The influence of awareness, knowledge and practices of communities on childhood dietary exposure to aflatoxins in Central Regions of Tanzania

A Thesis 2019

Complementary foods in Tanzania are heavily contaminated with aflatoxin (AFs), a group of highly toxic metabolites produced by the fungi Aspergillus flavus and Aspergillus parasiticus. Many people and especially children largely depend on consumption of cereal-based diets as complementary foods. Unfortunately, cereals and nuts have been associated with aflatoxin contamination where conditions favour growth and proliferation of the causative moulds. This study was conducted with an overall objective to examine the influence of awareness, knowledge and actions of communities on childhood dietary exposure to aflatoxins in Dodoma and Singida regions. The specific objectives were: (i) to assess communities’ level of awareness, knowledge, attitude and perceptions of aflatoxins, (ii) to identify practices that contribute to levels of contamination of aflatoxins in these areas (iii) to identify local barriers and practices associated with reducing aflatoxins contamination in complementary foods in the community (iv) to determine complementary feeding practices among infants aged between 6-23 months and (v) to determine the level of aflatoxins in ready-to-cook foods used in complementary feeding. A descriptive study of the awareness, attitude, perception and actions of communities towards aflatoxin contamination in complementary foods and its health risks was conducted in Bahi and Chamwino districts in Dodoma Region; and Manyoni and Ikungi districts in Singida Region, central Tanzania. The districts were chosen as they represented the semi-arid condition which is characterized by high temperature during the day up to 35°C and cool to 10°C during the night. Both temperature and humidity favour growth of fungi which indicate possibility of aflatoxin production. The respondent’s level of awareness of aflatoxin contamination in crops used in preparation of complementary foods, and health risks associated with its ingestion was assessed. A suitable scale was developed used to measure awareness of aflatoxins contamination in complementary foods and its health effects in the community of the children aged 6-23 months, and Likert-type scale was used to rate respondent’s attitude and perceptions towards aflatoxin contamination in complementary foods and its managements. Health Belief Model (HBM) was used to determine parents’ perception and attitude towards aflatoxins contamination and control. Exploratory Factor Analysis identified the underlying constructs of the Health Belief Model (HBM). Data were collected using an interview schedule which was administered to 364 randomly selected respondents and 228 ready-to-cook complementary foods samples collected with parents/caregivers of children aged between 6-23 months from households, and focus group discussions (FGDs) with 121 (105 females and 16 males) participants to obtain personal experiences about aflatoxin contaminations in complementary foods and its health effects on the community. The mean age of respondents was of 30 ± 8.3 years and the majority (73.1%) was married. Among 364 respondents, 87.6% were farmers and 70.3% earned less than or equal to US$ 22.8 per month. The majority of respondents (56%) had primary school education while 0.8% were university graduates. About 81.9% respondents were not aware of aflatoxin contamination and associated health effects, and half of parents who were responsible for preparation of complementary foods had low perception and attitude of harmful effects of aflatoxins contamination to human and animals in general. Fifty seven samples were collected from each of the four studied districts of Dodoma and Singida regions and used to determine aflatoxin (AF) contamination of ready-to-cook complementary foods of the children aged between 6-23 months. Contamination was correlated with levels of awareness, perception and actions of parents towards contamination and control. The Romar’s all-purpose method was used for the extraction of total aflatoxins for analysis by HPLC. The total aflatoxins contamination in 228 the ready-to-cook complementary food samples had level up to 60.3μg/kg. About 53% samples were contaminated by aflatoxins and 24.1% of the samples exceeding the maximum permissible levels of 10μg/kg. Samples with aflatoxin B 1 had level up to 38.2 μg/kg and 15.4% of all samples were contaminated. Samples that were contaminated, (45.7%) had levels above 5μg/kg which is the recommended limit. Manyoni and Chamwino had equal proportions of complementary food samples with aflatoxins B 1 contamination of 19.3%. Ikungi district had the least prevalence of aflatoxins B 1 (7%). The results of the Univariate analysis showed that, awareness, knowledge, perception, attitude and dehulling were all significantly associated with aflatoxins (AFB 1 ) contamination levels (p<0.05). The multiple logistic regression model of awareness of aflatoxins B 1 and the chance of having food with aflatoxins B 1 was significantly higher among respondents not aware of aflatoxins contamination (OR=2.929, p=0.015). People with no knowledge of aflatoxins (OR =2.739, p=0.019) had significantly greater odds of having food contaminated with aflatoxins B 1 in comparison to people with knowledge of aflatoxins. The odds of having food with aflatoxins B 1 contamination for individual with less than 22.23 perception score was almost 3 times that of people with at least 22.23 perception score (OR =3.101, p=0.022).Those respondents with less than 22.23 perception score toward aflatoxins contamination were significantly more likely to have food with aflatoxins B 1 contamination. The risk of having ready-to-cook complementary foods contaminated with aflatoxins B 1 were also found to be significantly higher among respondents not dehulling the crops used to make children's food than those who de- hulled grains (OR= 2.763, p=0.028). It might be concluded that considerable differences in contamination level were observed among the four districts. Parents in the four districts practiced similar post harvest actions though with varying degrees. Most processing activities like dehulling, milling, drying, and storage showed significant association with aflatoxins contamination of complementary foods. Due to food shortage and low knowledge or awareness on fungal and aflatoxins contamination in the study areas, the respondents sometimes ate undehulled, unsorted and mouldy crops without washing or winnowing them, hence exposing themselves to high health risks of aflatoxin contamination in their diet. Thus, it is recommended that an aggressive campaign on the use of best agricultural practices in pre- and post-harvest activities at the household level should be emphasized. There is an urgent need to raise awareness and educate parents/caregivers on aflatoxin health risks associated with complementary foods and the appropriate strategies to minimize contamination. In addition, research on climatic change and mycotoxin production during pre and post harvest practices such as tillage, breeding varieties resistance to mycotoxin, harvesting time, drying, storage, and dehulling practices of crops in Tanzanian is needed in order to improve food safety.