Rate of nosocomial MRSA transmission evaluated via contact screening

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

ISSN: 2047-2994