Taking a blood sample from a came (photo credit: Eric Fèvre).

‘African camels could hold important clues to controlling the potential spread of a respiratory disease transmitted by the animals.

‘For many years African camels have lived with the disease and the risk of it spreading to humans is still low. But more research is necessary to understand the disease better. This is even more important given the confirmation that the chains of transmission of the human Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection originated from contact with camels. MERS was first recognised in 2012.

Camels are an extremely important source of livelihood, nutrition and income in Africa. They are especially common in arid and semi-arid areas of the continent, particularly in East Africa. But having these animals around may not be risk-free for humans.

‘However, there have been no human cases of MERS diagnosed in Africa. This could be because of limited clinical or epidemiological surveillance for the virus where infections have gone unrecognised. It could also be because there is simply no zoonotic, human-infective virus circulating in sub-Saharan Africa, or indeed because risk factors for transmission differ in the two regions. . . .

‘The disease usually affects patients who are in some way immune-compromised or suffering from other conditions like diabetes, lung and liver disease.

Livestock dependent people in the Horn of Africa region who suffer from malnutrition are potentially at risk of contracting the disease. The case fatality rate of MERS is high, at around 37%. Outbreaks in other parts of the world like South Korea have been linked to individuals originally acquiring infections from chains of transmission originating in the Middle East and travelling.

‘In October, the Centre for Pastoral Areas and Livestock Development at the Intergovernmental Authority on Development and the UN Food and Agriculture Organisation co-hosted a scientific and policy meeting to discuss the MERS virus. The aim was to improve the understanding of this pathogen and its implications to the Horn of Africa region.

The meeting was prompted by the likely role of the dromedary camel as a reservoir of infection for MERS-CoV, and the high density of and trade importance of camels in the Horn of Africa region. The region supports more than 60% of the world’s population of single humped camels.

‘Studies in Kenya and elsewhere show that, despite its recent identification as a human pathogen, MERS has been circulating for many years over wide geographical areas. Camel sera collected as far back as 1983 shows high rates of seroconversion to the virus. This means that the animals have been infected, probably by a transient respiratory disease, and recovered. . . .

‘A crucial question in understanding the disease is establishing what the human risk is when the virus circulates so freely in the reservoir host. It is vital to learn whether dromedary camels in Africa harbour the same MERS-CoV as detected in the Arabian Peninsula. If so, or if not, is the epidemiology of the virus similar? . . .

Mapping trade routes and understanding the population structure of African camels better with their population density will also be key foresight information should large scale disease control interventions ever be necessary.

‘. . .This gives the livestock and health communities the opportunity to study and better understand this virus, ideally working on a joint agenda that shares knowledge. An example of this is the One Health philosophy between sectors that benefits all.’

Read the whole article by Eric Fèvre and Joerg Jores in The Conversation: Studying African camels is key to learning more about the MERS virus, 19 Oct 2015.

Eric Fèvre is a joint appointee at the University of Liverpool, where he is professor of veterinary infectious diseases, and the International Livestock Research Institute (ILRI), where he manages several field-oriented research projects on neglected zoonoses on behalf of the CGIAR Research Program on Agriculture for Nutrition and Health. Joerg Jores leads research at ILRI on vaccines and related work for contagious bovine pleuropneumonia (CBPP) and Middle East respiratory syndrome (MERS).

Read other articles about ILRI research on MERS:
UK chief scientific adviser visits Kenya: Part 4—Development of a field-friendly diagnostic test for MERS, 24 Jul 2015
New studies on MERS coronavirus and camels in eastern Africa published, 28 Aug 2014