June 4, 2014

expert reaction to reported camel-to-human MERS-CoV transmission

A study published in the New England Journal of Medicine reported that Middle East Respiratory Syndrome (MERS) viruses found in an owner of camels and the animals themselves were identical, providing strong evidence the virus can be passed from camels to humans.

Dr Jake Dunning, Centre for Respiratory Infection, National Heart and Lung Institute, Imperial College London, said:

“It’s a nicely conducted study, although they have only looked at camel-to-human transmission in a single patient. By using PCR detection of virus and also serial measurements of antibody production in response to infection with the virus, it supports what we thought was going on i.e. MERS-CoV transmits from camels to humans and leads to MERS-related illness, rather than the other way around. Other studies looking at the link between MERS-CoV in camels and humans have suggested this, but the evidence was somewhat weaker (because of the lack of serial antibody measurements in camels and humans). That said, although some patients with MERS have evidence of contact with camels or camel products, many do not. Several research groups have shown that this virus can be found in camels (and in bats) and that camel-to-human transmission of MERS-CoV is likely, but how do we explain infection in other patients outside of hospital outbreaks? To help answer this, we really need detailed epidemiological studies in affected countries, including carefully conducted case-control studies. At the same time, we should continue to look for other animal and environmental reservoirs of the virus.”

Prof Ian Jones, Professor of Virology, University of Reading, said:

“This is a further strengthening of the case for camels being an immediate source of human MERS infection. However, it remains to be seen if this finding is typical of the majority of cases or if it is one of many ways the virus can be contracted.”

‘Evidence for camel-to-human transmission of MERS Coronavirus’ by Esam I Azhar et al. published in the New England Journal of Medicine on Wednesday 4 June.

Declared interests

Jake Dunning helps develop guidance on potential treatment options for MERS-CoV infection and is a member of the International Severe Acute Respiratory and emerging Infections Consortium (www.isaric.org).