Asymptomatic pharyngeal carriage of beta-haemolytic streptococci and streptococcal pharyngitis among patients at an urban hospital in Croatia

Seasonal variations in use and outcome of rapid antigen detection tests and cultures in pharyngotonsillitis: a register study in primary care

Background

Diagnosis and treatment of pharyngotonsillitis are commonly focused on group A streptococci (GAS), although the disease is often associated with other pathogens. While the incidence of pharyngotonsillitis is known to vary with season, seasonal variations in the prevalence of potential pathogens are sparsely explored. The aim of this study was to explore any seasonal variations in the use and outcome of rapid antigen detection tests (RADTs) for GAS and throat cultures among patients diagnosed with pharyngotonsillitis in primary care.

Methods

We retrieved and combined retrospective data from the electronic medical record system and the laboratory information system in Kronoberg County, Sweden. Primary care visits resulting in a diagnosis of tonsillitis or pharyngitis were included, covering the period 2013–2016. The monthly rate of visits was measured, along with the use and outcome of RADTs for GAS and throat cultures obtained on the date of diagnosis. The variations between calendar months were then analysed.

Results

We found variations between calendar months, not only in the mean rate of visits resulting in a diagnosis of pharyngotonsillitis (p < 0.001), but in the mean proportion of RADTs being positive for GAS among the diagnosed (p < 0.001), and in the mean proportion of visits associated with a throat culture (p < 0.001). A lower mean rate of visits in August and September coincided with a lower proportion of RADTs being positive for GAS among them, which correlated with a higher proportion of visits associated with a throat culture.

Conclusions

This study suggests that the role of GAS in pharyngotonsillitis in Sweden is less prominent in August and September than during the rest of the year.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06774-5.

Group C beta hemolytic Streptococci as a potential pathogen in patients presenting with an uncomplicated acute sore throat - a systematic literature review and meta-analysis

Objective: The pathogenicity of beta-hemolytic Streptococcus group C (GCS) in patients attending for an uncomplicated acute sore throat is unknown and it was the objective to clarify this.Design: Systematic literature review with meta-analysis. Setting Medline and Scopus were searched from inception to February 2019, with searches of reference lists, Subjects case-control studies stating prevalence of GCS in patients as well as healthy controls presented for children and adults separately. Studies including patients already treated with antibiotics and studies focused on patients with HIV, malignancy or immunosuppression were not included. Main outcome measures Pooled prevalence of GCS was compared between patients and controls using chi-square and was further explored by calculating the positive etiologic predictive value (P-EPV) showing the post-test probability of a link between a sore throat and the bacterial finding. P-EPV for GCS was compared with that for group A Streptococci (GAS) using figures from the same publications and patients.Results: Eleven studies were included. The prevalence of GCS among patients versus controls was similar in children (3.15 versus 2.87%, p = .44) but for adults higher in patients (11%) than in controls (5.6%) (p < .0001). The P-EPV for finding GCS in children with a sore throat was 9.3% (0.0-41%). The corresponding P-EPV for GCS in adults with a sore throat was 53% (36-67%) while the corresponding P-EPV for GAS in adults was 94% (90-96%).Conclusions: GCS do not seem associated with the uncomplicated acute sore throat in children but there is support for an association in adults being weaker than for GAS. A possible consequence is to ignore GCS in otherwise healthy patients at their first visit for an uncomplicated sore throat. This would enable a stronger focus on the use of modern point of care tests (POCTs) to detect GAS.Key pointsThere is no current consensus on the pathogenicity of group C beta-hemolytic Streptococcus (GCS) in patients attending for an uncomplicated acute sore throat.This systematic literature review concludes it is unlikely that GCS is involved in the uncomplicated sore throat in otherwise healthy children.This meta-analysis found a moderate link between GCS and the uncomplicated sore throat in adults.The link in adults between GCS and the sore throat is much weaker than the corresponding link for group A beta-hemolytic Streptococcus.

