Concerns about Misinterpretation of Recent Scientific Data Implicating Dromedary Camels in Epidemiology of Middle East Respiratory Syndrome (MERS)

Samara, Emad M.; Abdoun, Khalid A.

To elucidate this issue, four possible routes of MERS-CoV transmission should be epidemiologically assessed: human to human, camel to camel, camel to human, and human to camel. Regarding human-to-human MERS-CoV transmission, clusters of infection cases have indicated that MERS-CoV actually can be spread horizontally from human to human through close contact (3) (4) (5) . Effective and successful emergence of MERS-CoV requires that the value of the basic reproduction number (R 0 ) should exceed 1 in the new host (presumably human) (6) . In the case of MERS, the R 0 is currently less than 1 (most likely 0.5), indicating that MERS-CoV infection will inevitably die out; however, it is recommended, in such cases, to take into account the demographic stochasticity of MERS-CoV transmission (7) . Despite the limited human-to-human transmission, the recent increases in the number of MERS-CoV infections among humans and the exceptionally high fatality rate associated with it as reported by WHO (8) represent a marked increase in MERS emergence (i.e., an increase in R 0 ) and subsequently an epidemic waiting to happen, which obviously is the key driver in the current debate.