Antimicrobial resistance (AMR) is recognized as one of the major threats to global health
[1], causing up to 25.000 deaths in the European Union every year, longer
hospitalizations and increased healthcare costs. It is well known that antimicrobial use
is the main driving force towards AMR and up to 50% of antimicrobial prescriptions are
either inappropriate or unnecessary [2]. It is then important to understand how to
optimize antimicrobial usage not only in adults but also in infants, as they show
different resistance patterns and have peculiar characteristics that may lead to
incorrect administration and alteration of the pharmacokinetic and pharmacodynamic
properties of the drug [3]. Antimicrobials are the most prescribed drugs in children
[4][5] and this excessive usage has been recorded not only in developed countries, but
also in low-income and middle-income ones [6]. In Europe, Italy reported one of the
highest prescriptions rates, four times higher than the UK and six times higher than the
Netherlands [7][8]. 84% of Italian infants in the community have already received at
least one course of antibiotics at 2 years of age [9]. A point-prevalence survey (PPS)
showed that 38.9% of hospitalized Italian infants received at least one antibiotic
prescription both for treatment and prophylaxis; in children, the most commonly used
antibiotic classes were third generation cephalosporins and penicillins plus enzyme
inhibitors, with a high prescription rates of carbapenems and quinolones as well, often
off-label [10]. In order to limit misuse and overuse of antibiotics in children, the
joint SHEA-IDSA-PIDS position paper states the importance of introducing antimicrobial
stewardship programs (ASPs) in all healthcare institutions [11].
Antimicrobial stewardship has been defined as "the optimal selection, dosage, and
duration of antimicrobial therapy that results in the best clinical outcome for the
treatment or prevention of infection, with minimal toxicity to the patient and minimal
impact on subsequent resistance" [12]. So far, little progress has been made with
developing pediatric ASPs, especially outside the United States healthcare system.
One of the most important studies conducted in Europe in this field, the ARPEC project,
was designed as a PPS: this type of strategy is very useful if repeated regularly, as it
allows to monitor prescription trends over time and to identify the problem of
inappropriate antibiotic usage [13]. However, it has been shown that PPSs are not
sufficient by themselves to change the clinical practice if not combined with other
methods [14], such as pre-prescription authorization, prospective audit and feedback,
educational and training programmes or technological means of support. In USA,
methicillin-resistant Staphylococcus aureus (MRSA) in children mainly causes skin and
soft tissue infections but invasive diseases were increasingly reported in 1995-2010
[15]. Studies on MRSA carriage in healthy children showed great geographic variation
(from less than 1% in Belgium to 15% in Taiwan) that depend on many local differences
[16]. Nevertheless, very few studies have been performed on the influence of antibiotic
prescription in the acquisition of resistant microorganism such MRSA in pediatric
population.
The aim of this study is to estimate the incidence of MRSA nasal colonization and
invasive disease and to investigate the impact of antibiotic treatment during
hospitalization on the acquisition of MRSA nasal colonization in children.