Figure 1. Family relationships and household distribution of persons infected with MERS-CoV, Al-Qouz, Saudi Arabia, 2014. Black lines denote standard family tree relationships. Patients are lettered in order of symptom onset or, if asymptomatic, by test date. Green boxes indicate households; all persons living in households 1–4 were tested, except for 2 adults living in household 4 (not shown). Index patient (person with earliest symptom onset diagnosed by rRT-PCR) in each household is underlined. Uninfected indicates person in household with negative rRT-PCR results and (if >14 years of age) negative serologic testing for MERS-CoV. Visiting relatives indicates extended family members who regularly visited the 4 households and were present in the households on the day of the field investigation. MERS-CoV, Middle East respiratory syndrome coronavirus; rRT-PCR, real-time reverse transcription PCR.