Re: Role of Non-Group A Streptococci in Acute Pharyngitis
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* Robert M. Centor

*To the Editor:* Jeffrey Tiemstra and Rosita L. F. Miranda1 have added important data concerning the diagnosis and management of acute pharyngitis. Like previous investigators, they found that a significant percentage of adolescents and young adults presenting with acute pharyngitis grow streptococci from a group other than group A strep, which is the classic concern.

Most other articles on this subject have focused on group C and group G streptococci. I doubt that clinical presentation of group B resembles the clinical presentation of group C. In unpublished data, we did not find group B patients having such a presentation. Zwart also found that only A, C, and G caused pharyngitis.2 Therefore, I would suggest that the authors look carefully at the distribution of clinical indicators in group B compared with group A and group C.

The Tiemstra article also shows that in practice (rather than in prospective studies) the sensitivity of the group A strep rapid test was only 75%. One can postulate several reasons for a difference in rapid test sensitivity from prospective studies. Just to suggest 2 possibilities: (1) sampling errors might occur more often in practice or (2) there may be publication bias for higher sensitivity studies.3

Like Zwart's classic 2000 BMJ study on treatment, the authors find a high probability of either group A or non-group A strep in patients having high pharyngitis scores.3 That article supports a clinical improvement from antibiotics for group C strep pharyngitis. In that article adults (ages 15–60) experienced a 2-day symptom improvement if they had group A pharyngitis and a 1-day symptom improvement if they had group C pharyngitis.

The addition of headache to the pharyngitis scores, although understandable, makes comparison of this study to previous studies more difficult.

A note of caution: these findings probably apply to the adolescent/young adult age group and not pre-adolescents. Previous studies have shown that non-group A infections occur commonly in college health populations but not pre-adolescents.

Congratulations for continuing the documentation that adolescent and adult pharyngitis is more complex than deciding whether the patient has group A strep.

## Notes

*   The above letter was referred to the author of the article in question, who offers the following reply.

## References

1.  Tiemstra J, Miranda RLF. Role of non-group A streptococci in acute pharyngitis. J Am Board Fam Med 2009; 22: 663–9.
    
    [Abstract/FREE Full Text](http://www.jabfm.org/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NToiamFiZnAiO3M6NToicmVzaWQiO3M6ODoiMjIvNi82NjMiO3M6NDoiYXRvbSI7czoyMjoiL2phYmZwLzIzLzMvNDIzLjEuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  Zwart S, Ruijs GJ, Sachs AP, van Leeuwen WJ, Gubbels JW, de Melker RA. Beta-haemolytic streptococci isolated from acute sore-throat patients: cause or coincidence? A case-control study in general practice. Scand J Infect Dis 2000; 32: 377–84.
    
    [CrossRef](http://www.jabfm.org/lookup/external-ref?access_num=10.1080/003655400750044944&link_type=DOI) 
    
    [PubMed](http://www.jabfm.org/lookup/external-ref?access_num=10959645&link_type=MED&atom=%2Fjabfp%2F23%2F3%2F423.1.atom) 
    
    [Web of Science](http://www.jabfm.org/lookup/external-ref?access_num=000088690200005&link_type=ISI) 

3.  Zwart S, Sachs AP, Ruijs GJ, Gubbels JW, Hoes AW, de Melker RA. Penicillin for acute sore throat: randomised double blind trial of seven days versus three days treatment or placebo in adults. BMJ 2000; 320: 150–4.
    
    [Abstract/FREE Full Text](http://www.jabfm.org/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6MzoiYm1qIjtzOjU6InJlc2lkIjtzOjEyOiIzMjAvNzIyOC8xNTAiO3M6NDoiYXRvbSI7czoyMjoiL2phYmZwLzIzLzMvNDIzLjEuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9)