Highly Sensitive Molecular Assay for Group A Streptococci Over-identifies Carriers and May Impact Outpatient Antimicrobial Stewardship

BACKGROUND

Timely, accurate diagnosis of group A streptococci (GAS) pharyngitis prevents acute rheumatic fever and limits antibiotic overuse. The illumigene group A Streptococcus assay (Meridian Bioscience, Cincinnati, OH) is a molecular test for GAS pharyngitis with high sensitivity and specificity. We sought to determine whether the illumigene test is more likely than throat culture to be positive in patients without pharyngeal symptoms and explore the limits of detection of the test.

METHODS

Patients 3-17 years of age were eligible if they had no history of pharyngitis or use of antibiotics within the previous 2 weeks; there were no upper respiratory infection symptoms, sore throat or fever and no signs of infection. Culture and illumigene were performed on duplicate throat swabs. Excess lysate from a subset of illumigene tests was evaluated by real-time polymerase chain reaction. Institutional Review Board approval was obtained.

RESULTS

We enrolled 385 patients from February 2016 to October 2017; mean age was 10 yr; 51% were male. Most visits were for health supervision (69%). Significantly more illumigene tests (78/385, 20.3%) than throat cultures (48/385, 12.5%) were positive (χ; P =0.0035). Illumigene was "indeterminate" for 3 patients, leaving 382 pairs of swabs for analysis. Results were discordant for 32 of 382 pairs (8.4%); 31 of 32 (97%) were illumigene-positive/culture-negative (McNemar test; P < 0.000001). Real-time polymerase chain reaction was negative in 4 of 13 (31%) tested illumigene-positive lysates; the paired culture had been negative in all four. The limit of detection for the illumigene test was 55 colony forming units/mL.

CONCLUSIONS

The illumigene test is significantly more likely than throat culture to yield positive results in patients without GAS pharyngitis. Failure to appropriately select patients for testing may negatively impact antimicrobial stewardship efforts without benefit to patients.

Signs and symptoms of Group A versus Non-Group A strep throat: A meta-analysis

INTRODUCTION

Both non-Group A streptococcal (non-GAS) pharyngitis and Group A streptococcal (GAS) pharyngitis are commonly found in patients with sore throat. It is not known whether or not they present with similar signs and symptoms compared to patients with non-streptococcal pharyngitis.

METHODS

MEDLINE was searched for prospective studies that reported throat culture for both GAS and non-GAS as a reference standard, and reported at least one sign, symptom, or the Centor score. Summary estimates of sensitivity, specificity, likelihood ratios (LR+ and LR-), and diagnostic odds ratios (DOR) were calculated using a bivariate random effects model. Summary receiver operating characteristic (ROC) curves were created for key signs and symptoms.

RESULTS

Eight studies met our inclusion criteria. Tonsillar exudate had the highest LR+ for both GAS and non-GAS pharyngitis (1.53 versus 1.71). The confidence intervals of sensitivity, LR+, LR-, and DOR for all signs, symptoms, and the Centor score between two groups overlapped, with the relative difference between sensitivities within 15% for arthralgia or myalgia, fever, injected throat, tonsillar enlargement, and tonsillar exudate. Larger differences in sensitivities were observed for sore throat, cervical adenopathy, and lack of a cough, although the difference for lack of a cough largely due to a single outlier.

DISCUSSION

Signs and symptoms of patients with GAS and non-GAS pharyngitis are generally similar. No signs or symptoms clearly distinguish GAS from non-GAS infection. Further work is needed to determine whether Group C streptococcus is a pathogen that should be treated.

