Diphtheria

Overview diphtheria (diphtheria) is caused by bacillus diphtheria inoculations. Clinical characteristics of the pharynx, larynx, nasal mucosal congestion, swelling and not shedding of gray and white pseudo form. As bacterial toxin outside the body caused by poisoning symptoms, severe cases can be complicated with myocarditis and peripheral nerve palsy. The disease is a worldwide distribution and the seasons can catch more winter to autumn. Etiology Diphtheria Diphtheria bacilli, or Campylobacter, Gram-positive, about 3 ~ 4μm, width 0.5 ~ 1μm. no spores, Clostridium and power. Micro-cell vertical bending, one end or both ends was drumstick-like swelling, appearing smear on the V, L, Y shaped arrangement. Using special stains, such as Neisseria (? Neisser) staining, cells uneven coloring, and the Portland-particle pollution. Diphtheria bacilli in serum - free medium or medium growth readers good. In the Asia-tellurium potassium colony on the medium was black or dark gray flat circular uplift. According to the colony morphology and biochemical response characteristics of a type of bacteria is heavy, light and intermediate type. Able to produce three-exotoxin, it is generally thought that the middle-heavy and caused severe illness, there were more nerve palsy, with a high fatality rate. But in recent years, reports of light caused by the bacteria in patients with severe than that caused by the heavy strain less. Diphtheria bacilli infected with a toxin-producing gene carrying the phage that have the ability to synthetic toxins. Bacterial toxin-producing capacity from phage genes, from the invasion of bacteria gene. Diphtheria toxin outside with a strong antigen, but not stable enough. Analysis of the dry, cold and sunny with low resistance than the other non - spore-forming bacteria stronger in dry pseudo-2 memory, in the water and milk can live for several weeks; Disseminated with dust when exposed to direct sunlight in the next few hours after having killed; But the heat and chemical disinfectants sensitive, and 56 ° C for 10 minutes; in 0.1% mercuric chloride. Carbolic 5% and 3 ~ 5% of the solution to the Soviet Union, can kill rapidly. Epidemiology (1) the source of infection is strictly Diphtheria bacilli in the parasitic bacteria infecting patients and HIV carriers. Diphtheria end of the incubation period the patient is infectious. Not typical of patients with mild and diphtheria spread more dangerous, generally healthy carriers of the total population below 1%. pop reach 10 ~ 20%. Due to the application of antibiotics, HIV infected recovery time significantly shorter, about 90% of patients within four days of bacteria disappear. (2) The main mode of transmission through respiratory droplets. Or by contaminated hands, toys, stationery, utensils and handkerchief and so on. Occasionally through contaminated milk caused pop reported. Damage can also be made through the skin and mucous membranes infected. (3) the susceptibility generally susceptible, susceptibility depends on the level of toxins in vivo volume. Children highest susceptibility; Newborn through the placenta and breast milk were immunity, to an age when almost all disappeared. After age increased susceptibility gradually increased. Because diphtheria vaccination of extensive, childhood immunization generally strengthened, high incidence of the disease after age shift. Available after illness lasting immunity, sometimes several times onset. Human immunity to diphtheria, decided to anti-blood endotoxin levels. Serum containing 0.01 mg / L that is a protective role. Sikh grandfather used test (schick's test) to determine whether the human body immune to diphtheria. Sikh's test was negative, the body of diphtheria infection immune, in the case of a positive, expressing diphtheria infection have no immunity. Since the law cumbersome, and has been sensitive, convenient and indirect hemagglutination test and replaced by ELISA. Drug crowds, diphtheria epidemic help to predict the possible extent, can also be detected in the prevention effect. Principle and the incidence of diphtheria pathological changes of the disease into local inflammation and antibiotics exotoxin caused by toxemia two aspects. Diphtheria bacilli invasive pharyngeal mucosa after the mucosal surface tissue growth and reproduction, is not usually cause bacteremia. Diphtheria bacilli exotoxin produced by the main pathogenic factors, the toxin A, B 2 fragment B fragment without direct toxicity, and when it is the cell surface receptor binding, A fragment enter cells, thus the cell death direct role. Manifestation of its local mucosal epithelial cell necrosis, and gradually expand the integration, we can see the mucosal vascular dilatation and congestion. a large number of fibrin. The fibrin exudation and necrotic cells, white blood cells and bacteria together condensation covering the mucosal surface damage, form of the disease characteristic ensued. Diarrhea normally gray and white, mixed infection or dirty yellow color, with bleeding black. Diarrhea dense texture and began thin, followed thicker than the edge of rows, not lost, forced stripping can hemorrhage. Diarrhea and formed around was mild congestive swelling. Diarrhea may be to swallow tonsil Gap, nose and throat, trachea, bronchus and other places to expand, nasopharynx, The trachea easily peeled off ensued caused respiratory asphyxia. Diarrhea more extensive scope, the greater absorption of toxins, poisoning the symptoms become more important. If toxins before adsorbed on the surface of cells, anti-toxins to which China and had already entered the cell, it can not be anti-toxin and the. Exotoxin with the cell combination can lead to sexually transmitted diseases systemic change. With cardiomyopathy, peripheral nerves, adrenal and other more significant. Myocytes turbidity swelling and fatty degeneration, glass-like and particle-like degeneration and interstitial edema, severe muscle fibers can be broken, myocardial necrosis and mononuclear cell infiltration, conduction beam can be involved. Neuropathy was particularly prevalent in the peripheral nerve, appearing fatty degeneration of myelin, axonal swelling, fracture, sensory and motor nerves were affected, but mainly by the motor neurons. Paralysis occurred in the eye, pharynx, larynx muscles, but also can occur in the limbs. Kidneys could turbidity was swelling and tubular epithelial desquamation. Liver cells were steatosis, the same was true was the central necrosis.