Session 6B: Human health and food safety
byANH Academy
Academy Week Research Conference
| Agriculture, Food Safety, Public Health
Date and Time
From: 27 June 2019, 14:10
To: 27 June 2019, 15:30
BST British Summer Time GMT+1:00
Country: India
Open Full Event


Five, 10-minute abstract-driven presentations.  

Speakers and Presentations:


  • Chair: Hung Nguyen, International Livestock Research Institute (ILRI)
  • Aderonke Mohammed, Kabba College of Agriculture, Nigeria
    Health status of farming households and crop productivity: Evidence from malaria infected households in Nigeria
    Slides/ Recording

  • Hugo De Groote, International Maize and Wheat Improvement Centre
    Biomarkers of aflatoxin exposure, diet, climate and children’s growth in rural Ethiopia
    Slides/ Recording

  • Johanna Andrews-Trevino, Tufts University, USA
    Seasonality of serum aflatoxin levels (AFB1) in pregnancy and early childhood in a longitudinal cohort study in Banke, Nepal
    Slides/ Recording

  • Julien Z.B. Zahouli, Centre Suisse de Recherches Scientifiques en Côte D'Ivoire
    Divergences in Anopheles gambiae behaviors and transmission of malaria and lymphatic filariasis along a rural-suburban gradient in large rice growing areas, Côte d’Ivoire
    Slides/ Recording

  • Tarique Mohammad Nurul, Icddr,B, Bangladesh
    “Safe and Nutritious Food: Ideal Family!”: Improving food hygiene behaviors in Bangladesh through emotional drivers
    Slides/ Recording

  • Q&A 



Health status of farming households and crop productivity: Evidence from malaria infected households in Nigeria

Aderonke Mohammed, Kabba College of Agriculture, Nigeria

Introduction:  When both health and agriculture thrive, a reinforcing cycle of health can result, but when either suffers, the cycle becomes one of lowered agricultural productivity and health. Health problems have been found to be a major influence on agricultural productivity in Nigeria, and malaria has been a contributor to ill health in Africa. Agricultural development and practices can exacerbate the incidence of malaria through an interaction with disease vectors and parasites. Our study focuses on establishing a link between malaria infection and food crop productivity in a direct manner.

Methods:  In a cohort of farming households in Kabba/Bunu Local Government Area of Kogi State in north central Nigeria, malaria incidence and malaria preventive measures were carefully monitored on a weekly basis over an 8-month period (May-Dec) during the farming season. Malaria testing was carried out and documented vis-à-vis other independent variables that were used for the study. Malaria diagnosis was confirmed among febrile household members using Plasmodium falciparunm Histidine Rich Protein II (PfHRP2) malaria rapid diagnostic test (mRDT) kits (Parachek®). The tests were conducted by trained health workers if the sick member of household reported to the health facility, or during the weekly rounds of visits by the health workers. Data was collected on febrile episodes among family members, i.e. household head, wives, children, and other relatives within the households. Data on household composition with malaria incidence per month, socioeconomic characteristics of household heads, day loss, and cost of treatment, prevention and caregiving were obtained. Data was also collected on the productivity of the households for a range of food crops such as maize, sorghum, cowpea, bambaranut, and millet. Data were analysed using descriptive and inferential statistics, OLS, and binary logistic regression models.

Findings:  Malaria testing was carried out on 432 household members out of which 358 household members representing 83% had malaria.  Malaria was observed more in children (55%) followed by male adults (25%) and female adults (20%). Findings revealed that output was higher for low-malaria infected households (LMIH) by 25% compared to high-malaria infected households (HMIH). Crop output for LMIH were significantly higher at 5% for all crops except sorghum, probably because less labour is demanded for its production. Household heads who are educated and used mosquito nets had decreased odds for malaria infection (OR = 0.131, 95% C.I: 0.037, 0.465, P-value = 0.002) and (OR = 0.218, 95% C.I: 0.059, 0.810, P-value = 0.023) respectively. Welfare loss in the study area was estimated as ₦148,888 (US $409.03) per farming season for malaria-infected households. Adjusted household size and malaria incidence were found to be the major determinants of welfare loss in the study area. Protective measures such as use of mosquito coils, clearing bushy environments, sleeping under mosquito nets, screening doors and windows with nets, and use of anti-malaria drugs and homemade medicinal herbs in the different months by the households were measures employed to reduce malaria incidence.

