Deprivation, urbanisation and Perthes' disease in Northern Ireland.
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It has been suggested that Perthes' disease is more prevalent in urban areas, and that the risk increases with deprivation. We present the findings of a preliminary analysis of Perthes' disease in Northern Ireland, which is shown to have one of the highest national annual rates of incidence in the world (11.6 per 100000). Of the 313 children diagnosed over a seven-year period, 311 were allocated to the enumeration districts of the 1991 census, thus allowing the incidence to be calculated using both spatial and non-spatial aggregation. The cases were grouped according to the size of the settlement from highly urbanised to open countryside and by level of area deprivation. While the incidence of Perthes' disease was found to be associated with indicators of the level of deprivation for areas, there was no evidence to suggest that there was an increased risk in urban areas; the highest rate was found in the most deprived rural category. (+info)
Malaria on the move: human population movement and malaria transmission.
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Reports of malaria are increasing in many countries and in areas thought free of the disease. One of the factors contributing to the reemergence of malaria is human migration. People move for a number of reasons, including environmental deterioration, economic necessity, conflicts, and natural disasters. These factors are most likely to affect the poor, many of whom live in or near malarious areas. Identifying and understanding the influence of these population movements can improve prevention measures and malaria control programs. (+info)
Seroprevalence of hepatitis C virus in the general population of northwest Tanzania.
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Sera from 516 participants enrolled in a population-based cross-sectional study in northwest Tanzania were tested for antibodies to hepatitis C virus (HCV). The mean age of study subjects was 29 years (range = 16-49 years); 43% were men, 6% reported a history of blood transfusion, and 4% were infected with human immunodeficiency virus-1 (HIV-1). Although 53 of 516 sera (10.3%, 95% confidence interval [CI] = 7.8-13.2%) were repeatedly reactive by a third-generation enzyme immunoassay (EIA-3), only 6 of the 53 were positive when tested with a third-generation recombinant immunoblot assay (confirmed HCV seroprevalence = 1.2%, 95% CI = 0.4-2.5%). The positive predictive value of the HCV EIA-3 in this population was 18.8% (95% CI = 7.0-36.4%). False positivity was not correlated with EIA-3 optical density values, age, sex, infection with HIV-1, or a history of blood transfusion, but it was marginally associated with increased serum IgG levels. We conclude that the prevalence of HCV is low in this region and that the HCV EIA-3 has a higher false-positivity rate in this population than has been reported among U.S. blood donors. (+info)
Aedes aegypti in Tahiti and Moorea (French Polynesia): isoenzyme differentiation in the mosquito population according to human population density.
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Genetic differences at five polymorphic isoenzyme loci were analyzed by starch gel electrophoresis for 28 Aedes aegypti samples. Considerable (i.e., high Fst values) and significant (i.e., P values >10(-4)) geographic differences were found. Differences in Ae. aegypti genetic structure were related to human population densities and to particularities in mosquito ecotopes in both Tahiti and Moorea islands. In highly urbanized areas (i.e., the Papeete agglomeration), mosquitoes were highly structured. Recurrent extinction events consecutive to insecticidal treatments during dengue outbreaks tend to differentiate mosquito populations. In less populated zones (i.e., the east coast of Moorea and Tahiti), differences in ecotope characteristics could explain the lack of differentiation among mosquitoes from rural environments such as the east coast of Tahiti where natural breeding sites predominate. When the lowest populated zones such as Tahiti Iti and the west coast of Moorea are compared, mosquito are less differentiated in Moorea. These results will be discussed in relation to the recent findings of variation in mosquito infection rates for dengue-2 virus. (+info)
Geographical patterns of cholera in Mexico, 1991-1996.
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BACKGROUND: The seventh cholera pandemic has been ongoing in Mexico since 1991 and threatens to become endemic. This paper aims to determine the geographical pattern of cholera in Mexico to define areas at high risk of endemic cholera. METHODS: Ecologic research was conducted based upon the cartography of disease incidence. The 32 Mexican states were grouped into five strata according to the value of the 1991-1996 cumulative incidence rate of cholera. Rate ratios were computed for strata of states classified by geographical situation, urbanization, and poverty level. RESULTS: Cholera incidence was 2.47 times higher in coastal states than in the interior (95% CI : 2.42-2.52). The disease was negatively associated with urbanization. Incidence in the least urbanized stratum was four times as high as in the most urban stratum (95% CI : 3.9-4.12). The poorest stratum showed the most remarkable incidence, i.e. 5.9 times higher than the rate in the least poor stratum (95% CI : 5.73-6.04). CONCLUSIONS: This ecologic research suggests that high poverty level, low urbanization, and southern location are the most important predictors of endemic cholera in Mexican states. It is hypothesized that the natural environment of the coastal plains in southern states may also play a significant role in cholera incidence. Poor communities residing in the southern, predominantly rural, coastal states should be prioritized when it comes to investing in safe water supply facilities, adequate excreta disposal systems and cholera surveillance. (+info)
Migration and urban schistosomiasis. The case of Sao Lourenco da Mata, northeast of Brazil.
