Knowledge, Attitudes, and Practices on COVID-19 Vaccination among General Adult Population in Malawi: A Countrywide Cross-Sectional Survey.

Vaccination is one of the essential measures in reducing transmission, morbidity, and mortality rates of a disease. However, the COVID-19 vaccination is facing hesitancy across the globe, Malawi included. A population-based cross-sectional study was conducted in Malawi to document knowledge, attitudes, and practices on COVID-19 vaccination. The study targeted the general adult population and employed a multi-stage sampling technique. The Census Enumeration Areas within the 16 selected districts served as a primary sampling unit. Among the total 3068 participants, 1947 (63.6%) were female. About 1039 (34.1%) participants had primary education, while only 169 (5.5%) had college education. A total of 2936 (95.7%) participants knew about the COVID-19 vaccine, and 2063 (68.4%) felt that the COVID-19 vaccine was effective. A total of 1180 (38.7%) got vaccinated. Knowledge of the COVID-19 vaccination was significantly associated with participants' education levels, location, occupation, marital status, household family income, and whether they were suffering from chronic illness or not. Overall, the level of knowledge and attitudes about the COVID-19 vaccination was good. This study has also established that different population groups have statistically different levels of knowledge and attitudes regarding COVID-19 vaccination. This study has also indicated a significant relationship between the rate of vaccination and several factors. Therefore, this calls for stakeholders to continue awareness and group-targeted tailored campaigns so as to increase COVID-19 vaccination.

Biofortified Maize Improves Selenium Status of Women and Children in a Rural Community in Malawi: Results of the Addressing Hidden Hunger With Agronomy Randomized Controlled Trial.

Background: Selenium deficiency is widespread in the Malawi population. The selenium concentration in maize, the staple food crop of Malawi, can be increased by applying selenium-enriched fertilizers. It is unknown whether this strategy, called agronomic biofortification, is effective at alleviating selenium deficiency. Objectives: The aim of the Addressing Hidden Hunger with Agronomy (AHHA) trial was to determine whether consumption of maize flour, agronomically-biofortified with selenium, affected the serum selenium concentrations of women, and children in a rural community setting. Design: An individually-randomized, double-blind placebo-controlled trial was conducted in rural Malawi. Participants were randomly allocated in a 1:1 ratio to receive either intervention maize flour biofortified with selenium through application of selenium fertilizer, or control maize flour not biofortified with selenium. Participant households received enough flour to meet the typical consumption of all household members (330 g capita -1 day-1) for a period of 8 weeks. Baseline and endline serum selenium concentration (the primary outcome) was measured by inductively coupled plasma mass spectrometry (ICP-MS). Results: One woman of reproductive age (WRA) and one school-aged child (SAC) from each of 180 households were recruited and households were randomized to each group. The baseline demographic and socioeconomic status of participants were well-balanced between arms. No serious adverse events were reported. In the intervention arm, mean (standard deviation) serum selenium concentration increased over the intervention period from 57.6 (17.0) µg L-1 (n = 88) to 107.9 (16.4) µg L-1 (n = 88) among WRA and from 46.4 (14.8) µg L-1 (n = 86) to 97.1 (16.0) µg L-1 (n = 88) among SAC. There was no evidence of change in serum selenium concentration in the control groups. Conclusion: Consumption of maize flour biofortified through application of selenium-enriched fertilizer increased selenium status in this community providing strong proof of principle that agronomic biofortification could be an effective approach to address selenium deficiency in Malawi and similar settings. Clinical Trial Registration: http://www.isrctn.com/ISRCTN85899451, identifier: ISRCTN85899451.

Spatial analysis of urine zinc (Zn) concentration for women of reproductive age and school age children in Malawi.

