Page 3 - Lesson 13.xps

Module -V
Biological Warfare
Warfare and
conditions for a long period extending to years. The bacteria, which form spores, Its Types
are also known as persistent BW agents. Bacillus anthracis, cause of anthrax, is
a very important BW agent, which produces spores.
(b) Rickettsia: These are primarily parasites of insects and appear only secondary
in man and other animals. The microorganisms characteristically inhabit the cell
lining of the intestines and other tissues of the insects. They are found in a certain
Note
group of blood sucking insects, such as fleas, mites, lice and ticks. The rickettsia
causes no injury to the insects but is often pathogenic to men and other animals.
Some rickettsia cause diseases that are severe and often fatal. They are susceptible
to antibiotic treatment. They grow only within living cells like viruses.

(c) Viruses: A virus is a small infectious agent that replicates only inside the living
cells of other organisms. Viruses can infect all types of life forms, from animals
and plants to microorganisms, including bacteria. Viruses are not cellular and
therefore do not possess typical structures of a cell. No specific treatment is
available against viruses; viruses do not respond to antibiotic treatment. However
vaccination is effective. e.g. Small Pox
(d) Fungi: A fungus (plural - fungi) is any member of the group of organisms that
includes microorganisms such as yeasts and molds. The most common example
is mushrooms. Fungi may be regarded as primitive plants that do not produce its
own food. They draw nutrition from decaying vegetation matter. Most fungi can
exist either in a yeast-like state or as resistant spores. The fungi which produce
toxins (mycotoxins) are important BW agents.

13.2.2 Essential Characteristics of BW Agents

A majority of BW agents employ germs. Some of these organisms can only grow and
reproduce under suitable conditions and they are regarded as non-persistent as they
are extremely susceptible to variation in temperature, humidity and sunlight. Some
agents, such as anthrax, are highly resistant to climatic effects and can be classified as
persistent. Some important and essential characteristic BW agents are: -

• Infectivity: The infectivity of microorganisms is defined as its ability to cause
disease. A greater infectivity means that fewer microorganisms are required. It
means how fast the microorganisms can enter the body of the target.
• Virulence: The infective penetration of sufficient microorganism may produce

diseases of different severity. The most virulent strain produces the most acute
or severe effects and is a better BW agent.
• Incubation: The incubation period is the time between the infective penetration
of sufficient microorganisms into the body and the appearance of the symptoms
of the disease. It is normally not less than 24 hours.

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MILITARY STUDIES 41