Neonatal jaundice with reference to aflatoxins: an aetiological study in Zaria, northern Nigeria

Endocrine Effect of Some Mycotoxins on Humans: A Clinical Review of the Ways to Mitigate the Action of Mycotoxins

Fungi such as Aspergillus spp. and Fusarium spp., which are commonly found in the environment, pose a serious global health problem. This study aims to present the results of epidemiological studies, including clinical cases, on the relationship between human exposure to some mycotoxins, especially zearalenone and aflatoxin, and the occurrence of reproductive disorders. In addition, examples of methods to reduce human exposure to mycotoxins are presented. In March 2023, various databases (PubMed, Google Scholar, EMBASE and Web of Science) were systematically searched using Google Chrome to identify studies evaluating the association between exposure to mycotoxins and the occurrence of complications related to impaired fertility or cancer incidence. The analysed data indicate that exposure to the evaluated mycotoxins is widespread and correlates strongly with precocious puberty, reduced fertility and increased cancer incidence in women and men worldwide. There is evidence to suggest that exposure to the Aspergillus mycotoxin aflatoxin (AF) during pregnancy can impair intrauterine foetal growth, promote neonatal jaundice and cause perinatal death and preterm birth. In contrast, exposure to the Fusarium mycotoxin zearalenone (ZEA) leads to precocious sexual development, infertility, the development of malformations and the development of breast cancer. Unfortunately, the development of methods (biological, chemical or physical) to completely eliminate exposure to mycotoxins has limited practical application. The threat to human health from mycotoxins is real and further research is needed to improve our knowledge and specific public health interventions.

Mycotoxin Exposure during the First 1000 Days of Life and Its Impact on Children’s Health: A Clinical Overview

The first 1000 days of life are very sensitive to any event that alters health programming, and they represent a window for intervention to improve population health. Pregnant women, fetuses, and infants are particularly vulnerable to exposure to food contaminated with mycotoxins. This review aimed to gather data from the literature on mycotoxins exposure during intrauterine life and early childhood, and associated health risks, as assessed through human biomonitoring and mycotoxins occurrence in foods, in different continents. Maternal internal exposure to aflatoxins is associated with fetal growth restriction, while exposure to fumonisins increases the risk of offspring’s neural tube defects. Mycotoxin contamination of breast milk is reported worldwide, but data on adverse effects of the lactational transfer of mycotoxins on infant health are lacking. Young children are exposed to mycotoxins through contaminated infant formulas and baby foods. Both external and internal exposure to aflatoxins and fumonisins in children are reported to be associated with growth impairment. In low-income settings, where other co-factors can affect growth, this association should be interpreted with caution. Further studies on human biomonitoring of mother–infant pairs and young children are needed to guide management strategies aiming to minimize mycotoxin exposure at critical developmental stages.

The Presence of Mycotoxins in Human Amniotic Fluid

Mycotoxin exposure assessments through biomonitoring studies, based on the analysis of amniotic fluid, provides useful information about potential exposure of mothers and fetuses to ubiquitous toxic metabolites that are routinely found in food and the environment. In this study, amniotic fluid samples (n = 86) were collected via abdominal amniocentesis at 15–22 weeks of gestation from pregnant women with a high risk of chromosomal anomalies or genetic fetal defects detected during 1st trimester prenatal screening. These samples were analyzed for the presence of the most typical Aspergillus, Penicillium and Fusarium mycotoxins, with a focus on aflatoxins, ochratoxins and trichothecenes, using the LC-FLD/DAD method. The results showed that the toxin was present in over 75% of all the tested samples and in 73% of amniotic fluid samples from fetuses with genetic defects. The most frequently identified toxins were nivalenol (33.7%) ranging from <LOQ to 4037.6 ng/mL, and aflatoxins (31.4%), including aflatoxin G1, ranging from <LOQ to 0.4 ng/mL. Ochratoxin A and deoxynivalenol were identified in 26.7% and 27.9% of samples, respectively. Bearing in mind the above, the detection of mycotoxin levels in amniotic fluid is useful for the estimation of overall risk characterization with an attempt to link the occurrence of fetal abnormalities with exposure to mycotoxins in utero.