Antibiotic Resistance Patterns and Related Mobile Genetic Elements of Pneumococci and β-Hemolytic Streptococci in Thai Healthy Children

Transmission of antibiotic resistance genes among Streptococcus pneumoniae and beta-hemolytic streptococcus (BHS) was generally associated with transmissible genetic elements. The objectives of this study were to investigate carriage rate, antibiotic resistance and related mobile genetic elements of pneumococci and BHS from school-children. The pneumococci and BHS were recovered from 220 Thai school-children, and then tested for antibiotic susceptibility pattern by disc diffusion. Antibiotic resistance genes and related genetic elements were detected by PCR with specific primers. A total of 77 pneumococcal isolates were resistant to erythromycin (42 %), tetracycline (44 %), clindamycin (8 %), or penicillin (3 %). Fifty-four BHS isolates were resistant to erythromycin (28 %), tetracycline (52 %), or clindamycin (13 %). All isolates tested were 100 % sensitive to penicillin and levofloxacin. Among erythromycin-resistant streptococcal isolates showed different phenotypes of clindamycin resistance. It was found that isolated pneumococci showed constitutive clindamycin resistance (19 %), and inducible clindamycin resistance (12 %). The BHS isolates exhibited constitutive clindamycin resistance (40 %), and inducible resistance (20 %) phenotypes. The predominant erythromycin resistance genes in pneumococci and BHS were mefE and ermB, while the most common tetracycline resistance gene in this population was tetM. Furthermore, almost all erythromycin- and tetracycline-resistant streptococci (97 %) mainly contained various genetic elements, including mega elements and six different transposon types (Tn2009, Tn2017, Tn917, Tn3872, Tn6002 and Tn916). Therefore, carriages of pneumococci and BHS with multidrug resistance in children might be important reservoirs of antibiotic-resistance genes carried by transposons. Tn916-like elements could lead to dissemination of the antibiotic resistance genes among genus streptococcus in human oral cavity and nasopharynx.

Group A Streptococcal Carriage and Seroepidemiology in Children up to 10 Years of Age in Australia

BACKGROUND

Group A streptococci (GAS) and other β-hemolytic streptococci (BHS) cause pharyngitis, severe invasive disease and serious nonsuppurative sequelae including rheumatic heart disease and post streptococcal glomerulonephritis. The aim of this study was to assess carriage rates and anti-streptococcal C5a peptidase (anti-SCP) IgG levels and identify epidemiologic factors related to carriage or seropositivity in Australian children.

METHODS

A throat swab and blood sample were collected for microbiological and serological analysis (anti-SCP IgG) in 542 healthy children aged 0-10 years. Sequence analysis of the SCP gene was performed. Serological analysis used a competitive Luminex Immunoassay designed to preferentially detect functional antibody.

RESULTS

GAS-positive culture prevalence in throat swabs was 5.0% (range 0-10%), with the highest rate in 5 and 9 years old children. The rate of non-GAS BHS carriage was low (<1%). The scp gene was present in all 22 isolates evaluated. As age of child increased, the rate of carriage increased; odds ratio, 1.14 (1.00, 1.29); P = 0.50. Geometric mean anti-SCP titers increased with each age-band from 2 to 7 years, then plateaued. Age, geographic location and number of children within the household were significantly associated with the presence of anti-SCP antibodies.

CONCLUSIONS

Children are exposed to GAS and other BHS at a young age, which is important for determining the target age for vaccination to protect before the period of risk.

Influence of a probiotic Lactobacillus casei strain on the colonisation with potential pathogenic streptococci and Staphylococcus aureus in the nasopharyngeal space of healthy men with a low baseline NK cell activity

The effect of a daily intake of the probiotic strain Lactobacillus casei Shirota (LcS) on the colonisation of pathogens, specifically streptococci and Staphylococcus aureus, in the nose and throat of healthy human volunteers with low natural killer cell activity, was investigated in a randomised and controlled intervention study. The study consisted of a 2-week run-in phase, followed by a 4-week intervention phase. The probiotic treatment group received a fermented milk drink with LcS, while the placebo group received an equally composed milk drink without the probiotic additive. To isolate potential pathogenic streptococci and Staph. aureus, samples from the pharynx, as well as of both middle nasal meati, were taken, once after the run-in phase and once at the end of the intervention phase. Isolated bacteria were identified as either Staph. aureus and α- or β-haemolytic streptococci in a polyphasic taxonomical approach based on phenotypic tests, amplified ribosomal DNA restriction analysis genotyping, and 16S rRNA gene sequencing of representative strains. Salivary secretory immunoglobulin A (SIgA) was used as marker of protective mucosal immunity to evaluate whether LcS treatment influenced SIgA production. No statistically significant effect could be determined for intervention with LcS on the incidence of Staph. aureus in the nasal space, Staph. aureus in the pharyngeal space or for β-haemolytic streptococci and Streptococcus pneumoniae in the pharyngeal space. Thus, the intervention did not influence the nasopharyngeal colonisation with Gram-positive potential pathogens. Production of salivary SIgA as a potential means of microbiota modulation was also not affected.

