Mers more widespread than thought after infected camels found in northern Africa

The deadly respiratory virus that has spread from Saudi Arabia around the world was found in camels in Nigeria, Tunisia and Ethiopia, showing the pathogen is more widespread than previously known.

Middle East respiratory syndrome, a coronavirus also known as Mers, was found in almost all blood samples taken from 358 dromedary camels in Nigeria and 188 camels in Ethiopia, according to a study published online by the journal.

In Tunisia, Mers was found in 54 per cent of adult camels, and in all of the animals from one southern province.

The findings add to previous studies that have found the virus in camels in Spain's Canary Islands and Egypt, as well as in several nations on the Arabian peninsula, and suggest that there may be undiagnosed human cases in Africa, researchers from the Netherlands wrote in the study.

The blood samples were collected between 2009 and 2011, suggesting the virus was circulating well before 2012 when the first human case was identified.

"The possibility exists that Mers illness occurred before its discovery in 2012 and that such infection has been overlooked in the areas with evidence for virus circulation among animals during the past 10 years," the authors wrote in the journal, published by the US Centres for Disease Control and Prevention.