Beta-hemolytic Streptococcal Pharyngitis Research Articles

Management of pediatric patients with group A beta-hemolytic Streptococcus pharyngitis

Pharyngitis caused by group A beta-hemolytic streptococci (GABHS) is one of the most common infections diagnosed in children. Orally administered penicillin is the standard treatment recommended for GABHS pharyngitis, but its use is compromised by the need for multiple daily doses and a relatively long (10O days) treatment regimen. Moreover, bacteriologic failures with penicillin treatment appear to be increasing, raising concerns about risk of sequelae and recurrence of symptomatic infection. Erythromycin, clindamycin and many cephalosporins are known to be safe and effective alternatives to penicillin for the treatment of pediatric patients with GABHS pharyngitis. Like penicillin, however, most of these agents require multiple daily doses for 10 days, making compliance difficult. The new azalide azithromycin has a markedly long half-life, allowing once daily administration for 5 days in the treatment of infections traditionally requiring a 10-day course of therapy with shorter acting drugs. Recent clinical trials have shown the suspension formulation of azithromycin to be safe and effective for treatment of children with GABHS pharyngitis. In these studies, azithromycin was statistically superior in both clinical outcome and bacteriologic eradication compared with penicillin. The abbreviated treatment course possible with this drug makes it a useful alternative for treatment of GABHS pharyngitis, particularly when compliance is a concern

Treatment of streptococcal pharyngitis with amoxycillin once a day.

To evaluate treatment of group A beta haemolytic streptococcal pharyngitis with amoxycillin once daily compared with phenoxymethylpenicillin three or four times a day. Randomised controlled study of consecutive patients presenting with symptoms suggestive of group A beta haemolytic streptococcal pharyngitis in whom culture of a throat swab yielded positive results. Five family medicine practices. 157 patients aged over 3 years who required treatment with antibiotics. Clinical response, bacteriological response, days at work and school lost, and compliance. During the period of the study 393 patients presented with symptoms suggesting streptococcal pharyngitis; 157 of them had throat swabs that yielded positive results on culture. Eighty two were treated with phenoxymethylpenicillin and 75 with amoxycillin. No difference was observed in the clinical response, days at work and school lost (139 days for 64 patients taking phenoxymethylpenicillin v 100 days for 57 patients taking amoxycillin; p > 0.2), or residual positive cultures after two days (6 (7.3%) v 3 (4%); p > 0.5). A significant difference in the bacteriological response was found after 14 days (5 (6.1%) v 0; p < 0.04) with no positive cultures observed in the amoxycillin group. These findings support the hypothesis that amoxycillin once daily is as effective as phenoxymethylpenicillin in the treatment of group A beta haemolytic streptococcal pharyngitis.

Food-borne outbreak of group A beta-hemolytic streptococcal pharyngitis

Food-borne outbreak of group A beta-hemolytic streptococcal pharyngitis

Comparative study of clarithromycin and penicillin V in the treatment of streptococcal pharyngitis

This study evaluated the safety and efficacy of clarithromycin in the treatment of patients with Group A beta-hemolytic streptococcal pharyngitis. Subjects were treated with either 250 mg clarithromycin twice daily or 250 mg penicillin V four times a day for 10 days and followed for approximately three weeks post-treatment. At the completion of therapy, 96% (45/47) of patients treated with clarithromycin and 89% (43/48) of patients treated with penicillin V were clinically cured or improved. Recurrence of symptoms occurred in 7 and 5 patients who were treated with clarithromycin and penicillin V respectively. Initial bacteriologic eradication was observed in all but one patient. Recurrence of Streptococcus pyogenes occurred in 5 (11%) patients who received clarithromycin and 7 (15%) patients who received penicillin V. The majority of adverse events reported during this study were mild and involved the gastrointestinal tract. Diarrhea was more frequent in patients who received clarithromycin. In this multicenter, randomized, double-blind trial, clarithromycin was as safe and effective as penicillin V in the treatment of Streptococcus pyogenes throat infections.

