Laboratory Technician Herbert Mtopa collects biological samples at a clinic in Zimbabwe's Shamva District under a CultiAF project to assess exposure of women and children to aflatoxins. Credit: Busani Bafana/IPS

By Miriam Gathigah
NAIROBI, Kenya, Feb 22 2018 (IPS)

In the absence of concerted efforts to raise awareness on the dangers of aflatoxin to humans and domestic animals, advances in technology for early detection of aflatoxin in cereals and seeds such as maize will come to naught, experts warn.

The first rapid aflatoxin testing kit is in the market for less than two dollars, even as some farmers unwittingly employ life-threatening tricks to earn a bit more from their harvests.

John Cheruiyot, a maize farmer in Uasin Gishu County, Rift Valley region revealed to IPS that farmers pour water on maize post-harvest to manipulate its weight in order to dupe buyers into paying more than the grains are worth.

“Maize is sold based on kilograms and so by pouring water on the maize after harvesting and drying it later, when taken to the weighing scale, the maize will weigh more,” he explains.

It is not the loss of a few thousands shillings in manipulated weight that has stakeholders in the ministry of health, ministry of agriculture as well as food security experts at the Food and Agriculture Organization of the United Nations (FAO) concerned, but the real threat of deadly aflatoxin poisoning from such high moisture levels.

According to FAO, aflatoxin contamination can occur when there are high moisture levels during storage and transportation of grain, particularly if not dried to the right moisture levels of about 13 percent.

Collins Omondi, a researcher at the Egerton University Department of Biochemistry, explains that aflatoxins are highly toxic carcinogens that derive from certain molds, and may cause immune-system suppression, retarded growth, liver disease and even death.

“In maize, for instance, which is a staple food, aflatoxins occur on the farm through fungus containing high toxins in the soil, when there is insect damage, poor harvesting practices as well poor storage,” he told IPS.

He added that in the first three months of grain storage, rural households lose 10 to 20 percent of grains, and the losses can go up to 50 percent after six months.

It is within this context that experts such as Omondi are encouraging farmers to embrace the first kit to detect aflatoxin on location before the grains enter the market.

The kit can detect contamination in less than 15 minutes and is easy to use as it is based on the strip test such as those used to detect the HIV virus or glucose in human blood.

Cheruiyot, who has been trained on how to use the device, says that “if aflatoxin is present in the sample being tested, one pink line appears on the strip. But if the sample does not have aflatoxin then two pink lines will appear.”

Domestic animals that feed on grain contaminated by aflatoxin can carry the deadly toxin in their milk or meat. Credit: Miriam Gathigah/IPS

While this technology has been lauded as a step in the right direction towards combating the aflatoxin menace in this East African country – with the most severe aflatoxin poisoning outbreak recorded in 2004, when 317 cases were reported by July of that year with a fatality rate of about 39 percent – very low levels of awareness persist on aflatoxin and its prevention.

FAO recently held training workshops in collaboration with the national and county governments of Nandi, Uasin Gishu and Trans Nzoia Counties on prevention of aflatoxins. This was done through the ministry of health as well as the ministry of agriculture with the three counties chosen because they are the country’s grain basket.

FAO cautions that the deficit in agricultural extension officers continues to frustrate efforts to empower farmers with information on how to embrace better harvesting and storage practices to effectively address the real threat of aflatoxin poisoning.

While FAO has recommended one extension officer for every 400 farmers, figures from the ministry of agriculture show that one extension officer caters for at least 1,500 farmers.

According to the ministry of agriculture, approximately 70 percent of local maize is informally traded at the village level by subsistence farmers.

This poses a significant threat since maize is grown by at least 90 percent of the rural farm households.

FAO estimates that 25 percent of all crops in the world are affected by aflatoxin, placing millions of people and domestic animals at risk of significant health problems and even death.

Experts such as veterinary epidemiologist Johanna Lindahl say that domestic animals that feed on grains contaminated by aflatoxins produce products such as milk and meat that are also contaminated with aflatoxin.

“Kenya is a hotspot for aflatoxin contamination, especially in maize, and farmers, traders and the general public need to be educated on the danger of aflatoxins. This will increase the use of the testing kit which does not require technical skills in testing and interpreting outcomes,” explains Lindahl.

The most recent major incident of aflatoxin contamination was in 2014 when 155 metric tonnes of maize were destroyed.

She emphasizes that the rapid aflatoxin test kit coupled with education on the dangers of aflatoxin will significantly contribute to the management and reduction of the entry of aflatoxins in the food value chain by critically improving diagnosis for local and export trade.

