Child development: risk factors for adverse outcomes in developing countries

Poverty and associated health, nutrition, and social factors prevent at least 200 million children in developing countries from attaining their developmental potential. We review the evidence linking compromised development with modifiable biological and psychosocial risks encountered by children from birth to 5 years of age. We identify four key risk factors where the need for intervention is urgent: stunting, inadequate cognitive stimulation, iodine deficiency, and iron deficiency anaemia. The evidence is also sufficient to warrant interventions for malaria, intrauterine growth restriction, maternal depression, exposure to violence, and exposure to heavy metals. We discuss the research needed to clarify the effect of other potential risk factors on child development. The prevalence of the risk factors and their effect on development and human potential are substantial. Furthermore, risks often occur together or cumulatively, with concomitant increased adverse effects on the development of the world's poorest children.     

How access to health care relates to under‐five mortality in sub‐Saharan Africa: systematic review

An estimated 9.7 million children under the age of five die every year worldwide, approximately 41% of them in sub‐Saharan Africa (SSA). Access to adequate health care is among the factors suggested to be associated with child mortality; improved access holds great potential for a significant reduction in under‐five death in developing countries. Theory and corresponding frameworks indicate a wide range of factors affecting access to health care, such as traditionally measured variables (distance to a health provider and cost of obtaining health care) and additional variables (social support, time availability and caregiver autonomy). Few analytical studies of traditional variables have been conducted in SSA, and they have significant limitations and inconclusive results. The importance of additional factors has been suggested by qualitative and recent quantitative studies. We propose that access to health care is multidimensional; factors other than distance and cost need to be considered by those planning health care provision if child mortality rates are to be reduced through improved access. Analytical studies that comprehensively evaluate both traditional and additional variables in developing countries are required.     

Strengthening the prevention and care of injuries worldwide

The global burden of injuries is enormous, but has often been overlooked in attempts to improve health. We review measures that would strengthen existing efforts to prevent and treat injuries worldwide. Scientifically-based efforts to understand risk factors for the occurrence of injury are needed and they must be translated into prevention programmes that are well designed and assessed. Areas for potential intervention include environmental modification, improved engineering features of motor vehicle and other products, and promotion of safe behaviours through social marketing, legislation, and law enforcement. Treatment efforts need to better define the most high-yield services and to promote these in the form of essential health services. To achieve these changes, there is a need to strengthen the capacity of national institutions to do research on injury control; to design and implement countermeasures that address injury risk factors and deficiencies in injury treatment; and to assess the effectiveness of such countermeasures. Although much work remains to be done in high-income countries, even greater attention is needed in less-developed countries, where injury rates are higher, few injury control activities have been undertaken, and where most of the world's population lives. In almost all areas, injury rates are especially high in the most vulnerable sections of the community, including those of low socioeconomic status. Injury control activities should, therefore, be undertaken in a context of attention to human rights and other broad social issues.     

Control and prevention of cardiovascular disease around the world

The situation regarding cardiovascular disease in different parts of the world is presented, and the prevalence and trends in main risk factors based on Omran's epidemiological transition model are reported. A World Heart Federation survey documenting the limited human and technical resources in some developing countries and inadequate use of these resources in others is discussed. This survey also shows that few countries have guidelines for the management of cardiovascular disease and its risk factors, and reveals a lack of relationship between the percentage of countries with guidelines and the importance of a given disease or risk factor. Because economic resources for health in highly populated developing countries are limited, preventive measures for cardiovascular disease and its risk factors must be combined with those for all other chronic diseases. We recommend the following actions: a). improve the use of facilities for the dissemination of information; b). create suitable conditions for the development of research in developing countries; c). incorporate into primary care the innovations proposed by the WHO in 2002 to control chronic diseases, and d). assist in the development of the program proposed by the World Heart Federation.     

Hypertension in the developing world: A consequence of progress

Hypertension is one of the leading causes of death and disability in developing countries. The increasing burden of hypertension in these countries has been attributed to several indicators of economic progress such as increased life expectancy, urbanization and its attendant lifestyle changes, and the overall epidemiologic transition these countries are experiencing currently. The public health response to this challenge must be to promote health among all sections of the populations of these countries, and a concerted effort to promote awareness about hypertension, its risk factors, and risk behaviors. The health policies of these countries need to be reoriented to include chronic diseases in their ambit. These efforts have the potential to reduce the emergence or lessen the toll of hypertension and its complication in many parts of the developing world.     

Child maltreatment: variation in trends and policies in six developed countries

We explored trends in six developed countries in three types of indicators of child maltreatment for children younger than 11 years, since the inception of modern child protection systems in the 1970s. Despite several policy initiatives for child protection, we recorded no consistent evidence for a decrease in all types of indicators of child maltreatment. We noted falling rates of violent death in a few age and country groups, but these decreases coincided with reductions in admissions to hospital for maltreatment-related injury only in Sweden and Manitoba (Canada). One or more child protection agency indicators increased in five of six countries, particularly in infants, possibly as a result of early intervention policies. Comparisons of mean rates between countries showed five-fold to ten-fold differences in rates of agency indicators, but less than two-fold variation in violent deaths or maltreatment-related injury, apart from high rates of violent child death in the USA. These analyses draw attention to the need for robust research to establish whether the high and rising rates of agency contacts and out-of-home care in some settings are effectively reducing child maltreatment.     

Positive parenting for positive parents: HIV/AIDS,poverty, caregiver depression,child behavior,and parenting in South Africa

Families affected by HIV/AIDS in the developing world experience higher risks of psychosocial problems than nonaffected families. Positive parenting behavior may buffer against the negative impact of child AIDS-orphanhood and caregiver AIDS-sickness on child well-being. Although there is substantial literature regarding the predictors of parenting behavior in Western populations, there is insufficient evidence on HIV/AIDS as a risk factor for poor parenting in low- and middle-income countries. This paper examines the relationship between HIV/AIDS and positive parenting by comparing HIV/AIDS-affected and nonaffected caregiver-child dyads (n=2477) from a cross-sectional survey in KwaZulu-Natal, South Africa (27.7% AIDS-ill caregivers; 7.4% child AIDS-orphanhood). Multiple mediation analyses tested an ecological model with poverty, caregiver depression, perceived social support, and child behavior problems as potential mediators of the association of HIV/AIDS with positive parenting. Results indicate that familial HIV/AIDS's association to reduced positive parenting was consistent with mediation by poverty, caregiver depression, and child behavior problems. Parenting interventions that situate positive parenting within a wider ecological framework by improving child behavior problems and caregiver depression may buffer against risks for poor child mental and physical health outcomes in families affected by HIV/AIDS and poverty.     

Biological and socioeconomic determinants of child survival

This document describes advances in a conceptual framework under development since 1984 for research on child survival in developing countries. The framework links variables explaining biologically determined disease processes to social determinants in the family and community. The major addition is the extension of previous models of proximate determinants to include fertility-child survival interactions, as well as the interaction between child growth and child survival. The role of health policies within the framework of proximate determinants is also explored. A strategy oriented toward specific diseases will not prove successful in developing countries, where most infant and child deaths are not due to a single cause but rather are the final product of a series of episodes of infection combined with malnutrition. Health policies must therefore identify the risk factors that reduce probabilities of survival as well as the pathologies that actually cause death. Risk factors can be classified as proximate determinants, the basic biological mechanisms that directly influence risks of morbidity and mortality, and underlying determinants, all the other social and environmental determinants that operate indirectly through the proximate determinants to influence infant survival. The 1st step in applying the focus on proximate determinants is to achieve a clear understanding of some measurable biological indicators of health and child survival or of their opposites, illness and death. Abnormal growth has been found to be a sensitive and nonspecific indicator of morbidity in children. Measurement of height and weight could serve as the social science counterpart of mortality measurement for a demographer. Mortality and permanent growth stunting are both indicators reflecting different points of chronic and irreversible physical deterioration on the continuum that ranges from good health to death. The proposed conceptual framework integrates Bongaarts' proximate fertility determinants with the proximate child survival determinants proposed in an earlier work by Mosley and Chen. 9 specific determinants are divided into 4 categories of factors that influence both child survival and fertility: factors regulating exposure to conception (sexual union, coital frequency), lactation, ecological risk (dietary deficiency, environmental contamination, accidents), and direct interventions (personal preventive measures, curative measures, and intentionally inflicted lesions). 5 groups of underlying determinants operate through the proximate determinants: individual factors, family factors, cultural factors, institutional factors, and environmental factors.     

