When knowledge is not enough: barriers to recommended cassava processing in resource-constrained Kwango, Democratic Republic of Congo.

Background: Despite interventions to provide knowledge and improve bitter cassava processing in the Democratic Republic of Congo (DRC), cassava processing is sub-optimal. Consumption of insufficiently processed bitter cassava is associated with konzo, a neurological paralytic disease. Objective: This study aimed to explore barriers to appropriate cassava processing carried out by women in one deep rural, economically deprived area of DRC. Methods: A qualitative design used focus group discussions (FGDs) and participant observation to collect data among purposively selected women aged 15-61 years in Kwango, DRC. Data were analyzed using thematic analysis. Results: 15 FGDs with 131 women and 12 observations of cassava processing were undertaken. Observations indicated women did not follow recommended cassava processing methods. Although women were knowledgeable about cassava processing, two main barriers emerged: access to water and lack of money. Accessing water from the river to process cassava was burdensome, and the cassava was at risk of being stolen by soaking it in the river; therefore, women shortened the processing time. Cassava was not only used as a staple food but also as a cash crop, which led to households shortening the processing time to reach the market quickly. Conclusion: Knowledge about the risks of insufficient cassava processing and about safe processing methods alone is insufficient to change practices in a context of severe resource constraints. When planning nutrition interventions, it is critical to view the intervention in light of the socio-economic context in which the intervention will take place to improve its outcomes.

Screening for neurocognitive deficits in adult populations reliant on toxic cassava as the main source of food

Context and objective. Chronic dietary reliance on improperly processed cyanogenic toxic cassava is widespread in sub-Saharan Africa. The objective of the present study was to screen for neurocognition impairments and daily-life functioning in adults with dietary dependency on cyanogenic cassava as the main source of food. Methods. A cross-sectional design enrolled heads of households (in couples) in the rural district of Kahemba, Democratic Republic of Congo. Participants were screened for neurocognitive impairments using the Community Screening Interview for Dementia (CSID). Detailed neuropsychiatric evaluations were performed and disease entities classified according to the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) criteria when applicable. Cassava cyanogenic exposure was ascertained by urinary concentrations of thiocyanate (SCN). Regression models were used to identify predictors of CSID performance at the 0.05 significance level. Results. For hundred and six households (203 couples, mean age 38.4 ± 11. 4 years) were involved. One hundred thirty-six subjects (33.5 %) [69 women and 67 men, mean age 39 ± 14.4 years)] and 13 (3.2 %) [7 women and 6 men, mean age: 32 ± 2.6 years] fulfilled the criteria for mild cognitive impairment (MCI) and Major Neurocognitive disorder (MNCD), respectively. The overall mean urinary concentration of SCN was 949.5+518.3 mol/l after adjusting Context and objective. Chronic dietary reliance on improperly processed cyanogenic toxic cassava is widespread in sub-Saharan Africa. The objective of the present study was to screen for neurocognition impairments and daily-life functioning in adults with dietary dependency on cyanogenic cassava as the main source of food. Methods. A cross-sectional design enrolled heads of households (in couples) in the rural district of Kahemba, Democratic Republic of Congo. Participants were screened for neurocognitive impairments using the Community Screening Interview for Dementia (CSID). Detailed neuropsychiatric evaluations were performed, and disease entities classified according to the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) criteria when applicable. Cassava cyanogenic exposure was ascertained by urinary concentrations of thiocyanate (SCN). Regression models were used to identify predictors of CSID performance at the 0.05 significance level. Results. For hundred and six households (203 couples, mean age 38.4 ± 11. 4 years) were involved. One hundred thirty-six subjects (33.5 %) [69 women and 67 men, mean age 39 ± 14.4 years)] and 13 (3.2 %) [7 women and 6 men, mean age: 32 ± 2.6 years] fulfilled the criteria for mild cognitive impairment (MCI) and Major Neurocognitive disorder (MNCD), respectively. The overall mean urinary concentration of SCN was . for age, gender, nutritional status, and history of konzo, neurocognition domain-specific deficits were independently associated with either hypertension or USCN (350mol / l incremental increase in excretion Functional impairments in daily-life activities increased as subjects poorly performed at the CSID screening (Spearman r = - .2, p < 0.01). Conclusion. Neurocognitive deficits in adults are common in Congolese adults relying on cyanogenic cassava as the main source of food. Our study findings warrant further studies to elucidate the overall lifespan brain/behavioral burden and mechanisms of cassava toxicity among adults with dietary dependency on cyanogenic cassava as the main source of food

Baseline characterization of epilepsy in an onchocerciasis endemic area of the Democratic Republic of Congo.