Mycotoxin exposure and pregnancy

Pregnancy is not a disease condition; it is a physiological process. However, the risks prevail until this process ends. While many pregnancies and births culminate without any problems, a considerable number of them end up with undesirable pregnancy outcomes such as intrauterine growth retardation, preterm labor, and low birth weight infants. Although the causes of these negative pregnancy outcomes are not fully understood, they occur in a multifactorial ways. One of the important issues here is the foods consumed by women with pregnancy. Pregnant women should avoid consuming fast food products, alcohol, or tobacco, which are already known to be harmful to human health, as well as harmful natural products containing mycotoxins. Mycotoxins are natural toxins with a wide range of chemical structures. While people can get these toxins directly from agricultural products, they can also be exposed indirectly through products of animals fed with contaminated feed. Mycotoxins have negative impacts on human health with their carcinogenic, teratogenic, and mutagenic effects. There are some evidences that mycotoxins can lead to negative pregnancy outcomes. These possible negative effects have been determined to be lower birth weight, neonatal jaundice, fetal loss, fetal defects, preterm birth, maternal anemia, and preeclampsia. However, more evidence is needed on this topic. This review aims to investigate the adverse effects of mycotoxins during pregnancy.

Maternal mycotoxin exposure and adverse pregnancy outcomes: a systematic review

Mycotoxin exposure from food occurs globally but is more common in hot humid environments, especially in low-income settings, and might affect pregnancy outcomes. This study aimed to synthesize the evidence from epidemiological studies on the relationship between maternal or fetal exposure to different mycotoxins and the occurrence of adverse pregnancy outcomes. Multiple databases were systematically searched up to December 2018 to identify studies that assessed the association between mycotoxin exposure in pregnant women or fetuses and at least one pregnancy outcome. Studies were appraised and results were synthesized using standard methods for conducting systematic reviews. This review identified and included 17 relevant studies. There is some evidence to suggest that exposure to various Aspergillus mycotoxins (e.g., aflatoxin) during pregnancy may impair intrauterine fetal growth and promote neonatal jaundice. Findings were inconclusive concerning the influence of aflatoxin exposure on perinatal death and preterm birth. Only two studies assessed effects of maternal exposure to Fusarium mycotoxins (e.g., fumonisin) on adverse pregnancy outcomes. These studies found that maternal fumonisin exposure may be associated with hypertensive emergencies in pregnancy and with neural tube defects. Studies using grain farming and weather conditions as a proxy measure for mycotoxin exposure found that such exposure was associated with an increased risk of preterm birth and late-term miscarriage. In conclusion, there is already some evidence to suggest that exposure to mycotoxins during pregnancy may have detrimental effects on pregnancy outcomes. However, given the limited number of studies, especially on effects of Fusarium mycotoxins, more studies are needed for a more comprehensive understanding of the effects of different mycotoxins on maternal and fetal health and to guide public health policies and interventions.

Dietary mycotoxins exposure and child growth, immune system, morbidity, and mortality: a systematic literature review

The aim of this study was to systematically review associations between dietary mycotoxins exposure and child growth and morbidity of children aged 5 years or younger. Peer-reviewed literature was searched in MEDLINE, EMBASE, COCHRANE, CINAHL, Web of Science, and PsycINFO. Experimental and observational studies were considered. The exposures were dietary mycotoxins during pregnancy, lactation and childhood, and mycotoxins concentrations in the diet, breast milk, urine, and blood. From a total of 4869 references, 86 full-text papers were extracted of which 50 were included in this review. The methodological quality and risk of bias were evaluated and quality of the collective evidence was assessed using GRADE. Uncertainty remains whether mycotoxins exposure affects child growth, immunity and mortality and the overall quality of the evidence is very low. Overall however, we cannot rule out a possible association between dietary mycotoxins, in particular, AF and FUM and child malnutrition. Our analyses were limited by the reporting quality, difference in findings, heterogeneity of outcomes, mycotoxins detection methods, and the observational nature of most studies. Robust study designs with adequate sample size, use of validated biomarkers of exposure and assessment of co-occurrence of mycotoxins and their synergistic effects are required to provide the further evidence regarding a potential effect of dietary mycotoxins exposure on child growth and immunity.

