Human Aflatoxin Exposure in Kenya, 2007: a Cross-Sectional Study

Abstract

Aflatoxins contaminate approximately 25% of agricultural products worldwide. They can cause liver failure and liver cancer. Kenya has experienced multiple aflatoxicosis outbreaks in recent years, often resulting in fatalities. However, the full extent of aflatoxin exposure in Kenya has been unknown. Our objective was to quantify aflatoxin exposure across Kenya. We analysed aflatoxin levels in serum specimens from the 2007 Kenya AIDS Indicator Surveya nationally representative, cross-sectional serosurvey. KAIS collected 15,853 blood specimens. Of the 3180 human immunodeficiency virus-negative specimens with ≥1 mL sera, we randomly selected 600 specimens stratified by province and sex. We analysed serum specimens for aflatoxin albumin adducts by using isotope dilution MS/MS to quantify aflatoxin B1-lysine, and normalised with serum albumin. Aflatoxin concentrations were then compared by demographic, socioeconomic and geographic characteristics. We detected serum aflatoxin B1-lysine in 78% of serum specimens (range = <LOD-211 pg/mg albumin, median = 1.78 pg/mg albumin). Aflatoxin exposure did not vary by sex, age group, marital status, religion or socioeconomic characteristics. Aflatoxin exposure varied by province (p < 0.05); it was highest in Eastern (median = 7.87 pg/mg albumin) and Coast (median = 3.70 pg/mg albumin) provinces and lowest in Nyanza (median = <LOD) and Rift Valley (median = 0.70 pg/mg albumin) provinces. Our findings suggest that aflatoxin exposure is a public health problem throughout Kenya, and it could be substantially impacting human health. Wide-scale, evidence-based interventions are urgently needed to decrease exposure and subsequent health effects.

Determinants of recent aflatoxin exposure among pregnant women in rural Zimbabwe

“…There are conflicting evidence for associations between wealth and AF exposure in prior studies. Four studies investigated the sociodemographic determinants of AF exposure: two (Kenya and Ghana) reported lower AF exposure in higher‐income households and two (also Kenya and Ghana) reported no relationship . Although AF exposure did not vary across wealth quintiles, it is possible that the pathways to exposure vary among economic subgroups.…”

Aflatoxin Exposure and Associated Human Health Effects, a Review of Epidemiological Studies

“…More recently, the AF-alb biomarker has revealed high aflatoxin exposure in East African countries including Kenya 14) , where AF-alb was detected in 78% of 597 serum samples (non detectable (ND) − 211 pg/mg); in Uganda 15) , where AF-alb was detected in 192/196 (98%) samples (range ND to 237.7 pg/mg) collected from adults and children; and in Tanzania 16) , where AF-alb was detected in 67% to 99% of samples collected from young children (see Table 1 for more details). In North and South Africa, where the climate is drier, the prevalence of aflatoxin exposure is lower than the levels observed in East and West Africa [17][18][19] .…”

Aflatoxin exposure in utero and birth and growth outcomes in Tanzania

“…Lastly, different researchers use different methods of sample analysis. Some have argued that the HPLC method for detecting aflatoxin levels is less sensitive than the ELISA and liquid chromatography with tandem mass spectrometry methods (McCoy et al, ), and Yard et al () found that the estimated AFB1‐lysine adduct values from the ELISA method are typically 4.6 times higher than those from the HPLC‐fluorescence measurement (Yard et al, ). As a result, aflatoxin levels differing across studies may also stem from differences in the laboratory method used, which should be noted when interpreting the results.…”