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

Define tests to measure muscular strength and endurance, Define Tests to Me...

Define Tests to Measure Muscular Strength and Endurance? It is important to first understand the difference between muscular strength and endurance. To know the muscular streng

Class arachnida of phylum arthropoda, Class Arachnida of Phylum Arthropoda ...

Class Arachnida of Phylum Arthropoda Body divided into cephalothorax and abdomen. Cephalothorax along with four (4) pairs of legs; abdomen segmented or unsegmented, with or wi

Mycroboilogy mycoplasma, How we write assimgment about mycobiology of mycop...

How we write assimgment about mycobiology of mycoplasma in detail

What is mdrtb, What is MDRTB MDRTB - For patients with known exposure t...

What is MDRTB MDRTB - For patients with known exposure to multi-drug resistant TB (MDRTB) and a high risk of developing active TB, there are no data-based recommendations. Regi

What are the risk factors for development of food allergy, What are the ris...

What are the risk factors for the development of food allergy? Having gone through the discussion above, can you identify at least one important factor leading to food allergy?

Water, Water Water usually forms about 50% to90% part of living protopl...

Water Water usually forms about 50% to90% part of living protoplasm. Life upon earth originated in the ocean and the conditions of that aqueous primeval environment have been r

Theory of germplasm - pre-mendelian theory, Theory of Germplasm (i)    ...

Theory of Germplasm (i)         'August Weismann' (1889) suggested the theory of continuity of germplasm. (ii)         He referred to the reproductive cells as germplasm and

Iodine - mineral elements, IODINE The element is available is drinking ...

IODINE The element is available is drinking water, vegetables and fish. Table salts are also compulsorily iodized to provide iodine in the diet. All sea foods are rich in

Why iodine is vital for human beings, Q. Why iodine is vital for human bein...

Q. Why iodine is vital for human beings? Iodine is a essential chemical element for the proper functioning of the thyroid since it is part of the hormones produced by this glan

Illustrate fundamental sexual life cycles, Q. What are the three fundamenta...

Q. What are the three fundamental sexual life cycles studied in Biology? Which of them corresponds to metagenesis? Which of them is the human life cycle? Sexual reproduction ma

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