Estimating the burden of selected non-communicable diseases in Africa: a systematic review of the evidence

Background The burden of non-communicable diseases (NCDs) is rapidly increasing globally, and particularly in Africa, where the health focus, until recently, has been on infectious diseases. The response to this growing burden of NCDs in Africa has been affected owing to a poor understanding of the burden of NCDs, and the relative lack of data and low level of research on NCDs in the continent. Recent estimates on the burden of NCDs in Africa have been mostly derived from modelling based on data from other countries imputed into African countries, and not usually based on data originating from Africa itself. In instances where few data were available, estimates have been characterized by extrapolation and over-modelling of the scarce data. It is therefore believed that underestimation of NCDs burden in many parts of Africa cannot be unexpected. With a gradual increase in average life expectancy across Africa, the region now experiencing the fastest rate of urbanization globally, and an increase adoption of unhealthy lifestyles, the burden of NCDs is expected to rise. This thesis will, therefore, be focussing on understanding the prevalence, and/or where there are available data, the incidence, of four major NCDs in Africa, which have contributed highly to the burden of NCDs, not only in Africa, but also globally. Methods I conducted a systematic search of the literature on three main databases (Medline, EMBASE and Global Health) for epidemiological studies on NCDs conducted in Africa. I retained and extracted data from original population-based (cohort or cross sectional), and/or health service records (hospital or registry-based studies) on prevalence and/or incidence rates of four major NCDs in Africa. These include: cardiovascular diseases (hypertension and stroke), diabetes, major cancer types (cervical, breast, prostate, ovary, oesophagus, bladder, Kaposi, liver, stomach, colorectal, lung and non-Hodgkin lymphoma), and chronic respiratory diseases (chronic obstructive pulmonary disease (COPD) and asthma). From extracted crude prevalence and incidence rates, a random effect meta-analysis was conducted and reported for each NCD. An epidemiological model was applied on all extracted data points. The fitted curve explaining the largest proportion of variance (best fit) from the model was further applied. The equation generated from the fitted curve was used to determine the prevalence and cases of the specific NCD in Africa at midpoints of the United Nations (UN) population 5-year age-group population estimates for Africa. Results From the literature search, studies on hypertension had the highest publication output at 7680, 92 of which were selected, spreading across 31 African countries. Cancer had 9762 publications and 39 were selected across 20 countries; diabetes had 3701 publications and 48 were selected across 28 countries; stroke had 1227 publications and 19 were selected across 10 countries; asthma had 790 publications and 45 were selected across 24 countries; and COPD had the lowest output with 243 publications and 13 were selected across 8 countries. From studies reporting prevalence rates, hypertension, with a total sample size of 197734, accounted for 130.2 million cases and a prevalence of 25.9% (23.5, 34.0) in Africa in 2010. This is followed by asthma, with a sample size of 187904, accounting for 58.2 million cases and a prevalence of 6.6% (2.4, 7.9); COPD, with a sample size of 24747, accounting for 26.3 million cases and a prevalence of 13.4% (9.4, 22.1); diabetes, with a sample size of 102517, accounting for 24.5 million cases and a prevalence of 4.0% (2.7, 6.4); and stroke, with a sample size of about 6.3 million, accounting for 1.94 million cases and a prevalence of 317.3 per 100000 population (314.0, 748.2). From studies reporting incidence rates, stroke accounted for 496 thousand new cases in Africa in 2010, with a prevalence of 81.3 per 100000 person years (13.2, 94.9). For the 12 cancer types reviewed, a total of 775 thousand new cases were estimated in Africa in 2010 from registry-based data covering a total population of about 33 million. Among women, cervical cancer and breast cancer had 129 thousand and 81 thousand new cases, with incidence rates of 28.2 (22.1, 34.3) and 17.7 (13.0, 22.4) per 100000 person years, respectively. Among men, prostate cancer and Kaposi sarcoma closely follows with 75 thousand and 74 thousand new cases, with incidence rates of 14.5 (10.9, 18.0) and 14.3 (11.9, 16.7) per 100000 person years, respectively. Conclusion This study suggests the prevalence rates of the four major NCDs reviewed (cardiovascular diseases (hypertension and stroke), diabetes, major cancer types, and chronic respiratory diseases (COPD and asthma) in Africa are high relative to global estimates. Due to the lack of data on many NCDs across the continent, there are still doubts on the true prevalence of these diseases relative to the current African population. There is need for improvement in health information system and overall data management, especially at country level in Africa. Governments of African nations, international organizations, experts and other stakeholders need to invest more on NCDs research, particularly mortality, risk factors, and health determinants to have evidenced-based facts on the drivers of this epidemic in the continent, and prompt better, effective and overall public health response to NCDs in Africa

