Vector-borne disease problems in rapid urbanization: new approaches to vector control.
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Owing to population growth, poor levels of hygiene, and increasing urban poverty, the urban environment in many developing countries is rapidly deteriorating. Densely packed housing in shanty towns or slums and inadequate drinking-water supplies, garbage collection services, and surface-water drainage systems combine to create favourable habitats for the proliferation of vectors and reservoirs of communicable diseases. As a consequence, vector-borne diseases such as malaria, lymphatic filariasis and dengue are becoming major public health problems associated with rapid urbanization in many tropical countries. The problems in controlling these diseases and eliminating vectors and pests can be resolved by decision-makers and urban planners by moving away from the concept of "blanket" applications of pesticides towards integrated approaches. Sound environmental management practices and community education and participation form the mainstay of some of the most outstanding successes in this area. On the basis of these examples, it is argued that the municipal authorities need to apply a flexible methodology, which must be based on the possibilities of mobilizing community resources, with minimal reliance on routine pesticidal spraying. In this way, vector control becomes a by-product of human development in the city environment. This is now a true challenge. (+info)
Effect of urbanization on bone mineral density: a Thai epidemiological study.
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BACKGROUND: The incidence of fractures in rural populations is lower than in urban populations, although the reason for this difference is unclear. This cross-sectional study was designed to examine the difference in bone mineral density (BMD), a primary predictor of fracture risk, between urban and rural Thai populations. METHODS: Femoral neck and lumbar spine BMD was measured by dual-energy X-ray absorptiometry (GE Lunar, Madison, WI) in 411 urban and 436 rural subjects (340 men and 507 women), aged between 20 and 84 years. Body mass index (BMI) was calculated from weight and height. RESULTS: After adjusting for age and body weight in an analysis of covariance model, femoral neck BMD in rural men and women was significantly higher than those in urban men and women (P < 0.001), but the difference was not observed at the lumbar spine. After stratifying by sex, age group, and BMI category, the urban-rural difference in femoral neck BMD became more pronounced in men and women aged <50 years and with BMI > or = 25 kg/m2. CONCLUSIONS: These data suggest that femoral neck BMD in rural men and women was higher than their counterparts in urban areas. This difference could potentially explain part of the urban-rural difference in fracture incidence. (+info)
Malaria and urbanization in sub-Saharan Africa.
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There are already 40 cities in Africa with over 1 million inhabitants and the United Nations Environmental Programme estimates that by 2025 over 800 million people will live in urban areas. Recognizing that malaria control can improve the health of the vulnerable and remove a major obstacle to their economic development, the Malaria Knowledge Programme of the Liverpool School of Tropical Medicine and the Systemwide Initiative on Malaria and Agriculture convened a multi-sectoral technical consultation on urban malaria in Pretoria, South Africa from 2nd to 4th December, 2004. The aim of the meeting was to identify strategies for the assessment and control of urban malaria. This commentary reflects the discussions held during the meeting and aims to inform researchers and policy makers of the potential for containing and reversing the emerging problem of urban malaria. (+info)
What is urban in the contemporary world?
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Central concepts of contemporary life such as politics, civilization, and citizenship derive from the city's form and social organization. The city expresses the socio-spatial division of labor, and Henri Lefebvre proposes to view its transformation within a continuum from the political city to the urban, whereby it completes its domination over the countryside. The city's transformation into the urban takes place when industry brings production (and the proletariat) into that space of power. The city, locus of surplus, power, and the fiesta, a privileged scenario for social reproduction, was subordinated to the industrial logic and underwent a dual process: its centrality imploded, and its outskirts exploded on surrounding areas through the urban fabric, bearing with it the seeds of the polis and civitas. The urban praxis, formerly restricted to the city, re-politicized social space as a whole. In Brazil, the urban has its origins in the military governments' centralizing and integrating policies, following Vargas's expansionism and Kubitschek's developmental interiorization (or occupation of the hinterlands). Today, urban-industrial processes impose themselves over virtually all social space, in contemporary extended urbanization. (+info)
Perspectives on urban conditions and population health.
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The majority of the world's population will live in cities in the next few years and the pace of urbanization worldwide will continue to accelerate over the coming decades. While the number of megacities is projected to increase, the largest population growth is expected to be in cities of less than one million people. Such a dramatic demographic shift can be expected to have an impact on population health. Although there has been historic interest in how city living affects health, a cogent framework that enables systematic study of urban health across time and place has yet to emerge. Four alternate but complementary approaches to the study of urban health today are presented (urban health penalty, urban health advantage, urban sprawl, and an integrative urban conditions model) followed by three key questions that may help guide the study and practice of urban health in coming decades. (+info)
Modelling malaria risk in East Africa at high-spatial resolution.