Maternal β-hemolytic streptococcal pharyngeal exposure and colonization in pregnancy

Objectives. To report the pharyngeal colonization rate of β-hemolytic streptococci and changes in the value of antistreptolysin O (ASO) and anti-DNase B serology titers during pregnancy. Methods. Healthy pregnant women were recruited and blood was drawn in each trimester. The upper limit of normal (ULN) values for ASO and anti-DNase B was calculated for each trimester. Throat swabs were collected for culture and positive cultures were further assessed for the identification of serogroup of the isolated β-hemolytic streptococcus. Results. Out of a total of 126 pregnant women, 34.1% had positive throat cultures. Group C and group G strains were isolated in 18.2% of throat cultures while group F was detected in 13.5% of cases. The rate of colonization with GAS was 1.6%. There was an overall drop in ASO titer during pregnancy while anti-DNase B titers remained relatively unchanged. ULN values of 164^IU, 157^IU, and 156^IU were calculated for ASO at the first, second, and third trimesters, respectively. Based on the ULN values, 28.6% of patients had recent streptococcal exposure. Conclusions. These results show that pregnant women act as a reservoir for spreading potentially immunogenic (groups C and G) and disease producing (group F) virulent strains of streptococci.

Are procalcitonin or other infection markers useful in the detection of group A streptococcal acute tonsillitis?

BACKGROUND

The Centor criteria and the streptococcal rapid antigen detection test (RADT) are commonly used to differentiate sore throat patients with group A streptococci (GAS) from patients with other pathogens. We aimed to investigate if procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC), and absolute neutrophil count (ANC) could increase the diagnostic accuracy when added to the Centor score and RADT, or be used instead of the RADT, in the differential diagnosis.

METHODS

A 6-month prospective study was carried out in a Danish general practice with 8 physicians. One hundred acute tonsillitis patients aged 15 to 40 y were included.

RESULTS

The prevalence of GAS was 26%. The sensitivity (90%) and specificity (97%) of the RADT were high. Mean values of CRP, WBC, and ANC were significantly higher in patients with GAS compared to non-GAS patients (p < 0.001). However, the sensitivities (66-90%) and specificities (45-75%) were low. No difference in PCT levels was found (p = 0.334). CRP was the most reliable infection marker (sensitivity 90% and specificity 45%) for GAS aetiology.

CONCLUSIONS

The sensitivity, specificity, and area under the curve of the RADT were higher than those of the 4 measured infection markers in the differentiation between GAS and non-GAS acute tonsillitis patients. The infection markers did not increase the diagnostic accuracy when added to the Centor score and RADT. When RADT is not available, measurement of CRP or ANC may increase the diagnostic accuracy in the detection of GAS-positive patients.

[Group A streptococcal meningitis: Streptococcus pneumoniae is not the only one to seep into the CSF fluid leak!]

We reported a case of group A streptococcal meningitis in a patient with a CSF fluid leak. This case underlined several relevant points: (i) an unfrequent cause of bacterial meningitis; (ii) the main diagnosis to evoke when the direct examination of CSF shows Gram+ cocci with a negative pneumococcal antigen; (iii) that bacteria other than Streptococcus pneumoniae are possible in front of a meningitis associated with a CSF fluif leak.

In primary health care, never prescribe antibiotics to patients suspected of having an uncomplicated sore throat caused by group A beta-haemolytic streptococci without first confirming the presence of this bacterium

BACKGROUND

There are several consensus-describing decision rules for patients in primary health care with a sore throat. The objective of this study was to estimate the number of unnecessary antibiotic prescriptions in primary health care given to patients with a sore throat, due to these different decision rules. A further aim was to suggest revised rules for decision-making in primary health care, when a sore throat caused by group A beta-haemolytic streptococci (GAS) is suspected.