Mycotoxin exposure and adverse reproductive health outcomes in Africa: a review

It is well established that mycotoxin exposure can have adverse effects on reproductive health resulting to poor reproductive potential. The most studied mycotoxin in relation to poor reproductive health in humans is aflatoxin, although fumonisins, trichothecenes and zearalenone have also been reported to impair reproductive function and cause abnormal foetal development. These potent fungal toxins contaminate many food products making them a prominent agricultural, food safety and public health challenge, especially in Africa due to little or lack of mycotoxin regulation in agricultural products. Neonates can be exposed to aflatoxins in utero, as the toxins pass from mother to the foetus through the placenta. This exposure may continue during breast feeding, to the introduction of weaning foods, and then foods taken by adults. The consequences of aflatoxin exposure in mothers, foetus and children are many, including anaemia in pregnancy, low birth weight, interference with nutrient absorption, suppression of immune function, child growth retardation and abnormal liver function. In males, reports have indicated a possible relationship between aflatoxin exposure and poor sperm quality culminating in infertility. Maternal exposure to fumonisin during early pregnancy has been associated with increased risk of neural tube defects among newborns in regions where maize is the common dietary staple with the possibility of chronic fumonisin exposure. Furthermore, zearalenone has been linked to precocious puberty and premature thelarche in girls, correlating with extremely high serum oestrogen levels. This review presents an overview of the several reports linking aflatoxins, fumonisins, trichothecenes, and zearalenone exposure to poor reproductive health outcomes in Africa, with emphasis on birth outcomes, foetal health and infertility.

Follow-up of Children with Kernicterus in Kano, Nigeria

INTRODUCTION

Acute bilirubin encephalopathy (ABE) is associated with long-term sequelae (kernicterus). It continues to be a significant issue in our region of Nigeria, accounting for much morbidity and mortality. Herein we report the outcome of neonates with ABE seen at our centre.

METHODOLOGY

We established a surveillance of children who had ABE and returned to follow-up from prospective cases of ABE (2012-2014). ABE was diagnosed based on a bilirubin-induced neurologic dysfunction score of ≥ 1. Kernicterus was subsequently established based on a history of developmental delays, hearing impairments and abnormal physical and neurologic examinations at follow-up age ≥3 months.

RESULT

Five hundred fifty-one neonates had hyperbilirubinaemia of whom 104 (18.8%) had ABE. Mean transcutaneous bilirubin using the Ingram icterometer was 18.3 mg/dl  ±  SD 1.9 [(12.5-19.1), total serum bilirubin of 18.1 ± 10.9] (range: 10.3-64 mg/dl). Sixty-five infants returned for follow-up (41 males and 24 females); mean age 9 months (22 days to 17 months). Most (58 of 65; 89.2%) had abnormal neurological findings and 15 (25.9%) had probable kernicterus.

CONCLUSION

There is a critical need for a National Kernicterus Registry to document all cases of kernicterus and formulate an effective treatment and prevention policy.

Aflatoxins and growth impairment: a review

Aflatoxins, fungal toxins produced by Aspergillus flavus and Aspergillus parasiticus in a variety of food crops, are well known as potent human hepatocarcinogens. Relatively less highlighted in the literature is the association between aflatoxin and growth impairment in children. Foodborne aflatoxin exposure, especially through maize and groundnuts, is common in much of Africa and Asia--areas where childhood stunting and underweight are also common, due to a variety of possibly interacting factors such as enteric diseases, socioeconomic status, and suboptimal nutrition. The effects of aflatoxin on growth impairment in animals and human children are reviewed, including studies that assess aflatoxin exposure in utero and through breastfeeding. Childhood weaning diets in various regions of the world are briefly discussed. This review suggests that aflatoxin exposure and its association with growth impairment in children could contribute a significant public health burden in less developed countries.

