Comparative Analysis of Aflatoxin Contamination of Maize in Two Different Physiographic Zones and Maize Seasons in Makueni County, Kenya
AbstractBackground: Aflatoxicosis resulting from consumption of contaminated maize poses a significant public health problem in many countries including Kenya, and many people living in developing countries could be chronically exposed to aflatoxin through their diet. It is caused by Aflatoxins produced by fungus of species Aspergillus parasiticus and Aspergillus flavus found mainly in cereals and other foodstuffs.
Objective: To determine and compare prevalence of aflatoxin contamination of household maize in two different altitude areas and different maize harvest seasons, in Makueni County in Kenya.
Design: A comparative descriptive analytical study.
Setting:Kibwezi and Kilome sub-counties of Makueni County, Kenya.
Subjects: Four hundred and fifty household heads or their representatives, who had maize in their household stores.
Results: The results of first maize harvest season indicated that the mean moisture content of household maize was 12.78% in high altitude area which was slightly lower than in high altitude which had 12.85%. The aflatoxin positivity rate of maize contamination was 25% in low altitude area and 4.2% in high altitude area. The results of second maize harvest season indicated that the mean moisture content of household maize was 13.48 % in high altitude area which was slightly lower than in high altitude area which was 13.63 %. The aflatoxin positivity rate of maize contamination was 33.3 % in low altitude area which was higher than high altitude which had 12.5%. The findings show that the low altitude maize had higher moisture content and aflatoxin contamination than high altitude maize. The results further indicated that the most common strain/type of aflatoxin in both low and high altitude areas, and in both maize harvest seasons, was AF B1 followed by AF B2, with maize harvested in low altitude and second season having higher quantities of these aflatoxin sub-types. These study findings indicate that there was higher aflatoxin contamination of maize, in both subtypes, for maize harvested in second season than maize harvested in first season, in both low and high altitude areas of Makueni County, with low altitude areas having comparatively higher aflatoxin contamination than high altitude areas for maize harvested in second season.
Conclusion: These findings indicate that a sizable proportion of Makueni households mainly relying on maize consumption as their staple foodstuff are likely to consume maize contaminated with aflatoxin. There is therefore need for further public education by local authorities on risks posed by continued consumption of maize contaminated with aflatoxin as well measures to reduce levels of contamination by improving methods of storage. Government authorities need also to periodically sample maize in order to monitor moisture and aflatoxin content of householdstored maize to enable timely interventions should aflatoxin content exceed permissible levels.