In these cases, the antibodies which the persons immune system developed to attack the group A streptococci are also able to attack the persons own tissues. The following complications result, depending on which tissues in the persons body are targeted by those antibodies. Acute rheumatic fever: This is a complication that results 2–6 weeks after a group A streptococcal infection of the upper respiratory tract. It presents in developing countries, where antibiotic treatment of streptococcal infections is less common, as a febrile illness with several clinical manifestations, which are organized into what is called the Jones criteria. These criteria include arthritis, carditis, neurological issues, and skin findings. Diagnosis also depends on evidence of a prior group A streptococcal infection in the upper respiratory tract (as seen in streptococcal pharyngitis and scarlet fever). The carditis is the result of the immunologic response targeting the persons heart tissue, and it is the most serious sequelae that develops from acute rheumatic fever. When this involvement of the heart tissue occurs, it is called rheumatic heart disease. In most cases of rheumatic heart disease, the mitral valve is affected, ultimately leading to mitral stenosis. The link to rheumatic fever and heart disease is a particular concern in Australia, because of the high prevalence of these diseases in Aboriginal and Torres Strait Islander communities. Poststreptococcal glomerulonephritis: This is inflammation of the kidney, which presents 1–2 weeks after a group A streptococcal pharyngitis.
Karelitz and Stempien discovered that extracts from human serum globulin and placental globulin can be used as lightening agents for scarlet fever and this was used later as the basis for the Dick test. The association of scarlet fever and bacteriophages was described in 1926 by Cantacuzène (Ioan Cantacuzino) and Bonciu.An antitoxin for scarlet fever was developed in 1924. The first toxin which causes this disease was cloned and sequenced in 1986 by Weeks and Ferretti. The discovery of penicillin and its subsequent widespread use has significantly reduced the mortality of this once feared disease. Reports of cases of scarlet fever have been on the rise in countries including England, Wales, South Korea, Vietnam, China, and Hong Kong in recent years. Researchers are unsure as to what has caused the spike in cases of the disease. The Dick test
The Dick test, invented in 1924 by George F. Dick and Gladys Dick, was used to identify those susceptible to scarlet fever. The Dick test consisted of injecting a diluted strain of the streptococci known to cause scarlet fever into a persons skin. A local reaction in the skin at the site of injection appeared in people who were susceptible to developing scarlet fever. The reaction was most notable around 24 hours after the injection but could be seen as early as 4 hours. If no reaction was seen in the skin, then that person was assumed to have already developed immunity to the disease and was not at risk of developing it. References


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