Retinol assessment among women and children in sahelian mobile pastoralists

Associations between livestock keeping, morbidity and nutritional status of children and women in low- and middle-income countries: a systematic review

Livestock keeping can positively influence the nutritional status of populations and households through increased consumption of animal-source foods (ASF) and other indirect pathways, but can also adversely affect health by increasing the risk of diseases. We conducted a systematic review synthesising the current state of knowledge on the associations among livestock keeping, infectious disease and the nutritional status of children under 5 years and women of reproductive age in low- and lower-middle-income countries (LMICs). A comprehensive search of 12 electronic databases and grey literature sources published from 1991 to the end of December 2020 was conducted. Investigations exploring relationships between livestock keeping and risk of infectious disease transmission and nutritional status were selected using pre-defined inclusion criteria. After screening and filtering of 34,402 unique references, 176 references were included in the final synthesis. Most (160/176, 90.1%) of the references included in the final synthesis were from sub-Saharan Africa (SSA) and Asia. About two out of every five (42%) studies reviewed showed that livestock production is associated with improved height-for-age Z scores (HAZ) and weight-for-length/height Z scores (WHZ), while close to a third (30.7%) with improved weight-for-age Z scores (WAZ). Similarly, livestock production showed a positive or neutral relationship with women's nutritional status in almost all the references that reported on the topic. Conversely, four-fifths (66/81, 79.5%) of the references reporting on infection and morbidity outcomes indicated that livestock keeping is linked to a wide range of infectious disease outcomes, which are spread primarily through water, food and insects. In conclusion, in many LMIC settings, livestock production is associated with better nutritional outcomes but also a higher risk of disease transmission or morbidity among women and children.This review was prospectively registered on PROSPERO 2020 [CRD42020193622].

Nutritional status and intestinal parasites among young children from pastoralist communities of the Ethiopian Somali region

Pastoralist children in the Ethiopian Somali Regional State (ESRS) are at high risk for undernutrition and intestinal parasitic infections (IPIs). We assessed the nutritional status and its association with IPIs in 500 children <5 years of age in a clustered cross‐sectional study in Adadle district, ESRS. Stool samples were microscopically examined for IPIs and biomarkers for iron and vitamin A status, anthropometry, and food variety score (FVS) were assessed. Median (interquartile range [IQR]) FVS was 2.0 (2.0, 4.0), and 35% of children were exclusively breastfed up to age 6 months. Prevalence of stunting, wasting, underweight and mid‐upper arm circumference (MUAC) <12.5 cm was 30, 34, 40, and 16%, respectively. Median (IQR) haemoglobin, ferritin, and retinol‐binding protein concentrations were 9.5 g dL^‐1 (8.2, 10.9), 6.2 μg L^‐1 (4.0, 10.2), and 0.8 μmol L⁻¹ (0.67, 0.91), respectively. Prevalence of anaemia, iron, and vitamin A deficiency was 75, 91, and 30%, respectively. IPIs' prevalence was 47%; the most prevalent IPIs were Giardia lamblia (22%) and Ascaris lumbricoides (15%). Giardial infections but not A. lumbricoides increased the risk for MUAC <12.5 cm (adjusted odds ratio [aOR]: 3.50, 95% confidence interval [CI] [2.21, 5.54]). The odds for anaemia were 97% (aOR: 0.03, 95% CI [0.03, 0.07]) and 89% (aOR: 0.11, 95% CI [0.11, 0.23]) less for children with FVS >2 or with exclusive breastfeeding up to 6 months, respectively. Undernutrition and IPIs are alarmingly high in <5 years of age children in ESRS. Giardial infections and low nutritional adequacy of the diet seem to be major contributing factors to the precarious nutritional status and should be addressed by appropriate interventions.