Zinc (Zn) is an essential micronutrient, and Zn deficiency remains a major global public health challenge. Recognised biomarkers of population Zn status include blood plasma or serum Zn concentration and proxy data such as dietary Zn intake and prevalence of stunting. Urine Zn concentration is rarely used to assess population Zn status. This study assessed the value of urine Zn concentration as a biomarker of population Zn status using a nationally representative sample of non-pregnant women of reproductive age (WRA) and school-aged children (SAC) in Malawi. Spot (casual) urine samples were collected from 741 WRA and 665 SAC. Urine Zn concentration was measured by inductively coupled plasma mass spectrometry with specific gravity adjustment for hydration status. Data were analysed using a linear mixed model with a spatially correlated random effect for between-cluster variation. The effect of time of sample collection (morning or afternoon), and gender (for SAC), on urine Zn concentration were examined. There was spatial dependence in urine Zn concentration between clusters among SAC but not WRA, which indicates that food system or environmental factors can influence urine Zn concentration. Mapping urine Zn concentration could potentially identify areas where the prevalence of Zn deficiency is greater and thus where further sampling or interventions might be targeted. There was no evidence for differences in urine Zn concentration between gender (P = 0.69) or time of sample collection (P = 0.85) in SAC. Urine Zn concentration was greater in afternoon samples for WRA (P = 0.003). Relationships between urine Zn concentration, serum Zn concentration, dietary Zn intake, and potential food systems covariates warrant further study.

Urine selenium concentration is a useful biomarker for assessing population level selenium status.

Plasma selenium (Se) concentration is an established population level biomarker of Se status, especially in Se-deficient populations. Previously observed correlations between dietary Se intake and urinary Se excretion suggest that urine Se concentration is also a potentially viable biomarker of Se status. However, there are only limited data on urine Se concentration among Se-deficient populations. Here, we test if urine is a viable biomarker for assessing Se status among a large sample of women and children in Malawi, most of whom are likely to be Se-deficient based on plasma Se status. Casual (spot) urine samples (n = 1406) were collected from a nationally representative sample of women of reproductive age (WRA, n =741) and school aged children (SAC, n=665) across Malawi as part of the 2015/16 Demographic and Health Survey. Selenium concentration in urine was determined using inductively coupled plasma mass spectrometry (ICP-MS). Urinary dilution corrections for specific gravity, osmolality, and creatinine were applied to adjust for hydration status. Plasma Se status had been measured for the same survey participants. There was between-cluster variation in urine Se concentration that corresponded with variation in plasma Se concentration, but not between households within a cluster, or between individuals within a household. Corrected urine Se concentrations explained more of the between-cluster variation in plasma Se concentration than uncorrected data. These results provide new evidence that urine may be used in the surveillance of Se status at the population level in some groups. This could be a cost-effective option if urine samples are already being collected for other assessments, such as for iodine status analysis as in the Malawi and other national Demographic and Health Surveys.

The risk of selenium deficiency in Malawi is large and varies over multiple spatial scales.

Selenium (Se) is an essential human micronutrient. Deficiency of Se decreases the activity of selenoproteins and can compromise immune and thyroid function and cognitive development, and increase risks from non-communicable diseases. The prevalence of Se deficiency is unknown in many countries, especially in sub-Saharan Africa (SSA). Here we report that the risk of Se deficiency in Malawi is large among a nationally representative population of 2,761 people. For example, 62.5% and 29.6% of women of reproductive age (WRA, n = 802) had plasma Se concentrations below the thresholds for the optimal activity of the selenoproteins glutathione peroxidase 3 (GPx3; <86.9 ng mL-1) and iodothyronine deiodinase (IDI; <64.8 ng mL-1), respectively. This is the first nationally representative evidence of widespread Se deficiency in SSA. Geostatistical modelling shows that Se deficiency risks are influenced by soil type, and also by proximity to Lake Malawi where more fish is likely to be consumed. Selenium deficiency should be quantified more widely in existing national micronutrient surveillance programmes in SSA given the marginal additional cost this would incur.

Can selenium deficiency in Malawi be alleviated through consumption of agro-biofortified maize flour? Study protocol for a randomised, double-blind, controlled trial.