Increased epilepsy prevalence is reported in onchocerciasis (OC) endemic areas and is associated with the occurrence of distinct syndromes such as nodding disease and Nakalanga syndrome. To date, a causal relationship between OC and epilepsy is still a matter of controversy. We conducted a case-control study of participants with epilepsy and age- and gender-matched presumably healthy controls to elucidate the relationships between OC and epilepsy and explore the role of inflammation and growth factors in an OC endemic area in the Democratic Republic of Congo (DRC). Eighty-two participants with epilepsy (mean age ± SD: 23.2 ± 8.7 years) and 27 controls (mean age ± SD: 22.3 ± 12.0 years) underwent snip skin biopsies to determine Onchocerca volvulus infection status. Serum concentrations of cytokines, chemokines, and growth factors were measured using a Luminex Multiplex Assay kit. Children <19 years of age underwent neurocognitive assessments using the Kaufman Assessment Battery for Children, 2nd edition (KABC-II). Overall, epilepsy was associated with OC (OR = 4.51, z = 3.11, p = 0.0019), and children with OC were more likely to be severely stunted (OR = 11.67, z = 2.62, p = 0.0087). The relationship between epilepsy and OC was no longer significant (z = 1.27, p = 0.20) when stunting was included as a correcting covariate. Epilepsy was associated with poor KABC-II test scores, high serum levels of IL-17, and low levels of IL-1RA, IL-8, and EGF. KABC-II testing scores correlated with serum levels of IL-10, MCP-1 and HGF. Familial history of epilepsy occurred frequently. Future studies should consider cytokines and/or growth factors when assessing susceptibility to epilepsy in OC endemic areas. Additional investigations, preferentially in low-prevalence OC areas, may provide further insights into the concept, risk, and burden of river epilepsy.

Dietary cyanogen exposure and early child neurodevelopment: An observational study from the Democratic Republic of Congo.

BACKGROUND: Dietary cyanogen exposure from ingesting bitter (toxic) cassava as a main source of food in sub-Saharan Africa is related to neurological impairments in sub-Saharan Africa. We explored possible association with early child neurodevelopmental outcomes. METHODS: We undertook a cross-sectional neurodevelopmental assessment of 12-48 month-old children using the Mullen Scale of Early Learning (MSEL) and the Gensini Gavito Scale (GGS). We used the Hopkins Symptoms Checklist-10 (HSCL-10) and Goldberg Depression Anxiety Scale (GDAS) to screen for symptoms of maternal depression-anxiety. We used the cyanogen content in household cassava flour and urinary thiocyanate (SCN) as biomarkers of dietary cyanogen exposure. We employed multivariable generalized linear models (GLM) with Gamma link function to determine predictors of early child neurodevelopmental outcomes. RESULTS: The mean (SD) and median (IQR) of cyanogen content of cassava household flour were above the WHO cut-off points of 10 ppm (52.18 [32·79]) and 50 (30-50) ppm, respectively. Mean (SD) urinary levels of thiocyanate and median (IQR) were respectively 817·81 (474·59) and 688 (344-1032) µmole/l in mothers, and 617·49 (449·48) and 688 (344-688) µmole/l in children reflecting individual high levels as well as a community-wide cyanogenic exposure. The concentration of cyanide in cassava flour was significantly associated with early child neurodevelopment, motor development and cognitive ability as indicated by univariable linear regression (p < 0.05). After adjusting for biological and socioeconomic predictors at multivariable analyses, fine motor proficiency and child neurodevelopment remained the main predictors associated with the concentration of cyanide in cassava flour: coefficients of -0·08 to -.15 (p < 0·01). We also found a significant association between child linear growth, early child neurodevelopment, cognitive ability and motor development at both univariable and multivariable linear regression analyses coefficients of 1.44 to 7.31 (p < 0·01). CONCLUSION: Dietary cyanogen exposure is associated with early child neurodevelopment, cognitive abilities and motor development, even in the absence of clinically evident paralysis. There is a need for community-wide interventions for better cassava processing practices for detoxification, improved nutrition, and neuro-rehabilitation, all of which are essential for optimal development in exposed children.

Cyanide and the human brain: perspectives from a model of food (cassava) poisoning.

