Showing papers by "World Health Organization published in 2003"

A novel coronavirus associated with severe acute respiratory syndrome.

Abstract: background A worldwide outbreak of severe acute respiratory syndrome (SARS) has been associated with exposures originating from a single ill health care worker from Guangdong Province, China. We conducted studies to identify the etiologic agent of this outbreak. methods We received clinical specimens from patients in six countries and tested them, using virus isolation techniques, electron-microscopical and histologic studies, and molecular and serologic assays, in an attempt to identify a wide range of potential pathogens. results No classic respiratory or bacterial respiratory pathogen was consistently identified. However, a novel coronavirus was isolated from patients who met the case definition of SARS. Cytopathological features were noted microscopically in Vero E6 cells inoculated with a throat-swab specimen. Electron-microscopical examination of cultures revealed ultrastructural features characteristic of coronaviruses. Immunohistochemical and immunofluorescence staining revealed reactivity with group I coronavirus polyclonal antibodies. Consensus coronavirus primers designed to amplify a fragment of the polymerase gene by reverse transcription–polymerase chain reaction (RT-PCR) were used to obtain a sequence that clearly identified the isolate as a unique coronavirus only distantly related to previously sequenced coronaviruses. With specific diagnostic RT-PCR primers we identified several identical nucleotide sequences in 12 patients from several locations, a finding consistent with a point source outbreak. Indirect fluorescent antibody tests and enzyme-linked immunosorbent assays made with the new coronavirus isolate have been used to demonstrate a virus-specific serologic response. Preliminary studies suggest that this virus may never before have infected the U.S. population. conclusions A novel coronavirus is associated with this outbreak, and the evidence indicates that this virus has an etiologic role in SARS. The name Urbani SARS-associated coronavirus is proposed for the virus.

Burden of major musculoskeletal conditions

Abstract: Musculoskeletal conditions are a major burden on individuals, health systems, and social care systems, with indirect costs being predominant. This burden has been recognized by the United Nations and WHO, by endorsing the Bone and Joint Decade 2000-2010. This paper describes the burden of four major musculoskeletal conditions: osteoarthritis, rheumatoid arthritis, osteoporosis, and low back pain. Osteoarthritis, which is characterized by loss of joint cartilage that leads to pain and loss of function primarily in the knees and hips, affects 9.6% of men and 18% of women aged > 60 years. Increases in life expectancy and ageing populations are expected to make osteoarthritis the fourth leading cause of disability by the year 2020. Joint replacement surgery, where available, provides effective relief. Rheumatoid arthritis is an inflammatory condition that usually affects multiple joints. It affects 0.3-1.0% of the general population and is more prevalent among women and in developed countries. Persistent inflammation leads to joint destruction, but the disease can be controlled with drugs. The incidence may be on the decline, but the increase in the number of older people in some regions makes it difficult to estimate future prevalence. Osteoporosis, which is characterized by low bone mass and microarchitectural deterioration, is a major risk factor for fractures of the hip, vertebrae, and distal forearm. Hip fracture is the most detrimental fracture, being associated with 20% mortality and 50% permanent loss in function. Low back pain is the most prevalent of musculoskeletal conditions; it affects nearly everyone at some point in time and about 4-33% of the population at any given point. Cultural factors greatly influence the prevalence and prognosis of low back pain.

The growing burden of tuberculosis: global trends and interactions with the HIV epidemic.

