An introduction – biothreats and biodefense

What is bioterrorism?

Outbreaks of pathogens in the human population have been responsible for millions of deaths historically, for example, pandemic influenza after the First World War (1918–1920) caused approximately 40 million mortalities worldwide.

However, this is not only a historical problem – infectious diseases remain a major cause of mortality across the globe. With increasing globalization and travel, large populations in dense, built-up areas and the continued potential for transmission from animals, disease outbreaks are certainly a major threat.

Moreover, factors such as growing resistance to both treatments and control measures only compounds the risks. If pathogens could therefore be harnessed as a weapon, the implications would certainly be severe and far-reaching.

A bioterrorism attack is classified as the deliberate release of a pathogen – viral, bacterial or otherwise – with the intention of causing harm to a human, animal, plant or other living organisms in order to influence government or to intimidate civilian populations [1]. Often these are pathogens that occur naturally, but theoretically they could be subject to gain-of-function processes to increase transmissibility, pathogenicity or ease of treatment.

Anthrax dissemination via the US mail in 2001 emphasized the very real danger of bioterrorism or biological warfare. Moreover, although there has not been a major incidence such as those often depicted in films, the possibility of a biothreat agent being used with malice, as part of a bioterrorism or biological warfare scenario, has become an increasing concern to both military officials and civil defence authorities worldwide [2].

What is a biothreat?

A biothreat is defined as the threat posed by a harmful biological agent – this includes bacterial, fungal and viral pathogens and toxins produced by a variety of organisms [3]. The National Institute of Allergy and Infectious Diseases (NIAID; MD, USA) have classified all emerging infectious diseases agents under three categories; A, B or C, depending on their propensity to being a risk, and this categorization is periodically reviewed and subject to revisions.

Category A comprises pathogens that pose the highest threat to national security and public health, including bacteria such as anthrax and plague, with category B and C being lower priority respectively [4].

For a biothreat agent to be categorized, there are several conditions that must be met. First, the agent should consistently produce the desired effect of death or disease, be highly contagious, have a short incubation period and be infective in low doses. Moreover, the pathogen should be suitable for mass production and storage, therefore be stable both in this period and during dissemination. Finally, the target population should have little or no immunity to the pathogen and there should be little or no access to treatment.

What is biodefense?

Biodefense constitutes the use of medical measures to protect individuals against bioterrorism – including interventions such as drugs and vaccinations but also research and public health preparations to defend against such biological attacks [5].

There are a combination of processes and systems that have been put in place by bioscience laboratories, agricultural managers, customs agents and many other parties in order to prevent the use of dangerous pathogens and toxins. Some examples include the imposition of regulations on the research carried out on certain pathogens, or preparatory plans for the case of a hostile disease outbreak.

However, there is some debate over how the threat of bioterrorism compares with the risks posed by, for example, natural disasters and pandemic outbreaks, and thus how it should be prioritized in terms of resources and finance.

References

1. Gostin LO, Sapsin JW, Teret SP et al. The Model Sate Emergency Health powers Act. JAMA. 288, 622–628 (2002)
2. Inglesby T. Straight talk with… Tom Inglesby. Interview by Kevin Jiang. Med. 19(657). doi: 10.1038/nm0613-657 (2013)
3. Definition of a biothreat. Merriam-Webster. merriam-webster.com/dictionary/biothreat (Accessed on 10th January 2017)
4. National Institute of Allergy and Infectious Diseases. Biodefense and Emerging Infectious Diseases.. niaid.nih.gov/research/biodefense-emerging-infectious-diseases (Accessed on 10th January 2017)
5. Health topics: Biodefense and bioterrorism. MedlinePlus. https://medlineplus.gov/biodefenseandbioterrorism.html (Accessed on 10th January 2017)