Aflatoxin B1 albumin adducts in plasma and aflatoxin M1 in urine are associated with plasma concentrations of vitamins A and E

BACKGROUND

Although aflatoxin exposure has been associated with micronutrient deficiency in animals, there are few investigations on the effects of aflatoxin exposure on micronutrient metabolism in humans.

OBJECTIVE

To examine the relationship between aflatoxin B1 (AFB1) albumin adducts (AF-ALB) in plasma and the aflatoxin M1 (AFM1) metabolite in urine and plasma concentrations of retinol (vitamin A) and alpha-tocopherol (vitamin E) in Ghanaians.

METHODS

A cross-sectional study of 147 adult participants was conducted. Blood and urine samples were tested for aflatoxin and vitamins A and E levels.

RESULTS

Multivariable analysis showed that participants with high AF-ALB (>or=0.80 pmol/mg albumin) had increased odds of having vitamin A deficiency compared to those with lower AF-ALB [Odds Ratio (OR)=2.61; CI=1.03-6.58; p=0.04]. Participants with high AF-ALB also showed increased odds of having vitamin E deficiency but this was not statistically significant (OR=2.4; CI=0.96-6.05; p=0.06). Conversely, those with higher AFM1 values had a statistically nonsignificant reduced odds of having vitamin A deficiency (OR=0.31; CI=0.09-1.02; p=0.05) and a statistically significant reduced odds of having vitamin E deficiency (OR=0.31; CI=0.10-0.97; p=0.04). Participants with high AF-ALB or high AFM1 (>or=437.95 pg/dL creatinine) were almost 6 times more likely to be hepatitis B virus surface antigen (HBsAg)-positive (OR=5.88; CI=1.71-20.14; p=0.005) and (OR=5.84; CI=1.15-29.54; p=0.03) respectively.

CONCLUSIONS

These data indicate that aflatoxin may modify plasma micronutrient status. Thus, preventing aflatoxin exposure may reduce vitamin A and E deficiencies.

Association between birth outcomes and aflatoxin B1 biomarker blood levels in pregnant women in Kumasi, Ghana

OBJECTIVE

To investigate the association between birth outcomes and blood levels of aflatoxin B(1) (AFB1)-lysine adduct in pregnant women in Kumasi, Ghana.

METHOD

A cross-sectional study of 785 pregnant women attending antenatal clinic was conducted. Aflatoxin B(1) (AFB(1))-lysine adduct levels were determined by high performance liquid chromatography (HPLC) on blood taken after delivery. The birth outcomes considered were small for gestation age, low birthweight, preterm delivery and stillbirth. Participants were divided into quartiles based on the distribution of aflatoxin B(1)-lysine adducts in pg/mg albumin ('low': <or=2.67, 'moderate': >2.67 to <or=4.97, 'high': >4.97 to <or=11.34, 'very high': >11.34). Statistical analysis involved models that included socio-demographic variables and other potential confounders.

RESULTS

The average AFB(1)-lysine adduct level in maternal serum was 10.9 +/- 19.00 pg/mg albumin (range = 0.44-268.73 pg/mg). After adjusting for socio-demographic variables and potential confounding factors, participants in the highest AFB(1)-lysine quartile with 'very high' AFB(1)-lysine level (>11.34 pg/mg) were more likely to have low birthweight babies (OR, 2.09; 95% CI, 1.19-3.68), and showed a trend of increasing risk for low birthweight (P(trend) = 0.007) compared to participants in the lowest quartile.

CONCLUSION

This study adds to the growing body of evidence that aflatoxins may increase the risk of adverse birth outcomes. The findings have implications for targeted nutritional education of pregnant women in areas with high levels of aflatoxin contamination of foods.

