Lower sulfurtransferase detoxification rates of cyanide in konzo-A tropical spastic paralysis linked to cassava cyanogenic poisoning.

Using a matched case-control design, we sought to determine whether the odds of konzo, a distinct spastic paraparesis associated with food (cassava) cyanogenic exposure in the tropics, were associated with lower cyanide detoxification rates (CDR) and malnutrition. Children with konzo (N=122, 5-17 years of age) were age- and sex-matched with presumably healthy controls (N=87) and assessed for motor and cognition performances, cyanogenic exposure, nutritional status, and cyanide detoxification rates (CDR). Cyanogenic exposure was ascertained by thiocyanate (SCN) concentrations in plasma (P-SCN) and urine (U-SCN). Children with a height-for-age z-score (HAZNCHS)<-2 were classified as nutritionally stunted. CDR was measured as time required to convert cyanide to SCN, and expressed as ms/µmol SCN/mg protein or as mmolSCN/ml plasma/min. Mean (SD) U-SCN in children with konzo was 521.9 (353.6) µmol/l and was, significantly higher than 384.6 (223.7) µmol/l in those without konzo. Conditional regression analysis of data for age- and sex- matched case-control pairs showed that konzo was associated with stunting (OR: 5.8; 95% CI: 2.7-12.8; p<0.01; N=83 paired groups) and higher U-SCN (OR: 1.1; 95% CI: 1.02-1.20 per 50-µmol increase in U-SCN; p=0.02; N=47 paired groups). After adjusting for stunting and U-SCN, the odds of developing konzo was reduced by 63% (95% CI: 11-85%, p=0.03; N=41 paired groups) for each 5mmol SCN/(ml plasma/min)-increase in CDR. Linear regression analysis indicated a significant association between BOT-2 or KABC-II scores and both the HAZNCHS z-score and the U-SCN concentration, but not the CDR. Our findings provide evidence in support of interventions to remove cyanogenic compounds from cassava prior to human consumption or, peharps, enhance the detoxification of cyanide in those relying on the cassava as the main source of food.

Lower serum levels of selenium, copper, and zinc are related to neuromotor impairments in children with konzo.

We assessed the relationship between key trace elements and neurocognitive and motor impairments observed in konzo, a motor neuron disease associated with cassava cyanogenic exposure in nutritionally challenged African children. Serum concentrations of iron, copper, zinc, selenium, and neurotoxic lead, mercury, manganese, cadmium, and cobalt were measured in 123 konzo children (mean age 8.53 years) and 87 non-konzo children (mean age 9.07 years) using inductively coupled plasma mass spectrometry (ICPMS). Concentrations of trace elements were compared and related to performance scores on the Kaufman Assessment Battery for Children, 2nd edition (KABC-II) for cognition and Bruininks-Oseretsky Test, 2nd edition (BOT-2) for motor proficiency. Children with konzo had low levels of selenium, copper, and zinc relative to controls. Selenium concentration significantly correlated with serum 8,12-iso-iPF2α-VI isoprostane (Spearman r=0.75, p<0.01) and BOT-2 scores (r=0.31, p=0.00) in children with konzo. Elemental deficiency was not associated with poor cognition. Mean (SD) urinary level of thiocyanate was 388.03 (221.75) µmol/l in non-konzo compared to 518.59 (354.19) µmol/l in konzo children (p<0.01). Motor deficits associated with konzo may possibly be driven by the combined effects of cyanide toxicity and Se deficiency on prooxidant mechanisms. Strategies to prevent konzo may include dietary supplementation with trace elements, preferentially, those with antioxidant and cyanide-scavenging properties.

Prevalence and risk factors for hepatitis C virus, hepatitis B virus, and human immunodeficiency virus in transfused children in Kinshasa.

