Correspondence: Antibiotic guidelines for managing sore throat

We invited Associate Professor Mark Thomas, Infectious Diseases Physician, to comment on this correspondence:

Dr Deacon expresses concern about current approaches to the treatment of sore throat for the prevention of rheumatic fever, and in particular may be concerned about the clinical practice of colleagues influenced by the recently updated New Zealand Heart Foundation guidelines for management of sore throat, available at: www.heartfoundation.org.nz

These guidelines do include some surprising recommendations that are likely to significantly increase antimicrobial prescribing for patients with a sore throat, and for asymptomatic carriers of Streptococcus pyogenes. Increased antimicrobial prescribing arising from these guidelines will inevitably contribute to increased antimicrobial resistance, and thus have unintended negative effects on the health of our community. In my opinion, there are a number of very contentious recommendations in the guidelines.

The guidelines recommend that people at high risk of rheumatic fever (Māori and Pacific peoples aged 3–35 years) who present with a sore throat, should not be clinically assessed to attempt to determine whether they are presenting either with an illness suggestive of streptococcal pharyngitis or with an illness suggestive of a viral upper respiratory infection. The effect is that a person who presents with a sore throat, plus rhinorrhoea, a hoarse voice, cough, no tonsillar erythema, no cervical lymphadenopathy, and no fever, will be treated in the same way as a person who presents with a sore throat, tonsillar erythema, cervical lymphadenopathy and fever. This will inevitably result in antimicrobial treatment of some people who, regardless of their throat swab results, are at very low risk of having streptococcal pharyngitis. This recommendation is not supported by high-level evidence and is not consistent with other international guidelines.

The New Zealand Heart Foundation guidelines recommend that “it might not be appropriate to collect a throat swab” in patients with a sore throat who “are not contactable by telephone, are not likely or able to return for a prescription if S.pyogenes is isolated, or who present at emergency departments or clinics where processes do not support follow-up”. This recommendation is not supported by high-level evidence and is not consistent with other international guidelines, and is completely inconsistent with the stated aim of the guideline: “to maximise diagnosis and management of pharyngitis in those who are at greatest risk of developing rheumatic fever”. When combined with the recommendation not to clinically assess patients at high risk of rheumatic fever for features suggestive of streptococcal pharyngitis, it will increase the proportion of people with a sore throat, who are treated with an antibiotic without having either clinical or microbiological evidence of streptococcal pharyngitis.

The guidelines recommend that a number of asymptomatic population groups should be swabbed and treated if found to be carriers of S. pyogenes. . These groups include: household contacts of patients who have had “recurrent S. pyogenes. pharyngitis”, those “at increased risk of spreading S. pyogenes. ” such as “healthcare and residential care workers, food handlers, teachers and childcare workers”. This recommendation also is not supported by high level evidence and is not consistent with other international guidelines.

In my opinion, the updated New Zealand Heart Foundation guidelines for diagnosis and management of sore throat encourage health care workers to provide low quality care for many patients at high risk of rheumatic fever. The risks of the low quality care that is recommended include reduced diagnostic certainty, a marked increase in unnecessary antimicrobial prescribing, and a consequent increase in antimicrobial resistance. I am concerned that these, and other, adverse effects have not been adequately considered, either by health professionals, or by those communities at highest risk of rheumatic fever.