Geographical information systems and tropical medicine.

In terms of their applicability to the field of tropical medicine, geographical information systems (GIS) have developed enormously in the last two decades. This article reviews some of the pertinent and representative applications of GIS, including the use of such systems and remote sensing for the mapping of Chagas disease and human helminthiases, the use of GIS in vaccine trials, and the global applications of GIS for health-information management, disease epidemiology, and pandemic planning. The future use of GIS as a decision-making tool and some barriers to the widespread implementation of such systems in developing settings are also discussed.

Trends in infant mortality inequalities in the Americas: 1955-1995.

STUDY OBJECTIVE: s: To describe overall and income related trends in infant mortality inequalities in the Region of the Americas from 1955 to 1995. DESIGN: Infant mortality rates (IMRs) were computed and their trends assessed by ordinary least squares. Overall trends in IMR inequalities among countries were analysed by comparing 10 year period IMRs, Gini coefficients, and Lorenz curves. Income related trends in IMR inequalities were assessed using 10 year period IMR ratios between the highest and the lowest quintiles of the per capita gross national product (GNP) distributions (adjusted for purchasing power). SETTING: Aggregated country data were used for all countries with over 200 thousand inhabitants (33 geopolitical units). The 10 year period midpoint IMR estimates used for the 1955-1995 time series were those published by the United Nations in 1997. MAIN RESULTS: IMRs decreased from 90.34 to 31.31 per 1000 live births between 1955 and 1995 at an average of 15.3 every 10 years. In contrast, Lorenz curves and Gini coefficients were similar for the five 10 year periods. After grouping by adjusted GNP distribution, a similar decreasing trend of IMR was observed in all groups. The rate ratio between the group at the lowest quintile and that at the highest quintile ranged from 4 to 5. The analysis of variance for repeated observations showed that there is a significant reduction in the IMR (F=130.18; p<0.01), that trends did not differ significantly among groups (F=1.16; p=0.32), and that they were approximately linear (F=155.83; p<0.01). CONCLUSIONS: Despite a sizable reduction in the infant mortality, whether or not income related, levels of IMR inequality among countries have remained almost constant between 1955 and 1995 in the Region of the Americas. Further analysis and focused interventions are needed to tackle the challenges of reducing these persistent mortality inequalities.

A subregional assessment of demographic and health trends in the Americas: 1980-1998.

Close to 14 percent of the world's population lives in the Americas and the total population of this area is expected to reach 823,225,000 by the year 2000. Periodic assessments of the health situation and trends in conditions throughout subregions of the Americas have been undertaken by the Pan American Health Organization (PAHO) since the mid-1950s. These assessments demonstrate and underscore some major disparities in social, health and economic conditions in the various countries within the region. Analysis of some 38 demographic, socioeconomic, vital statistics and resource availability indicators show encouraging health and social progress between 1980 and 1998. Data concerning the health situation and trends in eight subregions of the Americas show a demographic reshape and an overall improvement in a variety of health indicators over this period. Important changes occurred in the epidemiological profile of the populations, shifting from a mainly communicable disease profile to one in which chronic diseases also affect a major portion of the population. This double health burden is unique in the region of the Americas. Improvements in social as well as health indicators were evidenced throughout the various subregions but at differing levels and at varying rates. Marked changes in total fertility, infant mortality, life expectancy and morbidity rates characterized the period between 1980 and 1998. The discrepancies between countries are highlighted and areas in need of further improvement outlined.

Epidemiological risk stratification of malaria in the Americas.

During the last years, malaria had a significant increase in Latin America, emerging again as one critical health problem in the Region of the Americas. More than 1.04 million new cases were reported in 1990. This resurgence of malaria needed a comprehensive strategy for its prevention and control. National malaria control programs recognized the epidemiological stratification of malaria as a valuable method to assist them in the recognition of local variations and factors that specifically contribute to the level and intensity of transmission in critical malarious areas. Also it serves as a useful instrument for the selection of needed malaria prevention and control activities. The principal feature of this approach is to provide a dynamic and ongoing process for assessing the epidemiological importance of different risk factors (socio-economic, ecological, organization of health services) in malaria transmission. Health interventions are based on this assessment and are aimed directly at the reduction or elimination of the identified risk factors operating at the local level. Intersectorial co-participation and the integration of malaria programs in local health services are also important aspects of this public health approach.

Assessing recent developments and opportunities in the promotion of health in the American workplace.

The purpose of this paper is to offer, as a basis for discussion, a review of the two main interpretations of what constitutes the meaning and scope of health promotion in the workplace. The two interpretations analyzed are: (a) the individual-based lifestyle approach and (b) the environmental-social approach. This paper discusses the limitations of the individual-based lifestyle approach which postulates an individualistic and fragmentated vision of the process of health in the workplace. In contrast, the environmental-social approach provides a more comprehensive framework of reference in which the socioeconomic, environmental and political components are integrated in the primary prevention strategies of health promotion in the workplace. Under this health alternative it is crucial that workers or their representatives be included as full participants in the overall process of planning, organization and implementation of promotion of health in the workplace.