Intratracheal inoculation of severe acute respiratory syndrome coronavirus in monkeys macaca rhesus

An animal model for infection with Severe acute respiratory syndrome coronavirus (SARS-CoV) was evaluated in monkeys Macaca rhesus. The monkeys were inoculated into the trachea with NS-1 strain of SARS-CoV and the clinical manifestation of the illness was monitored. The clinical samples collected from infected monkeys were examined by immumnofluorescence assay (IFA), pathological inspection, RT-PCR, and by virus isolation. The infected animals demonstrated mild clinical symptoms including fever. Two of the six infected monkeys developed fever (1.5 above the level before challenge) on the day 10 post inoculation (p.i.). Although the severe clinical symptoms or mortality were not observed, the virological and histopathological evidences of the illness were evident. The specimens collected from the infected animals showed the presence of SARS-CoV detected by RT-PCR, IFA, and by virus isolation. From the organs examined postmortem, a major pathological change was observed in the lungs. The walls of the alveoli were thicker, infiltrated with inflammation cells and an exudative fluid was found in the alveolar spaces. In addition, some alveolar spaces showed hyaline membrane lining. The results showed that the monkeys infected with SARS-CoV developed the typical SARS according to clinical, virological, and pathological findings.