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

Molybdenum (mo), Molybdenum (Mo) Mo is absorbed as molybdate (MOO 2- ...

Molybdenum (Mo) Mo is absorbed as molybdate (MOO 2- 4 ) ion by plants. Its uptake can be competitively reduced by SO 2- 4 . The requirement of plants for Mo is very low. Mo

Define classification of carbohydrates - monosaccharide, Define Classificat...

Define Classification of Carbohydrates - Monosaccharide? Monosaccharides or simple sugars are those carbohydrates that cannot be hydrolyzed into simpler carbohydrates. E.g. gl

What is guided bone regeneration, What is Guided bone regeneration Gui...

What is Guided bone regeneration Guided bone regeneration (GBR) allow the practitioner to place implants in patients who would not have received this treatment option a few y

Explain the food security, Explain the Food Security? You were introduc...

Explain the Food Security? You were introduced to the concept of food security in Unit 2. Food security, we learnt, is access by all people at all times to enough food for an a

Explain some advantages of most probable number, Explain some Advantages of...

Explain some Advantages of Most Probable Number? 1. It is simple and method of choice for determining fecal coliform densities. 2. Results of different laboratories are comp

Circulatory system, Circulatory system, closed is a system which uses a co...

Circulatory system, closed is a system which uses a continuous series of the vessels of different sizes to deliver blood to body cells and return it back to the heart; it is found

Etiological factors contributing to lactose intolerance, Q. Etiological fac...

Q. Etiological factors contributing to lactose intolerance? The etiological factors contributing to lactose intolerance include: • Genetic factor • Reduction in jejunal

Explain sinus venosus defect with partial anomalous venous, Explain Sinus V...

Explain Sinus Venosus Defect with Partial Anomalous Venous Connection ? In this defect the atrial septal defect is situated just below the orifice of superior vena cava above

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