Conclusions:  The study demonstrates a high incidence of malaria among farming households in north central Nigeria and reveals that malaria incidence was remarkably high among children. Significant variables associated with malaria incidence were identified. Our results show that LMIH are more productive than HMIH. The use of malaria control measures impacted greatly on the variability in the level of output observed during the study period. Creating awareness on the use of insecticide-treated mosquito netd, targeting the area for free net distribution, and training on utilization will reduce malaria incidence and increase crop productivity in the study area.


Biomarkers of aflatoxin exposure, diet, climate and children’s growth in rural Ethiopia

Hugo De Groote, International Maize and Wheat Improvement Centre

Introduction:  Recently, there has been growing recognition that aflatoxins are associated with impaired linear growth of children. To date, the relationship between aflatoxin (AF) biomarkers in serum and child growth in Ethiopia has not been investigated. We assessed children’s exposure to AF in pre-harvest and post-harvest seasons using serum biomarkers and tested the association of their exposure with the linear growth. Further, the importance of diet is recognized (maize is more prone to aflatoxins than other cereals) as is that of climate, as fungi thrive better under humid and high-temperature conditions.

Methods:  AF biomarkers were quantitatively analyzed from a randomly-selected subsample of an ongoing intervention trial on the consumption of quality-protein maize in rural Ethiopia. Blood samples were collected from 6-36-month-old children (n=102) in the pre-harvest season (Aug-Sept 2016), and post-harvest season (Feb 2016). The AF biomarkers AF-lysine, AFB1, AFB2, AFG1, AFG2, and AFM1 were measured by high-performance liquid chromatography-tandem mass spectrometry. Children’s linear growth was assessed by length/height and age converted into Z-scores for height-for-age. Climate data were obtained from the World Meteorological Institute, in the format of grid layers with relative humidity and average temperature. From the grids, the values for the georeferenced homesteads of the children were extracted. Dietary information was obtained from the survey. Mixed linear regression, correlation, and logistic regression were used for the analysis.

Findings:  A high percentage of children were exposed to AF in serum in both pre-harvest (ranging from 7% to 31% by AF) and post-harvest (ranging from 5% to 33% by AF) seasons, however, the exposure did not differ statistically by seasons except for AFG2. Cumulative exposure, i.e. children with one or more AF biomarkers in serum, was higher in post-harvest (45%) compared with pre-harvest (40%) seasons (p=0.003). Cumulative AF exposure in serum (CAFES) was correlated with the linear growth of children in the post-harvest season (r=-0.21, p=0.034); however, CAFES and linear growth was not correlated in the pre-harvest season in this sample of children (r= 0.17, p=0.095). Analysis of the effect of climate and diet is ongoing.

Conclusions:  Our findings suggest that exposure to AF is prevalent in our study areas. Further longitudinal study with a larger samples size is needed to evaluate causal linkages between AF exposure and linear growth in children.


Seasonality of serum aflatoxin levels (AFB1) in pregnancy and early childhood in a longitudinal cohort study in Banke, Nepal

Johanna Andrews-Trevino, Tufts University, USA

Introduction:  Aflatoxin exposure in utero and early life is hypothesized to be associated with adverse health outcomes such as poor linear growth. Aflatoxin B1 (AFB1), a mycotoxin, is found primarily in maize and groundnuts though other foods such as chilies can also be contaminated with aflatoxin. Aflatoxin levels in crops are known to vary seasonally. There is little known about seasonality in serum levels of aflatoxin. The aim of the study was to assess aflatoxin exposure in pregnancy and early childhood, evaluating the role of seasonality in patterns of exposure.

Methods:  For this analysis, we utilize serum samples collected in an ongoing cohort study of 1675 maternal-infant dyads collected on a rolling basis, thereby providing us an opportunity to assess seasonal variation. The cohort study enrolled 1675 pregnant women and subsequently followed 88% of infants from birth to 12 months of age. One venous blood sample was collected from women at recruitment in pregnancy and three samples from infants at 3, 6 and 12 months of age respectively. Serum aflatoxin-lysine adducts (AF-alb) were measured once during pregnancy (n=1648) and thrice in early childhood, namely at 3 (n=1312), 6 (n=1126), and 12 (n=1315) months of age. Data were collected on maternal health status, pregnancy behaviors, height, weight, diets, food security, household variables, socioeconomic status, agricultural and food purchasing, and storage and processing practices. A high-performance liquid chromatography with fluorescence detection method was used to assay serum samples for the presence of aflatoxin-albumin conjugate. Data were analyzed separately for women and infants, and infant samples were separated out by age group for analyses. For the purpose of this analysis - winter months were defined as November-March. Descriptive statistics and bivariate analyses using logged aflatoxin were conducted in Stata® SE version 14.

