Illnesses caused by bacteria and other microorganisms are called infections. Plants and animals as well as human beings may suffer from infectious diseases. The infection may be caused by the microorganisms themselves or by their poisonous waste products, called toxins. The toxins are often more dangerous than the bacteria. Fortunately the body produces defenses against both.
Antibodies combat the microorganisms.
Other antibodies, called antitoxins, combat the toxins. Disease bacteria may be used by warring nations to spread disease among the enemy and to destroy livestock and farm crops. Water systems can be poisoned by bacterial toxins, which are among the most powerful poisons known. As a preventive measure, more than 70 nations, including the United States, signed an agreement in 1972 that banned the development, production, and stockpiling of such biological weapons. The pact also required the disposal of existing biological weapons.