FACTORS AFFECTING THE INCIDENCE OF GROUP A Β-HEMOLYTIC STREPTOCOCCI ISOLATED FROM THROAT CULTURE

Group A streptococcus (GAS) is an important cause of acute pharyngitis. We investigated the positive rate of GAS tests and clinical viral features in children with acute pharyngitis. A retrospective review was conducted for patients <15 years old with both rapid antigen detection test (RADT) and throat culture results. Patients were excluded if they were diagnosed with influenza or had received antibiotics within two weeks before these tests. A total of 377 patients were eligible. The median age of patients was 3.5 years, and 45.4% of total patients were <3 years old. Among all patients, 68.7% had at least one viral feature, and 39% had more than two. The overall positiv rate for GAS was 11.4%. The GAS positive rate was significantly lower in patients <3 years old than in older patients (1.8% vs. 19.4%, p < 0.0001). The overall sensitivity and specificity of RADT were 75.0% (95% CI: 57.8–87.9) and 97.9% (95% CI: 95.8–99.2), respectively. The GAS positive rate was not significantly different between patients with and without viral features (12.4% vs. 9.3%, p = 0.4854). In patients aged 3–14 years, the GAS positive rate was not associated with the modified Centor score or the frequency of clinical viral features. Despite a low prevalence of GAS pharyngitis, testing for GAS was frequently performed in children <3 years old in this study. Appropriate use of laboratory testing for GAS pharyngitis and judicious prescription of antibiotics were imperative.

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DIAGNOSIS AND TREATMENT: GROUP A STREPTOCOCCAL INFECTIONS

PEDIATRICS ◽

10.1542/peds.36.6.930 ◽

1965 ◽

Vol 36 (6) ◽

pp. 930-932

Author(s):

Edward A. Mortimer ◽

Bernard Boxerbaum

Keyword(s):

Treatment Group ◽

Oral Therapy ◽

Accurate Diagnosis ◽

Diagnosis And Treatment ◽

Streptococcal Infections ◽

Benzathine Penicillin ◽

Throat Culture ◽

Streptococcal Disease ◽

Group A ◽

And Control

In spite of adequate means of therapy, streptococcal disease and its complications continue to present problems to the physician who cares for children. For accurate diagnosis and control of streptococcal disease inexpensive bacteriologic culture facilities are required and the physician must assure himself of the accuracy of the results. To prevent the sequelae of streptococcal occal pharyngitis, therapy sufficient to eradicate the offending organism is required. Optimum therapy of streptococcal infections is intramuscular benzathine penicillin; oral therapy with penicillin or erythromycin should be followed by a throat culture to ensure that the streptococcus has been erdicated.

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The utility of rapid Group A streptococcus molecular testing compared with throat culture for the diagnosis of Group A streptococcal pharyngitis in a high-incidence rheumatic fever population.

Journal of Clinical Microbiology ◽

10.1128/jcm.00978-21 ◽

2021 ◽

Author(s):

Amanda Taylor ◽

Susan Morpeth ◽

Rachel Webb ◽

Susan Taylor

Keyword(s):

New Zealand ◽

Rheumatic Fever ◽

Predictive Value ◽

Gold Standard ◽

Molecular Test ◽

Throat Culture ◽

High Incidence ◽

Group A ◽

Sensitivity Specificity ◽

Culture Negative

Background: Group A Streptococcus (GAS) causes significant morbidity and mortality in New Zealand and is responsible for invasive disease and immune sequelae including acute Rheumatic Fever (ARF). Early treatment of GAS pharyngitis reduces the risk of ARF. In settings with a high-burden of GAS disease, a rapid GAS pharyngitis diagnostic test with a strong negative predictive value is needed to enable prompt and accurate treatment. Methods: This prospective study compares the Xpert® Xpress Strep A molecular test (Cepheid) to throat culture and a second molecular method, the BioGX Group A Streptococcus -OSR for BD MAX TM for the diagnosis of GAS pharyngitis. Throat swabs were collected from the emergency department and wards of Middlemore Hospital, New Zealand. The BioGX Group A Streptococcus - OSR for BD MAX TM , contributes to the composite gold-standard: throat culture or both molecular methods positive. Basic demographic, clinical and laboratory data was collected. Results: 205/214 swabs were suitable for analysis. 28/205 (13.7%) were GAS culture positive, 45/205 (22%) Xpert® Xpress Strep A positive and 38/205 (18.5%) BioGX positive. Compared to culture, the sensitivity, specificity, positive and negative predictive values of the Xpert® Xpress Strep A molecular test were 100%, 90.4%, 62.2% and 100%, respectively. Compared to the composite gold-standard, the sensitivity, specificity, PPV and NPV and were 100%, 95.8%, 84.4% and 100% respectively. 17 samples were Xpert® Xpress positive but culture-negative; 6 of these 17 swabs represent true positives with evidence of recent GAS infection. Ten samples were culture negative but both Xpert® Xpress and BioGX positive. Conclusion: The Xpert® Xpress Strep A molecular test is highly sensitive with a strong negative predictive value and rapid turnaround time. It can be safely introduced as a first line test for throat swabs in a high-incidence ARF population.

