LAUSR

Acute pyelonephritis is one of the most common serious bacterial infections, especially in young otherwise healthy women, followed by infants and older persons [1, 2]. Because of the frequency and potential seriousness of these infections, adequate knowledge and skills are required for optimal management and treatment. The adequacy of the therapeutic strategy is one of the critical aspects during the crisis of antibiotic resistance. For this reason, the Italian Society of Internal Medicine (SIMI) decided to adhere to the Choosing Wisely Campaign [3], a Campaign with the purpose to promote a patient-oriented, evidence-based and economical and biological sustainable medicine, of which one of the five items proposed was the reduction of the prescription of long term intravenous antibiotics if not indicated [4]. The treatment of pyelonephritis should be initiated without delay, considering the effectiveness, risk of adverse effects, and resistance rates in the local community, according to International Clinical Practice Guidelines [5, 6]. Most of the guidelines that deals with pyelonephritis [5–8] recommends 5–7 days of treatment with a fluoroquinolone (where the prevalence of resistance of community uropathogens is not known to exceed 10%), 7–10 days of treatment with a 3rd generation oral cephalosporin, 10–14 days of treatment with trimethoprim-sulphamethoxazol and 10–14 days of treatment with penicillin for mild or moderate (and in two instances [7, 8] also for severe) uncomplicated pyelonephritis. Nevertheless, guidelines’ recommendations are not supported by high-quality evidence and there is at present no scientific consensus on the efficacy of short-course antibiotic treatment compared with long course treatment. In this issue of "Internal and Emergency Medicine" Erba et al. [9] searched for all guidelines on pyelonephritis and systematic reviews assessing the optimal duration of antibiotic therapy in this type of infection and compared the recommendations of the three most cited and recent guidelines on the topic of interest [6–8]. In this systematic review of secondary studies, data of non-duplicated RCTs enrolled in four systematic reviews comparing treatments of different duration were investigated [10–13]. Considering clinical failure (defined as a lack of resolution of fever or signs and symptoms of UTI at the end of therapy) and microbiological failure (positive urine culture at the end of therapy) as main outcomes, the Authors assessed optimal length of antibiotic treatment to be ≤ 7 days in most cases of pyelonephritis. In the meta-analysis were included both in-patients and out-patients, mostly females (80%), with a pyelonephritis of different severity and etiology, treated with different antibiotic regimens. They conclude that short-course antibiotic treatment is at least as effective as longer courses for both microbiological and clinical success in the treatment of acute uncomplicated pyelonephritis. Duration of antibiotic therapy in pyelonephritis is not a simple matter, because of many factors that play a significant role in patient’s outcome. The type and length of therapy should be decided based on an individual case approach, depending on age, presence of comorbid conditions, such as diabetes mellitus and recurrent urinary tract infections, the severity of infection and culture susceptibility results. The historical approach to pyelonephritis has been hospitalization and treatment with intravenous antimicrobials for up to 6 week. More recent studies suggest that most young healthy women with acute pyelonephritis could have a satisfactory outcome with antimicrobial therapy lasting 2 weeks [14, 15] or even 5–7 days [16, 17]. The potential severity of infections, the need for hospitalization, and the possibility of recurrence have prompted physicians to longer treatment than recommended by Guidelines, as confirmed by several observational studies [18–20]. As a matter of fact, the prevalence of antibiotic resistance among community-acquired bacteria (in particular Escherichia coli) that produce extended-spectrum beta-lactamases is increased [21–24] and one of the most * Francesca Viazzi [email protected]