Empirical treatment of influenza-associated pneumonia in primary care: a descriptive study of the antimicrobial susceptibility of lower respiratory tract bacteria (England, Wales and Northern Ireland, January 2007-March 2010).

OBJECTIVES: To determine the susceptibility of lower respiratory tract (LRT) isolates of Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae to antimicrobial agents recommended by UK guidelines for treatment of pneumonia associated with influenza-like illness. METHODS: Analysis of antimicrobial susceptibility data from sentinel microbiology laboratories in England, Wales and Northern Ireland was carried out. Subjects comprised patients who had an LRT specimen taken in a general practitioner surgery or hospital outpatient setting between January 2007 and March 2010. The main outcome measurements were antimicrobial susceptibility trends of LRT isolates over time, between patient age groups and in different geographical regions. RESULTS: Susceptibility to tetracyclines or co-amoxiclav was high. Of the 70,288 and 45,288 isolates with susceptibility results for tetracyclines or co-amoxiclav, 96% and 92%, respectively, were susceptible. Overall susceptibility to ciprofloxacin, ampicillin/amoxicillin and macrolides was lower than for tetracyclines or co-amoxiclav and varied markedly by organism. There were few clinically relevant variations in susceptibility to doxycycline or co-amoxiclav over time, geographically or between age groups. CONCLUSIONS: The data support the use of doxycycline or co-amoxiclav as appropriate empiric treatment for LRT infection caused by the pathogens investigated, for patients in primary care.