Impact of Ethnicity on the Prevalence of Early Repolarization Pattern in Children: Comparison Between Caucasian and African Populations.

The patterns and prevalence of early repolarization pattern (ER) in pediatric populations from ethnic backgrounds other than Caucasian have not been determined. Black African children (ages 4-12) from north-west Madagascar were prospectively recruited and their ECGs compared with those of age- and sex-matched Caucasian ethnicity individuals. ER was defined by ≥ 0.1 mV J-point elevation in at least two contiguous inferior and/or lateral ECG leads. A total of 616 children were included. There was a trend toward a higher frequency of ER in the Africans compared to the Caucasians (23.3% vs. 17.1%, respectively, p = 0.053). The subtype (slurred vs. notched) and location of ER (lateral, inferior, or inferior-lateral) were significantly different in the two groups (p < 0.001 and p = 0.020, respectively). There was no significant difference in the number of high-risk ECG features of ERP (i.e., horizontal/descendent pattern, inferior or inferior-lateral location or J-waves ≥ 2 mm) between African and Caucasian children. On the multivariate analysis, African ethnicity was an independent predictive factor of ER (OR 3.57, 95% CI 2.04-6.25, p < 0.001). African children have an increased risk of ER compared to Caucasian counterparts. Future studies should clarify the clinical and prognostic significance of ER in the pediatric population, and whether ethnicity has an impact on the outcomes.

Evaluation of the Global Lung Initiative 2012 Reference Values for Spirometry in African Children.

RATIONALE: Despite the high burden of respiratory disease, no spirometry reference values for African children are available. OBJECTIVES: Investigate whether the Global Lung Initiative (GLI-2012) reference values for spirometry are appropriate for children in sub-Saharan Africa and assess the impact of malnutrition on lung function. METHODS: Anthropometry and spirometry were obtained in children aged 6 to 12 years from urban and semiurban schools in three African countries. Spirometry z-scores were derived using the GLI-2012 prediction equations for African Americans. Thinness (body mass index z-score < -2) was a surrogate for malnutrition. Spirometry outcomes were compared with those of African American children from the third National Health and Nutrition Survey. MEASUREMENTS AND MAIN RESULTS: Spirometry data were analyzed from 1,082 schoolchildren (51% boys) aged 6.0 to 12.8 years in Angola (n = 306), Democratic Republic of the Congo (n = 377), and Madagascar (n = 399). GLI-2012 provided a good fit with mean (SD) z-scores of -0.11 (0.83) for FEV1, -0.08 (0.86) for FVC, and -0.07 (0.83) for FEV1/FVC. Because of low scatter, the fifth centile corresponded to -1.3 z-scores in boys and -1.5 z-scores in girls. Malnourished African children had a normal FEV1/FVC ratio but significant reductions of ∼0.5 z-scores (∼5%) in FEV1 and FVC compared with African American peers from the third National Health and Nutrition Survey. Children in Angola had the lowest, and those in Madagascar had the highest, zFEV1 and zFVC. CONCLUSIONS: The results of this study support the use of GLI-2012 reference values for schoolchildren in sub-Saharan Africa. Malnutrition affects body growth, leading to a proportionately smaller FEV1 and FVC without respiratory impairment, as shown by the normal FEV1/FVC ratio.

Genetic diversity of hepatitis B virus (HBV) in Madagascar.

Hepatitis B virus (HBV) is a DNA virus belonging to Hepadnaviridae family. Chronic infection with HBV is one major risk factor of hepatic disease. In Madagascar, former studies classified the country as part of high endemic area, as HBV prevalence can reach 23% in general population. However, this prevalence differs largely between urban and rural areas and is estimated to be, respectively, 5% and 26%. The aims of the present study were to describe the genetic diversity of HBV strains from different regions of Madagascar, and to describe the viral gene flow throughout the country by using phylogenetic analysis. This is the first large-scale molecular and phylogenetic study analyzing HBV sequences from 28 different Malagasy areas, never sampled in the past. In this study, the most prevalent genotype/sub-genotypes was E. Migration analysis showed a gene flow from zone 3 (rural) to zone 2 (suburban), and a greater gene flow from the middle part of Madagascar to the north than to the south. It is important to study the HBV infections in Madagascar and to monitor the potential spread of this viral strain inside this country. J. Med. Virol. 88:2138-2144, 2016. © 2016 Wiley Periodicals, Inc.

