Etiology, Biology

Assignment Help:

M protein of rheumatogenic GAS has distinct structural characteristics that are akin to human heart tissue, particularly sarcolemmal membrane proteins and cardiac myosin. The major factors that lead to risk of ARF are the severity of the immune response to GAS pharyngitis and persistence of GAS organisms during convalescence. A very small proportion (0.3-3 per cent) of patients suffering from GAS throat infection ultimately develop ARF and this along with a familial predisposition of ARF points to a genetic susceptibility. However, in our Indian patients a genetic linkage to HLA DR3 in patients, with ARF has been demonstrated. For confirmation of the initial diagnosis of acute rheumatic fever, evidence of prior GAS infection is required. Several rapid GAS antigen tests are available. Majority of these tests has a high degree of specificity but low level of sensitivity in clinical practice.

However, it must be stressed that a negative test does not rule out the GAS infection in the throat. At the same time in presence of a positive antigen test and positive throat culture, it is difficult to distinguish between a recent infection which can be associated with ARF and chronic carrier of GAS infection with ARF. Elevated or rising ASO titres (> 250Todd units in adults and >333 Todd units in children) are more reliable evidence of recent GAS infection than a positive culture or positive rapid antigen test and such titres are also significant for diagnosis.


Related Discussions:- Etiology

Explain antibacterial activity, Antibacterial activity   Rifaximin reach...

Antibacterial activity   Rifaximin reaches high concentrations in the intestinal tract and is active in vitro against a broad range of enteropathogens, including ETEC, EAEC, Shi

Skeletal system - skull, SKULL- Present in head region. It is suppor...

SKULL- Present in head region. It is supported on the top of vertebral column. It is made up of the hardest and denest bones in the human body. It consists of cranium

Define control of infections for treatment for pem, Define Control of infec...

Define Control of infections for treatment for pem? Appropriate antibiotics should be started immediately since infections are the immediate cause of death in many children. Ch

Types of ovarian cycles in mammals, Types of Ovarian Cycles in Mammals ...

Types of Ovarian Cycles in Mammals Mammals exhibit two types of ovarian cycles; Estrous Cycle, exhibited by non-primates such as rats, cats, dogs, pigs, and Menstr

Define the skeletal muscle, Define the Skeletal muscle A. Binding of ca...

Define the Skeletal muscle A. Binding of calcium ion to its receptor site on the actin molecule blocks the attachment of the head of the tropomyosin molecule to its binding sit

Which type of genetic disease can be identified, Which type of genetic dise...

Which type of genetic disease can be identified from the visual analysis of the number of chromosomes present in a karyotype? The counting and identification of chromosomes in

Adaptations to high wind velocity, Adaptations to high wind velocity Th...

Adaptations to high wind velocity The mechanical force of the wind and the grinding action of sand, dust, snow and other materials driven by it cause the plants to adapt themse

Cation and anion, what is cation and anion? list of cation and anion and it...

what is cation and anion? list of cation and anion and its biological function?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd