New Issues in Developing Effective Approaches for the Prevention and Control of Vitamin A Deficiency

1998 ◽  
Vol 19 (2) ◽  
pp. 137-148 ◽  
Author(s):  
Martin W. Bloem ◽  
Saskia de Pee ◽  
Ian Darnton-Hill

Even mild to moderate vitamin A deficiency is now recognized as an important factor in child health and survival. This has given increased emphasis to the goal of virtually eliminating vitamin A deficiency and its consequences, including blindness, by the end of the decade. The implications of vitamin A deficiency, however, vary according to the group at risk, and this needs to be addressed when looking at ways to achieve the goal. In pre-school children, vitamin A deficiency can lead to increased risk of mortality and morbidity and to blindness. In pregnant and lactating women, it can lead to night-blindness and appears to have implications for maternal morbidity and mortality. Although the immediate health consequences for schoolchildren and adolescents are not completely known, they are probably less dramatic. Nevertheless, it is clear that there is a cross-generational cycle leading to and perpetuating vitamin A deficiency in affected communities. This also has implications when addressing prevention and control strategies. The existing, somewhat successful approach has been to target children aged six months to six years; it is implicit that this criterion is used to measure progress towards the end-of-decade goals. A broader, complementary, life-cycle approach to vitamin A deficiency is now appropriate in many countries. There is increasing emphasis on such approaches, i.e., fortifying foods with vitamin A and improving the diet, which address the whole population at risk. A mix of interventions will give governments the chance to shift from a subsidized vitamin A capsule programme to more sustainable, non-subsidized, consumer-funded vitamin A interventions, although in an appreciable number of countries, supplementation with vitamin A will be a necessity for some years to come. Guidelines to assist governments in such transitions are a high priority.

2021 ◽  
Vol 12 ◽  
Author(s):  
Mehrie Harshad Patel ◽  
Shrikanth Sampath ◽  
Anoushka Kapoor ◽  
Devanshi Narendra Damani ◽  
Nikitha Chellapuram ◽  
...  

Cardiac arrhythmias constitute a tremendous burden on healthcare and are the leading cause of mortality worldwide. An alarming number of people have been reported to manifest sudden cardiac death as the first symptom of cardiac arrhythmias, accounting for about 20% of all deaths annually. Furthermore, patients prone to atrial tachyarrhythmias such as atrial flutter and fibrillation often have associated comorbidities including hypertension, ischemic heart disease, valvular cardiomyopathy and increased risk of stroke. Technological advances in electrical stimulation and sensing modalities have led to the proliferation of medical devices including pacemakers and implantable defibrillators, aiming to restore normal cardiac rhythm. However, given the complex spatiotemporal dynamics and non-linearity of the human heart, predicting the onset of arrhythmias and preventing the transition from steady state to unstable rhythms has been an extremely challenging task. Defibrillatory shocks still remain the primary clinical intervention for lethal ventricular arrhythmias, yet patients with implantable cardioverter defibrillators often suffer from inappropriate shocks due to false positives and reduced quality of life. Here, we aim to present a comprehensive review of the current advances in cardiac arrhythmia prediction, prevention and control strategies. We provide an overview of traditional clinical arrhythmia management methods and describe promising potential pacing techniques for predicting the onset of abnormal rhythms and effectively suppressing cardiac arrhythmias. We also offer a clinical perspective on bridging the gap between basic and clinical science that would aid in the assimilation of promising anti-arrhythmic pacing strategies.


1988 ◽  
Vol 10 (3) ◽  
pp. 1-12 ◽  
Author(s):  
I. Darnton-Hill ◽  
F. Sibanda ◽  
M. Mitra ◽  
M. M. Ali ◽  
A. E. Drexler ◽  
...  

