Aflatoxin Contents and Exposure in Young Children, and Sensory Characteristics of a Nixtamalized Supplementary Porridge

Aflatoxin contamination of maize, is of major concern in Malawi, and levels are much higher than the tolerance limits for aflatoxin B1 and total aflatoxins. Maize is a staple for Malawians and the forms prepared for consumption are presumed to have carryover toxins.  Likuni phala; a porridge flour formulated from maize and soybean in the ratio of 4:1(w/w), was developed as a supplementary food to alleviate Protein Energy Malnutrition (PEM), which is highly prevalent  in under five year old children. It is assumed that the product is contaminated with carryover aflatoxin. Nixtamalization or alkali cooking has been found to reduce aflatoxin contents among other effects. The aim of this study was to establish the levels of total aflatoxin in the Likuni phala, determine their reduction in porridge preparation by addition of alkali, assess the exposure to aflatoxin in small children and also test for its sensory acceptability. Samples were collected from three factories, two cottage and one large, all located in districts of the Southern Region of Malawi. Three samples were collected from each factory at two week intervals. The samples were analysed for total aflatoxin, then cooked into porridge with addition of lime at levels between 0.1% – 0.8%. The porridges were analysed for aflatoxin and subjected to sensory evaluation. Exposure to aflatoxin on the children was also calculated.  Results showed that aflatoxin was absent in the samples from the cottage industries, but all the three samples from the large factory contained levels above the tolerance levels (10µg kg-1 for total and 5µg kg-1 for Aflatoxin B1). Cooking with alkali reduced the levels of aflatoxin to below the tolerance levels even at the lowest level of alkali addition. Sensory evaluation showed that the porridges were acceptable only up to 0.4% lime addition. The potential aflatoxin exposure to children was substantially reduced. The study concluded that acceptable Likuni phala porridge with aflatoxin levels below the tolerance levels, and substantially reduced exposure in children can be prepared by cooking with alkali addition. Keywords: Aflatoxin, Supplemental maize porridge, Nixtamalization, acceptability, Under 5 children

Distribution of Cassava Bacterial Blight and Reaction of Selected Cassava Genotypes to the Disease in Kenya

Cassava bacterial blight (CBB) disease is an important bacterial disease of cassava. A study was carried out to determine the distribution of CBB in Kenya and to evaluate selected cassava genotypes for reaction to the disease. A survey was conducted in all the cassava growing regions within the country where cassava leaves showing symptoms of CBB were collected and isolated for biochemical characterization and PCR detection of the causal agent. The isolates were then used to determine the reaction of seven cassava genotypes to the disease. The disease was present in 17 out of the 21 counties surveyed. The bacteria extracted from the leaf samples conformed to all the biochemical and physiological tests specific to Xanthomonas axonopodis pv manihotis and to xanthomonads in general.  Polymerase chain reaction amplified the expected 500 base pairs fragment. Disease prevalence was highest in Kwale County at 100% Kilifi County recorded the highest incidence at 64%. All the genotypes evaluated in the greenhouse had area under disease progress curve (AUDPC) values higher than 52 which grouped them as susceptible. The study confirms the wide distribution of CBB in Kenya and the presence of the disease in the coast region, which was previously considered CBB free. The study also shows that some of the cassava genotypes being targeted for improvement by other projects are susceptible to the disease, and therefore the need consider resistance to CBB in developing improved cassava genotypes. Keywords: Cassava bacterial blight, Distribution, Resistance DOI: 10.7176/JNSR/9-4-0

Dry matter yields and hydrological properties of three perennial grasses of a semi-arid environment in east Africa

Enteropogon macrostachyus (Bush rye), Cenchrus ciliaris L. (African foxtail grass) and Eragrostis superba Peyr (Maasai love grass) are important perennial rangeland grasses in Kenya. They provide an important source of forage for domestic livestock and wild ungulates. These grasses have been used extensively to rehabilitate denuded patches in semi-arid environment of Kenya. This study investigated the dry matter yields and hydrological properties of the three grasses under simulated rainfall at three phenological stages; early growth, elongation and reproduction. Laboratory seed viability tests were also done. Hydrological properties of the three grasses were estimated using a Kamphorst rainfall simulator. Results showed that there was a significant difference (p > 0.05) in dry matter yields and soil hydrological properties at the different grass phenological stages. Generally, all the three grasses improved the soil hydrological properties with an increase in grass stubble height. C. ciliaris gave the best soil hydrological properties followed by E. macrostachyus and E. superba, respectively. E. macrostachyus recorded the highest seed viability percentage. C. ciliaris and E. superba were ranked second and third, respectively. C. ciliaris yielded the highest biomass production at the reproductive stage followed by E. superba and E. macrostachyus, respectively. (Résumé d'auteur

Grass reseeding technology as a means of rehabilitating degraded lands and improving livelihoods of agro-pastoral communities in semi-arid Kenya

Land degradation is a major problem in the semi-arid environments of Sub-Saharan Africa. Fighting land degradation is essential to ensure the sustainable and long-term productivity of the inhabited semi-arid lands. Cenchrus ciliaris (African foxtail grass), Enteropogon macrostachyus (bush rye) and Eragrostis superba (Maasai love grass) are important perennial grasses in the Eastern African semi-arid lands. A study was conducted to establish the contribution of these indigenous grasses in improving soil hydrological properties, rehabilitation, food security and the livelihoods of agro-pastoral communities in semi-arid districts of Kenya. Soil hydrological properties were tested using a Kamphorst simulator at different stubble heights to represent three different grazing intensities (low, medium, high). Ground cover was estimated using the step-point method. A survey was also conducted across 50 agro-pastoral households to establish the multidimensional benefits of the grasses. Sediment production (as a function of run-off and infiltration capacity) was significantly different (P<0.05) at different stubble heights. Ground cover estimates of the grasses were also significantly different (P<0.05). Cenchrus ciliaris had the greatest influence in improving soil hydrological properties. Enteropogon macrostachyus and E. superba were ranked second and third, respectively. Enteropogon macrostachyus had the greatest ground cover. Cenchrus ciliaris and E. superba were ranked second and third, respectively. These results were attributed to the growth and morphological characteristics of the grasses. Generally, an increase in stubble height increased infiltration capacity and reduced run-off and sediment production. Results from the household survey showed that the grasses provide a source of income through the sale of hay, grass seeds and milk, which also achieve a balanced diet. The grasses also provide a cheap source of thatching materials and livestock feed. (Résumé d'auteur