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A population-based case-control design was used to investigate the association between migration, urbanisation and schistosomiasis in the Metropolitan Region of Recife, Northeast of Brazil. 1022 cases and 994 controls, aged 10 to 25, were selected. The natives and the migrants who come from endemic areas have a similar risk of infection. On the other hand, the risk of infection of migrants from nonendemic areas seems to be related with the time elapsed since their arrival in Sao Lourenco da Mata; those who have been living in that urban area for 5 or more years have a risk of infection similar to that of the natives. Those arriving in the metropolitan region of Recife mostly emigrate from "zona da mata" and "zona do agreste" in the state of Pernambuco. Due to the changes in the sugar agroindustry and to the increase in the area used for cattle grazing these workers were driven to villages and cities. The pattern of urbanisation created the conditions for the establishment of foci of transmission in Sao Lourenco da Mata. (+info)
Motor vehicle crashes in Pakistan: the emerging epidemic.
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SETTING: Motor vehicle injuries are increasingly being recognized as a growing public health issue in the developing world. Pakistan is a developing country in South Asia where motor vehicle use has increased since independence in 1947. OBJECTIVE: This paper explores the magnitude and impact of injuries from motor vehicle crashes in Pakistan. METHODS: An exhaustive review of published and gray literature, together with a detailed analysis of government data from 1956. RESULTS: The data indicate a persistent increase in the numbers of motor vehicle crashes, injuries, and fatalities. Changes in the reporting of rates are important to note in evaluating the data. Commercial vehicles contribute disproportionately to these motor vehicle injuries. CONCLUSIONS: There is a need to further the recognition of injuries as a public health issue in this country. Specific exploration of the epidemiological data; intersectoral collaboration between health, law, police and transport; and the development of appropriate information systems, will contribute to an appropriate response by Pakistan. (+info)
Determinants of infant and early childhood mortality levels and their decline in the Netherlands in the late nineteenth century.
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OBJECTIVE: To study the relative importance of various determinants of total and cause-specific infant and early childhood mortality rates and their decline in The Netherlands in the period 1875-1879 to 1895-1899. DATA AND METHODS: Mortality and population data were derived from Statistics Netherlands for 16 towns and 11 rural areas. Mortality levels and their decline were estimated with a Poisson regression model. The associations of the estimated levels and declines, and determinants of infant and early childhood mortality were analysed using multivariate linear regression analysis. The causes of death studied were major contributors to infant mortality (convulsions, acute digestive disease, acute respiratory disease) and early childhood mortality (encephalitis/meningitis, acute respiratory disease, measles). RESULTS: Infant mortality rates were high in the south-western part of The Netherlands in 1875-1879. Due to a rapid decline in the western regions, this pattern changed to a north-south gradient in 1895-1899. Early childhood mortality showed an urban-rural gradient in 1875-1879 with mortality high in towns. This gradient had largely disappeared by 1895-1899, due to a rapid decline in mortality in towns. Roman Catholicism was significantly associated with infant mortality (particularly from diarrhoeal disease) in 1875-1879 and 1895-1899. The association with Roman Catholicism was stronger in 1895-1899 because mortality declines were less rapid in Roman Catholic areas in 1875-1879 to 1895-1899. Urbanization was significantly associated with early childhood mortality (particularly from respiratory disease) in 1875-1879 and 1895-1899. This association weakened over time, due to the rapid decline in mortality in towns. CONCLUSIONS: Different determinants of mortality (decline) were important in infant and early childhood mortality and they acted on different causes of death. Therefore, infant and childhood mortality should be studied separately. International comparison of the results showed that findings with respect to determinants of mortality (decline) for one country do not necessarily apply to other countries. The results for The Netherlands with respect to infant mortality differed from England and Wales. (+info)