered cattle may remain active carriers of the FMD for as long as 18 to 24 months.

The FMD may be spread over long distances by wind-borne virus, and the virus survives well within various kinds of processed but uncooked meat products (frozen, salted, dried and cured meats). In Pakistan, although vaccination against the FMD is regular but in lieu of import of infected animals, outbreaks may occur.

Livestock bio-terrorism affects directly and indirectly. Last year in Pakistan sporadic cases of avian influenza occurred in different parts of the country. Although, the disease was reported on a few farms but due to extensive publicity significant losses were borne by the people engaged in the poultry sector.

Rinderpest is an acute, fatal disease of domestic cattle, buffaloes and yaks caused by an RNA Morbillivirus. Small ruminants like sheep, goat, pigs and wild ungulates may also be affected. Clinically the disease is characterized by pyrexia, the progressive development of shallow erosions on the gums, tongue, cheeks and hard palate together with serous or mucopurulent ocular and nasal discharges. The disease is highly contagious and has a case fatality rate exceeding 90 per cent in a susceptible animal population.

Breakdowns in medical and veterinary support systems during wars and civil conflict result in epidemic outbreaks of diseases among human, livestock and wildlife populations. Although it is claimed that rinderpest is eradicated from Pakistan but with the introduction of imported animals a serious outbreak involving a large number of livestock population can still occur.

Avian Influenza (AI) is a highly lethal disease of poultry caused by the type A virus. The most important means of spread is by contaminated persons or fomites and by introduction of infected birds or tissues. No specific treatment is available but vaccines are used with variable effects. So far the virus has never been used, even experimentally, as a biological weapon.

As a matter of fact some mild strains and occasionally virulent strains of AI virus are naturally spread by migratory wild water birds or seabirds and may infect domestic birds. Whenever this disease comes, it generally wipes out the whole flock and such cases have been reported in different parts of the world and this situation was also observed in Pakistan last year.

Transportation or import/export of animals leads to bio-terrorism. For example, parasites (organisms that live on the expense of others for food and shelter) have the potential for use as either bio-weapons or delivery systems for infectious diseases.

Anthrax is an acute, febrile disease of virtually all warm-blooded animals and man. It is caused by a large bacteria; Bacillus anthracis. In recent years, anthrax appears to be the favourite biological weapon of bio-terrorists.

In 1979, an accident (non-activation of the air filters) resulted in the release of virulent anthrax spores and the death of 66 laboratory workers, as well as of livestock to a distance of 50km in Russia’s Svedlovsk.

Infectious animal disease agents are readily available throughout the world and the means of dissemination are easy. Acquisition and dissemination do not require special skills but potential in some countries exist to develop specific bio-engineered weapons.

Policy makers must take actions to ensure that livestock and animal production sectors are well prepared to resist or minimize the impact of bio-terrorist attacks. Attention should be paid to the maintenance of a high capacity veterinary vaccine production sector.

Interdisciplinary and international efforts to increase the surveillance, identification and reporting of disease pathogens, and better understanding of the dynamics of disease transmission within and among human and animal populations will enhance the ability to combat the effects of bio-weapons and emerging diseases on biotas and biodiversity.

Improved mechanisms for interagency and intergovernmental communication, cooperation and collaboration are necessary to control the threats of bio-weapon disease outbreaks in livestock. Policy makers must consider its importance while signing documents of animal imports with any country.

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