Caractérisation de souches invasives de Neisseria meningitidis isolées à l’Hôpital d’enfants de Tunis, en Tunisie

International audienceالخلاصة: تعتبر النيسرية السحائية - أحد الأسباب الرئيسية لالتهاب السحايا الجرثومي وغيره من الأمراض المُعدية الخطيرة - مسؤولة عن حوالي ثلث حالات التهاب السحايا الجرثومي في مستشفى الأطفال بمدينة تونس. وقد حُدِّد توزع المجموعات المصلية، والحساسية للمضادات الحيوية، والمميزات المستضدية والجزيئية، للنيسرية السحائية المعزولة من مرضى تتراوح أعمارهم بين 3 أيام و 13 عاماً في الفترة ما بين فبراير/شباط 1998 ويونيو/حزيران 2013. لقد تم عزل 107 سلالات غازية للنيسيرية السحائية. وشوهد انخفاض في الحساسية للبنسلين G لدى %55.7 من المعزولات، مع تدني مستوى المقاومة في جميع الحالات؛ كما أظهرت %28.4 مستوى متدنياً من المقاومة للأموكسيسيلين. وكانت السلالات المعزولة للمجموعة المصلية B الأكثرَ شيوعاً (%80.4)، تليها المجموعة المصلية C (%12.2) و A (%5.6). وكان لمعزولات المجموعة المصلية A نفس الصيغة المستضدية (A:4:P1.9)، ونفس النواحي المتغيرة VR1 و VR2 و VR3، وتنتمي إلى نفس المجمع النسيلي (CC5). وكانت معزولات المجموعتين المصليتين B و C أكثر تغايراً وذات صيغ مستضدية متعددة. وكان المجمع النسيلي الأكثر شيوعاً في هذه السلالات CC35. وقد استأثرت المجموعة المصلية B بنسبة مئوية كبيرة من معزولاتنا، مع وجود تنوع ملحوظ.Neisseria meningitidis, a leading cause of bacterial meningitis and other serious infections, is responsible for approximately one-third of cases of bacterial meningitis in the Children's Hospital of Tunis. The serogroup distribution, antibiotic susceptibility and antigenic and molecular characteristics of N. meningitidis isolates were determined in patients aged 3 days-13 years between February 1998 and June 2013. In all 107 invasive strains of N. meningitidis were isolated. Reduced susceptibility to penicillin G was seen in 55.7% of isolates, with a low level of resistance in all cases; 28.4% showed a low level of resistance to amoxicillin. Serogroup B isolates were the most frequent (80.4%), followed by serogroups C (12.2%) and A (5.6%). Isolates of serogroup A had the same antigenic formula (A:4:P1.9), the same variable regions VR1, VR2 and VR3, and belonged to the same clonal complex (CC5). Isolates of serogroups B and C were more heterogeneous with several antigenic formulae. The most frequent clonal complex in these isolates was CC35. Serogroup B accounted for a large percentage of our isolates with marked diversity.La bactérie Neisseria meningitidis, l'une des causes principales de méningite bactérienne et d'autres infections graves, est responsable d'environ un tiers des cas de méningite bactérienne à l'Hôpital d'enfants de Tunis. La distribution par sérogroupe, la sensibilité aux antibiotiques et les propriétés antigéniques et moléculaires des isolats de N. meningitidis ont été déterminées chez des patients âgés de 3 jours à 13 ans entre février 1998 et juin 2013. En tout, 107 souches invasives de N. meningitidis ont été isolées. Une sensibilité réduite à la pénicilline G a été observée dans 55,7 % des isolats, avec un bas niveau de résistance pour tous les cas ; et 28,4 % ont montré un bas niveau de résistance à l'amoxicilline. Les isolats du sérogroupe B étaient les plus fréquents (80,4 %), suivis par les sérogroupes C (12,2 %) et A (5,6 %). Les isolats du sérogroupe A avaient la même formule antigénique (A:4:P1.9), les mêmes régions variables VR1, VR2 et VR3, et appartenaient au même complexe clonal (CC5). Les isolats des sérogroupes B et C étaient davantage hétérogènes, avec plusieurs formules antigéniques. Le complexe clonal le plus fréquent de ces isolats était CC35. Le sérogroupe B comptait pour un pourcentage élevé des isolats avec une diversité marquée

