Positive Throat Cultures For Group Research Articles

Case-control, exploratory study of cerebrospinal fluid chemokines/cytokines and lymphocyte subsets in childhood Tourette syndrome with positive streptococcal markers

A longstanding question is whether neuroinflammation is present in children symptomatic for Tourette syndrome (TS) with positive streptococcal serology and throat cultures. The objective was to directly test for it using modern hypothesis-driven approaches. Profiling studies for 14 immune cell types (flow cytometry), 7 chemokines/cytokines (ELISA), oligoclonal bands, and other immunoglobulins were performed in this IRB-approved study of 5 children with TS and streptococcal markers compared to data from 26 non-inflammatory pediatric neurological controls. Subjects were well-characterized clinically and with standardized scales for tics and obsessions/compulsions. Three subjects with TS (60%) had positive throat cultures for Group A beta-hemolytic strep, five had elevated anti-deoxyribonuclease-B titers (mean=444), and 4 (80%) had elevated anti-streptolysin O titers (981). There were no significant differences between groups in the frequency of CSF B and T cell subsets or NK cells; the proportion of intracellularly-stained T helper type 1 (IFN-γ) or type 2 (IL-4) cells; the concentrations of B cell chemoattractants CXCL13, CXCL10; the B cell proliferation/survival cytokines BAFF and APRIL, or other chemokines (CCL19, CCL21, CCL22). None of the patients had positive CSF oligoclonal bands or an abnormal IgG index/synthesis rate. Parallel blood studies were negative. This novel study found no group CSF lymphocyte phenotypic abnormalities or elevated inflammatory mediators in childhood TS despite positive serology and throat cultures for Group A beta-hemolytic streptococci. It demonstrates feasibility of the methodology, and should serve as the basis for a larger study of putative streptococcal-associated neuroimmunological disorders.

Group A streptococcal carriage: Can the troll be tamed?

The dilemma of determining optimal care for the child with repeatedly positive throat cultures for group A beta hemolytic streptococcus (group A strep) has bedevilled paediatricians, family practitioners and generalists for decades. Unfortunately, the state of the art has not changed substantially over the past 20 years, as attested to by the dearth of publications and the similarity of the definitive recommendations spanning that period (1,2). The purpose of this column is to review briefly the state of knowledge about chronic streptococcal carriage and to suggest a rational approach to treating children who present with this problem. The challenge of evaluating a child with a positive throat culture for group A strep results from the inability to distinguish between the carrier (one who harbours the organism without a host response) and the child who is acutely infected (one who has evidence of inflammation and host response). Carriers are often identified when they continue to harbour the organism in the throat asymptomatically after an appropriate 10-day course of penicillin or alternative agent (3). There is a high rate of carriage in the general population (approximately 5% to 15% of school-aged children are colonized but not infected with group A strep at any time), and there is no foolproof way to differentiate a priori between carriers and those who are acutely infected. Therefore, many children are diagnosed with streptococcal pharyngitis who are chronic carriers and who are probably acutely infected with another organism (such as a respiratory virus). In this era of evolving antibiotic resistance and a desire to limit unnecessary use of antimicrobial agents, a logical strategy for avoiding therapy of chronic carriers is required. Chronic carriers of group A strep probably do not pose a threat to themselves or to others. There is no evidence that these children or their contacts become infected with the strains that these children carry. Therefore, they do not require antibiotic therapy to prevent suppurative or nonsuppurative (acute rheumatic fever, acute poststreptococcal glomerulonephritis) complications. So why do doctors need to worry? The simple answer is that physicians are unable to differentiate at presentation between the child who is acutely infected and the one who is a chronic carrier presenting with acute nonstreptococcal pharyngitis. The methods for making that discrimination (testing for serological response and strain typing) require time and the aid of reference or research laboratories. What can the medical practitioner do when confronted with a child who repeatedly returns to the office or clinic for evaluation of or therapy for acute respiratory illnesses in which group A strep is recovered from the throat? If it could be determined a priori whether that child is a streptococcal carrier, antibiotic therapy could be avoided. A child is likely a carrier if he or she has symptoms most consistent with a viral upper respiratory infection and has consistently harboured group A strep in the past. However, the discriminatory power of clinical evaluation of such patients is notoriously unreliable. Perhaps the most expedient strategy is to attempt eradication of the carrier state. If successful, ie, the child has a negative culture after completion of therapy, one might assume that if the child presents again with pharyngitis and a throat culture positive for group A strep, this is evidence of bone fide acute streptococcal infection. Eradication of carriage should probably be reserved for children who remain culture-positive after a full and appropriate course of antibiotic therapy, and who have had at least three symptomatic episodes of pharyngitis with

A streptococcal score card revisited.