Threats by fundamentalist leaders to use chemical weapons have resulted in renewed interest in cyanide toxicity. Relevant insights may be gained from studies on cyanide mass intoxication in populations relying on cyanogenic cassava as the main source of food. In these populations, sublethal concentrations (up to 80 µmol/l) of cyanide in the blood are commonplace and lead to signs of acute toxicity. Long-term toxicity signs include a distinct and irreversible spastic paralysis, known as konzo, and cognition deficits, mainly in sequential processing (visual-spatial analysis) domains. Toxic culprits include cyanide (mitochondrial toxicant), thiocyanate (AMPA-receptor chaotropic cyanide metabolite), cyanate (protein-carbamoylating cyanide metabolite), and 2-iminothiazolidine-4-carboxylic acid (seizure inducer). Factors of susceptibility include younger age, female gender, protein-deficient diet, and, possibly, the gut functional metagenome. The existence of uniquely exposed and neurologically affected populations offers invaluable research opportunities to develop a comprehensive understanding of cyanide toxicity and test or validate point-of-care diagnostic tools and treatment options to be included in preparedness kits in response to cyanide-related threats.

Serum 8,12-iso-iPF2α-VI isoprostane marker of oxidative damage and cognition deficits in children with konzo.

We sought to determine whether motor and cognitive deficits associated with cassava (food) cyanogenic poisoning were associated with high concentrations of F2-isoprostanes, well-established indicators of oxidative damage. Concentrations of serum F2-isoprostanes were quantified by LC-MS/MS and anchored to measures of motor proficiency and cognitive performance, which were respectively assessed through BOT-2 (Bruininks/Oseretsky Test, 2nd Edition) and KABC-II (Kaufman Assessment Battery for Children, 2nd edition) testing of 40 Congolese children (21 with konzo and 19 presumably healthy controls, overall mean age (SD): 9.3 (3.2) years). Exposure to cyanide was ascertained by concentrations of its main metabolite thiocyanate (SCN) in plasma and urine. Overall, SCN concentrations ranged from 91 to 325 and 172 to 1032 µmol/l in plasma and urine, respectively. Serum isoprostanes ranged from 0.1 to 0.8 (Isoprostane-III), 0.8 to 8.3 (total Isoprostane-III), 0.1 to 1.5 (Isoprostane-VI), 2.0 to 9.0 (total Isoprostane-VI), or 0.2 to 1.3 ng/ml (8,12-iso-iPF2α-VI isoprostane). Children with konzo poorly performed at the BOT-2 and KABC-II testing relative to presumably healthy children (p<0.01). Within regression models adjusting for age, gender, motor proficiency, and other biochemical variables, 8,12-iso-iPF2α-VI isoprostane was significantly associated with the overall cognitive performance (ß = -32.36 (95% CI: -51.59 to -13.03; P<0.001). This model explained over 85% of variation of the KABC-II score in children with konzo, but was not significant in explaining the motor proficiency impairment. These findings suggest that cognitive deficits and, possibly, brain injury associated with cassava poisoning is mediated in part by oxidative damage in children with konzo. 8,12-iso-iPF2α-VI isoprostane appears to be a good marker of the neuropathogenic mechanisms of konzo and may be used to monitor the impact of interventional trials to prevent the neurotoxic effects of cassava cyanogenic poisoning.

Effectiveness of wetting method for control of konzo and reduction of cyanide poisoning by removal of cyanogens from cassava flour.

BACKGROUND: Konzo is an irreversible paralysis of the legs that occurs mainly among children and young women in remote villages in tropical Africa and is associated with a monotonous diet of bitter cassava. Konzo was discovered in 1938 by Dr. G. Trolli in the Democratic Republic of Congo (DRC). It also occurs in Mozambique, Tanzania, Cameroon, Central African Republic, and Angola. It was first controlled in Kay Kalenge village, DRC, in 2011 with the use of a wetting method to remove cyanogens from cassava flour. Fourteen months later, another visit was made to Kay Kalenge. OBJECTIVE: To determine whether Kay Kalenge women were still using the wetting method, whether there were new cases of konzo, and whether the wetting method had spread to other villages. METHODS: Meetings were held with chiefs, leaders, and heads of mothers' groups, women from 30 households were interviewed, and three nearby villages were visited. Total cyanide and thiocyanate were analyzed in cassava flour and urine samples, respectively. RESULTS: The women in Kay Kalenge village still used the wetting method. There were no new cases of konzo. The mean cyanide content of the flour samples was 9 ppm, and no child had a mean urinary thiocyanate content greater than 350 micromol/L. The use of the wetting method had spread naturally to three adjacent villages. CONCLUSIONS: The wetting method has been readily accepted by rural women as a simple and useful method to control konzo by removing cyanide from cassava flour, and its use has spread to nearby villages. The wetting method should be promoted by health authorities to control konzo and reduce cyanide poisoning from high-cyanide cassava flour.