Abstract: BACKGROUND: The increasing global burden of tuberculosis (TB) is linked to human immunodeficiency virus (HIV) infection. METHODS: We reviewed data from notifications of TB cases, cohort treatment outcomes, surveys of Mycobacterium tuberculosis infection, and HIV prevalence in patients with TB and other subgroups. Information was collated from published literature and databases held by the World Health Organization (WHO), the Joint United Nations Programme on HIV/Acquired Immunodeficiency Syndrome (UNAIDS), the US Census Bureau, and the US Centers for Disease Control and Prevention. RESULTS: There were an estimated 8.3 million (5th-95th centiles, 7.3-9.2 million) new TB cases in 2000 (137/100,000 population; range, 121/100,000-151/100,000). Tuberculosis incidence rates were highest in the WHO African Region (290/100,000 per year; range, 265/100,000-331/100,000), as was the annual rate of increase in the number of cases (6%). Nine percent (7%-12%) of all new TB cases in adults (aged 15-49 years) were attributable to HIV infection, but the proportion was much greater in the WHO African Region (31%) and some industrialized countries, notably the United States (26%). There were an estimated 1.8 million (5th-95th centiles, 1.6-2.2 million) deaths from TB, of which 12% (226 000) were attributable to HIV. Tuberculosis was the cause of 11% of all adult AIDS deaths. The prevalence of M tuberculosis-HIV coinfection in adults was 0.36% (11 million people). Coinfection prevalence rates equaled or exceeded 5% in 8 African countries. In South Africa alone there were 2 million coinfected adults. CONCLUSIONS: The HIV pandemic presents a massive challenge to global TB control. The prevention of HIV and TB, the extension of WHO DOTS programs, and a focused effort to control HIV-related TB in areas of high HIV prevalence are matters of great urgency.

The World Oral Health Report 2003: continuous improvement of oral health in the 21st century – the approach of the WHO Global Oral Health Programme

Abstract: Chronic diseases and injuries are the leading health problems in all but a few parts of the world. The rapidly changing disease patterns throughout the world are closely linked to changing lifestyles, which include diets rich in sugars, widespread use of tobacco, and increased consumption of alcohol. In addition to socio-environmental determinants, oral disease is highly related to these lifestyle factors, which are risks to most chronic diseases as well as protective factors such as appropriate exposure to fluoride and good oral hygiene. Oral diseases qualify as major public health problems owing to their high prevalence and incidence in all regions of the world, and as for all diseases, the greatest burden of oral diseases is on disadvantaged and socially marginalized populations. The severe impact in terms of pain and suffering, impairment of function and effect on quality of life must also be considered. Traditional treatment of oral diseases is extremely costly in several industrialized countries, and not feasible in most low-income and middle-income countries. The WHO Global Strategy for Prevention and Control of Noncommunicable Diseases, added to the common risk factor approach is a new strategy for managing prevention and control of oral diseases. The WHO Oral Health Programme has also strengthened its work for improved oral health globally through links with other technical programmes within the Department for Noncommunicable Disease Prevention and Health Promotion. The current oral health situation and development trends at global level are described and WHO strategies and approaches for better oral health in the 21st century are outlined.

Active ageing: a policy framework.

Abstract: The paper reflects the message of the WHO Policy Framework on Active Ageing. The Policy Framework is intended to inform discussion and the formation of action plans that promote healthy and active ageing. It was developed by WHO's Ageing and Life Course Programme as a contribution to the Second United Nations World Assembly on Ageing held in April 2002. The paper presents the challenge of rapid ageing population, especially in developing countries. And it discusses the concept and the rational of the active ageing. Policy Responses to this challenge are identify in the final part of the paper.

WHO Framework Convention on Tobacco Control: development of an evidence based global public health treaty

