Sore throat: Is it such a big deal anymore?

The feasibility of measuring calprotectin from a throat swab as a marker of infections caused by group A streptococcus: a case-control feasibility study

Background

Most people with sore throat do not benefit from antibiotic treatment, but nearly three-quarters of those presenting in primary care are prescribed antibiotics. A test that is predictive of bacterial infection could help guide antibiotic prescribing. Calprotectin is a biomarker of neutrophilic inflammation, and may be a useful marker of bacterial throat infections.

Aim

To assess the feasibility of measuring calprotectin from throat swabs, and assess whether individuals with sore throats likely to be caused by streptococcal infections have apparently higher throat calprotectin levels than other individuals with sore throat and healthy volunteers.

Design & setting

A proof of concept case–control study was undertaken, which compared primary care patients with sore throats and healthy volunteers.

Method

Baseline characteristics and throat swabs were collected from 30 primary care patients with suspected streptococcal sore throat, and throat swabs were taken from 10 volunteers without sore throat. Calprotectin level determination and rapid antigen streptococcal testing were conducted on the throat swab eluents. Calprotectin levels in the following groups were compared: volunteers without a sore throat; all patients with a sore throat; patients with a sore throat testing either negative or positive for streptococcal antigen; and those with lower and higher scores on clinical prediction rules for streptococcal sore throat.

Results

Calprotectin was detected in all throat swab samples. Mean calprotectin levels were numerically higher in patients with sore throat compared with healthy volunteers, and sore throat patients who had group A streptococci antigen detected compared with those who did not.

Conclusion

Calprotectin can be measured from throat swab samples and levels are consistent with the hypothesis that streptococcal infection leads to higher throat calprotectin levels. This hypothesis will be tested in a larger study.

Primary prevention of rheumatic fever in the 21st century: evaluation of a national programme

Background

Acute rheumatic fever (ARF) has largely disappeared from high-income countries. However, in New Zealand (NZ) rates remain high in indigenous (Māori) and Pacific populations. In 2011, NZ launched an intensive and unparalleled primary Rheumatic Fever Prevention Programme (RFPP). We evaluated the impact of the school-based sore throat service component of the RFPP.

Methods

The evaluation used national trends of all-age first episode ARF hospitalisation rates before (2009-11) and after (2012-16) implementation of the RFPP. A retrospective cohort study compared first-episode ARF incidence during time-not-exposed (23 093 207 person-days) and time-exposed (68 465 350 person-days) with a school-based sore throat service among children aged 5-12 years from 2012 to 2016.

Results

Following implementation of the RFPP, the national ARF incidence rate declined by 28% from 4.0 per 100 000 [95% confidence interval (CI) 3.5-4.6] at baseline (2009-11) to 2.9 per 100 000 by 2016 (95% CI 2.4-3.4, P <0.01). The school-based sore throat service effectiveness overall was 23% [95% CI -6%-44%; rate ratio (RR) 0.77, 95% CI 0.56-1.06]. Effectiveness was greater in one high-risk region with high coverage (46%, 95% CI 16%-66%; RR 0.54, 95% CI 0.34-0.84).

Conclusions

Population-based primary prevention of ARF through sore throat management may be effective in well-resourced settings like NZ where high-risk populations are geographically concentrated. Where high-risk populations are dispersed, a school-based primary prevention approach appears ineffective and is expensive.

Corticosteroids for treatment of sore throat: systematic review and meta-analysis of randomised trials

Objective To estimate the benefits and harms of using corticosteroids as an adjunct treatment for sore throat.Design Systematic review and meta-analysis of randomised control trials.Data sources Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), trial registries up to May 2017, reference lists of eligible trials, related reviews.Study selection Randomised controlled trials of the addition of corticosteroids to standard clinical care for patients aged 5 or older in emergency department and primary care settings with clinical signs of acute tonsillitis, pharyngitis, or the clinical syndrome of sore throat. Trials were included irrespective of language or publication status.Review methods Reviewers identified studies, extracted data, and assessed the quality of the evidence, independently and in duplicate. A parallel guideline committee (BMJ Rapid Recommendation) provided input on the design and interpretation of the systematic review, including the selection of outcomes important to patients. Random effects model was used for meta-analyses. Quality of evidence was assessed with the GRADE approach.Results 10 eligible trials enrolled 1426 individuals. Patients who received single low dose corticosteroids (the most common intervention was oral dexamethasone with a maximum dose of 10 mg) were twice as likely to experience pain relief after 24 hours (relative risk 2.2, 95% confidence interval 1.2 to 4.3; risk difference 12.4%; moderate quality evidence) and 1.5 times more likely to have no pain at 48 hours (1.5, 1.3 to 1.8; risk difference 18.3%; high quality). The mean time to onset of pain relief in patients treated with corticosteroids was 4.8 hours earlier (95% confidence interval -1.9 to -7.8; moderate quality) and the mean time to complete resolution of pain was 11.1 hours earlier (-0.4 to -21.8; low quality) than in those treated with placebo. The absolute pain reduction at 24 hours (visual analogue scale 0-10) was greater in patients treated with corticosteroids (mean difference 1.3, 95% confidence interval 0.7 to 1.9; moderate quality). Nine of the 10 trials sought information regarding adverse events. Six studies reported no adverse effects, and three studies reported few adverse events, which were mostly complications related to disease, with a similar incidence in both groups.Conclusion Single low dose corticosteroids can provide pain relief in patients with sore throat, with no increase in serious adverse effects. Included trials did not assess the potential risks of larger cumulative doses in patients with recurrent episodes of acute sore throat.Systematic review registration PROSPERO CRD42017067808.

