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Imported Case of MERS, United States, 2014associate in Illinois before seeking medical care at an Indianahospital; multiple healthcare personnel (HCP) at thehospital were exposed to the patient (14). Given the uncertaintyaround how MERS-CoV is transmitted, we conducteda comprehensive contact investigation of this caseto characterize exposures in household, community, andhospital settings and to quantify the risk of transmission.We also compared contact reported by HCP during standardizedinterviews with those in global positioning system(GPS) tracer tag recordings.MethodsEthical ReviewThis investigation was part of a public health response, so itwas determined by CDC to be a nonresearch investigationand not subject to review by the CDC Institutional ReviewBoard. All participants provided verbal consent before interview;parental permission and assent from from minorswere obtained as appropriate.Definitions and Identification of ContactsFor the purpose of this investigation, we defined contacts asall persons who had potential exposure to the case-patientbefore airborne and contact precautions were instituted.More specifically, we defined HCP contacts as all personswho had a face-to-face (within 1 meter) interaction withthe case-patient or who entered the case-patient’s roomwithout appropriate personal protective equipment (PPE;i.e., gloves, N95 respirator, gown, and eye protection)before airborne and contact precautions were instituted.HCP contacts were identified by reviewing GPS tracertag logs, the case-patient’s medical chart, and emergencydepartment (ED) security video footage or through thehospital hotline, on which personnel could self-identify.GPS tracer tags were worn routinely by registered nurses(RNs) and certified nursing assistants (CNAs). The tagstrack the date and time that staff enter and exit a patient’sroom. We reviewed hospital GPS records to determine theexposure time and number of patient visits for attendingRNs and CNAs.Hospital visitor contacts were defined as all personswho visited the case-patient at the hospital before airborneand contact isolation precautions were instituted. Householdcontacts were defined as all persons who stayedovernight in the same household as the case-patient betweenhis arrival in the United States and his admissionto the hospital. Community contacts were defined as allpersons, other than household or HCP contacts, who hadface-to-face exposure to the case-patient. Hospital visitor,household, and community contacts were identifiedfrom interviews with the case-patient, family members,and hospital staff.Duration of Exposure, Infection Monitoring,and QuarantineDuration of exposure was determined by asking contactshow much time they had spent with the case-patient. Durationof exposure was also calculated from GPS records.Following confirmation (on May 2, 2014) that the patientwas infected with MERS-CoV, HCP and householdcontacts checked their body temperature twice daily andself-monitored for respiratory or gastrointestinal symptomsfor a total of 14 days after their last exposure to the case-patient.HCP also reported to the hospital’s Employee HealthServices each day. In addition, nonphysician HCP contactswere requested to self-quarantine at home or wear surgicalmasks in the community, and physician HCP contacts wererequested to wear surgical masks at work.InterviewsThe case-patient was asked to report his medical and exposurehistory, health care–seeking behaviors, job-relatedactivities, and social activities during the 14 days beforeillness onset. HCP, household, and community contacts answeredstandard questionnaires covering basic demographicinformation; infection control practices when in contactwith the case-patient; type, length, and frequency of contactswith the case-patient; chronic medical conditions; andsymptoms since first exposure to the patient.Biologic Specimen CollectionSerum, nasopharyngeal swab, oropharyngeal swab, stool,and urine samples were collected from the case-patienton various dates (15). Two sets of nasopharyngeal andoropharyngeal swab samples and serum samples werecollected from all contacts. The initial and follow-up setsof specimens were collected on postexposure days 3–8and 12–14, respectively. An additional set of specimenswas collected within 48 hours from any contacts whobecame symptomatic.Nasopharyngeal and oropharyngeal swab sampleswere tested at the ISDH laboratory, Massachusetts Departmentof Public Health, Illinois Department of PublicHealth, or CDC within 72 hours of collection. Stool andurine samples were tested at the ISDH laboratory, and serumsamples were tested at CDC.Laboratory TestingNasopharyngeal, oropharyngeal, urine, serum, and stoolspecimens were tested by using a MERS-CoV real-timereverse transcription PCR (rRT-PCR) developed by CDC,as previously described (15). Serum specimens collectedon postexposure days 12–14 were screened for MERS-CoV–specific IgG, IgM, and IgA by using a recombinantnucleocapsid–based ELISA. Positive ELISA results wereconfirmed by MERS-CoV immunofluorescence assayEmerging Infectious Diseases • www.cdc.gov/eid • Vol. 21, No. 7, July 2015 1129