Mycotoxins and child health: the need for health risk assessment

The occurrences of mycotoxins as food contaminants in different localities particularly in developing countries and the inevitable exposure of populations and children to these toxins with probable adverse outcomes need be scientifically and systematically assessed. Health risk assessment developed in the 1980s is separate from risk management, both with risk communication form the risk analysis framework adopted by the World Health Organization. The process contributes increasingly to policy development, public health decision making, the establishment of mycotoxin regulations and research planning. However, the exercise of the risk assessment structured approach is not simple and is faced up to lack of data, capable infrastructure facilities and need for trained personnel and resources. Furthermore, adopted methodologies need be developed focusing on child characteristics and health concerns.

Maternal views on infant hearing loss in a developing country

BACKGROUND

Parental support for infant hearing loss is essential for a successful infant screening programme. However, in developing countries where unfavourable customs and beliefs towards childhood disabilities have been reported, parental support towards infant screening is uncertain and there is presently no published evidence on the subject.

OBJECTIVE

To elicit the views of mothers and would-be mothers in order to ascertain their knowledge on infant hearing loss and their attitudes towards infant hearing screening.

METHODS

A structured questionnaire consisting of 15 questions was administered to 101 mothers (mean age 31.6+/-7.3 years, range: 21-55 years) attending two community hospitals in Lagos, Nigeria. The responses were evaluated by descriptive statistics, factor analysis of the principal components and multiple regression analysis. The reliability of the two main domains (knowledge and attitude) was tested for internal consistency by Cronbach's alpha coefficient.

RESULTS

Maternal knowledge was highest for measles (73%; mean score 2.54) and ear discharge (73%; mean score 2.51) but low for birth asphyxia (37%; mean score 1.90), traditional medicine (42%; mean score 2.03) and jaundice (47%; mean score 2.09) as causes of hearing loss. Attitude towards neonatal screening was positive in majority of mothers (92%; mean score 2.84) and there was a high acceptance of hearing aids as an early intervention option (84%; mean score 2.70). Five factors (eigenvalue>1) were extracted after principal component analysis with the attitude variables loading highly and exclusively on one factor. Age was the only demographic variable that was associated with a domain (knowledge) after multiple regression analysis. The component scales for the two domains were highly internally consistent (alpha coefficients of 0.84 and 0.83).

CONCLUSIONS

Contrary to the concerns often expressed about parental support for infant hearing screening programmes in developing countries, this study suggests that current parental knowledge and attitude favour early detection and intervention of childhood hearing impairment.

Glucose-6-phosphate dehydrogenase deficiency in neonatal indirect hyperbilirubinemia

The aim of this article is to investigate the prevalence of Glucose-6-phosphate dehydrogenase (G6PD) deficiency in neonatal hyperbilirubinemia and to compare the clinical presentation and course of G6PD-deficient and normal patients. This study included a total of 624 term neonates with indirect hyperbilirubinemia from March 2001 to September 2004. Birth weight, sex, weight at admission, serum bilirubin at admission, maximum bilirubin, phototherapy duration, duration of hospitalization and the need for exchange transfusion were recorded. Laboratory evaluations included blood group typing of mother and newborn, complete blood count, peripheral blood smear, serum total and direct bilirubin, direct coombs test, reticulocyte count, serum-free T4 and TSH, urine analysis, urinary reducing substance and erythrocyte G6PD level. The analysis of the results indicated that 24 neonates with indirect hyperbilirubinemia were G6PD-deficient. No statistically significant difference was detected between G6PD-deficient and normal groups in relation to the time of onset of jaundice, reticulocyte count, hematocrit level, phototherapy duration and duration of hospitalization. Serum bilirubin at admission, maximum serum bilirubin level and the need for exchange transfusion were higher in G6PD-deficient group. From this study our conclusion is that the G6PD deficiency is a common enzyme defect causing severe indirect hyperbilirubinemia which may result in kernicterus. Early neonatal screening programmes should be instituted in countries where the deficiency is prevalent.

Morbidity in neonates of mothers who have ingested aflatoxins

This study was undertaken to assess whether aflatoxin M(1) concentrations in newborn infants correlated with those of their mothers and to determine whether the presence of aflatoxin M(1) in cord blood was associated with an increase in morbidity in the newborn. There was a strong correlation (r =0.797, p <0.0001) between mothers' and cord blood levels of aflatoxin. There was also a strong negative correlation between aflatoxin levels and birthweight (r =-0.565, p <0.001) but there was no association between aflatoxin M(1) concentration in maternal or cord blood and rates of jaundice or infection.