Strategies to avoid the loss of developmental potential in more than 200 million children in the developing world

This paper is the third in the Child Development Series. The first paper showed that more than 200 million children under 5 years of age in developing countries do not reach their developmental potential. The second paper identified four well-documented risks: stunting, iodine deficiency, iron deficiency anaemia, and inadequate cognitive stimulation, plus four potential risks based on epidemiological evidence: maternal depression, violence exposure, environmental contamination, and malaria. This paper assesses strategies to promote child development and to prevent or ameliorate the loss of developmental potential. The most effective early child development programmes provide direct learning experiences to children and families, are targeted toward younger and disadvantaged children, are of longer duration, high quality, and high intensity, and are integrated with family support, health, nutrition, or educational systems and services. Despite convincing evidence, programme coverage is low. To achieve the Millennium Development Goals of reducing poverty and ensuring primary school completion for both girls and boys, governments and civil society should consider expanding high quality, cost-effective early child development programmes.     

Occupational use syndromes

The prevalence of work-related musculoskeletal disorders is increasing worldwide. The association between job type and the specific activities within jobs that predispose to the risk of developing such disorders is well documented for developed countries. This review describes the evidence for such disorders in the developing world. The prevalence of any work-related musculoskeletal disorders in developing countries ranges from 37% among a general population-based sample of workers through to 92% among nurses. Some occupations unique to developing countries have particularly high prevalence of such disorders. These include cervical spondylosis among 'coolies' and spinal disorders among women carrying head loads. The risk factors for these disorders in the developing world are generally similar to those seen in developed countries; however, the higher and more demanding work loads and larger numbers of female and child workers place workers from developing countries at greater risk. The mainstay of management is work-place interventions. Low-cost interventions are possible through collaboration between medical practitioner, worker and employer.     

Hypertension in developing countries

Data from different national and regional surveys show that hypertension is common in developing countries, particularly in urban areas, and that rates of awareness, treatment, and control are low. Several hypertension risk factors seem to be more common in developing countries than in developed regions. Findings from serial surveys show an increasing prevalence of hypertension in developing countries, possibly caused by urbanisation, ageing of population, changes to dietary habits, and social stress. High illiteracy rates, poor access to health facilities, bad dietary habits, poverty, and high costs of drugs contribute to poor blood pressure control. The health system in many developing countries is inadequate because of low funds, poor infrastructure, and inexperience. Priority is given to acute disorders, child and maternal health care, and control of communicable diseases. Governments, together with medical societies and non-governmental organisations, should support and promote preventive programmes aiming to increase public awareness, educate physicians, and reduce salt intake. Regulations for the food industry and the production and availability of generic drugs should be reinforced.     