Findings:  AFB1 was detected in the serum of 94% of women in pregnancy, 84% of infants at 3 months, 86% at 6 months and 82% at 12 months of age. The geometric mean maternal serum AFB1 was 1.37 pg/mg albumin (range <0.4(undetectable)-147.32 pg/mg). Geometric means were 0.66 (range <0.4-24.72), 0.71 (range <0.4-41.60), and 0.79 pg/mg albumin (range <0.4-84.65 pg/mg) for infants at 3, 6 and 12 months, respectively. Of the women, 42% were measured in winter months. Mean maternal AFB1 concentrations were 5.08±11.49 compared to 1.85±4.31 for women measured in non-winter months. A total of 48%, 43% and 15% of 3, 6 and 12-month olds were measured in the winter months. Three month old infants measured in the winter had mean AFB1 concentrations of 1.00±1.33 compared to 0.75±0.56 in infants measured in non-winter months. Levels of aflatoxin for 6 and 12 month olds in the winter months were 1.34±2.74 and 2.63±7.96, respectively. Mean AF levels for 6 and 12 months old children measured in non-winter months were 0.83±1.03 and 1.50±2.99, respectively. Controlling for year of data collection, we find a significantly higher mean log serum AFB1 concentrations in samples collected during the winter months versus those collected in non-winter months (p<0.001).

Conclusions:  This study indicates a high occurrence of aflatoxin exposure during pregnancy and in the first year of life in infants from this region of Nepal. Further, seasonality has a significant relationship with higher levels being observed in the winter months in both mothers and infants. We postulate that the level of exposure and its relationship with health outcomes may be modulated by seasonality. This relationship needs to be considered in any analysis to ascertain the role of aflatoxin in modulating health outcomes such as linear growth and/or in strategies aiming to mitigate aflatoxin in the food system.


Divergences in Anopheles gambiae behaviors and transmission of malaria and lymphatic filariasis along a rural-suburban gradient in large rice growing areas, Côte d’Ivoire

Julien Z.B. Zahouli, Centre Suisse de Recherches Scientifiques en Côte D'Ivoire

Introduction:  Malaria and lymphatic filariasis (LF) cause considerable public health burden worldwide. Over 212 million cases and 450,000 deaths from malaria and 120 million cases of LF are recorded annually, with higher impacts in sub-Saharan Africa. The ecology of mosquito vectors and transmission of Plasmodium and Wuchereria bancrofti can be altered by hydro-agricultural land-use change and urbanization. Understanding the interactions between land-cover change, vector ecology and pathogen transmission is crucial. We assessed the ecology of Anopheles gambiae and transmission of Plasmodium falciparum and W. bancrofti in variously urbanized settings bordering large irrigated rice fields in Côte d’Ivoire.

Methods:  Mosquito larvae were collected in their natural breeding sites in irrigated rice fields. Adult mosquitoes were sampled indoor and outdoor in four rural and suburban villages bordering these hydro-agroecosystems using 72 light-traps and 72 man-nights, and pyrethroid spray inside 60 houses. Surveys were carried out at each of the seven different development stages (tillage, transplanting, tillering, elongation, maturation, harvesting and fallow) of irrigated rice fields. Larvae were reared until adult stage for species identification. All adults were identified at species level. The ovaries and salivary glands of adult females of An. gambiae were dissected and examined to determine the daily distribution of parous females, and P. falciparum and W. bancrofti infections, respectively.

Findings:  Totals of 10,312 and 7662 mosquitoes belonging to 19 and 14 species were collected in rural and suburban areas, respectively. An. gambiae was the predominant species showing the proportions of 97.4% in suburban and 81.5% in rural areas. An. gambiae larval densities and adult biting rates significantly correlated with rice field landscape development stages and peaked during transplanting and tillering. Biting rates increased gradually from 6 p.m., reached peaks around midnight and decreased progressively to reach minimum values at 6 a.m. in all areas. However, host-seeking and resting behaviors were centered indoor in rural areas and independent of houses in suburban areas; endophagic rate, exophagic rate and indoor resting density were estimated at 67.4%, 32.6% and 14.9 females/bedroom/day in rural areas, and 49.3%, 50.7% and 2.9 females/bedroom/day in suburban areas, respectively. The parturity rates were high in all areas, with values of 84.5% in suburban areas and 75.8% in rural areas. P. falciparium infection rates and inoculation entomological rates were estimated at 8.1% and 6.4 infected bites/person/night in rural areas, and 6.6% and 6.5 infected bites/person/night in suburban areas. W. bancrofti infection rates and average loads were of 0.53% and 1.86 L3/infective in suburban areas, and 0.34% and 2 L3/infective in rural areas, respectively.