To evaluate the utility of a simple scoring system as a predictor of obtaining a positive throat culture for group A streptococci (GAS). Prospective descriptive study. Scores were assigned prior to the availability of the results of throat cultures. Emergency department and walk-in clinic of the Children's Hospital of Pittsburgh. Patients were 365 children between the ages of two and 16 years with acute onset of sore throat and a history of or documentation of fever within the preceding 24 hours. A streptococcal score was assigned on the basis of a 6-point schema in which the features were 1) age; 2) season; 3) temperature of at least 38.3 degrees C; 4) adenopathy; 5) pharyngeal erythema, edema, or exudate; and 6) no symptoms of a viral upper respiratory infection (conjunctivitis, rhinorrhea, or cough). A throat culture was performed for the isolation of GAS. Positive predictive value of the streptococcal score in identifying children with a positive throat culture for GAS. A score of 5 or 6 predicted a positive culture for GAS in 59 and 75% of children, respectively. In patients with evidence of acute pharyngitis, the combination of age between five and 15 years, fever and absence of upper respiratory symptoms predicted a positive culture for GAS in 72% of patients. The score can be used to predict the likelihood that a throat culture will be positive for GAS.

Clinical comparison of cefaclor twice daily versus amoxicillin-clavulanate or erythromycin three times daily in the treatment of patients with streptococcal pharyngitis

The present study was undertaken to compare the efficacy and safety of a new regimen of cefaclor (25 mg/kg BID) with amoxicillin-clavulanate and erythromycin TID at standard doses for the treatment of pediatric patients with acute pharyngotonsillitis (APT). A total of 673 children (age range, 2 to 12 years) with signs and symptoms of APT were enrolled; 245 of these children who had a positive throat culture for group A beta-hemolytic streptococci (GABHS) entered the study and were randomly assigned to receive cefaclor 25 mg/kg BID, amoxicillin-clavulanate 15 mg/kg TID, or erythromycin 15 mg/kg TID. A 10-day antibiotic course was prescribed for each patient. Clinical and bacteriologic responses were assessed at the end of treatment (day 10) and at the follow-up visit (day 30). All GABHS strains isolated from throat cultures were tested for in vitro sensitivity to the antibiotics used in the study. Side effects (mainly nausea) were rare and mild in each group and did not require discontinuation of therapy. No GABHS strain was resistant to cefaclor or to amoxicillin-clavulanate; 37.9% of the strains were resistant to erythromycin. The results indicated that cefaclor given BID seems to be as effective as amoxicillin-clavulanate given TID (cure rate, 91.9% and 90.5%, respectively) and more effective than erythromycin given TID (cure rate, 76.8%) for the treatment of patients with APT. Erythromycin resistance among GABHS is an emerging problem in many geographic areas.

Randomized evaluation of benzathine penicillin V twice daily versus potassium penicillin V three times daily in the treatment of group A streptococcal pharyngitis

In a randomized, prospective, multicenter study the clinical and bacteriological efficacies of three dosage schedules with two different salts of oral penicillin V suspensions (regimen 1: potassium salt of penicillin V, 50,000 U/kg of body weight per day in three divided doses; regimen 2: benzathine salt of penicillin V, 50,000 U/kg of body weight per day in two divided doses; and regimen 3: benzathine salt of penicillin V, 100,000 U/kg of body weight in two divided doses) for the treatment of streptococcal pharyngitis were evaluated. Children with clinical signs of acute pharyngitis and a positive throat culture for group A beta-hemolytic streptococci (GABHS) were eligible. There was no difference between the treatment groups with respect to the overall clinical success rate. Eradication of the original serotype of GABHS from throat cultures was achieved in 87.1% (regimen 1), 85.5% (regimen 2) and 87.7% (regimen 3) of patients. The incidence of potential drug-related adverse events was significantly higher in patients treated with regimen 3. The results of this and earlier studies strongly suggest that oral penicillin given twice daily should be the recommended treatment for the initial treatment of pharyngitis due to GABHS. Doubling the total daily dose is not beneficial in the usual clinical setting. Because of its favorable pharmacokinetics, the benzathine salt of penicillin V appears to be well suited for a twice-a-day dosage schedule.

Throat Cultures

I read with great interest the article entitled "Duration of Positive Throat Cultures for Group A Streptococci After Initiation of Antibiotic Therapy" by Snellman et al.1 The study involved 47 patients in whom streptococcal pharyngitis was diagnosed, who were randomly selected to receive three different antimicrobial regimens with a varying number of doses before the performance of a repeat throat culture. The degree of positivity of the persistently positive cultures (1+, 2+, or 3+) was not shown.

