Estimating the risk of aflatoxin-induced liver cancer in Tanzania based on biomarker data.

Evidence about the magnitude of the aflatoxin menace can help policy makers appreciate the importance of the problem and strengthen policies to support aflatoxin mitigation measures. In this study, we estimated aflatoxin-induced liver cancer risk in 2016 for Tanzania and used the information to estimate the health burden due to the aflatoxin exposure in the country. The burden of aflatoxin-induced liver cancer was assessed based on available aflatoxin biomarker data from a previous epidemiology study, hepatitis B virus infection prevalence and population size of Tanzania in 2016. The health burden due to aflatoxin-induced liver cancer was estimated using disability adjusted life years (DALYs). The aflatoxin exposures ranged from 15.0-10,926.0 ng/kg bw/day (median, 105.5 ng/kg bw/day). We estimated that in 2016 there were about 1,480 (2.95 per 100,000 persons) new cases of aflatoxin-induced liver cancer in Tanzania and assumed all of them would die within a year. These morbidity and mortality rates led to a total loss of about 56,247.63 DALYs. These results show, quantitatively, the cases of liver cancer and related deaths that could be avoided, and the healthy life years that could be saved, annually, by strengthening measures to control aflatoxin contamination in Tanzania.

Estimating the health burden of aflatoxin attributable stunting among children in low income countries of Africa.

Numerous population-based studies have documented high prevalence of aflatoxin associated childhood stunting in low income countries. We provide an estimate of the disease burden of aflatoxin related stunting using data from the four African countries. For this empirical analysis, we obtained blood aflatoxin albumin adduct biomarker based exposure data as measured using ELISA technique and anthropometric measurement data from surveys done over a 12-year period from 2001 to 2012 in four low income countries in Africa. We used these data to calculate population attributable risk (PAR), life time disease burden for children under five by comparing two groups of stunted children using both prevalence and incidence-based approaches. We combined prevalence estimates with a disability weight, measuring childhood stunting and co-occurrence of stunting-underweight to produce years lived with disability. Using a previously reported mortality, years of life lost were estimated. We used probabilistic analysis to model these associations to estimate the disability-adjusted life-years (DALYs), and compared these with those given by the Institute for Health Metrics and Evaluation's Global Burden of Disease (GBD) 2016 study. The PAR increased from 3 to 36% for aflatoxin-related stunting and 14-50% for co-occurrence of stunting and underweight. Using prevalence-based approach, children with aflatoxin related stunting resulted in 48,965.20 (95% uncertainty interval (UI): 45,868.75-52,207.53) DALYs per 100,000 individuals. Children with co-occurrence of stunting and underweight due to exposure to aflatoxin resulted in 40,703.41 (95% UI: 38,041.57-43,517.89) DALYs per 100,000 individuals. Uncertainty analysis revealed that reducing aflatoxin exposure in high exposure areas upto non-detectable levels could save the stunting DALYs up to 50%. The burden of childhood all causes stunting is greater in countries with higher aflatoxin exposure such as Benin. In high exposure areas, these results might help guide research protocols and prioritisation efforts and focus aflatoxin exposure reduction. HEFCE Global Challenge Research Fund Aflatoxin project.

Deoxynivalenol exposure assessment in young children in Tanzania.

SCOPE: This study assessed deoxynivalenol (DON) exposure in children from three geographic locations within Tanzania, over three time points in 1 year, using a urinary biomarker of exposure. METHODS AND RESULTS: A total of 166 children aged 6-14 months were studied at a maize harvest and followed up twice at 6-month intervals. On two consecutive days, morning urine was collected from each child and urinary DON was measured using an LC-MS method, with and without ß-glucuronidase hydrolysis in order to assess free DON (fDON) and glucuronide DON. Overall, urinary DON increased significantly along with the three visits (geometric mean 1.1, 2.3, and 5.7 ng/mL, at visits 1, 2, and 3, respectively, p < 0.01). fDON was 22% of urinary total DON. Urinary DON excretion rate was 74% in village Kikelelwa based on food DON level and food consumption. Assuming 360 mL of urine excreted per day, 10, 19, and 29% of children at visits 1, 2, and 3, respectively, exceeded the provisional maximum tolerable daily intake of 1000 ng/kg b.w./day. CONCLUSION: Young children in Tanzania are chronically exposed to DON due to eating contaminated maize, although exposure levels varied markedly by region and season.