METHODS

The design was a reanalysis of previously published articles describing the prevalence of GAS and physician behaviour when treating patients with a sore throat. The risk of unnecessary antibiotic prescribing in different situations was estimated and applied to the Swedish population.

RESULTS

Introducing the rule of never prescribing antibiotics without first confirming the presence of GAS would result in an annual reduction in Sweden of 20,360-25,192 unnecessary antibiotic prescriptions in children and 65,311-98,160 in adults.

CONCLUSIONS

The single most important rule in primary health care to minimize the risk of unnecessary antibiotic prescription to patients with an uncomplicated sore throat, and where an infection with GAS is suspected, is to never prescribe antibiotics at the first visit without first confirming the presence of this bacterium. Adding more decision rules may to some extent further reduce the number of unnecessary antibiotic prescriptions.

Guideline for the management of acute sore throat

The European Society for Clinical Microbiology and Infectious Diseases established the Sore Throat Guideline Group to write an updated guideline to diagnose and treat patients with acute sore throat. In diagnosis, Centor clinical scoring system or rapid antigen test can be helpful in targeting antibiotic use. The Centor scoring system can help to identify those patients who have higher likelihood of group A streptococcal infection. In patients with high likelihood of streptococcal infections (e.g. 3-4 Centor criteria) physicians can consider the use of rapid antigen test (RAT). If RAT is performed, throat culture is not necessary after a negative RAT for the diagnosis of group A streptococci. To treat sore throat, either ibuprofen or paracetamol are recommended for relief of acute sore throat symptoms. Zinc gluconate is not recommended to be used in sore throat. There is inconsistent evidence of herbal treatments and acupuncture as treatments for sore throat. Antibiotics should not be used in patients with less severe presentation of sore throat, e.g. 0-2 Centor criteria to relieve symptoms. Modest benefits of antibiotics, which have been observed in patients with 3-4 Centor criteria, have to be weighed against side effects, the effect of antibiotics on microbiota, increased antibacterial resistance, medicalisation and costs. The prevention of suppurative complications is not a specific indication for antibiotic therapy in sore throat. If antibiotics are indicated, penicillin V, twice or three times daily for 10 days is recommended. At the present, there is no evidence enough that indicates shorter treatment length.

Long-term survival of salivary streptococci on dental devices made of ethylene vinyl acetate

Bacterial infection associated with the use of medical or dental devices is a serious concern. Although devices made of ethylene vinyl acetate (EVA) are often used in the oral cavity, there are no established standards for their storage. We investigated bacterial survival on EVA sheets under various storage conditions to establish a standard for hygienic storage of such dental devices. Bacterial counts were evaluated, which showed a significant decrease after washing with sterilized water, mechanical brushing and rinsing, and using Mouthguard Cleaner as compared to untreated samples. In addition, no bacteria were detected on samples stored 2 days or longer in a ventilated environment, whereas they were detected for up to 14 days on samples without any cleaning stored in a closed environment. Bacterial counts for the untreated samples gradually declined, while surviving bacteria on samples treated with sterilized water and mechanical brushing showed a rapid decrease. Additionally, bacterial identification using polymerase chain reaction (PCR) revealed that Streptococcus oralis was dominantly detected on salivary samples after 14 days of storage among both two subjects. For effective hygienic storage of dental devices made of EVA, washing with sterilized water is important to remove absorbed salivary compounds along with storage in a ventilated environment.

Association of pharyngitis with oral antibiotic use for the treatment of acne: a cross-sectional and prospective cohort study

OBJECTIVE

To prospectively evaluate the association between antibiotics used to treat acne and pharyngitis.

DESIGN

Cross-sectional and 9-month prospective cohort.

SETTING

Urban university setting.

PARTICIPANTS

University students.

INTERVENTION

Participants were asked to fill out a survey form, were swabbed for culture, and had a visual examination for acne.

