Drug-resistant bacteria may hide out in homes for many years before causing disease.
In the 1990s, methicillin-resistant Staphylococcus aureus (MRSA) moved out of hospitals in North America and started circulating in the community, causing skin and other infections. A team led by Michael David at the University of Chicago in Illinois and Timothy Read at Emory University in Atlanta, Georgia, sequenced the genomes of MRSA taken from 146 patients and members of their households. An evolutionary analysis that compared the sequence of a patient's strain with the one from their home determined that MRSA had been present in the household for between 2.3 and 8.3 years before being sampled.
Eradicating MRSA from homes, such as by treating asymptomatic household members, could help to bring the current epidemic under control, the authors say.