Anticoagulation for prosthetic valves during pregnancy

Antibiotics for the primary prevention of acute rheumatic fever: a meta-analysis

BACKGROUND

Rheumatic fever continues to put a significant burden on the health of low socio-economic populations in low and middle-income countries despite the near disappearance of the disease in the developed world over the past century. Antibiotics have long been thought of as an effective method for preventing the onset of acute rheumatic fever following a Group-A streptococcal (GAS) throat infection; however, their use has not been widely adopted in developing countries for the treatment of sore throats. We have used the tools of systematic review and meta-analysis to quantify the effectiveness of antibiotic treatment for sore throat, with symptoms suggestive of group A streptococcal (GAS) infection, for the primary prevention of acute rheumatic fever.

METHODS

Trials were identified through a systematic search of titles and abstracts found in the Cochrane Central Register of Controlled Trials (Cochrane Library Issue 4, 2003), MEDLINE (1966-2003), EMBASE (1966-2003), and the reference lists of identified studies. The selection criteria included randomised or quasi-randomised controlled trials comparing the effectiveness of antibiotics versus no antibiotics for the prevention of rheumatic fever in patients presenting with a sore throat, with or without confirmation of GAS infection, and no history of rheumatic fever.

RESULTS

Ten trials (n = 7665) were eligible for inclusion in this review. The methodological quality of the studies, in general, was poor. All of the included trials were conducted during the period of 1950 and 1961 and in 8 of the 10 trials the study population consisted of young adult males living on United States military bases. Fixed effects, meta-analysis revealed an overall protective effect for the use of antibiotics against acute rheumatic fever of 70% (RR = 0.32; 95% CI = 0.21-0.48). The absolute risk reduction was 1.67% with an NNT of 53. When meta-analysis was restricted to include only trials evaluating penicillin, a protective effect of 80% was found (Fixed effect RR = 0.20, 95% CI = 0.11-0.36) with an NNT of 60. The marginal cost of preventing one case of rheumatic fever by a single intramuscular injection of penicillin is approximately USD 46 in South Africa.

CONCLUSION

Antibiotics appear to be effective in reducing the incidence of acute rheumatic fever following an episode of suspected GAS pharyngitis. This effect may be achieved at relatively low cost if a single intramuscular penicillin injection is administered.

Penicillin for secondary prevention of rheumatic fever

BACKGROUND

People with a history of rheumatic fever are at high risk of recurrent attacks of rheumatic fever and developing rheumatic heart disease following a streptococcal throat infection. Giving penicillin to these people can prevent recurrent attacks of rheumatic fever and subsequent rheumatic heart disease. However, there is no agreement on the most effective method of giving penicillin.

OBJECTIVES

To assess the effects of penicillin compared to placebo and the effects of different penicillin regimens and formulations for preventing streptococcal infection and rheumatic fever recurrence.

SEARCH STRATEGY

We searched the Controlled Trials Register (Cochrane Library Issue 2, 2001), MEDLINE (1997 to July 2000), EMBASE (1998 to July 2000), reference lists of articles and we contacted experts in the field.

SELECTION CRITERIA

Randomised and quasi-randomised studies comparing (i) penicillin with control, (ii) oral with intramuscular penicillin (iii) 2- or 3-weekly with 4-weekly intramuscular penicillin in patients with previous rheumatic fever.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data.

MAIN RESULTS

Nine studies were included (n=3008). Data were not pooled because of heterogeneity. Overall, the methodological quality of included studies was poor. Three trials (n= 1301) compared penicillin with control. Only one of three studies showed that penicillin reduced rheumatic fever recurrence (RR 0.45, 95% CI 0.22 to 0.92) and streptococcal throat infection (RR 0.84, 95% CI 0.72 to 0.97). Four trials (n=1098) compared intramuscular with oral penicillin and all showed that intramuscular penicillin reduced rheumatic fever recurrence and streptococcal throat infections compared to oral penicillin. One trial (n= 360) compared 2-weekly with 4-weekly intramuscular penicillin. Penicillin given every two-weeks was better at reducing rheumatic fever recurrence (RR 0.52, 95% CI 0.33 to 0.83) and streptococcal throat infections (RR 0.60, 95% CI 0.42 to 0.85). One trial (n= 249) showed 3-weekly intramuscular penicillin injections reduced streptococcal throat infections (RR 0.67, 95% CI 0.48 to 0.92) compared to 4-weekly intramuscular penicillin.

REVIEWER'S CONCLUSIONS

Intramuscular penicillin seemed to be more effective than oral penicillin in preventing rheumatic fever recurrence and streptococcal throat infections. Two-weekly or 3-weekly injections appeared to be more effective than 4-weekly injections. However, the evidence is based on poor quality of trials.