kokyraluduty

Related post: ing and setting up an infection. In tuberculosis and typhoid fever and most of the infectious diseases it requires a rather lai^e number THE OHIO PUBLIC HEALTH JOURNAL. l8S before an infection will take place. The leucocytes, bactericidal sub- stances in the blood, and the body cells in general are capable of destroying many infectious agents. Furthermore, it can be readily understood how a few bacteria m^ht be able to cause a mild infection and an increasing number be able to so overcome the bodily resistance as to cause a more or less severe infection. Avenue. It has been pointed out previously how the avenue of infection modifies the infection. A very virulent microorganism may occasionally produce a very mild infection when introduced in a cer- tain locality while in another place the same organism may produce a very severe type. The results of the infection will be materially modified depending on the avenue of entrance which the virulent microorganism takes. For example, in addition to those mentioned previously, suppose Bad. pesHs, the causal agent of plague, enters the blood through the skin, or the lymphatics through the tonsils, it is carried to the lungs and there produces a very severe and usually fatal pneumonia; if bacteria enter the lymphatic system in large numbers they frequently localize in the lymph glands producing buboes or glandular enlargements which are always fatal. These bacteria may also enter the blood current and produce a rapidly fatal septicemia. It has not been established in man that plague can be produced by the ingestion of Bact. pestis, but in some susceptible animals such as rats, the disease in a very fatal form is rapidly acquired when the bacteria enter the intestines. Resistance. This factor is one of the prominent ones which modify the results of an infection. It is a familiar fact that two or more individuals may be infected with the same microorganism, as for example, B. typhosus and one will not become infected or have a very mild form of the disease, while the other will have the severest and most fatal form of typhoid fever known. Again, the age of the individual infected is important in determining the resistance. The adult resists infection such as diphtheria, scarlet fever, and measles more than the child. The very young child resists pneumonia and tuberculosis more than the adult. The resistance of the body depend.^ on the presence in that body of natural or acquired antibodies. It is therefore obvious that the higher resistance Buy Asendin Online or immunity of the in- dividual infected, the less severe will he the results of the infection on that individual. TIIK EXACT CAUSK OP INl'Efnil.V. We are familiar with the fact that all of our infectious diseases are dpe to microorganisms or viruses of some form or other. The L.Q;,z<.Jl.yLjOOglC l86 THE OHIO PUBUC HEALTH JOURNAL. causal agents of many of these diseases are known but in the case of those that are not known there is reasonable certainty as to the types of the infecting agents. The exact substances which are pro- duced by the microorganisms and which are responsible for symptoms of the various diseases will be briefly considered as follows : Soluble Toxins. It is a known fact that there are some path- ogenic bacteria which secrete through their cell walls poisons which diffuse into the surrounding media. To these poisons or toxins the disease symptoms are due. Bact. diphtheriae of diphtheria, B. tetcmi of lock-jaw or tetanus, Bact. dysenteriae of bacillary dysentery, B. botilinus of meat poisoning, and Ps. pyocyanea, the causal organism of blue-green pus, are about the only bacteria of this character. Some bacteria, such as Strept. pyogenes and M. pyogenes var. aureus pro- duce hemolytic toxins. There are certain protozoa as, for example, the Entamoeba colt and the various trypanosomes which secrete solu- ble poisons. Among the animals, the venmns of the poison snakes; the poison of the centipedes and spiders, the serum of the eel, and the excretion of the dermal glands of the toad are examples of secreted toxins (zootoxins). Again, among the plants are abrin from the jequerity bean, recin from the castor oil bean, and others, are ex- amples of soluble toxins the product of plant cells (phytotoxins). The cells producing these toxic substances, therefore, are only indirectly responsible for the infections for it is the toxins themselves which produce the pathogenic effect on the body. Endotoxins. Many of the pathogenic bacteria and some of the protozoa do not secrete their toxins outside the cell wall but hold them within the wall in combination with the protoplasm. They do not liberate these substances until the microorganisms die and are dis- integrated. Such