Aflatoxin exposure in children living in Mirpur, Dhaka: data from MAL-ED companion study

Abstract

Dietary exposure to aflatoxin is implicated in growth faltering of children. Despite the high burden of childhood stunting in urban Bangladesh, there are no data on long-term exposure to aflatoxin. This study aimed to explore aflatoxin exposure levels in a group of children followed longitudinally. The current study used data and biospecimens collected during 2010-2014 as part of the MAL-ED birth cohort study in an urban slum of Mirpur, Dhaka where children were followed from birth to 36 months. AFB1-lysine adduct concentrations were determined by isotope dilution mass spectrometry from plasma samples collected at 7, 15, 24, and 36 months of age. The limit of detection was 0.5 pg of AFB1-lys/mg albumin. In 744 plasma samples, the geometric mean of AFB1-lysine/mg albumin was 1.07 pg (range 0.04-123.5 pg/mg albumin). The proportion of children with detectable aflatoxin exposure was 10.1, 20.9, 17.9, and 61.7% for 7, 15, 24, and 36 months, respectively. Reduction in breastfeeding prevalence (80% at 24 months vs. 38% in 36 months) corresponded with the high-level detection of AFB1-lysine at the age of 36 months. AFB1-lysine concentrations were the highest at the end of monsoon. This study reveals that 62% of children in slum settlement were exposed to aflatoxin by the end of the third year of life. High aflatoxin exposure was detected at the end of rainy season and with the introduction of family food. These findings suggest interventions to ameliorate the problem of chronic aflatoxin exposure including childhood stunting.

Determination of aflatoxin M1 and deoxynivalenol biomarkers in infants and children urines from Bangladesh

“…These results, discussed by the authors in the context of biomarker data for cohorts in other countries, document rather high AFB 1 exposures of their cohort in the Northwest of Bangladesh between 2008 and 2012. A recent longitudinal study in an urban slum in Dhaka city assessed AFB 1 exposure of children at the age of 7, 15, 24 and 36 months and reported a geometric mean of 1.07 pg AFB 1 -Lys/mg albumin and a range of 0.04–123.5 pg AFB1-Lys/mg albumin (Mahfuz et al 2019 ). In this study, a reduction in breastfeeding prevalence, with concomitant introduction of family food, corresponded with an increase in AFB 1 -lysin adduct detection at 36 months, and 62% of the children were exposed at the end of their 3 rd year of life.…”

“…However, little is known so far about mycotoxin exposure in Bangladeshi children: two studies investigated AFB 1 exposure in young children, one in a rural site in the North of the country, the other in an urban slum in Dhaka (Groopman et al 2014 ; Mahfuz et al 2019 ). Both have analyzed AFB 1 -lysin albumin in blood, a biomarker which integrates exposure during the course of several weeks.…”

Human Biomonitoring of Mycotoxins in Blood, Plasma and Serum in Recent Years: A Review

“…To release AFB1-lysine (AFB1-lys) adduct from albumin, proteins in serum samples are digested with Pronase ® for a few hours at 37 • C. AFB1-lys is then extracted and purified with SPE by means of a mixed-mode anion exchange reversed-phase matrix. Next, the analytes are eluted, mainly through the use of methanol (MeOH) with formic acid, then concentrated and reconstituted in the mobile phase before analysis with LC-MS/MS [49,65,81,83,87,[112][113][114][115], LC-FLD [81,[88][89][90][91][92] or ELISA [73][74][75][76][77][78][79]117]. McCoy et al (2008) [70] and Scholl et al (2006) [123] reported good correlations of the concentration levels obtained from ELISA, LC-FLD and LC-MS.…”

“…A number of studies have been carried out to evaluate the presence of AFs in plasma or serum from children with severe acute malnutrition (SAM) in Kenya [92], Nigeria [49], Tanzania [113,117] Uganda [88,90], Mexico [81,91] and other countries [75,[77][78][79]83,87,114,115]. This is a particularly relevant topic due to the rates of childhood growth disorders in these countries.…”

“…2.3.1. Single-Biomarker Studies.Due to the complexity of the matrices and the physicochemical diversity of mycotoxins, most of the methods currently used to analyze these toxins in human plasma and serum samples focus on assaying one mycotoxin or some structurally related mycotoxins belonging to a single family, such as AFs (AFB1, AFB2, AFG1, AFG2, AFB1-lys)[49,57,64,65,[75][76][77][78][79]81,82,[86][87][88][89][90][91][92][112][113][114][115][116][117], OTA and OTα[54,55,[61][62][63]85,118,119], CIT and DH-CIT[23,[54][55][56] and ZEA and its metabolites[58,68,69].…”