BACKGROUND: Micronutrient deficiencies including selenium (Se) are widespread in Malawi and potentially underlie a substantial disease burden, particularly among poorer and marginalised populations. Concentrations of Se in staple cereal crops can be increased through application of Se fertilisers - a process known as agronomic biofortification (agro-biofortification) - and this may contribute to alleviating deficiencies. The Addressing Hidden Hunger with Agronomy (AHHA) trial aims to establish the efficacy of this approach for improving Se status in rural Malawi. METHODS: A double-blind, randomised, controlled trial will be conducted in a rural community in Kasungu District, Central Region, Malawi. The hypothesis is that consumption of maize flour agro-biofortified with Se will increase serum Se concentration. We will recruit 180 women of reproductive age (WRA) (20-45 years) and 180 school-age children (SAC) (5-10 years) randomly assigned in a 1:1 ratio to receive either maize flour enriched through agro-biofortification with Se or a control flour not enriched with Se. Households will receive flour (330 g per capita per day) for 12 weeks. The primary outcome is Se concentration in serum (µg/L). Serum will be extracted from venous blood samples drawn at baseline (prior to flour distribution) and end-line. Selenium concentration will be measured by using inductively coupled plasma mass spectrometry. DISCUSSION: Findings will be communicated to policy stakeholders and participating communities and reported in peer-reviewed journals. TRIAL REGISTRATION: The Addressing Hidden Hunger with Agronomy (Malawi) trial is registered (5th March 2019; ISCRTN85899451).

Soil-type influences human selenium status and underlies widespread selenium deficiency risks in Malawi.

Selenium (Se) is an essential human micronutrient with critical roles in immune functioning and antioxidant defence. Estimates of dietary Se intakes and status are scarce for Africa although crop surveys indicate deficiency is probably widespread in Malawi. Here we show that Se deficiency is likely endemic in Malawi based on the Se status of adults consuming food from contrasting soil types. These data are consistent with food balance sheets and composition tables revealing that >80% of the Malawi population is at risk of dietary Se inadequacy. Risk of dietary Se inadequacy is >60% in seven other countries in Southern Africa, and 22% across Africa as a whole. Given that most Malawi soils cannot supply sufficient Se to crops for adequate human nutrition, the cost and benefits of interventions to alleviate Se deficiency should be determined; for example, Se-enriched nitrogen fertilisers could be adopted as in Finland.

A high prevalence of zinc- but not iron-deficiency among women in rural Malawi: a cross-sectional study.

BACKGROUND: Zinc deficiency is often associated with nutritional iron deficiency (ID), and may be exacerbated by low selenium status. AIM: To investigate risk of iron and zinc deficiency in women with contrasting selenium status. METHODS: In a cross-sectional study, 1-day diet composites and blood samples were collected from self-selected Malawian women aged 18-50 years from low- (Zombwe) (n=60) and high-plant-available soil selenium (Mikalango) (n=60) districts. Diets were analyzed for trace elements and blood for biomarkers. RESULTS: Zinc deficiency (>90 %) was greater than ID anemia (6 %), or ID (5 %), attributed to diets low in zinc (median 5.7 mg/day) with high phytate:zinc molar ratios (20.0), but high in iron (21.0 mg/day) from soil contaminant iron. Zombwe compared to Mikalango women had lower (p<0.05) intakes of selenium (6.5 vs. 55.3 µg/day), zinc (4.8 vs. 6.4 mg/day), iron (16.6 vs. 29.6 mg/day), lower plasma selenium (0.72 vs. 1.60 µmol/L), and higher body iron (5.3 vs. 3.8 mg/kg), although plasma zinc was similar (8.60 vs. 8.87 µmol/L). Body iron and plasma zinc were positive determinants of hemoglobin. CONCLUSION: Risk of zinc deficiency was higher than ID and was shown not to be associated with selenium status. Plasma zinc was almost as important as body iron as a hemoglobin determinant.