Abstract: Many health problems require international action, but getting governments to agree on strategies for prevention or treatment is difficult. By making use of scientific evidence on the effects of tobacco, the member states of WHO have negotiated their first global health treaty. If the treaty can be implemented effectively, it could act as a possible model for tackling other health issues When Dr Gro Harlem Brundtland became director general of the World Health Organization in 1998, she clearly stated that the tobacco epidemic should be tackled by an international collective action and that WHO should take a leadership role.1 In 1999, WHO started work on the WHO Framework Convention on Tobacco Control, which was endorsed by member states on 21 May 2003. It is the first time WHO has used its constitutional authority in global public health to develop a legal instrument aimed at improving population health. The initiation and negotiation of the framework convention was based strongly on the accumulation of scientific evidence.2 We review the development and scientific basis of the convention and discuss its implications and the potential of international collective action against threats to global public health. The structural basis for framework conventions is to use an incremental process in making law. It begins with a framework convention that establishes a general consensus on the relevant facts and the system of governance for an issue. This is followed by the development of more specific commitments and institutional arrangements in subsequent protocols.3 However, depending on the political will, framework conventions can also include quite specific provisions. In the case of the WHO Framework Convention on Tobacco Control, the powerful political momentum behind the treaty has ensured that several detailed provisions have been incorporated into the final text.4 The framework convention is the first …

The epidemiology of major depressive episodes: results from the International Consortium of Psychiatric Epidemiology (ICPE) Surveys

Abstract: Absence of a common diagnostic interview has hampered cross-national syntheses of epidemiological evidence on major depressive episodes (MDE). Community epidemiological surveys using the World Health Organization Composite International Diagnostic Interview administered face-to-face were carried out in 10 countries in North America (Canada and the US), Latin America (Brazil, Chile, and Mexico), Europe (Czech Republic, Germany, the Netherlands, and Turkey), and Asia (Japan). The total sample size was more than 37,000. Lifetime prevalence estimates of hierarchy-free DSM-III-R/DSM-IV MDE varied widely, from 3% in Japan to 16.9% in the US, with the majority in the range of 8% to 12%. The 12-month/lifetime prevalence ratio was in the range 40% to 55%, the 30-day/12-month prevalence ratio in the range 45% to 65%, and median age of onset in the range 20 to 25 in most countries. Consistent socio-demographic correlates included being female and unmarried. Respondents in recent cohorts reported higher lifetime prevalence, but lower persistence than those in earlier cohorts. Major depressive episodes were found to be strongly co-morbid with, and temporally secondary to, anxiety disorders in all countries, with primary panic and generalized anxiety disorders the most powerful predictors of the first onset of secondary MDE. Major depressive episodes are a commonly occurring disorder that usually has a chronic-intermittent course. Effectiveness trials are needed to evaluate the impact of early detection and treatment on the course of MDE as well as to evaluate whether timely treatment of primary anxiety disorders would reduce the subsequent onset, persistence, and severity of secondary MDE.

The relationship of average volume of alcohol consumption and patterns of drinking to burden of disease: an overview.

Abstract: Aims As part of a larger study to estimate the global burden of disease attributable to alcohol: • to quantify the relationships between average volume of alcohol consumption, patterns of drinking and disease and injury outcomes, and • to combine exposure and risk estimates to determine regional and global alcohol-attributable fractions (AAFs) for major disease and injury categories. Design, methods, setting Systematic literature reviews were used to select diseases related to alcohol consumption. Meta-analyses of the relationship between alcohol consumption and disease and multi-level analyses of aggregate data to fill alcohol–disease relationships not currently covered by individual-level data were used to determine the risk relationships between alcohol and disease. AAFs were estimated as a function of prevalence of exposure and relative risk, or from combining the aggregate multi-level analyses with prevalence data. Findings Average volume of alcohol consumption was found to increase risk for the following major chronic diseases: mouth and oropharyngeal cancer; oesophageal cancer; liver cancer; breast cancer; unipolar major depression; epilepsy; alcohol use disorders; hypertensive disease; hemorrhagic stroke; and cirrhosis of the liver. Coronary heart disease (CHD), unintentional and intentional injuries were found to depend on patterns of drinking in addition to average volume of alcohol consumption. Most effects of alcohol on disease were detrimental, but for certain patterns of drinking, a beneficial influence on CHD, stroke and diabetes mellitus was observed. Conclusions Alcohol is related to many major disease outcomes, mainly in a detrimental fashion. While average volume of consumption was related to all disease and injury categories under consideration, pattern of drinking was found to be an additional influencing factor for CHD and injury. The influence of patterns of drinking may be underestimated because pattern measures have not been included in many epidemiologic studies. Generalizability of the results is limited by methodological problems of the underlying studies used in the present analyses. Future studies need to address these methodological issues in order to obtain more accurate risk estimates.