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OBJECTIVES: Malaria risk maps have re-emerged as an important tool for appropriately targeting the limited resources available for malaria control. In Sub-Saharan Africa empirically derived maps using standardized criteria are few and this paper considers the development of a model of malaria risk for East Africa. METHODS: Statistical techniques were applied to high spatial resolution remotely sensed, human settlement and land-use data to predict the intensity of malaria transmission as defined according to the childhood parasite ratio (PR) in East Africa. Discriminant analysis was used to train environmental and human settlement predictor variables to distinguish between four classes of PR risk shown to relate to disease outcomes in the region. RESULTS: Independent empirical estimates of the PR were identified from Kenya, Tanzania and Uganda (n = 330). Surrogate markers of climate recorded on-board earth orbiting satellites, population settlement, elevation and water bodies all contributed significantly to the predictive models of malaria transmission intensity in the sub-region. The accuracy of the model was increased by stratifying East Africa into two ecological zones. In addition, the inclusion of urbanization as a predictor of malaria prevalence, whilst reducing formal accuracy statistics, nevertheless improved the consistency of the predictive map with expert opinion malaria maps. The overall accuracy achieved with ecological zone and urban stratification was 62% with surrogates of precipitation and temperature being among the most discriminating predictors of the PR. CONCLUSIONS: It is possible to achieve a high degree of predictive accuracy for Plasmodium falciparum parasite prevalence in East Africa using high-spatial resolution environmental data. However, discrepancies were evident from mapped outputs from the models which were largely due to poor coverage of malaria training data and the comparable spatial resolution of predictor data. These deficiencies will only be addressed by more random, intensive small areas studies of empirical estimates of PR. (+info)
Unintentional deaths from drug poisoning by urbanization of area--New Mexico, 1994-2003.
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New Mexico experienced an increase in poisoning deaths during the 1990s and in 2002 was the state with the highest death rate (14.1 per 100,000 population) from unintentional poisoning, more than twice the national rate (6.1). The majority of these unintentional poisoning deaths were caused by ingestion of drugs, including illicit, prescription, and over-the-counter drugs. New Mexico is geographically diverse, with communities ranging from urban centers to sparsely populated counties. To examine the relationship between the types of drugs causing poisoning deaths and the levels of urbanization where the decedents resided, the New Mexico Department of Health analyzed data provided by the New Mexico Office of the Medical Investigator (OMI) for 1994-2003. All counties in New Mexico were classified as metropolitan or micropolitan statistical areas, or as nonstatistical areas, by using 2001-2002 population estimates in accordance with 2003 Office of Management and Budget (OMB) classifications. This report summarizes the results of that analysis, which indicated that deaths from illicit-drug poisoning were twice as likely to occur in metropolitan areas as nonmetropolitan areas (i.e., micropolitan and nonstatistical areas combined). However, deaths from prescription-drug poisoning were most likely to occur in micropolitan and nonstatistical areas. Investigation of drug-poisoning deaths by level of urbanization can be useful to public health programs to prevent unintentional drug-poisoning deaths. (+info)
Role of return migration in the emergence of multiple sclerosis in the French West Indies.
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The emergence of multiple sclerosis in island societies has been investigated only in a few Caucasian populations living in temperate regions. The effect of human migration on the risk of developing this disease is still an open question because of possible genetic selection. We conducted an epidemiological study of the multiple sclerosis population in the French West Indies (Martinique and Guadeloupe), a population which includes large numbers of West Indians who have returned after emigrating to metropolitan France. Standardized incidence ratios (SIRs) for multiple sclerosis among migrants were calculated and their genetic characteristics were compared to those of non-migrants. The crude prevalence of multiple sclerosis was 14.8/10(5) on December 31, 1999 (95% CI: 11.9-17.7); and its crude mean annual incidence for the period July 1, 1999 to June 30, 2002 was 1.4/10(5) (95% CI: 1.0-1.8), confirming its emergence in the French West Indies. Recurrent neuromyelitis optica, which is virtually the only form of multiple sclerosis in black African populations in tropical regions, represented not >17.8% of these cases. During the 1,440,000 person-years of follow-up, 33 incidence cases were identified in migrants. Since the number of expected cases was 19.3, the overall SIR was 1.71 (95% CI: 1.19-2.38; P < 0.01) among migrants. The increase in the SIR was more marked if the stay was made before the age of 15 years (4.05, 95% CI: 2.17-6.83; P < 0.0001). European ancestry in the two migrating and non-migrating populations was similar. Martinique, which has a higher rate of return migration, has a higher prevalence of multiple sclerosis (21.0/10(5) versus 8.5/10(5)) and a higher incidence (2.0/10(5) versus 0.7/10(5)) than Guadeloupe. The emergence of the disease in the French West Indies is of environmental rather than genetic origin. It may be explained either through the introduction by migrants of precipitating environmental factors that operate in a critical way before the age of 15 years, and/or by the recent disappearance from the French West Indies of protective environmental factors acting before this age. (+info)