Consequently, experts say that the food processing industry will maintain low exposure levels in food products for local markets, and continue to open regional as well as international markets that have largely remained hostile to countries such as Kenya, which is a hotspot for aflatoxins.

Application of Aflasafe in groundnut field. Photo courtesy of Aflasafe.com

By Ini Ekott
ABUJA, Dec 27 2016 (IPS)

As food contaminants, aflatoxins are amongst the deadliest. Between 2004 and 2007, contaminated maize killed nearly 200 people in Kenya, left hundreds hospitalised and rendered millions of bags of maize unfit for consumption.

On average, 25 to 60 percent of maize – a staple in many African countries – has high levels of aflatoxins in Nigeria, warns the International Institute of Tropical Agriculture (IITA). And with that comes the risk of liver cancer, suppressed immune system, stunted growth in children, and death.In the first year of the aflasafe trial, farmers recorded 13 percent average sales price over market rate, which is a 210 percent return on investment.

But despite such toxic potency, aflatoxins are hardly popular. Now, a made-in-Africa biocontrol product, Aflasafe, is taking on the poison, and is offering hope to millions across the continent who rely on vulnerable crops like maize.

“Aflatoxins are some of the most carcinogenic substances. But for four years that we have worked with farmers, we have seen great results in the use of aflasafe,” said Adebowale Akande, an aflasafe project lead at IITA, the institute that developed the product.

A four-year trial of aflasafe in Nigeria has yielded an impressive 80 to 90 percent reduction of aflatoxins, Akande said. “You will agree with me that four years is enough to know whether something is working or not,” he said.

Aflatoxin contamination is a global problem. But while developed countries regularly screen crops and destroy food supplies that test over regulatory limits, lax control and low awareness in developing countries mean billions of people face the risk of being exposed to the toxin daily.

The U.S-based Centre for Disease Control estimates that 4.5 billion people in developing countries may be chronically exposed to aflatoxins through their diet.

The toxins contaminate African dietary staples such as maize, groundnuts, rice either in the soil or during storage.

Countries in latitudes between 40 degrees north and 40 degrees south—which includes all of Africa—are susceptible to this contamination, the Partnership for Aflatoxin Control in Africa, PACA, an African Union body, said.

Besides health, aflatoxin also has serious economic implications.

“The direct economic impact of aflatoxin contamination in crops results mainly from a reduction in marketable volume, loss in value in the national markets, inadmissibility or rejection of products by the international market, and losses incurred from livestock disease, consequential morbidity and mortality,” said PACA in a 2015 paper.

Aflasafe production quality check after colonisation and drying. Photo courtesy of Aflasafe.com

Pull Mechanism

Aflasafe works by preventing the growth of aspergillus, the fungus that produces aflatoxin. It does so by stimulating the growth of large quantities of a harmless specie of aspergillus instead.

Developed over a decade by IITA, U.S. Department of Agriculture-Agricultural Research Service, University of Bonn and University of Ibadan, aflasafe is applied by hand on soil two to three weeks prior to crop flowering. It works only for maize and groundnuts for now, amid ongoing researches for other crops.

Within two to three days of application, the anti-toxigenic strain of the fungus builds up rapidly on the crop, colonizes it and stops the toxic strain from developing. With that, over 90 percent of aflatoxins can be eliminated.

Despite such promise, there are challenges. Low awareness of the dangers of aflatoxins means low demand for aflatoxin-free maize. Also, poor regulation has limited investments in the control of aflatoxin.

The IITA set up the “pull mechanism” to ultimately expand the use of aflasafe by providing economic and technical incentives to smallholder farmers, who work in groups through intermediaries called implementers. It features per-unit payments based on the number of kilograms of maize treated with aflasafe.

Premium payments equal to 18.75 dollars are paid for every metric ton of high-aflasafe maize delivered to designated collection points. This corresponds to a premium rate of 5 percent to 13 percent depending on the current price of maize.

The pull mechanism began in 2012 in Nigeria, with four implementers and 1,000 farmers. By 2016, the number has grown to 25 implementers and 15, 000 farmers, Mr. Akande said.

Abubakar Yambab, 43, is one of such farmers. At Abaji, a suburb of Abuja where he lives, Mr. Yambab grows maize on a 1⅟2 hectare of land. He told IPS he first used aflasafe in 2015, and his yields have since improved in quantity and quality.

