Alfaraj, Sarah H.Al-Tawfiq, Jaffar A.Altuwaijri, Talal A.Alanazi, MarzouqaAlzahrani, NojoomMemish, Ziad A.2018-05-032018-05-032018-02Alfaraj, S. H., Al-Tawfiq, J. A., Altuwaijri, T. A., Alanazi, M., Alzahrani, N., & Memish, Z. A. (2018). Middle East respiratory syndrome coronavirus transmission among health care workers: Implication for infection control. American Journal of Infection Control, 46(2), 165–168. https://doi.org/10.1016/j.ajic.2017.08.010https://hdl.handle.net/1805/16031Background Many outbreaks of Middle East respiratory syndrome coronavirus (MERS-CoV) have occurred in health care settings and involved health care workers (HCWs). We describe the occurrence of an outbreak among HCWs and attempt to characterize at-risk exposures to improve future infection control interventions. Methods This study included an index case and all HCW contacts. All contacts were screened for MERS-CoV using polymerase chain reaction. Results During the study period in 2015, the index case was a 30-year-old Filipino nurse who had a history of unprotected exposure to a MERS-CoV–positive case on May 15, 2015, and had multiple negative tests for MERS-CoV. Weeks later, she was diagnosed with pulmonary tuberculosis and MERS-CoV infection. A total of 73 staff were quarantined for 14 days, and nasopharyngeal swabs were taken on days 2, 5, and 12 postexposure. Of those contacts, 3 (4%) were confirmed positive for MERS-CoV. An additional 18 staff were quarantined and had MERS-CoV swabs. A fourth case was confirmed positive on day 12. Subsequent contact investigations revealed a fourth-generation transmission. Only 7 (4.5%) of the total 153 contacts were positive for MERS-CoV. Conclusions The role of HCWs in MERS-CoV transmission is complex. Although most MERS-CoV–infected HCWs are asymptomatic or have mild disease, fatal infections can occur and HCWs can play a major role in propagating health care facility outbreaks. This investigation highlights the need to continuously review infection control guidance relating to the role of HCWs in MERS-CoV transmission in health care outbreaks, especially as it relates to the complex questions on definition of risky exposures, who to test, and the frequency of MERS-CoV testing; criteria for who to quarantine and for how long; and clearance and return to active duty criteria.enPublisher PolicyMiddle East Respiratory Syndrome CoronavirusMERS-CoVInfection controlArticle