Aetiology of febrile pharyngitis in children: Potential of myxovirus resistance protein A (MxA) as a biomarker of viral infection

Objectives

Besides group A streptococcus (GAS), microbial causes of pharyngitis in children are not well known. We aimed to document the viral and bacterial aetiology of pharyngitis and to assess the pathogenic role of viruses by determining the myxovirus resistance protein A (MxA) in the blood as a marker of interferon response.

Methods

In this prospective observational study, throat swabs and blood samples were collected from children (age 1–16 years) presenting to the emergency department with febrile pharyngitis. Microbial cause was sought by bacterial culture, polymerase chain reaction, and serology. Blood MxA level was determined.

Results

A potential pathogen was detected in 88% of 83 patients: GAS alone in 10%, GAS and viruses in 13%, group C or G streptococci alone in 2% and together with viruses in 3%, and viruses alone in 59% of cases. Enteroviruses, rhinoviruses, and adenoviruses were the most frequently detected viruses. Blood MxA levels were higher in children with viral (880 [245–1250] μg/L; median [IQR]) or concomitant GAS-viral (340 [150–710] μg/L) than in those with sole GAS (105 [80–160] μg/L) infections.

Conclusions

Detection of respiratory viruses simultaneously with elevated blood MxA levels supports the causative role of viruses in the majority of children with pharyngitis.

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We evaluated the microbiological aetiology of febrile pharyngitis in 83 children.

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A potential pathogen could be detected in 88% and virus in 76% of patients.

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Blood myxovirus resistance protein A (MxA) levels were elevated in most of the patients with virus finding.

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MxA is a promising biomarker of virus infection.

Appropriateness of diagnosis of streptococcal pharyngitis among Thai community pharmacists according to the Centor criteria

Background Inappropriate use of antibiotic treatment for pharyngitis by community pharmacists is prevalent in developing countries. Little is known about how the pharmacists identify patients with bacterial pharyngitis. Objective To ascertain the appropriateness of diagnosis of streptococcal pharyngitis among Thai community pharmacists according to the Centor criteria and to identify factors related to antibiotic dispensing. Setting 1040 Thai community pharmacists. Method A cross-sectional survey of community pharmacists was conducted in November 2012 to March 2013. The self-administered questionnaires were mailed to 57 % of community pharmacists in the south of Thailand (n = 1040). The survey included questions on diagnosis of streptococcal pharyngitis, knowledge on pharyngitis, and attitudes and control beliefs regarding antibiotic dispensing. Main outcome measure The appropriateness of diagnosis of streptococcal pharyngitis according to the original and modified Centor criteria and determinants of antibiotic dispensing including demographic characteristics of pharmacists, knowledge on pharyngitis, and attitudes and control beliefs on antibiotic dispensing. Results Approximately 68 % completed the questionnaires (n = 703). Compared to the pharmacists who reported not dispensing antibiotics in the hypothetical case with common cold, those reported dispensing antibiotics were more likely to consider the following conditions-presence of cough, mild sore throat and patients with age >60 years as cues for diagnosis of streptococcal pharyngitis (p < 0.05). The use of fewer scores of the clinical prediction rules for diagnosis was observed in antibiotic dispensers, compared to who did not do so (p < 0.005). Antibiotic dispensing was positively associated with period of dispensing experience (>5 years) [odds ratio (OR) 1.52; 95 % confidence interval (CI) 1.03-2.23], belief that antibiotics could shorten duration of pharyngitis (OR 1.48; 95 % CI 1.11-1.99), belief that antibiotics could prevent the complications (OR 1.44; 95 % CI 1.09-1.91) and belief that dispensing antibiotics could satisfy the patients (OR 1.31; 95 % CI 1.01-1.71). Nonetheless, antibiotic dispensing was negatively associated with knowledge about pharyngitis (OR 0.83; 95 % CI 0.75-0.93). Conclusion Pharmacists who are knowledgeable on the Centor criteria are more likely to appropriately diagnose streptococcal pharyngitis and less likely to dispense antibiotics in such case.