Effect of reduced dietary zinc intake on carbohydrate and Zn metabolism in the genetically diabetic mouse (C57BL/KsJ db+/db+)

1. Male, 4-5-week-old, genetically diabetic mice (C57BL/KsJ db/db) and non-diabetic heterozygote littermates (C57BL/KsJ db/+) were fed on a diet containing 1 mg zinc/kg (low-Zn groups) or 54 mg Zn/kg (control groups) for 27 d. Food intakes and body-weight gain were recorded regularly. On day 28, after an overnight fast, animals were killed and blood glucose and insulin concentrations, liver glycogen, and femur and pancreatic Zn concentrations were determined. 2. The consumption of the low-Zn diet had only a minimal effect on the Zn status of the mice as indicated by growth rate, food intake and femur and pancreatic Zn concentrations. In fact, diabetic mice fed on the low-Zn diet had a higher total food intake than those fed on the control diet. The low-Zn diabetic mice had higher fasting blood glucose and liver glycogen levels than their control counterparts. Fasting blood insulin concentration was unaffected by dietary regimen. 3. A second experiment was performed in which the rate of loss of 65Zn, injected subcutaneously, was measured by whole-body counting in the two mouse genotypes over a 28 d period, from 4 to 5 weeks of age. The influence of feeding low-Zn or control diets was also examined. At the end of the study femur and pancreatic Zn and non-fasting blood glucose levels were determined. 4. All mice fed on the low-Zn diet showed a marked reduction in whole-body 65Zn loss compared with those animals fed on the control diet.(ABSTRACT TRUNCATED AT 250 WORDS

β-Caryophyllene ameliorates cisplatin-induced nephrotoxicity in a cannabinoid 2 receptor-dependent manner

(E)-β-caryophyllene (BCP) is a natural sesquiterpene found in many essential oils of spice (best known for contributing to the spiciness of black pepper) and food plants with recognized anti-inflammatory properties. Recently it was shown that BCP is a natural agonist of endogenous cannabinoid 2 (CB(2)) receptors, which are expressed in immune cells and mediate anti-inflammatory effects. In this study we aimed to test the effects of BCP in a clinically relevant murine model of nephropathy (induced by the widely used antineoplastic drug cisplatin) in which the tubular injury is largely dependent on inflammation and oxidative/nitrative stress. β-caryophyllene dose-dependently ameliorated cisplatin-induced kidney dysfunction, morphological damage, and renal inflammatory response (chemokines MCP-1 and MIP-2, cytokines TNF-α and IL-1β, adhesion molecule ICAM-1, and neutrophil and macrophage infiltration). It also markedly mitigated oxidative/nitrative stress (NOX-2 and NOX-4 expression, 4-HNE and 3-NT content) and cell death. The protective effects of BCP against biochemical and histological markers of nephropathy were absent in CB(2) knockout mice. Thus, BCP may be an excellent therapeutic agent to prevent cisplatin-induced nephrotoxicity through a CB(2) receptor-dependent pathway. Given the excellent safety profile of BCP in humans it has tremendous therapeutic potential in a multitude of diseases associated with inflammation and oxidative stress