Reducing mortality from sudden cardiac death in the community: lessons from epidemiology and clinical applications research

The reduction of mortality from sudden cardiac death (SCD) in the community remains a challenge. Clinical-epidemiologic studies have identified a range of factors that are associated with an increased risk of SCD. While of potential etiologic and prognostic importance, these factors have limited sensitivity and a low positive predictive value for SCD. On the other hand, clinical trials have suggested that a variety of interventions, including risk factor reduction, nutritional interventions, drug therapies, cardiac procedures, and new technologies, have the potential to reduce mortality from SCD. In this review, we examine what is known about the epidemiology and clinical application of interventions to reduce mortality from SCD; and, we consider the impact of both prevention and clinical interventions on mortality from SCD from a community perspective. There is mounting evidence that supports both public health and clinical efforts to prevent the occurrence of SCD. There also is evidence suggesting that new technologies, such as automated external defibrillators, have the potential to reduce case-fatality from SCD. Further progress will depend on improved methods to identify persons-at-risk, reduction of risk factors, and application of techniques -- both simple and advanced -- to improve survival in victims of SCD.     

The sexual and reproductive health of young people in Latin America: evidence from WHO case studies

This original article addresses the sexual and reproductive health needs of young people aged 15 to 24 in Latin America. It introduces five articles from original research projects in three countries: Argentina, Brazil, and Peru. These projects were funded by the World Health Organization. This article explains the importance of studies that address the sexual and reproductive health of young people in developing countries. It provides an overview of sexual and reproductive health issues in Latin America and a discussion these issues in the three study countries. The five articles deal with difficult and challenging issues, including: knowledge of STIs and HIV/AIDS; pregnancy related practices; quality of care; the role of young men in couple formation, pregnancy and adoption of contraceptive practice; and, the role of obstetricians and gynecologists in public policy debate about family planning and abortion. The four articles in this special section help to improve our understanding of the factors that contribute to risky sexual behavior and negative reproductive health outcomes among youth in Latin America. The findings are useful to help inform and improve health care interventions in various contexts.     

Measles: not just another viral exanthem

Measles is the most frequent cause of vaccine-preventable childhood deaths. Infants younger than the recommended age for vaccination are susceptible to the disease, and in developing countries they have a high risk of complications and mortality. Vaccine coverage in excess of 95% interrupts endemic transmission of measles in many countries, but achievement of such coverage almost always requires coordinated supplementary mass vaccination campaigns. There are substantial health gains if countries improve measles vaccine coverage, irrespective of whether or not high coverage is achieved; these gains include much lower measles complication and case fatality rates, long-term interepidemic duration, and possibly non-specific improvements in survival of children. Investigation into the cost-effectiveness of different strategies for measles control, including mass campaigns, two-dose schedules, and young-infant doses, would help countries to formulate control policies appropriate to their setting. Pneumonia is the most common fatal complication associated with measles, and at least 50% of measles-related pneumonias are due to bacterial superinfection. WHO has developed standard case management programmes for measles, but there are several unresolved clinical issues, including optimum indications for antibiotic treatment, the importance of intravenous immunoglobulin, the role of viral coinfection, and the risk of tuberculosis after measles. The priority in worldwide efforts to control measles is to lend support to poor countries, helping them to increase vaccine coverage and sustain improvements to vaccination infrastructure, and to address technical issues with respect to optimum vaccination schedules. Measles represents a specific challenge, whereby partnerships between high-income and developing nations would reduce child mortality in developing countries; such partnerships are not without incentive for high-income countries, since without them imported measles cannot be prevented.     

How could complementary feeding patterns affect the susceptibility to NCD later in life?

AimsThe purpose of this paper is to provide a general framework for thinking about pathways and potential mechanisms through which complementary feeding may influence the risk of developing non-communicable diseases (NCDs).Data synthesisTo provide a context for the lack of clear and consistent evidence relating complementary feeding to NCD risk, methodological challenges faced in trying to develop an evidence base are described. Potential pathways through which complementary feeding may influence obesity-related NCD risk are described and illustrated with examples.ConclusionsNumerous aspects of complementary feeding, including diet composition as well as patterns of feeding have the potential to influence the early development of obesity, which in turn predicts later obesity and NCD risk. Specific dietary exposures during the period of complementary feeding also have the potential to program future disease risk through pathways that are independent of adiposity. These factors all require consideration when making recommendations for optimal complementary feeding practices aimed at prevention of future NCDs.     

