After carefully reading the work of Salinas-Salvador et al., Estudio retrospectivo sobre la efectividad y seguridad de la pauta antibiótica reducida a 5–7 días en la faringoamigdalitis aguda estreptocócica comparada con la pauta clásica de 10 días,1 on a study of 2 paediatric caseloads in a primary care centre of Zaragoza conducted between June 2016 and April 2020, we consider that it is in line with the current trend of recommending a reduced course of antibiotherapy for the management of pharyngitis caused by group A beta-haemolytic streptococci (GAS).

Recently, we reviewed the history of the decline of acute rheumatic fever (ARF) in environments with an adequate public health system.2 In the 20th century, in so-called developed countries, the incidence of ARF decreased significantly until it all but disappeared. But ARF continues to be an important health problem in low-income countries and also in disadvantaged areas in middle- and high-income countries. Since we do not know the exact reasons for the historical decline of ARF, we cannot fully anticipate the potential results of a generalised reduction in the duration of antibiotherapy. In any case, this approach would not be appropriate in populations in which the risk of ARF and rheumatic heart disease continue to be high.

A 5- to 7-day course for treatment of streptococcal pharyngitis can generally prevent suppurative complications,1 but it does not eradicate the bacterium. This has to be taken into account in at-risk groups or when GAS needs to be eradicated. It is important to remain vigilant for outbreaks of disease.

At present, in the autumn of 2022, we are observing what may be an increase in the number of streptococcal infections in the United Kingdom3 and other countries, including cases of scarlet fever and infection by invasive strains. Reports of invasive disease chiefly correspond to individuals aged more than 75 years (2.4 cases per 100 000), children aged 1–4 years (2.3), infants under 1 year (1.3) and children aged 5–9 years (1.1). This could reflect an increase in respiratory viruses (especially influenza viruses and respiratory syncytial virus); there may be other causes.

This phenomenon was seen in previous decades. In fact, González-Abad and Alonso4 reported an increase in cases in Spain between 2011 and 2018: 29 cases of invasive Streptococcus pyogenes (in blood, pleural fluid and other sites) were documented. Between 2011 and 2013, a single strain was documented per year, but from 2014 to 2018, 2, 5, 4, 6 and 9 strains were identified each successive year.

While acknowledging the value of the work of Salinas-Salvador et al.,1 we would like to underscore the ever-shifting nature of the epidemiology of viral and bacterial infections and the need to keep a close watch of their incidence and severity. Viral infections are associated with a risk of bacterial complications.

Epidemic outbreaks must be notified to the health care authorities. It is worth noting that ARF was a reportable disease in Spain from 1951 to 1996 (BOE no. 21, 24 January 1996, p. 2153). Although some autonomous communities maintained it as a reportable disease for a few more years, it was only until 2006 (Appendix I of Order SAN/2128/2006, of 27 December, regulating the reportable disease system of Castilla-Leon).