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

Tanco beans plant, what are the origin, morphology, active constituents, us...

what are the origin, morphology, active constituents, uses and market preparation of tanco beans ?

Sources of water are to contain pathogenic bacteria, What sources of water ...

What sources of water are (a) most likely, (b) least likely to contain pathogenic bacteria?   (a) Water most likely to have pathogenic bacteria will be that which receives u

How drugs increase food intake, How Drugs Increase Food Intake? You mus...

How Drugs Increase Food Intake? You must understand that drugs may also increase food intake. This is because they can: Stimulate appetite : This is a common side effect

Types of transport process in sieve tubes, Types of Transport Process in Si...

Types of Transport Process in Sieve Tubes The metabolites of all the mesophyll cells around the sieve elements join in a common pool to load via the surrounding transfer cells

What do you mean by diabetes mellitus, Q. What do you mean by Diabetes Mell...

Q. What do you mean by Diabetes Mellitus? Diabetes Mellitus as you know is a metabolic disorder, which is characterized by high blood sugar. It is a chronic disease condition,

Explain dna binding domains, Helix-turn-helix This  motif  have  of  tw...

Helix-turn-helix This  motif  have  of  two    -helices  divided  by  a  short  (four-amino   acid) peptide  sequence  which  forms  a   -turn that shown in above figure.  When

Describe the two pieces of evidence, Describe two pieces of evidence indica...

Describe two pieces of evidence indicating that speciation does not always occur at the same rate. Some species of moths on the Hawaiian Islands appear to have evolved during t

Define some major source of sodium and chloride, Define some major source o...

Define some major source of sodium and chloride? The major source of sodium and chloride is common salt added to our food in the form of sodium chloride. Naturally occurring so

Are environmental phenotypical changes transmitted offspring, Are environme...

Are environmental phenotypical changes transmitted to the offspring? Changes caused on the phenotypes by the environment are not transmitted to the offspring unless their prima

Set up of phototherapy unit, Set Up of Phototherapy Unit Phototherapy ...

Set Up of Phototherapy Unit Phototherapy generally consists of four to eight cool white, day bright, or special blue fluroescent tube lights covered by a plastic shield and p

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