MAIN OUTCOME MEASURE

Report of pharyngitis.

RESULTS

In the cross-sectional study, 10 of the 15 students receiving oral antibiotics for acne reported an episode of pharyngitis in the previous 30 days, whereas 47 of the 130 students not receiving oral antibiotics, but who had acne, reported an episode of pharyngitis in the prior month. The unadjusted odds ratio (OR) (95% CI) associating current oral antibiotic use in acne patients with a self-reported episode of pharyngitis was 3.53 (95% CI, 1.14-10.95). In the cohort study, there were 358 female and 218 male participants; 36 (6.2%) received oral antibiotics for acne during the study, and 96 (16.6%) received topical antibiotics for acne. Using mixed model logistic regression, the OR was 4.34 (95% CI, 1.51-12.47) associating oral antibiotic use with pharyngitis. Less than 1% of participants were colonized by group A streptococcus, which was not associated with pharyngitis.

CONCLUSIONS

Our studies show that that the odds of reporting pharyngitis is more than 3 times baseline in patients receiving oral antibiotics for acne vs those who are not receiving oral antibiotics. The true clinical importance of these findings needs to be evaluated further by prospective studies, but this finding is not associated with group A streptococcus.

Antibiotic resistance and molecular analysis of Streptococcus pyogenes isolated from healthy schoolchildren in China

Streptococcus pyogenes are highly prevalent bacterial pathogens, especially in school-aged children. However, the characteristics of asymptomatic carriers vary geographically in different countries. We aimed to investigate S. pyogenes isolated from healthy schoolchildren in China. From 2007 to 2008, a total of 94 S. pyogenes isolates were obtained from healthy schoolchildren in Beijing and Chongqing, China. Antimicrobial susceptibility testing, determination of macrolide resistance genes (ermB, ermA and mefA), emm genotyping, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) were performed. The resistance rate to macrolides was 96.8% and to tetracycline was 92.6%. All macrolide-resistant isolates exhibited constitutive resistance; 77 isolates (84.6%) had the ermB gene, while 14 isolates (15.4%) had the ermA gene. Among the macrolide-resistant isolates, the most frequent emm type was emm12 (51.6%), followed by emm22 (14.3%) and ST1815 (8.8%). PFGE analysis revealed 12 different patterns, with a given pattern having the same sequence type (ST) by MLST and the same emm type. In conclusion, the rate of macrolide resistance to S. pyogenes is currently very high in China. This is due primarily to the dissemination of a limited number of clones.

Generation of metabolically diverse strains of Streptococcus pyogenes during survival in stationary phase

Streptococcus pyogenes, in addition to causing fulminant disease, can be carried asymptomatically and may survive in the host without causing disease. Long-term stationary-phase cultures were used to characterize the metabolism of cultures surviving after glucose depletion. Survival of stationary-phase cultures in glucose-depleted rich medium was truncated by switching the cells to phosphate-buffered saline or by the addition of antibiotics, suggesting that survival depended on the presence of nutrients and metabolic activity. The metabolites of the pyruvate-to-acetate (PA) pathway (acetate and formate) and amino acid catabolic pathways (ammonia) accumulated throughout long-term stationary phase (12 weeks). Acid and ammonia production was balanced so that the culture pH was maintained above pH 5.6. Strains isolated from long-term stationary-phase cultures accumulated mutations that resulted in unique exponential-phase metabolisms, with some strains expressing the PA pathway, some strains producing ammonia, and some strains expressing both in the presence of glucose. Strains expressing high levels of PA pathway activity during exponential growth were unable to survive when regrown in pure culture due to the production of excess acid. These data suggest that S. pyogenes diversifies during survival in stationary phase into distinct strains with different metabolisms and that complementary metabolism is required to control the pH in stationary-phase cultures. One of three survivor strains isolated from tonsillar discard material from patients expressed high levels of the PA pathway during exponential growth. Sequencing of multiple group A streptococcus regulators revealed two different mutations in two different strains, suggesting that random mutation occurs during survival.