Asthma in developing countries in the Asia-Pacific Region (APR)

There is growing interest in the epidemiology of asthma in developing countries, especially in the Asia-Pacific Region (APR). A number of reviews have been published in this field, but a comprehensive synthesis of overall data has not been reported. Here, we summarized the burden, risk factors and challenges of asthma management in developing countries with a specific emphasis on the APR by consolidating evidence from both systematic and narrative reviews published up until February 2023. We found that although asthma prevalence in low and low-middle-income countries (LMICs) is known to be generally lower compared to high-income countries, the burden is substantially greater. Studies conducted in APR LMIC have reported a range of risk factors, including pre- and post-natal factors, environmental considerations, lifestyle measures, individual features and genetics. The low and inequitable distribution of quality preventive and curative health care, a lack of advanced diagnostic measures, non-availability and non-affordability of novel therapeutics, cultural beliefs and practices, and diverse disease phenotypes make it challenging to achieve optimal asthma control in the region. Hence, we call for the development of a region-specific blueprint for action to mitigate this challenging situation, to help reduce the burden of asthma in APR LMIC.     

Clinical risk factors and evaluation of the risk of osteoporosis in clinical practice

Bone health is determined by influences that accumulate over one's entire lifetime. Numerous factors including age, heredity, nutrition, physical activity, sex steroids and other medical problems all influence the possibility of an individual developing osteoporosis. Fractures due to minimal trauma are the important consequence of osteoporosis, but the risk of fractures is also determined by many non-skeletal risk factors such as body size and the frequency of injury. We now have effective therapeutic options to prevent bone loss and to reduce fracture risk. Assessing risk factors for both osteoporosis and for fractures allows clinicians to identify individuals for whom these therapies are most appropriate.     

Incidence of diarrhea in children living in urban slums in Salvador, Brazil.

Diarrhea remains a major health issue in developing countries, with high morbidity and mortality rates. Determining the incidence of acute diarrhea in children and its associated factors is crucial to the planning of preventive approaches. The objective of this study was to determine the incidence of diarrhea and to assess some relevant associated factors to it in children younger than 40 months living in two slums of Salvador, Brazil. This is the first prospective cohort, community-based study that was performed in two periurban slums of Salvador, Brazil. Eighty-four children younger than 40 months were randomly selected and visited every other day for one year. The chi-square test was used to evaluate the occurrence of diarrhea and its associated factors. During the surveillance period, 232 diarrhea episodes were identified, resulting in an incidence rate of 2.8 episodes/child/year. In average (mean value of 84 children),each child suffered 11.1 days of diarrhea per year, yielding an average duration of 3.9 days per episode. The highest incidence rates were found among children under one year old. Early weaning, male sex, malnutrition, having a mother younger than 25 years or who considered her child malnourished, missed immunizations and previous pneumonia were associated factors for suffering diarrheal episodes. The rates of incidence and duration of diarrhea that we found are in accordance to those reported by others. Additionally, our results reinforce the importance of environmental and health-related associated factors to the onset of diarrhea.     

Evaluation of risk factors for severe pneumonia in children: the Pneumonia Etiology Research for Child Health study

As a case-control study of etiology, the Pneumonia Etiology Research for Child Health (PERCH) project also provides an opportunity to assess the risk factors for severe pneumonia in hospitalized children at 7 sites. We identified relevant risk factors by literature review and iterative expert consultation. Decisions for inclusion in PERCH were based on comparability to published data, analytic plans, data collection costs and logistic feasibility, including interviewer time and subject fatigue. We aimed to standardize questions at all sites, but significant variation in the economic, cultural, and geographic characteristics of sites made it difficult to obtain this objective. Despite these challenges, the depth of the evaluation of multiple risk factors across the breadth of the PERCH sites should furnish new and valuable information about the major risk factors for childhood severe and very severe pneumonia, including risk factors for pneumonia caused by specific etiologies, in developing countries.