Work of an In-patient Department

44. Immunity
. Infectious diseases are known to be caused by the invasion and growth of
microorganisms in the human body. Infection may result from direct contact
with patients or from indirect one. ч
But the human organism is known to have a specific capacity of resistance against infection, which is called immunity, it being natural and artificial. Un­der various conditions it may be entirely lacking, it may be relative, rarely it may be absolute. A previous attack of an infectious disease produces a more or less permanent protection against its subsequent infection.-
In the course of their growth in the body many pathogenic microorganisms produce virulent poisons or toxins, they causing the characteristic symptoms of a particular disease. To meet the infection the cells of the body produce a chemical antidote which is specific for this particular infection and is known as an anti-toxin._tIf the patient can produce a sufficient amount of this antidote to neutralize the toxins before the vital organs are injured recovery occurs, If the human bod. Asepsis
If all the works carried out by the great French researcher Pasteur were^ divided into three groups they would form three great discoveries.
The first one might be formulated thus: "Each fermentation is produced by the development of a particular microbe."
The second one might be given this formula: "Each infectious disease is produced by the development of a particular microbe within the human organ­ism."
The third one might be the following: "The microbe of an infectious dis­ease, under certain conditions, is attenuated¹ in its pathogenic activity; from a microbe it becomes a vaccine."
In 1878 while delivering his lecture on the theory of microbes at the Acad­emy of Sciences in Paris Pasteur said that if he were a surgeon, who knew of the dangers produced by microbes existing on the surface of every object, particu­larly in hospitals, not only should he use clean instruments, but after washing his hands with the greatest care, he would employ only those bandages and charpie² which had been heated to a temperature of 130° or 150°C.
if he employed the water he would heat it to ^ temperature of 110° or 120°C, since observation had shown the clearest water to contain still greater number of microbes.
Had those principles of asepsis, on which Pasteur insisted, not been strictly followed in medicine thousands and thousands of human lives would have been lost because of sepsis.
y had not this capacity we should suffer from all infectious diseases.
If the toxin can be isolated from bacterial cultures and injected into men an artificial immunity can be produced which results from the formation of anti­toxin.
The cellular elements of the tissues also take an active part in the protection of the organism against the infection. The presence of any infection usually produces leucocytosis and bacteria in the tissues are surrounded by white cells or phagocytes which prevent the spread of bacteria destroying them.
If the reaction against invading bacteria is insufficient, vaccines may be injected subcutaneously to produce a more active resistance of the protective mechanisms of the body. Vaccines are employed not only to contribute to the treatment of a disease, but to establish an active artificial immunity.