Influence of gender and malnutrition on QT dispersion in a north-Malagasy children population.

BACKGROUND: Children malnutrition involves simultaneous deficiency of nutrients, leading to cardiac morphological and functional alterations. In this complex condition repolarization abnormalities can evolve. Also, sexual dimorphism is a well-established phenomenon, but its influence on ventricular repolarization varies tremendously among races. No data are available about African children, so the aim of our work was to study the correlation between malnourishment and electrocardiographic repolarization parameters and evaluating the sex influence. METHODS: Three hundred seven children (mean age 7.6±3 years old) were consecutively enrolled in the north of Madagascar. The QT interval was measured and corrected (QTc) following the Bazett formula (QT/√RR). QT dispersion (QTcd) was defined as the difference between maximum and minimum QTc. Malnutrition was defined in relation to age and sex specific BMI values. Grade mild, moderate and severe were defined as the value to pass through BMI of 16, 17 and 18.5 at the age of 18. RESULTS: One hundred twenty-six children (41%) were malnourished, 42 (13%) with mild, 61 (20%) moderate and 23 (7%) with a severe grade. No differences were found between normal weight and malnourished regarding the gender, age, height, or heart rate. They had similar QT and QTc intervals (respectively 362.4±36 ms vs. 365.1±47 ms for QT, P=0.59 and 476.9±43 ms vs. 470±53 ms for QTc, P=0.70). QTcd was statistically higher in malnourished children (53.2±16 ms vs. 44.4±15 ms, P<0.001). QTcd progressively increased from normal weight to severe malnutrition (P<0.001). At multivariate analysis, independently from sex category, children with moderate (C.I. 3.94-13.1, P<0.001) and severe (C.I. 8.38-22.0, P<0.001) malnutrition had a higher risk to have a higher QTcd). 146 children (48%) were male. Prolonged QTcd was found more frequently in male children (58% vs. 44%, P=0.04), showing also longer QTc and QTcd (respectively 475.8±52 ms vs. 462.3±42 ms, P=0.01; and 50.1±16 ms vs. 46.2±16 ms, P=0.03). At the multivariate analysis, males had a higher risk (C.I. 0.28-7.35, P=0.03) to have higher QTc dispersion with respect to female children, independently to the nutrition state. CONCLUSIONS: Moderate to severe malnourishment and male sex independently influence ventricular repolarization, with higher QTc dispersion times and eventually higher risk of future arrhythmic complications. In these children, precaution must be taken with intensive correction of malnutrition and a strict ECG follow-up.

Unexpectedly high rates of obesity and dysglycemia among villagers in Cameroon.

Our survey in Cameroon recorded obesity and dysglycemia in inhabitants, which are similar to those reported elsewhere in the region. Typically these metabolic disturbances are attributed to the adoption of a new urban lifestyle including diminished physical activity and an altered ('Western') diet. Unexpectedly we found that, like urban populations, our rural population had high rates of metabolic disturbances, despite living in villages and being physically active and consuming traditional diet that is high in plant sources of food and low in meat. From our preliminary study, we raise the possibility that the environmental elements that are driving the pandemic of obesity and diabetes in sub-Saharan Africa are far more complex than heretofore appreciated.

High Prevalence of Autoimmune Diabetes and Poor Glycaemic Control among Adults in Madagascar: A Brief Report from a Humanitarian Health Campaign in Ambanja.

