Cross host transmission in the emergence of MERS coronavirus

- MERS-CoV genomes have been detected in nasal swabs of dromedaries.
- Bat CoVs characterized thus far are relatively distantly related to MERS-CoV.
- Routes of MERS-CoV zoonotic transmission are not well established.
- Preventive measures should be taken to reduce zoonotic transmission of MERS-CoV.

Coronaviruses (CoVs) able to infect humans emerge through cross-host transmission from animals. There is substantial evidence that the recent Middle East respiratory syndrome (MERS)-CoV outbreak is fueled by zoonotic transmission from dromedary camels. This is largely based on the fact that closely related viruses have been isolated from this but not any other animal species. Given the widespread geographical distribution of dromedaries found seropositive for MERS-CoV, continued transmission may likely occur in the future. Therefore, a further understanding of the cross host transmission of MERS-CoV is needed to limit the risks this virus poses to man.