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Evaluation of the Mean Platelet Volume and Red Cell Distribution Width in FMF: Are They Related to Subclinical Inflammation or Not?

International Journal of Chronic Diseases ◽

10.1155/2014/127426 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 3

Author(s):

Gozde Yildirim Cetin ◽

Ozlem Gul ◽

Fatma Kesici-Metin ◽

İrem Gokalp ◽

Mehmet Sayarlıoglu

Keyword(s):

Negative Correlation ◽

Treatment Decision ◽

Control Group ◽

Subclinical Inflammation ◽

Distribution Width ◽

Factors Affecting ◽

Additional Information ◽

Large Numbers ◽

Healthy Control ◽

Group A

In this paper we want to demonstrate whether higher than normal levels of RDW, and lower than normal levels of MPV can be used as indicators of subclinical inflammation and tools for treatment decision in FMF or not. The participants in this study included 89 patients with FMF during attack-free periods and 30 healthy controls. The RDW and platelet counts were significantly higher, while the MPV was significantly lower in the patients with FMF group than healthy control group (P<0.001;P=0.005;P<0.001, resp.). In the attack-free FMF group, a negative correlation was found between the MPV and RDW values (P<0.001,r=-0.40). The positive correlation was found between the RDW and ESR (r=0.23,P=0.028). And the negative correlation was found between the MPV and CRP (r=-0.216,P=0.042). Consequently, our results suggest that low MPV and high RDW levels may provide additional information about subclinical inflammation in FMF patients. But other strong predisposing factors affecting subclinical inflammation in FMF should be considered. Further studies with large numbers of patients are needed. Treatment of FMF should include not only prevention of acute attacks but also decreasing of the subclinical inflammation.

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Significance of Quantitative Salivary Cultures for Group A and Non-group A β-Hemolytic Streptococci in Patients with Pharyngitis and in Their Family Contacts

PEDIATRICS ◽

10.1542/peds.64.6.904 ◽

1979 ◽

Vol 64 (6) ◽

pp. 904-912

Author(s):

Edward L. Kaplan ◽

Robert Couser ◽

Barbara Ballard Huwe ◽

Carolyn Mckay ◽

Lewis W. Wannamaker

Keyword(s):

Antibody Response ◽

Respiratory Tract ◽

Group A Streptococci ◽

Upper Respiratory Tract ◽

C Reactive Protein ◽

Throat Culture ◽

Reactive Protein ◽

Group A ◽

Bona Fide ◽

Upper Respiratory

One hundred ninety-six individuals, 86 with clinically overt pharyngotonsillitis and 110 of their clinically negative contacts were studied to evaluate the sensitivity and the specificity of quantitative saliva cultures for group A β-hemolytic streptococci. We also compared this technique with semiquantitative throat cultures as a means of isolating group A streptococci and of differentiating the streptococcal carrier state from patients with bona fide streptococcal upper respiratory tract infection as defmed by the presence of an antibody response. The data indicate that the throat culture is a more reliable means of identifying group A β-hemolytic streptococci in the upper respiratory tract than is the saliva culture. The converse is true for non-group A β-hemolytic streptococci; the saliva culture is a much better means for isolating these organisms. In individuals positive by both techniques we found good correlation between the degree of positivity of the saliva culture and the degree of positivity of the throat culture. Furthermore, while there was a definite trend for individuals with strongly positive cultures to demonstrate more often an antibody rise in either antistreptolysin O and/or antideoxynibonuclease B—indicating bona fide infection—this relationship was not sufficiently constant to provide a clear differentiation. This study also indicates that discordance (one positive, one negative) of simultaneous duplicate semiquantitative throat cultures is much more common among individuals who do not show an antibody response ("carriers") than among those with an antibody response (bona fide infection). This study confirms our previous observations suggesting that the presence of C-reactive protein in the serum of patients with a positive culture for group A streptococci and clinical signs and symptoms of pharyngitis is often an indication of true streptococcal upper respiratory tract infection, and that even with a positive saliva culture at the initial visit, a negative C-reactive protein is only infrequently (25%) associated with an antibody response.

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