Tuesday, February 17, 2009


The infamous letter bomb episodes in USA using Anthrax spores are still fresh in the memory of the public though the origin of the crime was never satisfactorily traced. Research on Anthrax spores was known to be one of the priority areas of research in Defense laboratories of some countries though internationally these activities were frowned upon and criticized by the world community at large. It is only after the 9/11 attack in USA in 2001 that the area of bio-terrorism was formally considered as potential threat to all countries from fanatics and terrorists trying to impose their beliefs on others by threats and coercion.

What is bio-terrorism? It can be described as intentional release or spreading of biological agents such as bacteria, viruses or toxins, either in their natural form or in modified forms developed through man's intervention which causes illness or death to people, animals and plants. The intention is to cause immeasurable causalities and spread panic amongst the targeted population. Romans were known to have used dead and rotting animals to poison water bodies on the enemy lines to disable their opponents' capacity to fight. In the 14th century bubonic plague was used to infiltrate enemy lines and disable them. Anthrax emerged as the most preferred bio-terrorism agent since early 19th century because it can be easily transferred, has high mortality rate but limited ability to spread beyond the targeted population area. The fact that it still retains its potential is reflected by the most recent scare in the US where Anthrax spores from a Defense Laboratory working on biological warfare were smuggled out and sent to scores of offices through the postal mail delivery system. It took more than 5 years to solve this case ending in the suicide of the person, a Defense Scientist who was suspected for the crime.

There are three categories of biological agents based on some parameters. Group A has some of the most lethal agents such as Anthrax, Botulinum toxin, Virus responsible for hemorrhagic fever and Tularemia responsible for Rabbit fever. Group B has Brucellosis, small pox virus, Epsilon toxin, Viral encephalitis, Q fever etc. Group C has various pathogens modified to enhance their destructive power. Though UNO wants biological warfare to be shunned by all member countries, very little is done to eliminate these agents of terror and stop research on them.

It is in this context western countries, mortally afraid of the consequences of bio-terrorism, are developing antidotes and preemptive steps to counter act the designs of terrorists in using biological agents against their population. Latest endeavor is the development of a vaccine to neutralize the effect of botulinum toxin if used as a weapon for mass killing of innocent people. Clostridium botulinum(Cb) is a food spoilage bacteria, found in improperly processed canned foods of low acid types. Since it is an anaerobic bacteria, it grows in evacuated and aseptically sealed can containers if processing parameters are not adequate. The vegetative cells are killed at 60C but the spores can survive extreme processing temperatures and germinate subsequently under favorable conditions. The toxin excreted by Cb called Botulinum Neuro Toxin (BoNTs), causes paralysis and invariably deaths as the muscles controlling breathing fail. Though death toll due to botulism is less than 150 cases an year, what causes alarm is the fact that only 15% of these deaths were traced to food poisoning while the rest were due to inhalation. Infants are specially vulnerable to Cb spore dusts as their intestines are critically affected.

Botulinum toxin became famous when it was discovered that minute concentrations can have beneficial effects in cosmetic surgery. Though it has an LD50 value as low as 0.005-0.05 micro gram per kg body weight when ingested, external application through surgery causes decreased muscle activity locally by blocking the release of acetyl choline at the neuro muscular junction. 'Botox' procedure, as it is popularly known, can ensure freedom from wrinkles in the face for a period of 3-4 months. World over more than 5 million botox procedures have been performed for improved facial appearance by women.

In the preparation for defense against botulism, injectible vaccines have been developed containing detoxified versions of 5 types of BoNTs (serotypes A,B,C,D and E) but the dangerous procedure involved while handling active bacteria is a major constraint. Recent development of a nose-spray vaccine against botulism has many features that make it universally acceptable. They are made from non-toxic proteins that resemble those created by the bacteria. The preparedness for eventualities like this is the hall mark of countries who value life of their citizens and spares no efforts to invest on preventive measures to meet the challenge of terrorism, no matter how minor it may turn out to be.


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