Abstract

In this issue, Witte and colleagues report on the emergence, since 2002, of cases in Germany of infection with community-acquired methicillin-resistant Staphylococcus aureus (c-MRSA) producing the Panton-Valentine leukocidin. This report adds evidence to the rapid geographical dissemination of this emerging, hyper-virulent variant of an 'old pathogen' across Europe. First reported in the early 1990s among aboriginal populations in Western Australia, outbreaks of c-MRSA infections have more recently been described in population groups such as prison inmates, injecting drug users, sports teams and schoolchildren, in the United States and Europe. Current evidence from molecular studies points to the spread in each continent of a limited number of PVL-producing MRSA clones that are genetically distinct from epidemic nosocomial strains. This represents a public health threat, because these strains are associated with severe soft tissue and pulmonary infection and the outcome of MRSA infection is worse than with infection caused by beta-lactam susceptible S. aureus, especially if inappropriately treated with beta-lactams that are usually prescribed for these infections. We must, therefore, upgrade the diagnostic work-up for this kind of infection in the outpatient setting and adapt empirical therapy accordingly. Moreover, surveillance should be intensified to monitor the incidence of MRSA and detect and control outbreaks in the community. In this respect, the report by Witte et al underscores the important early warning role that reference laboratories can play by using high resolution molecular markers based on routine typing and susceptibility data.