toxic substances are called endotoxins to distinguish them from those secreted frtMn the cell, namely, the soluble toxins. Two of the best examples of pathogenic bacteria of this type are the Msp. comma of Asiatic cholera and B. typhosus of typhoid fever. Toxic Bacterial Proteins. There are_ some bacteria and other parasitic cells which produce a small amount of endotoxin and in certain instances some soluble toxin but not enough of either of these substances to account for the toxicity of the organism. It has been found that, when organisms of this character are ground up and washed to free them of their endotoxin and are washed free of all soluble toxins, they are still toxic. It has been shown that this toxicity is due to the protein substances of the cell. The Bact. tuber- culosis and the Bact. mallei of glanders are two notable examples of microorganisms of this character. When, for example the proteins - THE OHIO PUBLIC HEALTH JOUSNAL. iS? of Bact. tubercuiosis are injected into the circulation of susceptible animals tubercle formation occurs showing that these proteins are Other Possible Exact Causes. In certain infectious diseases it is also daimed by certain writers that enzymes are re^wnsible. This lacks substantiation. It is also stated that in such infections as anthrax that the mechanical effect of the bacteria plugging up the capillaries and producing micotic emboli is a factor. This may be true but jn addition other factors are concerned as previously mentioned. In mixed infections of two or more organisms, which frequently occurs, the infected individual may have within the body soluble toxins, endotoxins, and toxic bacterial proteins and in such a case it is difficult to differentiate their action. THE METHODS BY WHICH INFECTIOUS MICROORGANISMS ARE DISSEMINATED. The microorganisms of some of the infectious diseases such as diphtheria and Asiatic cholera and usually tetanus remain local and seldom enter the body generally. From the locus of the infection they disseminate their toxic or poisonous products. In the case of tetanus the toxin is carried over the body along the sheaths of the motor nerves ; in diphtheria the toxin is usually carried by the lymph, and occasionally by the blood ; and in the case of cholera the blood and I)miph both serve to carry the toxic agents. In diphtheria and cholera the microorganisms very frequently extend along the mucous mem- branes from the original point of infection. There are other infec- tions in which the causal microorganisms extend only from the point of original invasion into the surrounding areas. Such is the case with Strept. pyogenes m the infection of the lymphatics of the skin in erysipelas and of Bad. infiuensae in all infection through the respiratory tract. Many of infectious agents are carried by the blood, and occasionally by the lymph, as for example, in tuberculosis, syphilis, glanders, plague, leprosy, Buy Asendin pneumonia, and the septicemias due to the pyogenic cocci. It is possible in certain cases that the leucocytes acting as phagocytes may carry virulent infectious agents through the blood and lymph from one part of the body to the other. THE METHODS BY WHICH INFECTIOUS AGENTS ARE ELIMINATED FROM THE BODY. The etiolc^ial microorganisms of the various infectious diseases may be eliminated from the body in two general ways, namely, by a direct method and by an indirect method. For a microorganism to l88 THE OHIO PUBLIC HEALTH JOURNAL. be directly eliminated from the body it is necessary for the focus of the infection to communicate with the outside of the body in some way or other. In the case of infections of the mucous membranes and the skin there is, of course, direct communication with the out- side. In diseases of the respiratory organs and the intestines the in- fectious agents are discharged info the lumen of the air passages and the intestines and then thrown out from these passages. Examples of the partial direct elimination from the skin may be found in such disease as smallpox, measles, syphilis, scarlet fever, lupus vulgaris, and in suppurative conditions such as carbuncles and furuncles. From the present evidence little significance is to be attached to the elimination of the infectious agents mentioned directly from the skin. It is probable that the microorganisms which are eliminated remain alive for only a short time and are not factors of consequence in the transmission of these infections. As examples of diseases in which direct elimination from the various mucous membranes occurs Related links: Seroquel Order, Paxil And Paxil Cr, Price Of Orlistat, Indocin Injection, Buy Januvia, Cellcept 250, much does generic propecia cost, Buy Ethambutol Hydrochloride, purchase clomid online, wellbutrin buy cheap