MERS-CoV can infect a person regardless of his/her health status or age group. Recent travelers returning from the Arabian Peninsula and neighboring countries who develop severe acute respiratory infection should be tested for MERS-CoV. Elderly people and those with underlying medical conditions such as diabetes, heart disease, or liver disease are at risk of severe infection. Close association with any person infected with MERS-CoV, as in caregivers, health-care workers, or household contacts, is a major risk factor.