Objective: To prevent spreading of MRSA into the community and to prevent recolonisation by MRSA after decolonisation, index patients and their positive household contacts received eradication therapy simultaneously. We assessed the rate and possible determinants of transmission to household contacts.
Methods: All MRSA positive patients treated or followed up by the Erasmus MC between January 2005 and December 2007 were asked to participate in the study. Screening cultures (nose, throat and perineum) of index patients were obtained. Just before start of MRSA eradication therapy, all household contacts were screened (nose, throat, perineum) to determine whether transmission of index patients to household contacts has occurred. Medical data of index patients and household related data were determined.
Results: 71 MRSA positive index persons and 184 household contacts were included. Transmission from index person to household contacts occurred in 43.7% (n=31) of index persons, who had together 94 household contacts. 62.8% (n=59) of the household contacts were found MRSA positive. MRSA nasal colonisation in combination with other positive MRSA sites was significantly associated with transmission (p=0.037, OR 4.125, 95% CI 1.092 – 15.585). HCWs were less likely to transmit to their households compared to patients (p=0.044, OR 0.300, 95% CI 0.091 – 0.989). Younger persons showed higher transmission rates compared to older persons (p=0.042). A positive association was observed between transmission rates and exposure time of MRSA positive persons to their household before eradication treatment was started (p=0.074).
Conclusion: MRSA transmission to household contacts occurs frequently. To prevent transmission into the community or recolonisation of MRSA through household contacts it is important to screen household contacts. Therefore, index persons and their positive household contacts should be treated simultaneously.