Nasopharyngeal aerobic bacterial flora and Staphylococcus aureus nasal carriage in deaf children

OBJECTIVE

To determine the nasopharyngeal aerobic bacterial flora and Staphylococcus aureus nasal carriage in deaf children and the role of flora in deafness.

STUDY DESIGN

A prospective, controlled study.

METHODS

Nasopharyngeal and nasal swabs were collected from 87 deaf children with acquired etiology at Zonguldak primary school for the deaf and 56 healthy children. The children with genetic base (syndromic or nonsyndromic, familial or sporadic, AD, AR or X-linked recessive), and also with the history of drug exposure, head trauma, birth trauma, prematurity, hyperbilirubinemia and the viral diseases with high fever (like mumps and measles) were excluded from the study. Swabs were inoculated on to a variety of bacteriological culture media, which were then incubated in an appropriate atmosphere. Colonisation of Group A beta hemolytic streptococcus, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria menengitidis, Moraxella catarrhalis and S. aureus in upper respiratory tract were investigated. Antimicrobial susceptibility testing of the isolates were determined according to National committee for clinical laboratory standards (NCCLS) guidelines.

RESULTS

Although, the rates of colonization of the nasopharyngeal aerobic bacteria and nasal S. aureus did not differ significantly between deaf children and normal healthy subjects, less colonization rates were found in deaf children than normal healthy subjects. S. aureus was isolated from 18 (20.7%) deaf children. All S. aureus isolates from deaf children were susceptible to oxacillin. Penicillin susceptibility rate was 22.2%.

CONCLUSION

It is considered that nasopharyngeal and nasal colonizations of deaf children with potentially pathogenic aerobic bacterial flora is not a significant risk factor for acquired infections when compared with healthy children.

Penicillin for acute sore throat in children: randomised, double blind trial

OBJECTIVE

To assess the effectiveness of penicillin for three days and treatment for seven days compared with placebo in resolving symptoms in children with sore throat.

DESIGN

Randomised, double blind, placebo controlled trial.

SETTING

43 family practices in the Netherlands.

PARTICIPANTS

156 children aged 4-15 who had a sore throat for less than seven days and at least two of the four Centor criteria (history of fever, absence of cough, swollen tender anterior cervical lymph nodes, and tonsillar exudate). Interventions Patients were randomly assigned to penicillin for seven days, penicillin for three days followed by placebo for four days, or placebo for seven days.

MAIN OUTCOME MEASURES

Duration of symptoms, mean consumption of analgesics, number of days of absence from school, occurrence of streptococcal sequelae, eradication of the initial pathogen, and recurrences of sore throat after six months.

RESULTS

Penicillin treatment was not more beneficial than placebo in resolving symptoms of sore throat, neither in the total group nor in the 96 children with group A streptococci. In the groups randomised to seven days of penicillin, three days of penicillin, or placebo, one, two, and eight children, respectively, experienced a streptococcal sequela.

CONCLUSION

Penicillin treatment had no beneficial effect in children with sore throat on the average duration of symptoms. Penicillin may, however, reduce streptococcal sequelae.

The predictive value of microbiologic diagnostic tests if asymptomatic carriers are present

If a proper gold standard is not available, then the predictive value of a test cannot be estimated. In this paper the concept of etiologic predictive value (EPV) is introduced. It is a quantity that will yield the predictive value of a test to predict presence of a specified disease in situations for which no proper gold standard is available. This is achieved by using information obtained from a healthy control population. This quantity requires that the marker in our test is present in all individuals having the specified disease, as in the case where the marker is the aetiologic factor for the specified disease. Furthermore this quantity requires that asymptomatic carriers are present. This means that not all individuals with the marker has the specified disease. EPV is developed with special reference to the evaluation of bacterial cultures, or rapid tests to detect a bacterium, but the quantity might be used in other circumstances as well. EPV is applied to an example in which conventional throat culture is evaluated. Further information concerning EPV can be found at http://www.infovice.se/fou/epv.