Transcutaneous bilirubin measurements and serum total bilirubin levels in indigenous African infants

OBJECTIVE

The objective of this study was to determine whether transcutaneous bilirubin (TcB) measurements correlate with serum total bilirubin (STB) levels in indigenous, darkly pigmented African newborns with varying degrees of skin pigmentation, some of which had developed kernicterus.

METHODS

Jaundiced infants who were < or =2 weeks of age and admitted to Baptist Medical Center-Eku (Eku; n = 29) and Jos University Teaching Hospital (Jos; n = 98) in Nigeria were studied. TcB measurements using the BiliChek were made simultaneously with blood sampling for STB measurements by spectrophotometry before phototherapy.

RESULTS

Using linear regression analysis, we found that measurements of TcB correlated well with those of STB with r values of.90 and.88 for Eku and Jos, respectively. Mean bias and imprecision of TcB measurements as compared with STB measurements for the total population was 0.5 +/- 7.6 mg/dL using the method of Bland and Altman. At STB > or 12 mg/dL, correlation (r =.84) and bias and imprecision (-1.2 +/- 8.6 mg/dL) of measurements were only slightly poorer. Furthermore, when infants were grouped by degree of skin pigmentation, correlations of TcB and STB measurements remained strong.

CONCLUSIONS

From these results, we can conclude that TcB measurements are a useful and reliable index for estimating STB levels in pigmented neonates, including those with hyperbilirubinemia and kernicterus. In the absence of reliable STB measurements, the relatively simple and noninvasive TcB measurements can be an important adjunct in directing phototherapy and exchange transfusions, thereby preventing bilirubin-induced morbidity and mortality in low-technology clinical environments.

Benefits and challenges of newborn hearing screening for developing countries

The late detection of permanent congenital and early-onset hearing loss (PCEHL) often has severe effects on linguistic, speech, cognitive and educational development in affected children. Since newborn hearing screening (NHS) allows most PCEHL to be detected early enough for optimal intervention, the prospects of its introduction in the developing world are reviewed in this paper. It is observed that a simple generalisation on the feasibility of NHS for the developing countries seems inappropriate in view of the diversities in the health and socio-economic status of these countries and the recent favourable reports of universal newborn hearing screening from the region. NHS empowers parents to make timely choices that will allow their hearing impaired children to be given a good start in life and be fully integrated into the wider community. It also compels attention towards the development of essential hearing healthcare services, besides the specific documented benefits. Existing child-healthcare structures such as the expanded programme on immunisation (EPI), baby friendly hospital initiatives (BFHI) and integrated management of childhood illness (IMCI) provide opportunities for the introduction of some form of NHS in many of these countries where routine or systematic childhood hearing screening does not exist. Limited funding, manpower shortages, inadequate support services, low public awareness and the uncertainty regarding the commitment from healthcare practitioners may present some challenges but these are not insurmountable. Pilot studies are necessary in each country to provide empirical data that will guide healthcare providers who wish to introduce such a programme at any level of healthcare delivery.

Aflatoxins in the lungs of children with kwashiorkor and children with miscellaneous diseases in Nigeria

Autopsy lung specimens from 20 children with kwashiorkor and 20 with other miscellaneous diseases, at the Obafemi Awolowo Teaching Hospital complex, Ile-Ife, Nigeria, were analyzed for the presence of aflatoxin using high-performance liquid chromatography. Aflatoxins were detected in 18 children who died from kwashiorkor but only in 13 of those who died from miscellaneous diseases. Of the 10 children, 5 in each group, who died with pneumonia, all had detectable levels of aflatoxins in their lungs. The two children with congestive cardiac failure, one secondary to pneumonia and the other secondary to tuberculous pericarditis, had more than two detectable aflatoxins in their lungs. These findings demonstrate that Nigerian children are exposed to aflatoxins and that high levels can accumulate in lung tissue.