Type: Invited Presentation| Volume 21, SUPPLEMENT 1, 40, April 2014

Implication of current resistance trends on community-acquired respiratory tract infection (CA-RTI) management

      As the prevalence of antibiotic-resistant Streptococcus pneumoniae, including multidrug-resistant strains is variable world-wide1, first-line therapy with beta-lactams, macrolides, and increasingly quinolones, in some regions has become limited in the treatment of respiratory tract infections (RTIs). Therefore, one of the important principles for appropriate antibiotic prescribing and effective outcomes in this clinical setting is to recognise local resistance prevalence.2 The aim of surveillance is both to guide empirical antibiotic use and to improve the quality of empirical antimicrobial treatment in the community (as well as the hospital setting).3 In addition, introduction of pneumococcal vaccines may alter the predominant serotypes with potentially unique antimicrobial susceptibility patterns.
      There have been a number of international surveillance systems established including the ALEXANDER PROJECT, PROTEKT, LIBRA, SENTRY, ANSORP4 and SIREVA.5 Survey Of Antibiotic Resistance (SOAR)6 is the latest of the international surveillance studies that offer standardised, internationally recognised methods that provide quantitative data (minimum inhibitory concentrations [MIC]) that may show slight shifts in resistance - as seen in published SOAR data.6 These ‘shifts’ in antibiotic MICs can be overcome by extending the time above MIC (T > MIC) for which amoxicillin, for example, is present in serum.7
      In addition to MIC shifts, an increase in the prevalence of Haemophilus influenzae has been observed in upper RTIs subsequent to wide-scale use of pneumococcal conjugate vaccines in children.8 This phenomenon, as well as an increase in beta-lactamase production amongst H.influenzae in certain parts of the world, has necessitated the first line empirical use of amoxiciilin-clavulanate as opposed to amoxicillin alone.9 Continuous surveillance through standardised systems is therefore crucial to guide clinicians in rational antibiotic prescribing for community acquired RTIs.