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Mycotoxins in Crops: A Threat to Human and Domestic Animal Health

David G. Schmale III
Virginia Polytechnic Institute and State University, Blacksburg, VA

Gary P. Munkvold
Iowa State University, Ames, IA


Figure 24

Figure 25

Figure 26

Within the last decade, a number of important outbreaks of mycotoxicoses have been reported worldwide. Two of the most devastating and widely reported outbreaks in humans and domestic dogs are presented here. These outbreaks emphasize the need for (1) a universal (global) set of regulatory guidelines for mycotoxins in food and feed [e.g., Table 2] and (2) routine testing of staple foods and feeds for mycotoxins, particularly in developing countries.

In 2004, 125 people died following a major outbreak of aflatoxicosis in the eastern and central provinces of Kenya. Three hundred and seventeen cases were reported, and most were linked to aflatoxin poisoning from contaminated maize. Click here for a report on the Kenya outbreak by the CDC.  Maize is the main dietary staple food in Kenya, and it distributed primarily through a network of small family-owned shops and markets [Figure 24]. More than half of the maize samples tested from markets supplying the contaminated maize had aflatoxin levels greater than 20 ppb, the U.S. regulatory standard for human consumption [Table 2]. Rainfall surrounding harvest and poor storage conditions [Figure 25] may have favored the growth of aflatoxin-producing fungi, resulting in high levels of aflatoxins in maize. Though the government of Kenya provided replacement food for many of the areas that were impacted by the outbreak, sources of homegrown maize in the region were difficult to eliminate in the absence of an established system for routine testing of aflatoxin contamination. Smaller outbreaks occurred in 2005 and again in 2006 in Kenya, with another 53 fatalities.

In 2005, more than 75 dogs died in the United States after consuming pet food contaminated with aflatoxins, and hundreds more experienced severe liver problems associated with the intoxication. Click here for a news report on the pet food scare on MSNBC. The contaminated pet food was shipped to 22 different states and at least 29 different countries. The U.S Food and Drug Administration (FDA) posted a recall on December 20, 2005, and nineteen different types of pet food produced at a single facility in Gaston, South Carolina were removed from sale. Click here for the recall posted by the FDA. Sixteen batches of pet food were found to be contaminated with aflatoxins at levels greater than or equal to 20ppb. The widespread panic that followed this tragic event motivated many pet food companies to set-up routine testing services for aflatoxins [Figure 26].

Table 2. Recommendations and regulations for safe limits on mycotoxin concentrations in grain in the United States and European Union, as of 2008.


Grain for human food

Grain for animal feed






20 ppb

2-4 ppbc

20-300 ppbd

10-50 ppbd


1000 ppb

750 ppb

5,000-10,000 ppbd

1,750 ppb


200-4,000 ppbc

1,000 ppb

5,000-100,000 ppbd

4,000 ppb


No guidance levels; case-by-case basis

75-100 ppbc

1,000-200,000 ppbd

100-350 ppbd


aMunkvold, 2003a

bCommission Regulation (EC) No 1126/2007

cVaries among specific food items

dVaries among livestock species

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