Mycotoxins are toxic secondary metabolites produced by filamentous fungi. Aflatoxins and
fumonisins are among the most toxic mycotoxins. They are a significant risk factor for a
cocktail of chronic health conditions including cancer of the liver, oesophagus and kidney,
teratogenicity, neural tube defects, interference with lipid metabolism, a weakened immune
system and a negative impact on micronutrient absorption in both man and animals. This
study compared natural contamination of peanuts, peanut butter and sorghum from Gaborone,
Botswana and Bulawayo, Zimbabwe with aflatoxins and fumonisins. In total 34 peanut
samples, 34 sorghum samples and 11 peanut butter samples were collected randomly from
retail shops and informal markets in the two cities. Fungal contamination was determined
using standard mycology methods. Aflatoxin and fumonisin contamination was determined
using HPLC-FLD. A. flavus/parasiticus species were detected in 66% and 100% of randomly
analysed peanut samples from Bulawayo and Gaborone respectively and 27% (3/11) of
peanut butter samples from Bulawayo. 67% of randomly analysed sorghum samples from
Bulawayo showed A. flavus/parasiticus and Fusarium species contamination while none of
the randomly analysed sorghum samples from Gaborone showed any fungal contamination.
Furthermore aflatoxins were not detected in any of the sorghum samples; however 61%
(11/18) of the Bulawayo sorghum samples showed fumonisin contamination (Range: 8 – 187
ng/g). Three of the peanut samples from Bulawayo were contaminated with aflatoxins (range:
6.6 – 622 ng/g) and no aflatoxins were detected in Gaborone peanuts. All 11 peanut butter
samples from Bulawayo were contaminated with aflatoxins (Mean: 73.5 ng/g, Range: 6.8-
250 ng/g) and AFB1 was the most prevalent. These preliminary results indicate that peanut
butter and peanuts from Bulawayo are contaminated with high levels of aflatoxins. Stricter
policing of regulations should be implemented to ensure compliance by manufacturers and
public health interventions implemented in vulnerable communities.