Occurrence and factors associated with aflatoxin contamination of raw peanuts from Lusaka district's markets, Zambia

• We estimated the occurrence and concentration of aflatoxins in raw peanuts.
• Aflatoxin B1 occurred more frequently and in high concentrations.
• Virginia runner peanut variety was the most susceptible to aflatoxin contamination.
• Occurrence of AFs in raw peanuts from supermarkets and open markets was similar.
• High proportion of raw peanuts from open markets exceeded international standards.

Peanuts, one of the most susceptible crops to aflatoxin (AF) contamination, are widely produced and consumed in Zambia. This cross-sectional study was designed to determine the levels of AFs in raw peanuts sold in Lusaka district's markets as well as identify factors associated with increased AF presence. Raw peanut samples were collected from open markets and supermarkets and analyzed for aflatoxin contamination using high performance liquid chromatography (HPLC). A questionnaire was also administered to the peanut vendors to investigate factors contributing to increased levels of AFs in peanuts. Of the 92 samples, 51 (55.4%; 95% CI: 44.9–65.4) tested positive for presence of AFs. The overall median and geometric mean ± standard deviation (SD) concentration for AF were 0.23 ppb (range: 0.014–48.67 ppb) and 0.43 ± 9.77 ppb, respectively. The association between market types and presence of AFs was not statistically significant (Pearson Χ2 = 0.0587, p = 0.809). Of 51 samples that tested positive to AF, 6.5% and 12% were above the maximum permissible limits (MPLs) set by the Codex Alimentarius Commission and European Union standards, respectively. There was a significant difference in the levels of AF between Chalimbana and Kadononga (p<0.0001), and also Chalimbana and Makulu red (p<0.0001). Chalimbana was the most at risk of AF contamination, when compared to other peanut varieties. The high level of AFs in raw peanuts from both supermarkets and open markets samples constitutes a health hazard for the population of Lusaka district. Therefore, intervention strategies that reduce the levels of AF contamination in peanuts should be given priority.