Comparative efficacy and safety of cefprozil (BMY-28100) and cefaclor in the treatment of acute group A beta-hemolytic streptococcal pharyngitis

Cefprozil (BMY-28100) is a semisynthetic cephalosporin with broad-spectrum antibacterial activity and prolonged serum elimination half-life allowing for once-a-day oral administration. In vitro, cefprozil demonstrates excellent activity against Staphylococcus aureus, Streptococcus pyogenes, Haemophilus influenzae, and Moraxella catarrhalis. Cefprozil (500 mg once daily) was compared to cefaclor (250 mg three times daily) in an open, randomized, comparative trial for the treatment of acute group A beta-hemolytic streptococcal pharyngitis. Ninety-four patients were enrolled in this study; 53 patients were evaluable for clinical and bacteriological response assessment. Seventy-eight patients were evaluable for safety assessment. Three patients (all in the cefprozil treatment group) required disenrollment because of side effects, mainly nausea. Clinical and bacteriological responses were comparable for both study drugs. Leukopenia and nausea, the most common side effects observed, were more common in the cefprozil-treated group. Cefprozil appears to be an appropriate alternative to cefaclor for the treatment of acute group A beta-hemolytic streptococcal pharyngitis. However, because of the small number of patients eligible for efficacy assessment, a large type II (beta) error was expected in our study, which may have resulted in a potential failure to detect a difference between both treatment groups. A larger study would be required to determine the proper role of cefprozil in the treatment of group A beta-hemolytic streptococcal infections.

The Impact of a Rapid Screen for Streptococcal Pharyngitis on Clinical Decision Making in the Emergency Department

The impact of a rapid streptococcal screening test (RSS) on clinical decision making in the management of patients with acute pharyngitis was evaluated. Physicians managing 95 ambulatory patients with the complaint of sore throat were asked to estimate the probability of group A beta-hemolytic streptococcal pharyngitis (GRABS) in each patient and whether they intended to treat with antibiotics both before and after the results of the RSS were known. Simultaneous throat cultures were obtained for 80 patients at the discretion of the treating physicians. Regression analysis revealed that the RSS result was an important independent predictor for the posttest decision to treat with antibiotics and for the estimated probability of disease. The mean absolute log-likelihood ratio was used to quantify the effect of the RSS on diagnostic certainty; a greater contribution to diagnostic certainty occurred when the RSS was positive. Physicians would have prescribed an antibiotic 49 times without the benefit of the RSS and prescribed an antibiotic 48 times given the RSS result. Without the RSS, the treatment decision contradicted the throat culture result in 25 cases. With the RSS, this occurred in 26 cases. The RSS, while influencing decision making, especially when positive, did not decrease the use of antibiotics.

A comparison of cephalosporins and penicillins in the treatment of Group A beta-hemolytic streptococcal pharyngitis

Although penicillin has been the antibiotic of choice for therapy of Group A beta-hemolytic streptococcal pharyngitis for more than four decades, reports of bacteriologic and clinical treatment failures with penicillin have increased in recent years. We conducted a meta-analysis of 19 studies to examine whether oral cephalosporins were associated with lower failure rates than oral penicillin in the treatment of Group A beta-hemolytic streptococcal pharyngitis. The overall bacteriologic cure rate for penicillin was 84% (95% confidence interval (CI), 82%, 86%) compared with 92% (95% CI, 91%, 94%) among patients treated with cephalosporins (P less than 0.0001). The overall clinical cure rate in the penicillin groups was 89% (95% CI, 87%, 91%) compared with 95% (95% CI, 94%, 96%) in the cephalosporin group (P less than 0.001). There was no significant difference between the cephalosporins and the penicillins with respect to adverse events. There may be clinical circumstances in which treatment of Group A beta-hemolytic streptococcal pharyngitis with cephalosporins is indicated.

Immediate vs. delayed treatment of Group A beta-hemolytic streptococcal pharyngitis with penicillin V

Three hundred six children with probable Group A beta-hemolytic streptococcal pharyngitis were enrolled in a randomized double blind trial to compare the effects of immediate vs. delayed treatment with oral penicillin V. Among the 229 culture-positive patients, 111 were randomly assigned to receive penicillin V immediately and 118 to receive a placebo for 48 to 52 hours followed by penicillin V. Patients were evaluated clinically for 48 to 52 hours following initiation of treatment. The Streptozyme test was used to measure acute to convalescent antibody titer. Both regimens resulted in a greater than 92% cure rate. Early treatment was associated with significantly fewer and milder signs and symptoms on Day 3 and a significantly lower rise in the antibody titer. On the other hand we found 8 (7%) relapses and 18 (16%) early and 14 (13%) late recurrences in this group; all were significantly higher than the corresponding numbers of 2 (2%), 6 (5%) and 4 (3%), respectively, in the late treatment group. This study shows the beneficial effect of early treatment with penicillin V on the clinical course of Group A beta-hemolytic streptococcal pharyngitis. This study also shows that delayed penicillin treatment may be associated with a lower incidence of subsequent Group A beta-hemolytic streptococcal pharyngitis.

