Dietary exposure to aflatoxin and fumonisin among Tanzanian children as determined using biomarkers of exposure

Abstract

Scope The study aims to evaluate the status of dietary exposure to aflatoxin and fumonisin in young Tanzanian children, using previously validated biomarkers of exposure. Methods and results A total of 148 children aged 12 to 22 months, were recruited from three geographically distant villages in Tanzania; Nyabula, Kigwa and Kikelelwa. Plasma aflatoxin-albumin adducts (AF-alb) and urinary fumonisin B1 (UFB1) were measured by ELISA and LC-MS, respectively. AF-alb was detectable in 84% of children, was highest in fully weaned children (p<0.01) with higher levels being associated with higher maize intake (p<0.05). AF-alb geometric mean (95% CI) was 43.2 (28.7–65.0), 19.9 (13.5–29.2) and 3.6 (2.8–4.7) pg/mg albumin in children from Kigwa, Nyabula and Kikelelwa, respectively. UFB1 was detectable in 96% of children and the level was highest in children who had been fully weaned (p<0.01). The geometric UFB1 mean (95% CI) was 327.2 (217.1–493.0), 211.7 (161.1–278.1) and 82.8 (58.3–117.7) pg/ml in Kigwa, Nyabula and Kikelelwa, respectively. About 82% of all the children were exposed to both mycotoxins. Conclusion Young children in Tanzania are chronically exposed to both aflatoxin and fumonisin through contaminated diet, although the level of exposure varies markedly between the three villages studied.

Longitudinal evaluation of aflatoxin exposure in two cohorts in south-western Uganda

“…The averaged adduct level is actually higher than the levels found in children from Kikelelwa, Tanzania (0.78 pg mg −1 albumin after conversion by division of 4.6) (Shirima et al 2013;Yard et al 2013). However, the adduct level is still lower than averaged levels found from neighbouring countries, such as Kenya and Tanzania, and West African countries, such as Ghana, Gambia, Benin and Togo (Gong et al 2002(Gong et al , 2012Ofori-Adjei 2012;Shirima et al 2013). This may be again due to different diet patterns in study participants or different AF exposure levels, or the degradation of AFB-Lys adducts in our serum samples analysed.…”

“…If taking their proposed 4.6 conversion, the AFB-Lys adduct level in our study using GPC study samples is similar to that of Asiki et al (2014). The averaged adduct level is actually higher than the levels found in children from Kikelelwa, Tanzania (0.78 pg mg −1 albumin after conversion by division of 4.6) (Shirima et al 2013;Yard et al 2013). However, the adduct level is still lower than averaged levels found from neighbouring countries, such as Kenya and Tanzania, and West African countries, such as Ghana, Gambia, Benin and Togo (Gong et al 2002(Gong et al , 2012Ofori-Adjei 2012;Shirima et al 2013).…”

Comparison of urinary aflatoxin M1 and aflatoxin albumin adducts as biomarkers for assessing aflatoxin exposure in Tanzanian children

“…The methodology for collection of blood samples from these children and the subsequent analysis of AF-alb is as previously reported (Shirima et al, 2013). Briefly, albumin was extracted from blood, digested, purified and AF-alb was detected by a competitive ELISA using a rabbit polyclonal antibody (Chapot and Wild 1991).…”

“…We have previously published results from a study of dietary exposure of Tanzanian children to mycotoxins, in which AF-alb was used to assess exposure to aflatoxin (Shirima et al, 2013;Routledge et al, 2014). The urine samples collected from the children during the previous study provides an opportunity to analyse urinary AFM1, using an optimised commercial direct ELISA kit, and compare AFM1 and AF-alb biomarkers of aflatoxin exposure in young children.…”

A review of agricultural aflatoxin management strategies and emerging innovations in sub-Saharan Africa

“…Global risk assessment studies associate between 25,200 and 155,000 human liver cancer cases per year with aflatoxin exposure [7]. Aflatoxins have also been reported to cause immune suppression in children and there is an association between aflatoxins and stunting in children [8][9][10] as well as lower weight babies at birth [11,12], but this has not been proven to be a causal relation. In Kenya, consumption of aflatoxincontaminated maize affected 317 people with 125 deaths in 2004 [13].…”