Table 2.
Overview of MRSA transmissions and incidental findings among screened contacts, sorted by setting and hospital
| Type of contact | No. contacts | No. likely transmissions | No. incidental findings | NNS | Transmission rate (%) | CI 95% |
|---|---|---|---|---|---|---|
| All contacts* | 27,377 | 41 | 72 | 667 | 0.15% | 0.11–0.20% |
| HCW Clinic total | 15,874 | 19 | 22 | 835 | 0.12% | 0.07–0.2% |
| HCW Clinic LUMC | 5648 | 8 | 8 | 706 | 0.14% | |
| HCW Clinic Haga | 6935 | 10 | 14 | 694 | 0.14% | |
| HCW Clinic RdGG | 3291 | 1 | 3 | 3291 | 0.03% | |
| HCW Outpatient total | 2834 | 0 | 4 | – | >0.001–0.09% | |
| HCW Outpatient LUMC | 712 | 0 | 0 | – | ||
| HCW Outpatient Haga | 1751 | 0 | 4 | – | ||
| HCW Outpatient RdGG | 371 | 0 | 0 | – | ||
| Patient total | 4816 | 22 | 37 | 219 | 0.46% | 0.29–0.68% |
| Patient LUMC | 454 | 6 | 0 | 76 | 1.32% | |
| Patient Haga | 4054 | 13 | 37 | 312 | 0.32% | |
| Patient RdGG | 308 | 3 | 0 | 103 | 0.97% | |
| HCW unspecified | 2780 | 0 | 8 | |||
| Non-specified | 1073 | 0 | 1 |
* ‘All contacts’ include 2780 HCW with unknown setting and 1073 contacts of unknown type.
For the 2780 HCW of unknown type, it was unclear if the contact occurred in an outpatient or ward setting. Similarly, no information was recorded for the unknown type contacts regarding the setting or whether they involved patients or HCW.
HCW Clinic: inpatient setting on the ward, HCW Outpatient: outpatient setting, Patient: patient-to-patient contacts, Number of Transmissions/Incidental Findings: This number is based on a comparison between the typing results of the detected MRSA isolates from the index cases and from their contacts. All matching isolates are considered likely transmissions, while the remaining cases are classified as incidental findings.
NNS: Number of contacts needed to screen to detect one transmission.
“–“indicates not applicable.
CI 95%: The accuracy of the proportions of transmission to contacts as calculated by means of Jeffrey’s method