Madagascar is a geographically isolated country considered a biodiversity hotspot with unique genomics. Both the low-income and the geographical isolation represent risk factors for the development of diabetes. During a humanitarian health campaign conducted in Ambanja, a rural city in the northern part of Madagascar, we identified 42 adult subjects with diabetes and compared their features to 24 randomly enrolled healthy controls. 42.9% (n = 18) of diabetic subjects showed HbA1c values ≥ 9.0%. Unexpectedly, waist circumference and BMI were similar in people with diabetes and controls. Different from the healthy controls, diabetic subjects showed a low prevalence of obesity (5.7% versus 30%, p = 0.02). Accordingly, we found a high prevalence of autoimmune diabetes as 12% of people with diabetes showed positivity for the autoantibody against glutamic acid decarboxylase. Diabetic subjects with positive autoantibody had higher HbA1c values (11.3 ± 4.1% versus 8.3 ± 2.6%, p = 0.03) compared to diabetic subjects with negative autoantibody. In conclusion, here we describe the presence of diabetes and its features in a rural area of Northern Madagascar, documenting poor glycaemic control and a high prevalence of autoimmune diabetes. These data highlight that the diabetes epidemic involves every corner of the world possibly with different patterns and features.

Origin and evolutionary dynamics of Hepatitis B virus (HBV) genotype E in Madagascar.

Africa is one of the endemic regions of HBV infection. In particular, genotype E is highly endemic in most of sub-Saharan Africa such as West African countries where it represents more than 90% of total infections. Madagascar, which is classified as a high endemic area for HBV and where the most prevalent genotype is E, might play a relevant role in the dispersion of this genotype due to its crucial position in the Indian Ocean. The aim of this study was to investigate the origin, population dynamics, and circulation of HBV-E genotype in Madagascar through high-resolution phylogenetic and phylodynamic approaches. The phylogenetic tree indicated that Malagasy isolates were intermixed and closely related with sequences mostly from West African countries. The Bayesian tree highlighted three statistically supported clusters of Malagasy strains which dated back to the years 1981 (95% HPD: 1971-1992), 1986 (95% HPD: 1974-1996), and 1989 (95% HPD: 1974-2001). Population dynamics analysis showed an exponential increase in the number of HBV-E infections approximately from the year 1975 until 2000s. The migration analysis was also performed and a dynamic pattern of gene flow was identified. In conclusion, this study confirms previous observation of HBV-E circulation in Africa and expands these findings at Madagascar demonstrating its recent introduction, and highlighting the role of the African countries in the spread of HBV-E genotype. Further studies on molecular epidemiology of HBV genotype E are needed to clarify the evolutionary history of this genotype.

ECG is an inefficient screening-tool for left ventricular hypertrophy in normotensive African children population.

BACKGROUND: Left ventricular hypertrophy (LVH) is a marker of pediatric hypertension and predicts development of cardiovascular events. Electrocardiography (ECG) screening is used in pediatrics to detect LVH thanks to major accessibility, reproducibility and easy to use compared to transthoracic echocardiography (TTE), that remains the standard technique. Several diseases were previously investigated, but no data exists regarding our study population. The aim of our study was to evaluate the relationship between electrocardiographic and echocardiographic criteria of LVH in normotensive African children. METHODS: We studied 313 children (mean age 7,8 ± 3 yo), in north-Madagascar. They underwent ECG and TTE. Sokolow-Lyon index was calculated to identify ECG-LVH (>35 mm). Left ventricle mass (LVM) with TTE was calculated and indexed by height(2.7) (LVMI(2.7)) and weight (LVMI(w)). We report the prevalence of TTE-LVH using three methods: (1) calculating percentiles age- and sex- specific with values >95th percentile identifying LVH; (2) LVMI(2.7) >51 g/m(2.7); (3) LVMI(w) >3.4 g/weight. RESULTS: 40 (13%) children showed LVMI values >95th percentile, 24 children (8%) an LVMI(2.7) >51 g/m(2.7) while 19 children (6%) an LVMI(w) >3.4 g/kg. LVH-ECG by Sokolow-Lyon index was present in five, three and three children respectively, with poor values of sensitivity (ranging from 13 to 16%), positive predictive value (from 11 to 18%) and high values of specificity (up to 92%). The effects of anthropometrics parameters on Sokolow-Lyon were analyzed and showed poor correlation. CONCLUSION: ECG is a poor screening test for detecting LVH in children. In clinical practice, TTE remains the only tool to be used to exclude LVH.