Diphtheria: a Scientific Overview

The word diphtheria has come from Greek (pair of leather scrolls). This disease is said to be a respiratory tract illness. There are naturally different forms of diphtheria such as mild and severe. Both are characterized with certain symptoms and signs. A milder form though does have its expression on the skin only. The illness could be only manifested through sore throat, low fever a pseudomembrane on the pharynx and nasal cavity.

When dialing with diphtheria you are to come across the influence on central and peripheral nervous system. This may be resulted in loss of sensation. Such illness is very dangerous as it may be transmitted by physical contact. In other words you are most likely to catch diphtheria while being in the same room with the infected person, as the aerosolized secretions are the main culprits for the appearance of the illness.

For a long time diphtheria has been met in various countries. The government and scientists tried to prevent diphtheria from spreading all other the country. Naturally industrially developed ones did have more chances or struggle with diphtheria. According to the statistics, for example, within some last years there were only a few cases of diphtheria in the United States of America in comparison with 52 ones mentioned between 1980 and 2000. The doctors advised Diphtheria Pertussis Tetanus to prevent school age children. This type of the vaccine was also widely used among people going to the infected areas in order to protect them from catching small particles of the illness located in the air around an infected illness. In other words before you travel to the infected area you have to take a vaccine. Diphtheria was even mentioned with the UN Development Goals as one of the goals concerning Child Mortality and Health.

But let’s talk about the symptoms of diphtheria. Like any other illness it has anincubatiom period of 2-5 days. At the beginning it is usually not spreading rapidly. You may observe fatigue, fever and problems swallowing. Some kids may express vomiting, chills, high fever. You are to keep in mind that sometimes the infection may show no signs of presence due to its specificity. The so-called “bull neck” appears sometimes revealed by neck swelling. Definitely the more cases you observe the more possibilities to have further development of diphtheria. That’s why catching the illness at the beginning is supposed to be your primary goal when dealing with diphtheria. Do not forget though that listlessness or fast heart rate may take place in some cases. They are general to a certain extent; therefore an infected peros may even be unaware of the illness. As a result they observe low blood pressure. There also does exist the so-called secondary infection which is the result of the cutaneous form of diphtheria. It takes seven days for the signs to appear.

Let’s observe the whole process of its development.

Diphtheria toxin consists of a single polypeptide. There are two fragments in Proteolysis yields held together by a disulfide bond. The toxin binds to EGF-like domain of Heparin-binding EGF-like growth factor through fragment B and is internalized with HB-EGF by receptor-mediated endocytosis. The low pH in the late endosomes induce pore formation by fragment B as well as catalyses the release of catalytic fragment A into the cytosol. The ADP-ribosylation of the elongation factor EF-2 is catalyzed by diphtheria toxin. So during eukaryotic protein synthesis it inhibits translation. The toxin enters the host cell and takes hydrolysation by a trypsin-like protease in order to provide a fragment with certain activity. The cell needs EF-2 for translocation of tRNA from the A-site to the P-site of the ribosome. The ADP-ribosylation could be performed by managing sufficient concentrations of nicotinamide (a product of the raction). Diphtheria toxin is only infected with a bacteriophage. The last one integrates a gene into the bacteria that results in the production of the toxin.

The definition of diphtheria was given according to certain laboratory and clinical criteria. So the Centers for Disease Control and prevention expressed the following laboratory and clinical criteria.

Laboratory criteria had included isolation of Corynebacterium from a specimen or Histopathologic diagnosis of the illness.

Such notions as upper respiratory tract illness with sore throat, high-grade fever, and the mentioned above adherent pseudomembrane of the tonsil are included into the clinical criteria.

Here we also do observe case classification: possible and confirmed. A possible one is not laboratory-confirmed. A confirmed one is on the contrary a clinically compatible case.

In some cases the disease may remain manageable but in certain cases it requires treatment. For example, lymph nodes in the neck can swell and as result it will be rather difficult breath. People with such signs should have immediate medical attention as obstruction in the throat may require intubation. Abnormal cardiac rhythms can occur early in the course of the illness or weeks later, and may be resulted in heart failure. Diphtheria can also cause paralysis in the eye, throat, and respiratory muscles.

Patients suffering from heavy cases of diphtheria will be put in a hospital and be prescribed a diphtheria anti-toxin. Since antitoxin does not neutralize toxin that is already bound to muscles, mortality risk will be increased due to delay of its administration. So the decision to manage diphtheria antitoxin is based on clinical diagnosis only, and should not be confirmed in a laboratory

Antibiotics have not been demonstrated to affect healing of local infection in diphtheria patients. Antibiotics are used in patients or carriers to prevent the disease from transmission to other people. Among the most common treatments we are to name erythromycin. It is taken orally or injected, or Procaine penicillin G (intramuscularly).

In cases that progress beyond a throat infection, diphtheria toxin spreads through the bloodstream and can lead to really life-threatening complications that affect other parts of the body, for example the heart and kidneys. The toxin can cause damage to the heart that affects its ability to pump blood or the kidneys' ability to clear wastes. It can also cause nerve damage, eventually leading to paralysis.