Principal Supervisor: Dr Christopher GreenLink opens in a new window
Co-supervisor: TBC – Alex Richter (University of Birmingham), Natalia Falagan (University of Cranfield), Carol Verheecke-Vaessen (University of Cranfield) or Yun Gong (University of Leeds).
PhD project title: Understanding the needs of African farming communities to reduce the burden of disease from mycotoxins
University of Registration: University of Birmingham
Mycotoxins are chemical hazards produced by fungal genera (such as Aspergillus, Fusarium, Penicillium and Alternaria) and are known to contaminate 60-80% of the world’s food supply. In humans, exposure to mycotoxins has been associated with liver cancer, stillbirth and excess mortality. In particular, Aflatoxins produced by Aspergillus fungi (frequently associated with staple foods like maize and groundnut) are a WHO/IARC classified group I liver carcinogen. In developed settings there are regulated standards for agricultural imports, but in low-to-middle income countries (LMICs) mycotoxin exposure can be high, resulting in an exacerbation of food security issues, limited access to international markets and increased food losses/malnutrition in addition to the health impacts. This problem will be increasingly exacerbated by global warming. 83% of the Rwanda population where this research is based live and work in rural farming communities, which is common with many other African nations.
In parallel, an estimated 325 million people globally suffer from chronic viral hepatitis infection (hepatitis B or C virus infection, HBV and HCV), which is over 10-times the global HIV burden. HBV is vaccine preventable and HBV vaccines are included in the WHO expanded programme of immunisation (EPI) schedule, and HCV is now curable with modern anti-viral drug therapies. However, EPI vaccination coverage is incomplete and HCV drugs are prohibitively expensive in many parts of Africa, resulting in an especially high-burden of mortality in younger adults on the continent.
Mycotoxin (Aflatoxin) exposure and chronic HBV infection each confer an approximate 3 and 6-fold increased risk of developing liver cancer respectively. However, concurrent Aflatoxin exposure and chronic HBV infection increases the risk of developing liver cancer by an estimated 60-fold. Animal studies have further elucidated the mechanisms; chronic HBV infection predisposes hepatocytes to carcinogenic effects of Aflatoxins, and at the same time Aflatoxins may cause DNA damage that facilitates HBV genome integration.
Aflatoxin exposure can be measured and quantified by ELISA methods and is a useful biomarker for studies that aim to identify and quantify the impact of future interventions, such as early post-harvest crop storage in cooled fridges, to reduce toxin exposure to farmers and their families. Equally, several assays have been developed to detect persons with chronic hepatitis B infection and/or immunity, and need for vaccination.
The project would involve data collection and blood sample collection at research sites in Rwanda, with the support by our clinical research team members there. We aim to test the blood samples with our project partners in Rwanda for HBV infection and/or the need for an HBV vaccine, and concurrent blood analysis with project partners in the UK will work on the detection and quantification of mycotoxin levels. Combined with the clinical, occupational and environmental metadata we aim to map ‘hot spots’ of high liver cancer risk to farming communities that need priority intervention in the form of educating farming practices, the placement and use of community cooling hubs in post-harvest management, and the focus for HBV screening and vaccination of non-immune individuals.
BBSRC Strategic Research Priority: Sustainable agriculture and food - Microbial Food Safety
Techniques that will be undertaken during the project:
- Data analysis
- Field sampling – human and crops
- ELISA assays