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Observational Study
. 2021 Sep 17;21(1):971.
doi: 10.1186/s12879-021-06665-9.

The aetiology of pharyngotonsillitis in primary health care: a prospective observational study

Jon Pallon  1   2   3 , Mattias Rööst  4   5 , Martin Sundqvist  6 , Katarina Hedin  4   7
Affiliations
Observational Study

The aetiology of pharyngotonsillitis in primary health care: a prospective observational study

Jon Pallon et al. BMC Infect Dis. .

Abstract

Background: Few studies on pharyngotonsillitis have examined the clinical presentation of different aetiologies where pathogens have been detected using molecular methods. We aimed to assess how well clinical signs and symptoms can predict (1) the presence or absence of a broad range of viruses and bacteria, and (2) reconsultations for a sore throat or a complication.

Methods: In this descriptive observational prospective study in primary health care 220 patients aged 15-45 with suspected pharyngotonsillitis were sampled from nose, throat and blood and screened for 20 bacteria and viruses using polymerase chain reaction (PCR), culture and serology. Odds ratios (OR) and predictive values with 95% confidence intervals (CI) were used to show association between microbiological findings and clinical signs and symptoms. Patients were followed up after 3 months by reviewing electronic medical records.

Results: Both cough and coryza were more common in patients with only viruses (67%) than in patients with only bacteria (21%) (p < 0.001), whereas tonsillar coating was more common in patients with only bacteria (53%) than in patients with only viruses (29%) (p = 0.006). Tonsillar coating (adjusted OR 6.0; 95% CI 2.5-14) and a lack of cough (adjusted OR 3.5; 95% CI 1.5-8.0) were significantly associated with Streptococcus pyogenes (group A streptococci; GAS) and with any bacterial finding. A Centor score of 3-4 had a positive predictive value of 49% (95% CI 42-57) for GAS and 66% (95% CI 57-74) for any bacterial findings. The use of rapid antigen detection test for GAS increased the positive predictive value for this group to 93%.

Conclusions: Signs and symptoms, both single and combined, were insufficient to rule in GAS or other pathogens. However, both cough and coryza were useful to rule out GAS. The results support the clinical approach of restricting rapid antigen detection testing to patients with 3-4 Centor criteria. The low carriage rate of bacteria among asymptomatic controls implied that most detections in patients represented a true infection.

Keywords: Group A streptococci; Pharyngotonsillitis; Predictive values; Primary health care; Symptoms.

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Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
ROC-curves of a rapid antigen detection test (RADT) for group A streptococci (GAS) at different Centor scores, with throat culture as reference. AUC area under the curve. Confidence intervals for the AUC values are given in Table 3
See this image and copyright information in PMC

References

    1. Tyrstrup M, Beckman A, Molstad S, Engstrom S, Lannering C, Melander E, et al. Reduction in antibiotic prescribing for respiratory tract infections in Swedish primary care- a retrospective study of electronic patient records. BMC Infect Dis. 2016;16(1):709. doi: 10.1186/s12879-016-2018-9. - DOI - PMC - PubMed
    1. Shulman ST, Bisno AL, Clegg HW, Gerber MA, Kaplan EL, Lee G, et al. Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America. Clin Infect Dis. 2012;55(10):1279–1282. doi: 10.1093/cid/cis847. - DOI - PubMed
    1. Pelucchi C, Grigoryan L, Galeone C, Esposito S, Huovinen P, Little P, et al. Guideline for the management of acute sore throat. Clin Microbiol Infect. 2012;18(Suppl 1):1–28. doi: 10.1111/j.1469-0691.2012.03766.x. - DOI - PubMed
    1. Aalbers J, O'Brien KK, Chan WS, Falk GA, Teljeur C, Dimitrov BD, et al. Predicting streptococcal pharyngitis in adults in primary care: a systematic review of the diagnostic accuracy of symptoms and signs and validation of the Centor score. BMC Med. 2011;9:67. doi: 10.1186/1741-7015-9-67. - DOI - PMC - PubMed
    1. Fine AM, Nizet V, Mandl KD. Large-scale validation of the Centor and McIsaac scores to predict group A streptococcal pharyngitis. Arch Intern Med. 2012;172(11):847–852. doi: 10.1001/archinternmed.2012.950. - DOI - PMC - PubMed

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