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

Goat pox, Goat pox Goat-pox is common in occurrence, and its nature is ...

Goat pox Goat-pox is common in occurrence, and its nature is similar to sheep pox. The incubation period varies from 5 to 10 days. The disease tends to attack male kids and ewe

Biological diversity of an ecosystem, Q. Is monoculture a system that contr...

Q. Is monoculture a system that contributes to great biological diversity of an ecosystem? The Monoculture implies that in a large area a single crop (only one species of plant

Left antero lateral thoracotomy approach, Left Antero Lateral Thoracotomy A...

Left Antero Lateral Thoracotomy Approach :  Arterial and central venous pressure monitoring lines are placed. A left antero lateral thoracotomy is done through the 5th or 4th

What are the hormones that release of the female gamete, What are the hormo...

What are the hormones that promote the release of the female gamete from the follicle and at which day of the menstrual cycle does this phenomenon happen? What is this event called

Taxonmy, classification on taxonomy

classification on taxonomy

Describe the benefits of neuropsychological test, Describe the benefits of ...

Describe the benefits of Neuropsychological test The tests can be helpful in the assessment of: Change in mental status Abnormalities in function before abnormalitie

Explain about simple proteins, Explain about Simple proteins Simple pro...

Explain about Simple proteins Simple proteins are those which are made of amino acid units only joined by peptide bond.  Upon hydrolysis they yield a mixture of amino acids and

Can you explain radula, Q What is the radula? What is the function of this ...

Q What is the radula? What is the function of this organ? Some molluscs have a tongue-like structure with harsh saliences similar to small teeth. This structure is called as ra

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