“Using aflasafe has a multiplier effect,” he said. “It removes the coloured particles (aflatoxin) we used to notice in the harvested maize and I don’t think I can grow maize now without aflasafe.”

Yambab said he receives subsidized fertilizers, farming equipment, tractors and chemicals from IITA, and has relied on his farm proceeds to feed his six children and two wives, in addition to recently completing a block home.

Receiving premium payment on aflatoxin-reduced maize makes business sense for the farmers despite investment in the aflasafe technology.

IITA said in the first year of its trial, farmers recorded 13 percent average sales price over market rate, which is a 210 percent return on investment. In 2015, average sales price stood at 15 percent over market rate, translating to 524 percent return on investment.

Commercialization

Nigeria was chosen as pilot location for aflasafe as it is the leading producer and consumer of maize in sub-Saharan Africa and up to 60 percent of its maize may be affected. The country is for now the only developing country in which aflasafe is ready for use by farmers.

But similar work is going to Senegal and Kenya. A manufacturing plant capable of producing 5 tons of aflasafe per hour is operational at IITA headquarters in Nigeria, Ibadan. Another is under construction in Kenya and a third is underway in Senegal.

The institute is also working on transferring the technology to allow companies produce and distribute aflasafe to millions of farmers throughout sub-Saharan Africa.

“It is slated to cover 500,000 hectares in 11 countries where aflasafe will soon be registered,” Matieyedou Konlambigue, who leads IITA’s Aflasafe Technology Transfer Commercialization Project, said at the launching of the project on Dec. 1 at Ibadan, Nigeria.

The targeted countries are Burkina Faso, Ghana, Kenya, Malawi, Mozambique, Nigeria, Senegal, Tanzania, Gambia, Uganda and Zambia, Konlambigue was quoted by the News Agency of Nigeria as saying. The project is to last from 2016 to 2020.

Yamdab said he would advise other farmers to use aflasafe for their crops. “If all farmers in the FCT (Federal Capital Territory) use aflasafe, it will really improve the quality of food products here,” he said.

Laboratory Technician, Herbert Mtopa collects biological samples at a clinic in Zimbabwe's Shamva District under a CultiAF project to assess exposure of women and children to aflatoxins. Credit: Busani Bafana/IPS

By Busani Bafana
Bulawayo, Zimbabwe, Nov 20 2015 (IPS)

Aflatoxin contamination is a growing threat to trade, food and health security in sub-Saharan Africa, where smallholder farmers are challenged by food production and now climate change, researchers said.

Aflatoxins are toxic and cancer causing poisons produced by certain green mould fungus that naturally occurs in the soil. The poisons have become a serious contaminant of staple foods in sub-Saharan Africa including maize, cassava, sorghum, yam, rice, groundnut and cashews.

The International Institute of Tropical Agriculture (IITA), an international not for profit organisation based in Nigeria has led pioneering research in reducing mycotoxin contamination in Africa through rolling out innovative approaches.

According to IITA researchers, exposure to mycotoxins is an important constraint to improving the health and well-being of people in Africa where high levels of aflatoxin contamination have been confirmed. Many smallholder farmers fail to prevent contamination during production and storage of their crops because they lack cost-effective ways to determine the poisons.

Sub-Saharan Africa is annually losing more than 450 million dollars in trade revenue of major staples, particularly maize, and groundnuts as a result of contamination from aflatoxins, researchers told IPS. The health bill as a result of people unknowingly eating contaminated food runs into millions of dollars in a region with over burdened health facilities.

Africa is at risk of toxins which are linked to suppressed immunity, liver cancer in humans and stunting in children. UNICEF says 40 per cent of children in sub-Saharan Africa are stunted or have low height for their age which can be associated with impaired brain development.

Researchers say high temperatures and drought conditions favour the growth of fungus, while poor farming practises and food insecurity status of many people in sub-Saharan Africa increase their exposure to aflatoxin contamination. In addition high soil moisture content at harvest attributed to off-season rains as a result of climate variability increases contamination.

“Climate change is indeed predicted to have a profound effect on aflatoxin contamination of food and feed crops,” said Joao, adding that, “Consequently, any reduction in precipitation level or increment in temperature is expected to make aflatoxin problem more acute.”

In 2009, the IITA, the African Agriculture Technology Foundation (AATF), United States Department of Agriculture –Agriculture Research Service (USDA-ARS) and other partners developed an indigenous biological control technology, named AflaSafe to mitigate aflatoxin contamination in maize and groundnuts.

