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

Who are atopic individuals, Atopic individuals are those who are having abn...

Atopic individuals are those who are having abnormal high levels of circulating IgE and more than normal number of oesinophils.

Zoonoses disease-cryptococcosis, Cryptococcosis An opportunistic infect...

Cryptococcosis An opportunistic infection, caused by Cryptococcus neoformans is affecting immunocompromised individuals mainly with impaired cell mediated immunity. The disease

Explain rabies, Rabies  Rabies is highly prevalent in Africa, India, As...

Rabies  Rabies is highly prevalent in Africa, India, Asia and parts of Latin America, but the risk to travelers is low. Pre-exposure immunizationagainst rabies is recommended f

Sketch cis-trans isomer of the first molecule, Please help with the followi...

Please help with the following: a) Draw a diagram (showing all the C and H atoms, and their bonds) for a hydrocarbon with 5 carbons with a double bond between carbons 2 and 3.

Explain the function of myosin and albumin, What are respectively some rema...

What are respectively some remarkable functions of myosin, CD4, albumin, keratin, immunoglobulin, reverse transcriptase, hemoglobin and insulin? Myosin is a protein that when a

Polynephritis in cattle, Polynephritis in cattle Contagious bovine pol...

Polynephritis in cattle Contagious bovine polynephritis is a specific infection of urinary tract of cattle. The causative agent is Corynebacterium renale, a rod shaped gram-po

Animal biodiversity, why obwlia is considered to be of special interest in ...

why obwlia is considered to be of special interest in zoologyas an animal showing an intermediate grade of organisation

Control of aflatoxin, Q. Control of Aflatoxin? Control: Because aflatox...

Q. Control of Aflatoxin? Control: Because aflatoxins are potentially widespread in occurrence and have an insidious combination of acute and chronic toxicity, it is prudent to

Define reagents required and methodology for fehling's test, Define Reagent...

Define Reagents required and Methodology for Fehling's Test? - Sugar solutions of glucose, fructose, galactose, lactose, maltose, sucrose, starch - Fehling A (Copper sulphat

What is the conjugate acid, Calculate the pH: 300mL of 0.25M sodium ascorba...

Calculate the pH: 300mL of 0.25M sodium ascorbate plus 150mL of 0.2M HCl (the pKa of ascorbic acid is 4.04) okay, what's the conjugate acid and base of this problem? Can someone wa

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