Conclusions:  Irrigated rice growing correlated with An. gambiae abundance, longevity and vector competence in completing P. falciparium and W. bancrofti life cycle and transmitting pathogens to humans thus increasing people exposure to vector bites, malaria and lymphatic filariasis. Moreover, the tendency of An. gambiae populations to change or reverse their biting and resting behaviors as a function of urbanization levels may compromise vector control strategies based on insecticide-treated nets and indoor residual spray. Integrated vector management encompassing inter-sectorial approaches including agricultural sector (farmers/researchers), health sector (epidemiologists/entomologists) and urbanism (urban planners) should be recommended to control diseases in intensive irrigated rice fields.


“Safe and Nutritious Food: Ideal Family!”: Improving food hygiene behaviors in Bangladesh through emotional drivers

Tarique Mohammad Nurul, Icddr,B, Bangladesh

Introduction:  Child undernutrition is caused by insufficient dietary intake or poor nutrient absorption. Absorption is inhibited by frequent gastrointestinal infections linked to poor sanitation and food hygiene practices. Although microbial contamination of food is a known cause of gastrointestinal infections and highly prevalent, it has received relatively little attention in nutrition programs. Consistent adoption of food hygiene practices could considerably reduce microbial food contamination and thereby improve nutrient absorption, but is challenging to achieve. We aimed to design, implement, and evaluate an innovative food hygiene behavior change module within a nutrition-sensitive intervention in rural Bangladesh.

Methods:  The “Food and Agricultural Approaches to Reducing Malnutrition” (FAARM) cluster-randomized trial (2015-2019) is evaluating the impact of a homestead food production program on child undernutrition in Habiganj District, Sylhet, Bangladesh. We designed a behavior change intervention to strengthen the food hygiene component in FAARM, and trained 1341 participant women from July 2017 to February 2018. The module used emotional drivers, engaging group activities and individual household visits to improve six key feeding and food hygiene behaviors:  exclusive breastfeeding up to six months, increased food variety, cleanliness of serving utensils, proper hand-washing before feeding/eating, adequate food storage, and thorough reheating of stored food. To support these behaviors, the intervention undertook two competitions. The first was for a “clean kitchen” where the household had to have a clean and demarcated kitchen, a handwashing station inside or next to the kitchen, a separate area for animals/poultry, and keep rubbish in a covered container. The second competition was to be an "ideal family" where the caregivers had to maintain five out of six food hygiene practices. The process evaluation of the program described here utilizes program attendance data and women’s practice of food hygiene behaviors collected by the food hygiene promoters.

Findings:  The food hygiene intervention was well accepted, with 80% attendance during group events and 87% attendance during household visits. Uptake of food hygiene behaviors varied by behavior. Only 49% of intervention households continuously practiced cleaning of utensils and 48% handwashing before food preparation and feeding, while 70% continuously practiced safe food storage and 89% reheated leftover foods.

649 households (51%) succeeded in the "clean kitchen" competition (scored positive on at least 3 out of 4 clean kitchen indicators). While only 46% had a functioning handwashing facility in or nearby the kitchen (which is in accordance with the low handwashing and utensils cleaning practices), 60% of households had rubbish covered or kept outside, 82% had a separate animal area, and 63% had a clean and demarcated kitchen area. At the end of the intervention, 496 households (39%) were awarded a prize as an “ideal family”, meaning they practiced at least 5 out of 6 behaviors. Households with high attendance were more likely to be classified as an “ideal family” than households with low attendance, as were richer households and those with higher educated women.

Conclusions:  The integrated feeding and food hygiene intervention was well attended and accepted by households, however, uptake of behaviors varied, suggesting that some behaviors were easier to adopt than others. Lack of a facility for washing hands and utensils in or near the kitchen seemed a particular barrier. Future food hygiene interventions should give special attention to improve handwashing and cleaning utensils by ensuring enabling technologies close to the kitchen. Results from the full evaluation are forthcoming, including structured observations of behaviors and assessment of bacterial food contamination against a control group.

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