Aflasafe is a mixture of four non-aflatoxin producing strains of the green mould fungus (Aspergilllus flavus) of native origin. The formulated Aflasafe product is then broadcast in the field where it grows and prevents the toxin producing strains from colonizing, multiplying and contaminating crops.

Focused aflatoxin biocontrol research in Africa first started in Nigeria where Aflasafe is today a fully registered commercial product. Country specific products have been developed and introduced in Kenya, Burkina Faso, Senegal, The Gambia and Zambia.

In all the six countries where the bio control products have been tested since 2008 to date, IITA said farmers have consistently achieved up to 99 per cent reduction in aflatoxin contamination by using Aflasafe in maize and groundnut fields.

“The benefits attributed to using the Aflasafe bio control product for mitigating aflatoxin contamination far outweighs its cost,” said Juliet Akello, a plant pathologist and member of the IITA team in Zambia under Aflatoxin Biocontrol. “Exposure to aflatoxin through consumption of contaminated foods is a combination of unawareness, poverty and poor enforcement of standards by governments.”

Globally aflatoxins are a known threat that have been reduced thanks to investment in food safely controls. Smallholder farmers in Africa rely on a combination of traditional storage methods and use of pesticides to prevent weevils. However, these methods are not always pest proof leading to them losing a bulk of the stored crop by the time they need it most.

Other innovative approaches are being tried in Africa to curbing pre and post harvest losses in addition to eliminating aflatoxin contamination using Aflasafe.

In Zimbabwe, researchers at the University of Zimbabwe and Action Contre la Faim are working with communities in two districts to investigate whether improved storage can reduce aflatoxin contamination in local maize grain. The two-year research, supported by the Cultivate Africa’s Future (CultiAF) programme, an initiative funded by Canada’s International Development Research Centre (IRDC) and the Australian Centre for International Agriculture Research, will also assess levels of exposure suffered by women and infants. The project has introduced a metal silos and thick plastic “super bags,” allowing maize to be stored in air-tight conditions.

Farmers in sub-Saharan Africa are challenged by lack of drying equipment, with most maize and groundnut farmers keeping their crops in fields to dry out before harvest. Sometimes, they store it before it has dried properly, making it vulnerable to aflatoxin attack.

Exports of agricultural commodities particularly peanuts from Africa have declined by as much as 20 per cent over the past two decades. The commodities have been rejected after failing to meet the European Union’s market regulations on aflatoxin levels in foods for human consumption, a serious hurdle to international trade.

According to the United Nations Food and Agriculture Organisation, only 15 African countries had regulatory limits for aflatoxins by 2013.

In Zambia, for example, nearly 100 per cent of the peanut butter brands sampled between 2012 and 2014 from supermarkets and local markets were found to contain unsafe levels of aflatoxins above 20ppb. Less than 30 per cent of milled groundnut flour collected from markets and homesteads had levels within the 4 ppb set by the EU as safe limits.

While in Kenya, considered the number one aflatoxin hotspot in East Africa, nearly 200 died due to acute aflatoxicosis after eating aflatoxin contaminated maize between 2004 and 2006. About 2 million maize bags were found unfit for human consumption due to high levels of aflatoxins in 2010.

IITA’s programme manager for Aflasafe in Malawi, Dr. Joseph Atehnkeng, said between 40 and 100 per cent of groundnut based-commodities in Malawi, were found to contain unsafe toxin levels.

Former net groundnut exporters; Mozambique, Senegal, The Gambia, Zambia and Malawi have lost lucrative markers in the EU, the United States and South Africa because of high aflatoxin levels in their commodities, says IITA scientist and plant pathologist, Dr. Joao Augusto.

Mozambique has since the late 70s, recorded a high prevalence of liver cancer in the southern part of the country which has been associated with consumption of aflatoxin contaminated food, especially groundnuts.

According to the Partnership for Aflatoxin Control (PACA), a regional project formed in 2009 to minimise and ultimately eradicate aflatoxins using proven and innovative strategies, there is a need for effective aflatoxin regulation policies and country-specific standards.

Researcher, Chapwa Kasoma from Zambia, warns that left unchecked, aflatoxin contamination could retard development in sub-Saharan Africa.

“If we want to overcome poverty in all its forms; combating not only the inadequacy of food but also addressing any forms of malnutrition we need to be worried,” Chapwa, also a field supervisor with Pioneer DuPont, told IPS. “Being potent carcinogens, aflatoxins are clearly a nutrition problem.”

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