Researchers have assessed the role of certain food types in causing illness from different pathogens in three African countries.

They presented attribution estimates for Campylobacter, enterotoxigenic E. coli (ETEC), Shiga-toxin producing E. coli, Salmonella, Cryptosporidium, Brucella, and Mycobacterium bovis for beef, dairy, poultry and vegetable products in Burkina Faso, Ethiopia and Rwanda.

Findings help support three projects aiming to improve food safety in these African countries. All of them needed foodborne disease burden data attributed to specific products as part of work to improve the safety of beef, dairy, poultry meat and vegetables and inform national decision making.

Eleven experts from Ethiopia, 12 in Burkino Faso and nine in Rwanda participated in the study, published in the journal Neglected Tropical Diseases.

Specialists were interviewed remotely and completed calibration questions without access to resources. They then answered target questions after the interview, using resources. Data were validated using two measures and performance-based weights were applied. 

Pathogen and food group findings
about three-quarters of the foodborne burden by ETEC in Ethiopia was attributed to beef, dairy, poultry, and vegetables. In Burkina Faso, about 40 percent of the burden was attributed to poultry and vegetables. Attribution to dairy was lower in Burkina Faso than in Ethiopia.

There is no evidence that animal pathogenic ETEC strains are infectious to humans but a sizeable proportion of ETEC illness was attributed to animal source foods as experts considered contamination of products by infected food handlers can occur at any step in the supply chain.

In Ethiopia, about 70 percent of infections with Campylobacter, Salmonella and Shiga-toxin producing E. coli (STEC) from dairy was attributed to milk from cattle and about a third of the burden of dairy was linked to drinking raw cattle milk. about 60 percent of the burden of these pathogens in beef was from red meat and about 30 percent from beef consumed raw. 

On the burden of Campylobacter and Salmonella from poultry meat, 56 percent was attributed to chicken bought raw and prepared at home. Attribution of the burden from vegetables to Salmonella and ETEC in Burkina Faso was similar to Ethiopia.

For Rwanda, most of the burden of dairy for all pathogens was attributed to cattle milk. The link to raw milk varied by pathogen with the highest proportions for Brucella and Cryptosporidium and the lowest for Campylobacter. A substantial proportion of the burden was also attributed to traditionally fermented cattle milk and industrially fermented products.

Attribution estimates in the study will be combined with national level estimates of foodborne infection from WHO’s Foodborne Disease Burden Epidemiology Reference Group (FERG), to present estimates of the burden of specific food groups and products. Such data will inform control activities and can be combined with risk assessment and economic estimates for cost-benefit analyses.

Separate studies will report burden figures based on FERG data and other attribution estimates.