Enhancing the Validity and Cross-cultural Comparability of Measurement in Survey Research

Abstract: We address two long-standing survey research problems: measuring complicated concepts, such as political freedom and efficacy, that researchers define best with reference to examples; and what to do when respondents interpret identical questions in different ways. Scholars have long addressed these problems with approaches to reduce incomparability, such as writing more concrete questions—with uneven success. Our alternative is to measure directly response category incomparability and to correct for it. We measure incomparability via respondents’ assessments, on the same scale as the self-assessments to be corrected, of hypothetical individuals described in short vignettes. Because the actual (but not necessarily reported) levels of the vignettes are invariant over respondents, variability in vignette answers reveals incomparability. Our corrections require either simple recodes or a statistical model designed to save survey administration costs. With analysis, simulations, and cross-national surveys, we show how response incomparability can drastically mislead survey researchers and how our approach can alleviate this problem.

A new global strategy for infant and young child feeding.

Abstract: 1. Some 1.5 million children still die every year because they are inappropriately fed, less than 35% of infants worldwide are exclusively breastfed for the first four months of life, and complementary feeding practices are frequently inappropriate and unsafe. The growing scale, variety and frequency of major emergencies, the HIV/AIDS pandemic, complexities of modern lifestyles, coupled with continued promulgation of mixed messages and changing fashion with regard to breastfeeding complicate meeting the nutritional needs of infants and young children.

Comparative quantification of health risks: Conceptual framework and methodological issues

Abstract: Reliable and comparable analysis of risks to health is key for preventing disease and injury. Causal attribution of morbidity and mortality to risk factors has traditionally been conducted in the context of methodological traditions of individual risk factors, often in a limited number of settings, restricting comparability.In this paper, we discuss the conceptual and methodological issues for quantifying the population health effects of individual or groups of risk factors in various levels of causality using knowledge from different scientific disciplines. The issues include: comparing the burden of disease due to the observed exposure distribution in a population with the burden from a hypothetical distribution or series of distributions, rather than a single reference level such as non-exposed; considering the multiple stages in the causal network of interactions among risk factor(s) and disease outcome to allow making inferences about some combinations of risk factors for which epidemiological studies have not been conducted, including the joint effects of multiple risk factors; calculating the health loss due to risk factor(s) as a time-indexed "stream" of disease burden due to a time-indexed "stream" of exposure, including consideration of discounting; and the sources of uncertainty.

Aetiology: Koch's postulates fulfilled for SARS virus.

Abstract: Severe acute respiratory syndrome (SARS) has recently emerged as a new human disease, resulting globally in 435 deaths from 6,234 probable cases (as of 3 May 2003). Here we provide proof from experimental infection of cynomolgus macaques (Macaca fascicularis) that the newly discovered SARS-associated coronavirus (SCV) is the aetiological agent of this disease. Our understanding of the aetiology of SARS will expedite the development of diagnostic tests, antiviral therapies and vaccines, and may allow a more concise case definition for this emerging disease.

The utilisation of health research in policy-making: concepts, examples and methods of assessment.

Abstract: The importance of health research utilisation in policy-making, and of understanding the mechanisms involved, is increasingly recognised. Recent reports calling for more resources to improve health in developing countries, and global pressures for accountability, draw greater attention to research-informed policy-making. Key utilisation issues have been described for at least twenty years, but the growing focus on health research systems creates additional dimensions.

