Fig. 4

Estimated transmission routes for the 16 outbreak patients using the modified time-place-sequence (TPS) algorithm. Arrow colours reflect the estimated transmission probability between two patients. Criteria 1–4 are described briefly as: criterion 1, same ward, same time; criterion 2, same room consecutively within 14 days; criterion 3, same room, same time; and criterion 4, close genetic relatedness. Each patient is outlined as a circle. Figure 4(a) shows the probability of transmission based on the three epidemiological criteria alone: criterion 1 (black arrows), criterion 3 (green arrow), no patients fulfilled criterion 2. The colour of the circle indicates the patient’s location at the date of first VREfm isolation. White stands for ward 2 (ICU), yellow stands for ward 3 (Intermediate Care Unit), blue stands for general ward 4, red stands for general ward 5, black stands for general ward 6, green stands for general ward 7, grey stands for general ward 8, and purple stands for the Emergency Room (ER). In the case of 4 patients (P2, P4, P11, P16), their location at the date of first VREfm isolation varied within the same day. Similarly, for patients P14 and P15, they had not completed 24 h of stay in a ward when the fist isolation was detected; all of them are thus represented with 2 colours. Figure 4(b) shows the probability of transmission based on the three epidemiological criteria in combination with the genetic relatedness criterion (pink arrows). The colour of the circle indicates an isolate’s clonal profile. Purple is clonal profile “A”, pink profile “B”, yellow “C” and Green “D”