A comparative study of clarithromycin and penicillin VK in the treatment of outpatients with streptococcal pharyngitis

This double-blind, randomized 17-centre clinical trial compared the safety and efficacy of clarithromycin (2 x 125 mg capsules) 12-hourly and penicillin VK (2 x 125 mg tablets in capsules) 6-hourly in the treatment of proven Group A, beta-haemolytic streptococcal pharyngitis. One hundred and twenty-eight patients (clarithromycin: 65, penicillin VK: 63) were enrolled in the study and included in the safety analysis. Clinical and bacteriological evaluations were performed on treatment days 5-7, and within two to ten and 15 to 56 days post-treatment. The post-treatment clinical success and bacteriological cure rates for clarithromycin were 95% (41/43) and 88% (38/43), respectively, with both rates 91% (43/47) for penicillin VK. Three clarithromycin patients withdrew because of adverse events, but only one of these events was possibly drug related. More clarithromycin patients (19/65) reported digestive system related adverse events than did penicillin VK patients (8/63); however, there was no significant difference between treatment groups in the overall number of patients reporting adverse events. Clarithromycin (250 mg, 12-hourly) is a safe and effective as penicillin VK (250 mg, 6-hourly) in the treatment of streptococcal pharyngitis.

Lack of influence of beta-lactamase—producing flora on recovery of group A streptococci after treatment of acute pharyngitis

Because production of beta-lactamase by normal pharyngeal flora could account for penicillin treatment failure, we studied the effect of anaerobic and aerobic beta-lactamase-producing bacteria on bacteriologic outcome in acute group A beta-hemolytic streptococcal (GABHS) pharyngitis. We compared 10-day courses of orally administered phenoxymethyl penicillin and amoxicillin-clavulanic acid, using a randomized, single-blind treatment protocol. Eligible patients were 2 to 16 years of age and had culture-proven acute GABHS pharyngitis; 89 patients (43 penicillin, 46 amoxicillin-clavulanic acid) were compliant with therapy. beta-Lactamase-producing organisms were isolated before therapy from the throats of 67% of patients treated with penicillin and 63% treated with amoxicillin-clavulanic acid. Throat cultures after completion of therapy were positive for GABHS in 7 (7.9%) of 89 patients. The initial GABHS T type persisted (treatment failure) in only 4 (4.5%) of 89 patients, including 3 (6.5%) of 46 who received amoxicillin-clavulanic acid and in 1 (2.3%) of 43 who received penicillin (not statistically significant). Bacteriologic treatment failure was unrelated to recovery of beta-lactamase-producing bacteria at the time of enrollment or after treatment. We conclude that beta-lactamase production by normal pharyngeal flora does not fully explain the failure of penicillin therapy for acute streptococcal pharyngitis. Using an antibiotic effective against beta-lactamase-producing bacteria will not eliminate the problem of bacteriologic treatment failure.

Monocytes and polymorphonuclear neutrophils of patients with streptococcal pharyngitis express increased numbers of type I IgG Fc receptors.

Studies using cultured cells have shown that gamma interferon (IFN-gamma) induces the expression of Fc gamma RI (the type I Fc receptor for IgG) on human polymorphonuclear neutrophils (PMN) and greatly increases the number of these receptors on human monocytes. Administration of rIFN-gamma in vivo also causes enhanced Fc gamma RI expression on these cell populations. Because streptococcal antigens are potent inducers of IFN-gamma in vitro, we postulated that IFN-gamma would be produced endogenously in vivo in patients with streptococcal infections. Such production of IFN-gamma in vivo, even at low levels, might be expected to induce the expression of Fc gamma RI on monocytes and neutrophils. To evaluate this possibility, we used monoclonal antibody 32 (mAb 32), which is specific for Fc gamma RI, to quantitate the expression of this receptor on human peripheral blood cells. We measured the binding of mAb 32 to monocytes and PMNs isolated from healthy donors and from patients with group A beta-hemolytic streptococcal (GABHS) pharyngitis. PMNs from healthy donors (n = 12) had 700 +/- 600 (mean +/- SD) mAb 32 binding sites. Patients with pharyngitis and negative throat culture for GABHS (n = 11) had 2,100 +/- 1,600 sites on their PMNs. In contrast, the PMNs from patients with documented GABHS pharyngitis (n = 12) had 11,600 +/- 7,500 mAb 32 binding sites on their surface. There was a similar change in the expression of Fc gamma RI on monocytes, with control monocytes having a mean of 19,900 +/- 3,200 mAb 32 binding sites per cell and the GABHS-positive monocytes having 47,500 +/- 21,400 sites. The GABHS-negative throat culture group had a slightly elevated number of Fc gamma RI with a mean of 28,200 +/- 8,400 sites. 10 patients with documented urinary tract infections and three patients with uncomplicated pyelonephritis had no elevation in Fc gamma RI expression. These studies demonstrate that a localized group A streptococcal infection can cause systemic activation of the entire circulating pool of phagocytes, and suggest that a similar level of activation is uncommon in localized gram-negative infections of the urinary tract.

