Incidence of Severe Streptococcal-Related Diseases in Italian Children in an Era of High Group A Streptococcal Resistance to Macrolides

Macrolides are still widely prescribed for adult and pediatric respiratory infections in Italy despite the fact that it is known that the resistance of group A streptococci has dramatically increased since 1994, The aim of this study was to evaluate the incidence of severe streptococcal-related diseases from 1990 to 1996 on the basis of data derived from computer-generated lists of children hospitalized in 35 Pediatric Departments. The clinical record of each case was reviewed in order to gather data concerning clinical diagnoses, laboratory investigations and antibiotic therapies in the preceding four weeks, Six hundred and twenty of the total of 321,612 hospitalized children had severe streptococcal diseases; the overall annual rate remained stable at 2.13/1000 admissions in 1990 to 1.7/1000 admissions in 1996, Severe diseases were preceded by a microbiologically confirmed acute streptococcal infection treated with antibiotics in only 392 of the 620 children (63.2%), Between 1993 and 1996 (with the exception of 1995), macrolides were more frequently prescribed than beta-lactam antibiotics for acute streptococcal infections that subsequently developed into severe disease. There was no difference in the rate of severe streptococcal complications between the patients adequately treated with antibiotics and those who were inadequately or not treated. Possible explanations for the relatively stable rate of severe streptococcal complications in Italian children could be (1) a relative absence of invasive, rheumatogenic or nephritogenic strains and/or (2) a difference between in vitro and in vivo resistance of group A streptococci to macrolides. Further studies are needed to investigate the biological characteristics of resistant group A streptococcal strains and their relationships to short- and long-term clinical outcomes.