Household dietary exposure to aflatoxins from maize and maize products in Kenya

Aflatoxicosis has repeatedly affected Kenyans, particularly in the eastern region, due to consumption of contaminated maize. However, save for the cases of acute toxicity, the levels of sub-lethal exposure have not been adequately assessed. It is believed that this type of exposure does exist even during the seasons when acute toxicity does not occur. This study, therefore, was designed to assess the exposure of households to aflatoxins through consumption of maize and maize products. Twenty samples each of maize kernels, muthokoi and maize meal were randomly sampled from households in Kibwezi District of Makueni County in Eastern Kenya and analysed for aflatoxin contamination. The samples were quantitatively analysed for aflatoxin contamination using HPLC. The uncertainty and variability in dietary exposure was quantitatively modelled in Ms Excel using Monte Carlo simulation in @Risk software. Aflatoxins were found in 45% of maize kernels at between 18 and 480 μg kg–1, 20% of muthokoi at between 12 and 123 μg kg–1, and 35% of maize meal at between 6 and 30 μg kg–1. The mean dietary exposure to aflatoxin in maize kernels was 292 ± 1567 ng kg−1 body weight day−1, while the mean dietary exposure to aflatoxin in maize meal and muthokoi were 59 ± 62 and 27 ± 154 ng kg−1 body weight day−1 respectively. The results showed that the amount and frequency of consumption of the three foods is the more important contributing factor than the mean aflatoxin concentration levels, to the risk of dietary exposure to aflatoxins.http://www.tandfonline.com/loi/tfac202016-05-30hb201

Kidney disease risk factors associate with urine biomarkers concentrations in HIV-positive persons; a cross-sectional study.

BackgroundHIV-positive persons bear an excess burden of chronic kidney disease (CKD); however, conventional methods to assess kidney health are insensitive and non-specific for detecting early kidney injury. Urinary biomarkers can detect early kidney injury, and may help mitigate the risk of overt CKD.MethodsCross-sectional study of HIV-positive persons in the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study. We measured levels of 14 biomarkers, capturing multiple dimensions of kidney injury. We then evaluated associations of known CKD risk factors with urine biomarkers using separate multivariable adjusted models for each biomarker.ResultsOf the 198 participants, one third were on HAART and virally suppressed. The vast majority (95%) had preserved kidney function as assessed by serum creatinine, with a median eGFR of 103 ml/min/1.73 m2 (interquartile range (IQR): 88, 116). In our multivariable analyses, the associations of each CKD risk factor with urinary biomarker levels varied in magnitude. For example, HIV viral load was predominantly associated with elevations in interleukin(IL)-18, and albuminuria, while higher CD4 levels were associated with lower monocyte chemoattractant protein-1 (MCP-1) and β2-microglobulin. In contrast, older age was significantly associated with elevations in α1-microglobulin, kidney injury marker-1, clusterin, MCP-1, and chitinase-3-like protein-1 levels, as well as lower epidermal growth factor, and uromodulin levels.ConclusionsAmong HIV-positive persons, CKD risk factors are associated with unique and heterogeneous patterns of changes in urine biomarkers levels. Additional work is needed to develop parsimonious algorithms that integrate multiple biomarkers and clinical data to discern the risk of overt CKD and its progression

Kidney disease risk factors associate with urine biomarkers concentrations in HIV-positive persons; a cross-sectional study

Abstract Background HIV-positive persons bear an excess burden of chronic kidney disease (CKD); however, conventional methods to assess kidney health are insensitive and non-specific for detecting early kidney injury. Urinary biomarkers can detect early kidney injury, and may help mitigate the risk of overt CKD. Methods Cross-sectional study of HIV-positive persons in the Multicenter AIDS Cohort Study and the Women’s Interagency HIV Study. We measured levels of 14 biomarkers, capturing multiple dimensions of kidney injury. We then evaluated associations of known CKD risk factors with urine biomarkers using separate multivariable adjusted models for each biomarker. Results Of the 198 participants, one third were on HAART and virally suppressed. The vast majority (95%) had preserved kidney function as assessed by serum creatinine, with a median eGFR of 103 ml/min/1.73 m2 (interquartile range (IQR): 88, 116). In our multivariable analyses, the associations of each CKD risk factor with urinary biomarker levels varied in magnitude. For example, HIV viral load was predominantly associated with elevations in interleukin(IL)-18, and albuminuria, while higher CD4 levels were associated with lower monocyte chemoattractant protein-1 (MCP-1) and β2-microglobulin. In contrast, older age was significantly associated with elevations in α1-microglobulin, kidney injury marker-1, clusterin, MCP-1, and chitinase-3-like protein-1 levels, as well as lower epidermal growth factor, and uromodulin levels. Conclusions Among HIV-positive persons, CKD risk factors are associated with unique and heterogeneous patterns of changes in urine biomarkers levels. Additional work is needed to develop parsimonious algorithms that integrate multiple biomarkers and clinical data to discern the risk of overt CKD and its progression