Diagnosis of Group A β-Hemolytic Streptococcus Using Clinical Scoring Criteria, Directigen 1-2-3 Group A Streptococcal Test, and Culture

Cultures for group A beta-hemolytic Streptococcus were performed on 806 patients presenting with a sore throat to five urgent care centers. The accuracies of a clinical scoring system and of a liposomal in-office direct test for Streptococcus were compared with culture results. The Directigen 1-2-3 group A streptococcal test had a sensitivity of 67%, a specificity of 85%, a positive predictive value of 61%, and a negative predictive value of 89% compared with culture. The scoring system had a sensitivity of 26%, a specificity of 94%, a positive predictive value of 58%, and a negative predictive value of 79%. Using a combination of the direct test results and the clinical score did not improve the accuracy significantly over the use of either alone. The rates of delayed treatment, unnecessary treatment, and increased costs were compared using different combinations of the clinical scoring system, the in-office streptococcal test, and culture. Neither the Directigen 1-2-3 group A streptococcal test nor the clinical score can replace culture in the diagnosis of group A beta-hemolytic streptococcal pharyngitis.

Liposome immunoassay for rapid identification of group A streptococci directly from throat swabs

The Q Test Strep (Becton Dickinson and Co., Franklin Lakes, N.J.) is a new solid-phase liposome immunoassay for the rapid diagnosis of group A beta-hemolytic streptococcal pharyngitis. Compared with blood agar plate cultures, the Q Test Strep had a sensitivity of 91%, a specificity of 83%, a positive predictive value of 88%, and a negative predictive value of 87%. Liposome technology can be used to facilitate the rapid diagnosis of group A beta-hemolytic streptococcal pharyngitis.

Latex agglutination for the rapid diagnosis of streptococcal pharyngitis

A rapid latex agglutination (LA) method was evaluated in 2401 consecutive pediatric patients presenting to an emergency service with suspected group A beta-hemolytic streptococcal pharyngitis. LA tests were performed by the treating physicians, who were not blinded to the clinical condition of the children and who made therapeutic decisions based on the results of the tests. When compared with anaerobic culture, the LA method had a sensitivity of 91%, a specificity of 82%, and a positive predictive value of 43%. There was a marked seasonal variation in the positive predictive value: 62% in winter and 16% in summer. However, even in peak streptococcal pharyngitis season (January to March), basing therapy on a positive LA test leads to the unnecessary treatment of a large number of patients. Therefore, we cannot recommend the routine performance of this test by all practitioners in all clinical settings.

Comparison of the clinical and bacteriological efficacy of clarithromycin and erythromycin in the treatment of streptococcal pharyngitis

The efficacy and tolerability of clarithromycin and erythromycin stearate in the treatment of documented Group A beta-haemolytic streptococcal pharyngitis were compared in a single-centre, open, out-patient study. One hundred and twenty patients were randomly assigned to each treatment group. Dosage of clarithromycin and erythromycin was 250 mg twice daily and 500 mg twice daily, respectively; each patient was given a 10-day supply of medication. Clinical success (cured or improved) was observed in 111 (96.5%) of 115 and in 108 (93.9%) of 115 clinically-evaluable patients treated with clarithromycin and erythromycin, respectively. Eradication of the pathogen occurred in 108 (97.3%) of 111 and in 98 (92.5%) of 106 bacteriologically-evaluable clarithromycin and erythromycin patients, respectively. Adverse events reported by 7 (5.8%) of the clarithromycin-treated and by 12 (10%) of the erythromycin-treated patients included epigastritis and nausea and vomiting. In general, the severity of adverse events was greater for the patients treated with erythromycin, necessitating the discontinuation of therapy in 8 (6.7%) patients treated with erythromycin as opposed to 1 (0.8%) patient treated with clarithromycin. Although clarithromycin and erythromycin were comparable in terms of efficacy, clarithromycin was better tolerated.

Streptococcal pharyngitis in children.

Children with suspected group A beta-hemolytic streptococcal pharyngitis are encountered daily in outpatient settings. Despite the ubiquity of this condition, important management issues still remain unresolved. This article will review selected epidemiologic, diagnostic, and therapeutic topics germane to clinical practice.

