Chikungunya virus (CHIKV) is a mosquito-borne alpha virus that induces in humans a disease characterized by fever, rash, and pain in muscles and joints. The virus causing Chikungunya disease was identified over 50 years ago; however, because the disease appeared only in developing countries, little research on it has been done. CHIKV infection in these animals recapitulated the viral, clinical, and pathological features observed in human disease. In the macaques, long-term CHIKV infection was observed in joints, muscles, lymphoid organs, and liver, which could explain the long-lasting CHIKV disease symptoms observed in humans. In addition, the study identified macrophages as the main cellular reservoirs during the late stages of CHIKV infection in vivo.