Duration of Positive Throat Cultures for Group A Streptococci After Initiation of Antibiotic Therapy

To determine if it is appropriate to recommend that patients with group A beta-hemolytic streptococcal pharyngitis, who are clinically well by the morning after starting antibiotic treatment, can return to school or day care, or if they should wait until they have completed 24 hours of antibiotics as recommended by the American Academy of Pediatrics Committee on Infectious Diseases. We examined the duration of positivity of the throat culture after antibiotics were begun as a means of assessing the potential risk of transmission to close school contacts. Forty-seven children (4 to 17 years of age) with pharyngitis and a positive throat culture for group A streptococci in an outpatient, staff model health maintenance organization clinic were enrolled and were randomly selected to receive therapy with either oral penicillin V, intramuscular benzathine penicillin G, or oral erythromycin estolate. Additional throat cultures were obtained and clinical findings were recorded for each child during three home visits in the 24 hours after their initial clinic visit. Acute and convalescent sera were obtained for determination of anti-streptolysin O and anti-DNase B titers. Seventeen (36.2%) of the 47 patients had a positive culture the morning after initiating antibiotic therapy. However, thirty-nine (83%) of the patients became "culture negative" within the first 24 hours. Neither the time interval to the first negative culture nor the presence or absence of group A streptococcal organisms on any single convalescent culture could be predicted by clinical findings. Six of the eight children who failed to convert to a "negative" throat culture within 24 hours of initiating therapy were receiving erythromycin. We could detect no difference in either time to conversion to a negative culture or the presence of a positive culture 24 hours after starting antibiotics between those who demonstrated a significant antibody increase and those who did not. The data from this study strongly suggest that children with group A beta-hemolytic streptococcal pharyngitis should complete a full 24 hours of antibiotics before returning to school or daycare.

Inhibitory substances produced byStreptococcus salivariusand colonization of the upper respiratory tract with group A streptococci

It has been proposed that inhibitory substances produced by viridans streptococci colonizing the upper respiratory tract aid in eradication of established group A streptococcal colonization of that site. We studied the prevalence of inhibitory-substance producing strains of Streptococcus salivarius in throat cultures from three groups of children: 16 children with persistently positive throat cultures for group A streptococci despite receiving recommended therapeutic courses of antibiotics (group I), 26 children from whom group A streptococci were eradicated from the upper respiratory tract by antibiotic therapy (group II), and 18 children who never harboured group A streptococci in their upper respiratory tract during the study period (group III). An in vitro deferred antagonism method was employed to detect inhibitory substances; 5233 strains of S. salivarius were examined. Strains of S. salivarius producing inhibitory substances were isolated from 76-88% of the children in each group on at least one occasion. However, only a small percentage of subjects in each group harboured strains producing these substances in every throat culture. The mean total percentage of S. salivarius strains producing inhibitory substances was 21.8% in children in group I, 22.4% in children in group II, and 16.4% in children in group III; these percentages were not statistically different (P greater than 0.1). In this study, we could not confirm a significant role for inhibitory substances produced by S. salivarius in the eradication of group A streptococci from the upper respiratory tract of colonized individuals.

Hoigne's Syndrome

Sir .—Eight years ago when I was an intern in pediatrics, I ordered an injection of 1.2 million units of penicillin G benzathine for a 12-year-old girl with a positive throat culture for group A β-hemolytic Streptococcus . Immediately after the injection was given into one of her buttocks, she began to hallucinate. Then, she jumped off the table and attempted to run up the wall of the room. My colleagues and I held her down to the floor because she was also combative. Vital signs that were taken were stable. We did not know what kind of reaction she was having and did not know what to do for her until one of the foreign medical residents stated that he had seen this reaction before. He said that he did not know what it was, but that the treatment was steroids. We then administered 5 mg/kg of hydrocortisone intravenously. A

Acquisition of group A streptococcal M protein antibodies.

Seventy-five children who acquired positive throat cultures for Group A streptococci among 250 cultured weekly were studied during the school years 1972-1973 and 1973-1974 in order to investigate streptococcal M protein antibodies. Eleven (14.7%) of the children had strain-specific serum M protein antibodies at the time a positive throat culture was first detected or 6 weeks previously. Eight of 64 (12.5%) children acquired strain specific serum M protein antibodies within 6 weeks and another 6 of 46 (13%) did so within 1 year of infection. The presence of strain-specific serum M protein antibodies did not appear to be protective. One-third of the 75 children who acquired positive throat cultures had a significant rise in anti-streptolysin O or anti-hyaluronidase antibody titers. Among those who acquired Group A streptococci, 25 children had positive cultures on 7 or more culture dates.

Study on serum antistreptococcal esterase among school children.

