Study calls for One Health approach in continued research on potential role of pigs in Ebola transmission in Uganda

Local breed sow and piglets on a farm in Masaka district, Uganda (photo credit: ILRI/Eliza Smith).

Zoonotic diseases are most dangerous when they take animal and human health workers by surprise, giving the public and disease control officials no advance warning or time to put prevention measures in place. The recent Ebola outbreak in West Africa illustrates the adverse consequences of trying to tackle a disease outbreak too late and with little information.

Ebola is a serious but mysterious disease; in Uganda, there is little solid information on the reservoir and transmission of Ebola. However, research findings in the last few decades have given rise to speculation that there could be associations between pigs and Ebola.

Currently, there is no evidence that pigs have had any role in past outbreaks of Ebola virus disease. But given the huge importance of pigs to the Ugandan economy, diet and livelihoods, it is important to investigate any potential links sooner rather than later.

A recent study by the International Livestock Research Institute (ILRI) argues there are several factors that support the potential role of pigs in the transmission of Ebola to humans in Uganda. It is critical that this hypothesis be investigated in order to understand the risks to the country’s burgeoning pig production industry.

A spatial representation of potential risk factors for zoonotic transmission involving pigs in Uganda could be used to initiate further investigations into Ebola and other zoonotic diseases known to affect pigs in Uganda.

The researchers call for a One Health approach to the continued research. The benefit of this multidisciplinary approach is that limited resources can be utilized efficiently to improve the health and livelihoods of Ugandans through enhanced food safety and security, and the preservation of important ecosystem services, such as those provided by bats and other wildlife.

Clear and consistent risk communication from all research partners will be of utmost importance in preventing hysteria and delivering good outcomes for wildlife conservation and livelihoods.

Download the policy brief, One Health approach recommended in investigating and communicating the potential role of pigs in transmitting Ebola in Uganda written by Eliza Smith of KYEEMA Foundation and Christine Atherstone and Delia Grace of ILRI.

 

New ILRI report assesses risk of Ebola in Uganda’s pig value chain

Local breed sow and piglets on a farm in Masaka district, Uganda. A new research report assesses the risk of Ebola in the pig value chain in Uganda. (photo credit: ILRI/Eliza Smith).

Scientists from the International Livestock Research Institute (ILRI) have published a report of a risk assessment to determine the threat of the deadly Ebola virus in the pig value chain in Uganda.

Uganda is currently witnessing a rise in demand for pork and this has led to increased pig production in the country, mostly under smallholder production systems.

These higher pig populations raised under free-range or tethering systems may create overlap of fruit bat habitats where the pigs scavenge for food, thereby presenting a possible risk of Ebola transmission as some bat species have been identified as reservoir hosts of the Ebola virus.

Uganda has experienced outbreaks of Ebola virus disease in the past. However, there are still many unanswered questions on the ecology and mode of transmission of the Ebola virus.

The risk assessment study, based on a systematic review of literature, identified possible routes of transmission of the Ebola virus if pigs are involved, for example, spread between wild and domestic pigs, direct contact between infected pigs and humans, and contact between pigs and fruit bats.

The study recommends more research on the possible role of pigs in Ebolavirus transmission, an area that is not well understood at the moment.

“The present data suggest that pigs may act as amplifying hosts, but likely not reservoir hosts. This suggests the conditions under which pigs become infected with Ebolavirus and the role they play in transmission may have many variables that will have to be elucidated,” the report states.

Further research is underway to investigate the possible role of domestic pigs in the ecology of Ebola virus in Uganda and understand the public health significance of the virus to the pig value chain in this country.

The work includes laboratory diagnostics from a large sample of blood from domestic pigs collected as part of the initial wider value chain disease assessment.

This will be accompanied by a risk mapping study using spatial epidemiology and key informant surveys as well as some participatory techniques with key stakeholders to better understand risk factors and to serve as a ‘ground-truthing’ exercise for the risk map.

It is hoped that this research will lead to further collaborations with other public health organizations and serve as a potential predictive tool in the event of future outbreaks of Ebola in Uganda.

Access the research report here

Citation
Atherstone C, Roesel K and Grace D. 2014. Ebola risk assessment in the pig value chain in Uganda. ILRI Research Report 34. Nairobi, Kenya: ILRI.