Knowledge of pastoralists on livestock diseases and exposure assessment to brucellosis within rural and peri-urban areas in Kajiado, Kenya

Background: Livestock diseases impact the livelihoods of pastoralists. Brucellosis, a neglected zoonotic disease is highly prevalent in this system with an estimated 16% of livestock population in sub-Saharan Africa infected with the disease. The objective of this study was to assess knowledge of livestock diseases and the risk of exposure to brucellosis among pastoralists living in Kajiado County of Kenya. Methods: The study sites included pastoralist communities living in rural and peri-urban areas within the County. Both primary and secondary data were collected using participatory methods including pairwise ranking, proportional piling and probing and a review of the published literature. Exposure risk assessment was conducted according to the CODEX Alimentarius framework: Hazard identification, hazard characterization, exposure assessment and risk estimation. Results: According to pastoralists, livestock diseases that frequently occurred in their flocks and herds were contagious caprine pleuropneumonia, lumpy skin disease and foot and mouth disease; but zoonoses, including anthrax and brucellosis, were also mentioned during focus group discussions. Potential pathways of exposure to brucellosis and other zoonoses included consumption of unpasteurized milk, handling infected aborted materials without protective measures and consumption of raw meat and raw blood. Consumption of unpasteurized milk and handling infected aborted materials without protectives were linked with high risk of exposure to household members living in rural areas, with the risk level within the peri-urban areas ranked very low to low for most of these risk practices. Conclusions: The results call for enhanced public education targeting vulnerable groups to mitigate risks of disease spread and other impacts of brucellosis within the affected pastoralist production systems.

African fermented dairy products - Overview of predominant technologically important microorganisms focusing on African Streptococcus infantarius variants and potential future applications for enhanced food safety and security

Milk is a major source of nutrients, but can also be a vehicle for zoonotic foodborne diseases, especially when raw milk is consumed. In Africa, poor processing and storage conditions contribute to contamination, outgrowth and transmission of pathogens, which lead to spoilage, reduced food safety and security. Fermentation helps mitigate the impact of poor handling and storage conditions by enhancing shelf life and food safety. Traditionally-fermented sour milk products are culturally accepted and widely distributed in Africa, and rely on product-specific microbiota responsible for aroma, flavor and texture. Knowledge of microbiota and predominant, technologically important microorganisms is critical in developing products with enhanced quality and safety, as well as sustainable interventions for these products, including Africa-specific starter culture development. This narrative review summarizes current knowledge of technologically-important microorganisms of African fermented dairy products (FDP) and raw milk, taking into consideration novel findings and taxonomy when re-analyzing data of 29 publications covering 25 products from 17 African countries. Technologically-important lactic acid bacteria such as Lactococcus lactis and Streptococcus infantarius subsp. infantarius (Sii), Lactobacillus spp. and yeasts predominated in raw milk and FDP across Africa. Re-analysis of data also suggests a much wider distribution of Sii and thus a potentially longer history of use than previously expected. Therefore, evaluating the role and safety of African Sii lineages is important when developing interventions and starter cultures for FDP in Africa to enhance food safety and food security. In-depth functional genomics, epidemiologic investigations and latest identification approaches coupled with stakeholder involvement will be required to evaluate the possibility of African Sii lineages as novel food-grade Streptococcus lineage.

Seasonal dynamics of human retinol status in mobile pastoralists in Chad

Vitamin A deficiency is a prevalent public health problem in Africa and South-East Asia, although national population based surveys are lacking in many countries. This study investigated seasonal variation of human retinol concentrations in Chadian mobile pastoralists to identify critical time periods for interventions addressing vitamin A deficiency. The repeated cross-sectional study design used convenience sampling during three seasons to include 327 Fulani, Gorane and Arab adult mobile pastoralists in nine camps in the Lake Chad area. Human blood and pooled cattle milk retinol concentrations were rapidly assessed by portable flourometer (iCheck™). Linear regression models with random effects for correlation within camps were applied with human retinol concentration as outcome. Logistic regression models, with camp as random effect, were evaluated for the outcome human retinol deficiency. Human seasonal means were 2.14μmol/L (95% CI 1.82-2.46) in rainy, 0.99μmol/L (95% CI 0.91-1.07) in cold and 1.86μmol/L (95% CI 1.63-2.09) in dry season. Retinol concentration and deficiency varied according to season and ethnic group. Average values were highest in Gorane during rainy and in Fulani in the cold and dry seasons. Arabs had lowest average values in all seasons. Retinol deficiency (<0.70μmol/L) was found in 15% of study participants in the dry, 25% in the rainy and 32% in the cold season. Retinol concentrations varied according to age, sex, milk consumption level and pooled cattle milk retinol concentration. Effect sizes varied and not all were statistically significantly different. Pooled cattle milk retinol concentrations varied seasonally and were positively associated to human retinol concentrations. This study establishes seasonal variation in human blood and pooled cattle milk retinol concentrations in Chad, demonstrating a linkage from animals to humans through milk. Rapid analysis using portable technology is feasible in remote populations under harsh climatic conditions.

