In outbreak investigations, PCR is used to identify the causative agent and trace the source of infection. By comparing the genetic sequences of pathogens isolated from different cases, epidemiologists can determine whether they originate from a common source. This information is crucial for implementing control measures and preventing further spread. For example, PCR played a critical role in identifying the source of the 2011 E. coli outbreak in Germany, leading to the rapid containment of the outbreak.