Short-course therapy with cefaclor for treatment of streptococcal pharyngotonsillitis

Short-course treatments for streptococcal pharyngotonsillitis with oral cephalosporins or macrolides have resulted in a similar bacteriological and clinical cure rate and better compliance compared with the conventional 10-day course. One hundred and thirty eight of 420 recruited patients had a positive culture for Streptococcus pyogenes and were randomly assigned to receive cefaclor (25 mg/kg/bid) for a 5-day (70 patients) or 10-day (68 patients) course. Patients were assessed clinically and bacteriologically 2-3 days after completing the course and followed up after 20-30 days. All 420 recruited patients belonged to a population of 2800 children who had been previously screened for a streptococcal carrier state to exclude carriers from final evaluation. Clinical cure and bacterial eradication was recorded in 92.8 and 92.6% of patients in groups A and B, respectively. Therefore, short-course therapy with cefaclor may offer an effective alternative treatment to conventional regimens, with potential for better compliance.

Etiology and Management of Acute and Recurrent Group A Streptococcal Tonsillitis

Tonsillitis is one of the most prevalent infections in children and adolescents. The etiologic agents might be viral or bacterial. About 30% of cases are reported to be of bacterial origin, mainly due to group A Streptococcus (GAS). Although in most instances GAS tonsillitis is a self-limited disease, antibiotic treatment is recommended, mainly to prevent the suppurative and nonsuppurative poststreptococcal sequelae of acute rheumatic fever and to prevent glomerulonephritis. In this paper we review the current knowledge of the etiology of acute and recurrent GAS tonsillitis, with special emphasis on a recent hypothesis regarding the etiology of bacterial eradication failure. While penicillin V remains the drug of choice for acute tonsillitis, other antibiotics are being approved and recommended for particular indications in both Europe and the United States.

Why do we fail with penicillin in the treatment of group A streptococcus infections?

Acute pharyngotonsillitis caused by beta-haemolytic group A streptococcus (GAS) is a common childhood disease. Phenoxymethyl penicillin remains the drug of choice, as no resistance has been reported so far. Nevertheless, the failure of penicillin to eradicate streptococci from the throat occurs in up to 35% of patients with pharyngotonsillitis, and might present clinical concern. Various explanations have been proposed over the years to account for this perplexing phenomenon. Among these are coexistence of oropharyngeal beta-lactamase-producing bacteria that degrade penicillin, growth interference by aerobic and anaerobic commensals, penicillin tolerance, reinfection, and poor antibiotic compliance. Although GAS has been considered an extracellular pathogen, recent studies have demonstrated that strains of this bacterium can internalize epithelial cells both in vitro and in vivo. The intracellular niche may protect the bacterium from penicillin that does not gain high intracellular concentration. In support of this hypothesis, GAS strains were shown to survive 4-7 days inside cultured epithelial cells. In addition, it was found that GAS strains isolated from patients with eradication failure harbour the internalization-associated gene, prtF1/sfbI, in higher prevalence than do strains recovered from patients with successful eradication. Thus, internalization and intracellular survival represent a novel explanation for penicillin eradication failure.

The prevalence of beta-haemolytic streptococci in throat specimens from healthy children and adults. Implications for the clinical value of throat cultures

OBJECTIVE

To examine the influence of age and season of the year on the carrier rate of beta-haemolytic streptococci (BHS) in healthy individuals and patients with throat pain.

DESIGN

The prevalence of BHS in throat specimens from healthy individuals was compared with that from patients with throat pain of the same age in a defined geographical area, collected during the same mid-winter and late summer periods.

RESULTS

The prevalence of BHS in healthy individuals was low before the age of 3 years (1.9-7.1%) and in adults > or = 16 years (2.4-3.7%) and highest in the age group 3-15 years (5.0-21.2%). The difference in prevalence of BHS between healthy individuals and patients with throat pain was small during the late summer season and large during the mid-winter season.

CONCLUSION

Prevalence of BHS varies with age and season in healthy individuals and patients with throat pain. During the summer, it is much more difficult to interpret the result of a throat culture in individuals aged < 16 years.