The International Classification of Functioning, Disability and Health: a new tool for understanding disability and health

Abstract: Reliable and timely information about the health of populations is part of the World Health Organization's mandate in the development of international public health policy. To capture data concerning functioning and disability, or non-fatal health outcomes, WHO has recently published the revised International Classification of Functioning, Disability and Health (ICF). In this article, the authors briefly outline the revision process and discuss the rationale for the ICF and the needs that it serves in rehabilitation. The ICF is shown to be an essential tool for identifying and measuring efficacy and effectiveness of rehabilitation services, both through functional profiling and intervention targeting. Existing applications of the ICF in rehabilitation are then surveyed. The ICF, in short, offers an international, scientific tool for understanding human functioning and disability for clinical, research, policy development and a range of other public health uses.

The World Health Organization Global Database on Child Growth and Malnutrition: methodology and applications

Abstract: Background: For decades nutritional surveys have been conducted using various definitions indicators and reference populations to classify child malnutrition. The World Health Organization (WHO) Global Database on Child Growth and Malnutrition was initiated in 1986 with the objective to collect standardize and disseminate child anthropometric data using a standard format. Methods: The database includes population-based surveys that fulfil a set of criteria. Data are checked for validity and consistency and raw data sets are analysed following a standard procedure to obtain comparable results. Prevalences of wasting stunting under- and overweight in preschool children are presented using z-scores based on the National Center for Health Statistics (NCHS)/WHO international reference population. New surveys are included on a continuous basis and updates are published bimonthly on the database’s web site. Results: To date the database contains child anthropometric information derived from 846 surveys. With 412 national surveys from 138 countries and 434 sub-national surveys from 155 countries the database covers 99% and 64% of the under 5 year olds in developing and developed countries respectively. This wealth of information enables international comparison of nutritional data helps identifying populations in need evaluating nutritional and other public health interventions monitoring trends in child growth and raising political awareness of nutritional problems. Conclusions: The 15 years experience of the database can be regarded as a success story of international collaboration in standardizing child growth data. We recommend this model for monitoring other nutritional health conditions that as yet lack comparable data. (authors)

Global burden of maternal death and disability

Abstract: Sound information is the prerequisite for health action: without data on the dimensions, impact and significance of a health problem it is neither possible to create an advocacy case nor to establish strong programmes for addressing it. The absence of good information on the extent of the burden of maternal ill-health resulted in its relative neglect by the international health community for many years. Maternal deaths are too often solitary and hidden events that go uncounted. The difficulty arises not because of lack of clarity regarding the definition of a maternal death, but because of the weakness of health information systems and consequent absence of the systematic identification and recording of maternal deaths. In recent years, innovative approaches to measuring maternal mortality have been developed, resulting in a stronger information base. WHO, UNICEF and UNFPA estimates for the year 2000 indicate that most of the total 529,000 maternal deaths globally occur in just 13 countries. By contrast, information on the global burden of non-fatal health outcomes associated with pregnancy and childbearing remains patchy and incomplete. Nonetheless, initial estimates based on systematic reviews of available information and confined to the five major direct pregnancy-related complications indicate a problem of considerable magnitude.

Beyond the Numbers: reviewing maternal deaths and complications to make pregnancy safer

Abstract: 'Whose faces are behind the numbers? What were their stories? What were their dreams? They left behind children and families. They also left behind clues as to why their lives end so early 1 ' Avoiding maternal deaths is possible, even in resource-poor countries, but requires the right kind of information on which to base programmes. Knowing the level of maternal mortality is not enough; we need to understand the underlying factors that led to the deaths. Each maternal death or case of life-threatening complication has a story to tell and can provide indications on practical ways of addressing its causes and determinants. Maternal death or morbidity reviews provide evidence of where the main problems in overcoming maternal mortality and morbidity may lie, produce an analysis of what can be done in practical terms and highlight the key areas requiring recommendations for health sector and community action as well as guidelines for improving clinical outcomes. The information gained from such enquiries must be used as a prerequisite for action.

