Primary Prevention
Acute GAS pharyngitis should be treated promptly by penicillin or other antibiotics. Indian Council of Medical Research (ICMR) recommends that all cases of pharyngitis must receive penicillin. One need not wait to isolate GAS organisms. A single dose of 1.2 mega units of Benzathine penicillin given IM or a ten day course of oral penicillin V is given. In case of allergy to penicillin, one uses macrolides or cephalosporins.
Acute GAS pharyngitis should be treated promptly by penicillin or other antibiotics. Indian Council of Medical Research (ICMR) recommends that all cases of pharyngitis must receive penicillin. One need not wait to isolate GAS organisms. A single dose of 1.2 mega units of Benzathine penicillin given IM or a ten day course of oral penicillin V is given. In case of allergy to penicillin, one uses macrolides or cephalosporins.
 |
| Prophylaxis of Rheumatic Fever |
Secondary Prevention
Benzathine penicillin given every three weeks as IM injection (1.2 mega units) has given the best results. Oral agents (penicillin V) are given in patients with lower risk of rheumatic recurrence. In patients with penicillin allergy, sulphadiazine or erythromycin is used. According to ICMR recommendation, secondary prophylaxis should be carried out till 35 years of age. As per American Heart Association (AHA, 1995), the recommendations vary for secondary rheumatic prophylaxis. In general it is recommended that patients with established rheumatic heart disease,should receive prophylaxis till 10 years after the last episode or 40 years of age, which ever is longer. Some patients who develop post streptococcal reactive arthritis without carditis are given Benzathine penicillin 1.2 mega units ever three weeks for 1 year.
Vaccines for GAS Infections
In developing countries because of poor compliance, poverty, ignorance, primary and secondary prevention strategies are difficult to implement properly. Also in western countries (USA), where there is resurgence of ARF, interest in vaccine development has appeared. However, there are quite a few technical problems in development of vaccines. There are 2 types of vaccines.
I)Vaccines Against Virulence Factors Conserved Amongst Various GAS Despite antibodies to these conserved antigens, people are affected by multiple serotypes of GAS. Hence there remains a doubt regarding the protective efficacy of antibodies against GAS infections.
II)Vaccines Based on Type Specific, Hypervariable N-terminal Regions of M Proteins Life long immunity which is protective (25 to 30 years after infection) is achieved by antibodies against the hypervariable N-terminal of M-Protein. Considering this fact, using recombinant DNA technology, synthetic peptide copies of the hypervariable N-terminal of the M-protein are being manufactured. These synthetic peptides produce only bacterial anti-bodies without host cross-reactive antibodies. Currently N-terminal synthetic peptides of multiple serotypes of GAS are linked to a carrier protein to produce opsonizing antibodies. Tetra, hexa and octavalent vaccines incorporating M 1, 2, 3, 5, 6, 18, 19 and 24 N-terminal peptides are being evaluated in animals.
Benzathine penicillin given every three weeks as IM injection (1.2 mega units) has given the best results. Oral agents (penicillin V) are given in patients with lower risk of rheumatic recurrence. In patients with penicillin allergy, sulphadiazine or erythromycin is used. According to ICMR recommendation, secondary prophylaxis should be carried out till 35 years of age. As per American Heart Association (AHA, 1995), the recommendations vary for secondary rheumatic prophylaxis. In general it is recommended that patients with established rheumatic heart disease,should receive prophylaxis till 10 years after the last episode or 40 years of age, which ever is longer. Some patients who develop post streptococcal reactive arthritis without carditis are given Benzathine penicillin 1.2 mega units ever three weeks for 1 year.
Vaccines for GAS Infections
In developing countries because of poor compliance, poverty, ignorance, primary and secondary prevention strategies are difficult to implement properly. Also in western countries (USA), where there is resurgence of ARF, interest in vaccine development has appeared. However, there are quite a few technical problems in development of vaccines. There are 2 types of vaccines.
I)Vaccines Against Virulence Factors Conserved Amongst Various GAS Despite antibodies to these conserved antigens, people are affected by multiple serotypes of GAS. Hence there remains a doubt regarding the protective efficacy of antibodies against GAS infections.
II)Vaccines Based on Type Specific, Hypervariable N-terminal Regions of M Proteins Life long immunity which is protective (25 to 30 years after infection) is achieved by antibodies against the hypervariable N-terminal of M-Protein. Considering this fact, using recombinant DNA technology, synthetic peptide copies of the hypervariable N-terminal of the M-protein are being manufactured. These synthetic peptides produce only bacterial anti-bodies without host cross-reactive antibodies. Currently N-terminal synthetic peptides of multiple serotypes of GAS are linked to a carrier protein to produce opsonizing antibodies. Tetra, hexa and octavalent vaccines incorporating M 1, 2, 3, 5, 6, 18, 19 and 24 N-terminal peptides are being evaluated in animals.
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.