It is invisible to the naked eye -- until it has taken hold. And unlike many food contaminants, it can survive a wide range of processing techniques, including cooking. Aflatoxin, a toxic metabolite produced by fungi that form on certain foods and feeds, is hard to prevent. But its effects are all too evident. Each year, Africa loses US$670 million (€630 million) due to aflatoxin contamination of food products.
Earlier this year, 14 people died in Tanzania and scores of others fell seriously ill after consuming contaminated maize. According to the World Health Organization, some 4.5 billion people are chronically exposed to aflatoxin around the world. Public health aside, this mycotoxin can have a devastating effect on producer incomes, trade and food security.
In West Africa, aflatoxin is a serious threat to the fledgling inter-regional grain trade. Maize and rice, two of the products with strong potential for more vigorous trade in the region, are particularly vulnerable to this silent killer.
"In Africa, aflatoxin is one of the most pervasive food safety challenges, because of its impact on food and nutrition security, trade and public health," said Winta Sintayehu, Programme Officer at the Partnership for Aflatoxin Control in Africa (PACA), speaking at the conference on How to structure the grain trade in West Africa: which market instruments and public policy measures? organised by CTA and partners in Ouagadougou, Burkina Faso. "Aflatoxins affect access to markets and rural incomes, so it is extremely important to examine how this can impact the West African grain trade."
Natural compounds produced by the mould Aspergillus flavus, which occur in soil, aflatoxins are highly poisonous to humans and animals, causing liver disease and cancer. Currently, 30 percent of all cases of liver cancer diagnosed in Africa are caused by this extraordinarily resilient toxin. Chronic exposure to aflatoxins is also associated with stunting and immune system suppression.
Aflatoxin producing moulds affect grain and other food crops and can occur both pre-harvest and post-harvest, and be carried along the food chain. As well as causing direct damage to humans, they also cause health problems in livestock, through contaminated feed.
Africa is particularly vulnerable to aflatoxin due to its climate, inadequate harvesting and storage conditions and low food safety inspection and enforcement capabilities. Lack of awareness among producers, processors and consumers compound the problem. Some 40 percent of commodities in local African markets exceed allowable levels of the toxin.
In West Africa, there is an urgent need for harmonisation of food standards, which in turn will have a knock-on effect on improved trade. A 2015 study commissioned by PACA in the region revealed that only eight of the fifteen Economic Community of West African States (ECOWAS) currently have food standards, and only three of those have specific standards for aflatoxin.
Generating -- and especially sharing -- information will play an important role in any strategy to combat aflatoxin. In November, CTA and PACA teamed up to publish a working paper on Improving the Evidence Base on Aflatoxin Contamination and Exposure in Africa: Strengthening the Agriculture-Nutrition Nexus. The report is based on a detailed review of more than 800 references in published literature, bringing together some of the substantial knowledge that is already available on the issue of aflatoxin.
For the West African grain trade in particular, building blocks are needed for more comprehensive food laws and regulations, better food control and management and more effective laboratory and inspection services.
"Grain production in West Africa faces some serious challenges, among them mycotoxin attacks – particularly aflatoxin," said CTA Director Michael Hailu. "Aflatoxin is a silent killer that must be eradicated."
Given the complex nature of the aflatoxin problem, the most effective way of combatting the challenge will be through an integrated approach. These include encouraging good agricultural practices, drawing up more stringent regulations and standards and introducing good policies to enforce them.
A number of technological solutions are also showing promise for tackling the aflatoxin challenge. Among them are simple and affordable testing kits for producers and a biological control currently being rolled out in a number of African countries. In Nigeria, field testing of aflasafe, a biological solution developed by the International Institute of Tropical Agriculture (IITA) has produced positive results, with reductions in levels of aflatoxin contamination of maize and groundnuts consistently reduced by up to 90 percent.