2005 ◽  
Vol 288 (1) ◽  
pp. R73-R79 ◽  
Author(s):  
D. Downie ◽  
C. Antipatis ◽  
M. I. Delday ◽  
C. A. Maltin ◽  
A. A. Sneddon

Vitamin A deficiency is one of the most common dietary deficiencies in the developing world and is a major health concern where it is associated with increased risk of fetal and infant mortality and morbidity. Early studies in the rat demonstrated that, in addition to respiratory problems, neonates showed evidence of mobility problems in response to moderate vitamin A deficiency. This study investigated whether moderate deficiency of this vitamin plays a role in regulating key skeletal muscle regulatory pathways during development. Thirty female rats were fed vitamin A-moderate (VAM) or vitamin A-sufficient diets from weaning and throughout pregnancy. Fetal and neonatal hindlimb and muscle samples were collected on days 13.5, 15.5, 17.5, and 19.5 of pregnancy and 1 day following birth. Mothers fed the VAM diet had reduced retinol concentrations at all time points studied ( P < 0.01), and neonates had reduced relative lung weights ( P < 0.01). Fetal weight and survival did not differ between groups but neonatal survival was lower in the VAM group where neonates had increased relative heart weights ( P < 0.05). Analysis of myogenic regulatory factor expression and calcineurin signaling in fetuses and neonates demonstrated decreased protein levels of myf5 [50% at 17.5 dg ( P < 0.05)], myogenin [70% at birth ( P < 0.001)], and myosin heavy chain fast [50% at birth ( P < 0.05)] in response to moderate vitamin A deficiency. Overall, these changes suggest that vitamin A status during pregnancy may have important implications for fetal muscle development and subsequent muscle function in the offspring.


2019 ◽  
Vol 3 (9) ◽  
Author(s):  
Ian Darnton-Hill

ABSTRACT Vitamin deficiencies remain major etiological factors in the global burden of disease, especially in low- and middle-income countries. The purpose of this state-of-the-art review was to update current information on deficiencies of vitamins and public health approaches to addressing them. Some stages of life present a higher risk of deficiency than others: risks are higher in pregnant women, children (from conception to young childhood), adolescents, the elderly, and all of the over 800 million people globally who are undernourished. At risk are approximately 125 million preschool children with vitamin A deficiency, as well as sub-populations at risk of deficiencies of folate, thiamin, vitamin B12, niacin, riboflavin, other B vitamins. and vitamin D. Addressing micronutrient deficiencies requires identifying those at risk and then working to prevent and manage that risk. Public health approaches include improved, diversified diets; supplementation; fortification and biofortification; and other supportive public health measures. Historically, as with pellagra and beriberi and, in the last 3 decades, with vitamin A and folic acid, there has been encouraging progress, but much remains to be done.


BMJ Open ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. e048551
Author(s):  
Peter Suwirakwenda Nyasulu ◽  
Jacqueline Weyer ◽  
Rea Tschopp ◽  
Adane Mihret ◽  
Abraham Aseffa ◽  
...  

ObjectiveThe objective of this scoping review was to map the current situation and available evidence and gaps on rabies morbidity, mortality, integrated rabies surveillance programmes, and existing prevention and control strategies in Africa.MethodsWe conducted a systematic scoping review following the Joanna Briggs methodology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews checklist. Medline, Embase, CINAHL (EBSCOHost), Scopus, Web of Science and rabies web conferences were used to search for peer-reviewed publications between January 1946 and May 2020. Two researchers reviewed the studies and extracted data based on author (year) and region, study design and data collection duration, participants/comparators, interventions, control conditions/exposures and outcomes (rabies mortality and morbidity) and key findings/gaps/challenges. The results were reported narratively using Arksey and O’Malley’s methodological framework.ResultsElectronic search yielded 2775 records, of which 43 studies were included. A total of 543 714 bite victims were censored through the included studies. Most of the victims were less than 15 years of age. The studies included rabies morbidity (21) and mortality (15) fluctuating in space and time across Africa depending on countries’ rabies prevention and control practices (16). Others were surveillance (nine studies); surveillance and prevention (five studies); management and control (seven studies); and surveillance, prevention and control (six studies). We found challenges in rabies reporting, existing dog vaccination programmes and post-exposure prophylaxis availability or compliance.ConclusionThis study found challenges for dog rabies control and elimination in Africa and the need for a policy to drive the goal of zero dog-transmitted rabies to humans by 2030.This is an open-access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build on this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated and the use is non-commercial (see http://creativecommons.org/licenses/by-nc/4.0/).


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