OBJECTIVE: To determine seroprevalence of hepatitis C virus (HCV), human immunodeficiency virus (HIV), and hepatitis B virus (HBV) and associated factors among transfused children. METHODS: A multicenter cross-sectional study of transfused children aged between 18 mo and 13 y old was conducted in 4 hospitals in Kinshasa. Blood samples were collected for the detection of Hepatitis B surface antigen (HBsAg) and antibodies to HCV, HIV 1 and 2. RESULTS: A total of 177 (47.7 %) boys and 194 (52.3 %) girls participated in the study. The median age was 59.5 mo (Interquartile range IQR = 60.6). The prevalence rates of HCV, HBV, and HIV infection were 13.5 %, 1.6 %, and 1.3 %, respectively. Frequency of transfusion events were significantly associated with HCV (p < 0.001) and HIV (p < 0.05) infections. CONCLUSIONS: HCV infection was by far more frequently identified than HBV and HIV infections among Congolese transfused children. Frequency of transfusion events was the only significant risk factor associated with HCV and HIV infections but not for HBV.

Caries experience and related factors in 4-6 year-olds attending dental clinics in Kinshasa, DR of Congo.

OBJECTIVES: The aim of this study was to examine the prevalence and severity of caries experience (CE) in 4-6 year-olds attending dental clinics in Kinshasa, DR Congo, and to explore possible associations with reported behavioural and socio-demographic factors. METHODS: A convenience sample of children attending five dental clinics was recruited. Carers, usually parents, completed a questionnaire consisting of socio-demographic information, oral health and tobacco consumption profile of parents, socio-economic family situation and oral health habits of the child. Children were clinically examined using WHO criteria by trained dentist-examiners. To investigate factors associated with CE, multivariate logistic regression was applied with the significance level set at 0.05. RESULTS: Some 158 children with mean age 5.3 (sd 0.7) years were recruited; 80% presented with clinical signs of CE. Between-meal snacking and drinking was reported by 78% and 65%; 35% had sugar-containing drinks. Most (81%) brushed once a day and 82% brushed in the morning. Prevalence of CE was associated with gender, frequency of meals, consumption of drinks during meals and consumption of sugar-containing drinks; severity with type of infant feeding and sugar-content of the last meal at night. CONCLUSION: The present study shows that both prevalence and severity of caries experience were associated with reported dietary habits, confirming the importance of preventive interventions dealing with these habits in young children living in a developing country.

Correlates of serum lipids and lipoproteins in Congolese patients with arterial hypertension.

OBJECTIVE: The purpose of this study was to assess the prevalence of dyslipidaemia and the correlates of serum lipids and lipoproteins among Congolese subjects with and without arterial hypertension. METHODS: One hundred hypertensive patients attending the outpatient clinics at the University of Kinshasa Hospital, and 100 age- and sex-matched controls recruited among hospital personnel or blood donors entered the case-control study. Their blood pressure (BP), heart rate (HR), body mass index (BMI), waist-to-hip ratio (WHR), serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), plasma fibrinogen (only in patients) and fasting glucose, serum uric acid, creatinine and creatinine clearance (CrCl) were compared using the Student's t-test or Chi-square test as appropriate. Associations between continuous variables were assessed with Pearson correlation coefficients, and correlates of lipids and lipoproteins were determined using multiple linear-regression analysis. RESULTS: Compared to healthy controls, hypertensive patients had greater BMI (p or= 6.20 mmol/l. In hypertensive patients, TC (r = 0.24; p < 0.01) and LDL-C (r = 0.20; p < 0.05) were positively correlated to plasma fibrinogen. A positive correlation was also observed between TC and LDL-C (r = 0.91; p < 0.001), HDL-C and CrCl (r = 0.28; p < 0.001), and TG and glucose (r = 0.24; p < 0.01), whereas TG were negatively correlated to HDL-C (r = -0.38; p < 0.001). In multiple linear-regression analysis, LDL-C, HDL-C, TG and age accounted for 87% (R2) of variation in TC levels; plasma glucose and HDL-C for 19% (R2) of variation in TG levels; and TG and CrCl for only 17% (R2) of variation in HDL-C levels. CONCLUSIONS: The present data indicate that dyslipidaemia affects a substantial proportion of healthy and hypertensive Congolese subjects. Furthermore, hypertension is associated with a cluster of risk factors characteristic of the metabolic syndrome, of which overweight/central obesity could be the cornerstone. Management of arterial hypertension should therefore focus both on lowering high blood pressure and correcting associated lipid disorders.