Assessment of a portable device to quantify vitamin A in fortified foods (flour, sugar, and milk) for quality control

BACKGROUND

Simple-to-use quantitative methods are needed to check the adequacy of vitamin A fortification levels.

OBJECTIVE

To assess the capacity of a portable fluorometer (iCheck FLUORO) and its test kit vials (iEx Mila) to quantify retinyl palmitate in fortified milks, flours (wheat, maize), and sugar.

METHODS

The portable fluorometer was assessed in a three-step procedure to determine its working range and linearity, intra-assay precision, and interperson precision. Measurements were compared with the results obtained by high-performance liquid chromatography (HPLC), commonly regarded as the standard method for vitamin A analysis.

RESULTS

The portable fluorometer (iCheck FLUORO) and its test kit vials (iEx Mila) precisely determined the vitamin A contents in fortifed flours, sugar, and milks. Its working range was 1 to 10, 0.5 to 3.0, and 5 to 15 mg retinol equivalents (RE) kg(-1) for flours (wheat and corn), milks, and sugar, respectively; these values are in accordance with the World Health Organization recommendations for food fortification in least developed countries. The limits of detection are higher than those of HPLC but are all satisfactory (< 1.46 mg RE kg(-1)). The coefficients of variation within and between observers were satisfactory, especially for sugar and milk.

CONCLUSIONS

The linear relationship between the data from the portable fluorometer and the HPLC data confirms that the portable fluorometer provides a good determination of the vitamin A content of the fortified products in the tested range.

The plasma proteome identifies expected and novel proteins correlated with micronutrient status in undernourished Nepalese children

Micronutrient deficiencies are common in undernourished societies yet remain inadequately assessed due to the complexity and costs of existing assays. A plasma proteomics-based approach holds promise in quantifying multiple nutrient:protein associations that reflect biological function and nutritional status. To validate this concept, in plasma samples of a cohort of 500 6- to 8-y-old Nepalese children, we estimated cross-sectional correlations between vitamins A (retinol), D (25-hydroxyvitamin D), and E (α-tocopherol), copper, and selenium, measured by conventional assays, and relative abundance of their major plasma-bound proteins, measured by quantitative proteomics using 8-plex iTRAQ mass tags. The prevalence of low-to-deficient status was 8.8% (<0.70 μmol/L) for retinol, 19.2% (<50 nmol/L) for 25-hydroxyvitamin D, 17.6% (<9.3 μmol/L) for α-tocopherol, 0% (<10 μmol/L) for copper, and 13.6% (<0.6 μmol/L) for selenium. We identified 4705 proteins, 982 in >50 children. Employing a linear mixed effects model, we observed the following correlations: retinol:retinol-binding protein 4 (r = 0.88), 25-hydroxyvitamin D:vitamin D-binding protein (r = 0.58), α-tocopherol:apolipoprotein C-III (r = 0.64), copper:ceruloplasmin (r = 0.65), and selenium:selenoprotein P isoform 1 (r = 0.79) (all P < 0.0001), passing a false discovery rate threshold of 1% (based on P value-derived q values). Individual proteins explained 34-77% (R(2)) of variation in their respective nutrient concentration. Adding second proteins to models raised R(2) to 48-79%, demonstrating a potential to explain additional variation in nutrient concentration by this strategy. Plasma proteomics can identify and quantify protein biomarkers of micronutrient status in undernourished children. The maternal micronutrient supplementation trial, from which data were derived as a follow-up activity, was registered at clinicaltrials.gov as NCT00115271.

Health of mobile pastoralists in the Sahel - assessment of 15 years of research and development

In the Sahel, between Mauritania and Somalia including Northern Kenya, about 20-30 million people live as mobile pastoralists. The rhythm of their migration follows the seasons and the availability of resources such as water, pasture and salt. Despite their high exposure to zoonoses and problems caused by extreme climatic conditions, mobile pastoralists are virtually excluded from health services because the provision of social services adapted to their way of life is challenging. In cooperation with various partners in the region, the Swiss Tropical and Public Health Institute has been active in research and development in the Sahel for 15 years. Based on the perceived needs of mobile pastoralists and the necessities of development, interdisciplinary research has considerably contributed to better understanding of their situation and their problems. Close contact between humans and livestock necessitates close cooperation between human and animal health specialists. Such useful approaches should be continued and extended.