Antistreptococcal esterase (an antibody to extracellular esterase produced by Group A streptococci: ASE) was evaluated according to Hayano's method by using an assay kit on sera of children from two schools, one (F-school) in a non-epidemic state and the other (I-school) in an epidemic state of Group A streptococcal infection. Out of 104 children of F-school, 51 with negative throat cultures for Group A streptococci showed a mean serum ASE titer of 191 +/- 144 unit, and 53 with positive throat cultures for Group A streptococci showed a mean serum ASE titer of 360 +/- 147 unit. Follow-up determinations on serum antibodies to four Group A streptococcal antigens were performed on the children from I-school during a period of 13 months after an epidemic infection of Group A streptococci. The initially elevated serum ASE titer showed a decreasing trend on subsequent bleedings during the study period as well as antistreptolysin O (ASO) and antideoxyribonuclease B (ADN-B) titers. However, the changing pattern of the antistreptococcal polysaccharide (ASP) titer was different from that of the other three antibodies. A positive correlation was observed statistically between ASE and ASO titers, and also between ASE and ADN-B titers. The ASE tests appear to be useful for serological evidence of a streptococcal infection.

Beta-Hemolytic Streptococcal Pharyngitis

Infectious mononucleosis (IM) and beta-hemolytic streptococcal pharyngitis may present similar clinical pictures and may occur concurrently; however, recent studies have differed sharply with older ones that cited high rates of concurrent disease. Our study of 100 consecutive new patients meeting strict criteria for a diagnosis of IM found only 4% with positive throat cultures for group A beta-hemolytic streptococci at the time of diagnosis. Use of antibiotics for presumed streptococcal pharyngitis in patients with IM is unjustified. Only patients with positive cultures should be treated.

Emergency room management of patients with sore throats in a teaching hospital: influence of non-physician factors.

The care of 169 patients with sore throats was evaluated retrospectively to determine if the quality of medical care received in a teaching hospital's emergency room is associated with the degree of control managing physicians have over the medical care process. Diagnostic evaluation (temperature, throat and cervical node examination, and throat culture) was controlled by physicians and was judged adequate in 78% to 98% of the patients. Therapy, defined as appropriate antibiotics prescribed only for patients with positive throat cultures for group A beta-hemolytic streptococcus, was dependent on hospital support services, and the patients, as well, and was judged adequate for 62% of the patients; however, in only one of the 67 patients treated with antibiotics was the culture result known before treatment. The bacteriology laboratory processed the cultures slowly; no administrative mechanism existed to follow up patients. Thus, when medical care involved factors outside physicians' direct control, lower qualtiy care was given.

Upper Respiratory Tract Protocol

To the Editor. —The presentation of an upper-respiratory tract complaint protocol by Greenfield et al ( Arch Intern Med 133:294-299) and the result achieved with the use of this protocol were impressive from the standpoint of the organization of the data collection form and the decision-making algorithm; however, two additional interpretations of their results deserve mention. Although the statement is made that the protocol manifested equal or better judgement compared to the physicians, an examination of their results showed that, under the protocol's disposition, 22 patients would have received penicillin, seven of whom were shown to have positive throat cultures for group A β-hemolytic streptococci. This is a treatment accuracy of 32% as compared to the physicians' 25% accuracy, probably an insignificant difference. More important however, is the fact that the accuracy was only 32% and, taking into account that an additional four patients who did not receive penicillin under the

A Longitudinal Study of Streptococcal Antibody Dynamics Showing Unusual Seasonal Fluctuations

A population of 160 children (mean age = 6.6 years) was followed at 2-month intervals over a 2-year period with serial determinations for 3 streptococcal antibodies: antistreptolysin O (ASO), antideoxyribonuclease B (anti-DNAse B) and anti-nicotinamide-adenine-dinucleotidase (anti-NADase). Antibody dynamics of the more than 1,000 sera collected (mean no. bleedings/child = 7.3) were examined by comparing geometric mean titers (GMT) and significant rises at different times of the year. GMTs for all 3 antibodies increased during the summer and fall when streptococcal skin infections were common but leveled off or fell during the winter and spring despite a high prevalence of respiratory illness and positive throat cultures for group A streptocci (up to 70%). The smallest number of rises for all 3 antibodies occurred during the respiratory season. During the summer anti-DNAse B titers tended to rise more sharply and reached maximum levels sooner than the other two antibodies. Although GMTs were lowest in the 1–3-year age group, these children also showed marked rises during the summer and fall. Rises in ASO were less frequent than responses in the other two antibodies, especially after 3 years of age. Plateauing of GMTls occurred at a later age for anti-DNAse B than for the other two antibodies. This extraordinary, inverse seasonal pattern of antibody levels and responses emphasizes the predominant influence of skin infections in this population and raises the possibility of a curious immunological unresponsiveness to streptococcal respiratory infections during the winter month, behavior which may contribute to the low frequency of acute rheumatic fever relative to acute nephritis in this population.