Cutoff Values for Normal Anthropometric Variables in Asian Indian Adults

Abstract: OBJECTIVE —Asian Indians have a high risk of developing glucose intolerance with small increments in their BMI. They generally have high upper-body adiposity, despite having a lean BMI. Therefore, this analysis was performed to find out the normal cutoff values for BMI and upper-body adiposity (waist circumference [WC] or waist-to-hip ratio [WHR]) by computing their risk associations with diabetes. RESEARCH DESIGN AND METHODS —The risk of diabetes with stratified BMI, WC, or WHR was computed in 10,025 adults aged ≥20 years without a history of diabetes, and they were tested by oral glucose tolerance tests, using World Health Organization criteria. The calculations were performed separately in men and women using diabetes as the dependent variable versus normoglycemia (normal glucose tolerance) in multiple logistic regression analyses. Age-adjusted and stratified BMI, WC, or WHR were used as the independent variables, using the first stratum as the reference category. The upper limit of the stratum above which the risk association became statistically significant ( P < 0.05) was considered to be the cutoff for normal values. RESULTS —Normal cutoff values for BMI was 23 kg/m2 for both sexes. Cutoff values for WC were 85 and 80 cm for men and women, respectively; the corresponding WHRs were 0.88 and 0.81, respectively. Optimum sensitivity and specificity obtained from the receiver operator characteristic curve corresponded to these cutoff values. CONCLUSIONS —The cutoff value for normal BMI for men and women was 23 kg/m2. The cutoff values for WC and WHR were lower in women than in men. The values were significantly lower compared with the corresponding values in white populations.

The impact of migration on HIV-1 transmission in South Africa: a study of migrant and nonmigrant men and their partners.

Abstract: Background: To investigate the association between migration and HIV infection among migrant and nonmigrant men and their rural partners. Goal: The goal was to determine risk factors for HIV-1 infection in South Africa. Study Design: This was a cross-sectional study of 196 migrant men and 130 of their rural partners as well as 64 nonmigrant men and 98 rural women whose partners are nonmigrant. Male migrants were recruited at work in two urban centers 100 km and 700 km from their rural homes. Rural partners were traced and invited to participate. Nonmigrant couples were recruited for comparison. The study involved administration of a detailed questionnaire and blood collection for HIV testing. Results: Testing showed that 25.9% of migrant men and 12.7% of nonmigrant men were infected with HIV (P = 0.029; odds ratio = 2.4; 95% CI = 1.1–5.3). In multivariate analysis main risk factors for male HIV infection were being a migrant ever having used a condom and having lived in four or more places during a lifetime. Being the partner of a migrant was not a significant risk factor for HIV infection among women; significant risk factors were reporting more than one current regular partner being younger than 35 years and having STD symptoms during the previous 4 months. Conclusion: Migration is an independent risk factor for HIV infection among men. Workplace interventions are urgently needed to prevent further infections. High rates of HIV were found among rural women and the migration status of the regular partner was not a major risk factor for HIV. Rural women lack access to appropriate prevention interventions regardless of their partners’ migration status. (authors)

Generalized cost-effectiveness analysis for national-level priority-setting in the health sector

Abstract: Cost-effectiveness analysis (CEA) is potentially an important aid to public health decision-making but, with some notable exceptions, its use and impact at the level of individual countries is limited. A number of potential reasons may account for this, among them technical shortcomings associated with the generation of current economic evidence, political expediency, social preferences and systemic barriers to implementation. As a form of sectoral CEA, Generalized CEA sets out to overcome a number of these barriers to the appropriate use of cost-effectiveness information at the regional and country level. Its application via WHO-CHOICE provides a new economic evidence base, as well as underlying methodological developments, concerning the cost-effectiveness of a range of health interventions for leading causes of, and risk factors for, disease. The estimated sub-regional costs and effects of different interventions provided by WHO-CHOICE can readily be tailored to the specific context of individual countries, for example by adjustment to the quantity and unit prices of intervention inputs (costs) or the coverage, efficacy and adherence rates of interventions (effectiveness). The potential usefulness of this information for health policy and planning is in assessing if current intervention strategies represent an efficient use of scarce resources, and which of the potential additional interventions that are not yet implemented, or not implemented fully, should be given priority on the grounds of cost-effectiveness. Health policy-makers and programme managers can use results from WHO-CHOICE as a valuable input into the planning and prioritization of services at national level, as well as a starting point for additional analyses of the trade-off between the efficiency of interventions in producing health and their impact on other key outcomes such as reducing inequalities and improving the health of the poor.