Failure of Once-Daily Penicillin V Therapy for Streptococcal Pharyngitis

To determine if a single daily dose of penicillin V would be effective in the treatment of group A beta-hemolytic streptococcal (GABHS) pharyngitis, 154 patients with GABHS pharyngitis were randomly assigned to receive 750 mg of penicillin V once daily for ten days or 250 mg of penicillin V three times daily for ten days. The two regimens were comparable in their ability to eradicate GABHS from the upper respiratory tract in 18 to 24 hours and in their impact on the clinical course of the disease. However, a bacteriologic treatment failure occurred in six (8%) of the 76 patients in the three-times-daily group and in 16 (22%) of the 74 patients in the once-daily group. These findings support the current recommendation that penicillin V be given in two or more divided doses for a full ten days for the treatment of GABHS pharyngitis.

Streptococcal pharyngitis. What's new.

Group A beta-hemolytic streptococcal pharyngitis continues to be a major problem and accounts for a large number of physician visits. The recent resurgence of acute rheumatic fever in several areas in the United States underlines the need to accurately diagnose and correctly treat streptococcal pharyngitis. Appropriate treatment with antibiotics effectively prevents rheumatic fever. Early institution of treatment also leads to prompt alleviation of symptoms. The "gold standard" for diagnosing group A streptococcal pharyngitis is the throat culture. Newer rapid diagnostic tests may be used, but the clinician must recognize that there are a substantial number of false-negative tests (low sensitivity). Therefore, patients with negative rapid tests should have standard throat cultures as well. Patients with positive rapid tests should be treated with appropriate antibiotics, as should patients with positive throat cultures. Patients with signs and symptoms that are highly suggestive of streptococcal pharyngitis can also be treated, pending throat culture results. Penicillin continues to be the drug of choice for treatment, and American Heart Association guidelines suggest the use of oral penicillin V for ten days or intramuscular benzathine penicillin G. Alternative antibiotics commonly used include erythromycin and various cephalosporins. Throat cultures need not be obtained from most patients after therapy. However, some patients may seem to be having frequent streptococcal infections or may be recognized as asymptomatic carriers. Carriers may be considered for therapy with intramuscular benzathine penicillin G plus oral rifampin.

Clinical assessment of pharyngitis in general practice.

The present study investigates the feasibility of the clinical differentiation between patients with beta-haemolytic streptococcal pharyngitis from those with pharyngitis caused by other agents, based on the patients' symptoms, symptom duration, and the clinical findings. Twenty-four general practitioners recruited 225 patients for the study. Fifty-six patients had positive and 169 patients negative group A beta-haemolytic streptococcal throat cultures. Twenty-two patients in the streptococcal group and 76 patients in the non-streptococcal group were initially correctly diagnosed based on an overall clinical assessment (sensitivity 0.39, specificity 0.55 and accuracy 0.51). This is as accurate as "flipping a coin". Similar figures were found with regard to the individual symptoms (accuracy 0.38-0.68) and clinical findings (accuracy 0.36-0.65). Taking the duration of symptoms into account and applying discriminant function analysis did not significantly improve these figures. In order to obtain a sufficiently accurate diagnosis in general practice, the use of the new rapid agglutination test for streptococcal identification is recommended.

Once daily therapy for streptococcal pharyngitis with cefadroxil

To determine if a single daily dose of cefadroxil would be effective in the treatment of group A beta-hemolytic streptococcal (GABHS) pharyngitis, 196 patients with GABHS pharyngitis were randomly assigned to receive either penicillin V 250 mg three times daily or cefadroxil 30 mg/kg once daily, for 10 days. Outcome was measured by the ability to isolate GABHS from the upper respiratory tract 18 to 24 hours after the onset of therapy, the impact on the clinical course, and the bacteriologic treatment failure rate. There was no significant difference in the number of patients in the cefadroxil and penicillin V treatment groups with throat cultures positive for GABHS at the 18 to 24-hour follow-up visit (0% and 2%, respectively), and the clinical responses of the patients in the two treatment groups were similar. Of the 99 patients in the three times daily penicillin V group, six (6%) had strains of GABHS isolated on one of the follow-up cultures that were identical to the strains isolated from their initial throat cultures and were considered to have bacteriologic treatment failures. Of the 96 patients in the once daily cefadroxil group, two (2%) were considered to have bacteriologic treatment failures. A single daily dose of cefadroxil appears to be as effective in the treatment of GABHS pharyngitis in this population as penicillin V given three times daily.