The cost of diabetes in Latin America and the Caribbean

Abstract: OBJETIVE: To measure the economic burden associated with diabetes mellitus in Latin America and the Caribbean. METHODS: Prevalence estimates of diabetes for the year 2000 were used to calculated direct and indirect costs of diabetes mellitus. Direct costs included costs due to drugs, hospitalizations, consultations and management of complications. The human capital approach was used to calculate indirect costs and included calculations of forgone earnings due to premature mortality and disability attributed to diabetes mellitus. Mortality and disability attributed to causes other than diabetes were subtracted from estimates to consider only the excess burden due to diabetes. A 3% discount rate was used to convert future earnings to current value. FINDINGS: The annual number of deaths in 2000 caused by diabetes mellitus was estimated at 339 035. This represented a loss of 757 096 discounted years of productive life among persons younger than 65 years (US$ 3 billion). Permanent disability caused a loss of 12 699 087 years and over US$ 50 billion, and temporary disability caused a loss of 136 701 years in the working population and over US$ 763 million. Costs associated with insulin and oral medications were US$ 4720 million, hospitalizations US$ 1012 million, consultations US$ 2508 million and care for complications US$ 2 480 million. The total annual cost associated with diabetes was estimated as US$ 65 216 million (direct US$ 10 721; indirect US$ 54 496). CONCLUSION: Despite limitations of the data, diabetes imposes a high economic burden to individuals and society in all countries and to Latin American and the Caribbean as whole.

Refractive Error and Visual Impairment in African Children in South Africa

Abstract: Purpose To assess the prevalence of refractive error and visual impairment in school-aged African children in South Africa. Methods Random selection of geographically defined clusters was used to identify a sample of children 5 to 15 years of age in the Durban area. From January to August 2002, children in 35 clusters were enumerated through a door-to-door survey and examined in temporary facilities. The examination included visual acuity measurements, ocular motility evaluation, retinoscopy and autorefraction under cycloplegia, and examination of the anterior segment, media, and fundus. In nine clusters, children with reduced vision and a sample of those with normal vision underwent independent replicate examinations for quality assurance. Results A total of 5599 children living in 2712 households were enumerated, and 4890 (87.3%) were examined. The prevalence of uncorrected, presenting, and best-corrected visual acuity of 20/40 or worse in the better eye was 1.4%, 1.2%, and 0.32%, respectively. Refractive error was the cause in 63.6% of the 191 eyes with reduced vision, amblyopia in 7.3%, retinal disorders in 9.9%, corneal opacity in 3.7%, other causes in 3.1%, and unexplained causes in the remaining 12.0%. Exterior and anterior segment abnormalities were observed in 528 (10.8%) children, mainly corneal and conjunctival. Myopia (at least -0.50 D) in one or both eyes was present in 2.9% of children when measured with retinoscopy and in 4.0% measured with autorefraction. Beginning with an upward trend at age 14, myopia prevalence with autorefraction reached 9.6% at age 15. Myopia was also associated with increased parental education. Hyperopia (+2.00 D or more) in at least one eye was present in 1.8% of children when measured with retinoscopy and in 2.6% measured with autorefraction, with no significant predictors of hyperopia risk. Conclusions The prevalence of reduced vision is low in school-age African children, most of it because of uncorrected refractive error. The high prevalence of corneal and other anterior segment abnormalities is a reflection of the inadequacy of primary eye care services in this area.