HTLV in the Americas: challenges and perspectives

The first description of the human T-lymphotropic virus type 1 (HTLV-1) was made in 1980 followed closely by the discovery of HTLV-2, in 1982. Since then, the main characteristics of these viruses, commonly referred to as HTLV-1/2, have been thoroughly studied. Central and South America and the Caribbean are areas of high prevalence of HTLV-1 and HTLV-2 and have clusters of infected people. The major modes of transmission have been through sexual contact, blood, and mother to child via breast-feeding. HTLV-1 is associated with adult T-cell leukemia/lymphoma (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and HTLV-associated uveitis as well as infectious dermatitis of children. More clarification is needed in the possible role of HTLV in rheumatological, psychiatric and infectious diseases. Since cures for ATL and HAM/TSP are lacking and no vaccine is available to prevent HTLV-1 and HTLV-2 transmission, these illnesses impose enormous social and financial cost on infected individuals, their families, and health care systems. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of vital importance. In the Americas this is especially important in the areas of high prevalence(AU)

From the old world to the new world: an ecologic study of population susceptibility to HIV infection

It remains unclear why the global distribution of human immunodeficiency virus (HIV), between and within continents, is so heterogeneous. This ecologic study of 34 populations of the Americas explored the hypothesis that populations differ in their intrinsic, biological susceptibility to HIV which, together with exposure, might determine the ultimate 'mature' prevalence. If true, national HIV prevalence in populations of the Americas should be predictable from each country's ethnic mosaic, inter-racial admixture and HIV prevalence in regions of Africa, Europe and Asia from where their ancestors migrated. For each country, the adult population (15-49years) was multiplied by the proportion corresponding to each ethnic group by HIV prevalencein the country/region of origin of each group, yielding the predicted prevalences, which were then compared with observed prevalences documented by UNAIDS for 2001. Predicted and observed HIV prevalences were highly correlated (r=0.70, P<0.001). In North America, predicted prevalences were within 0.5 percent of the observed values, except for African-Americans and African-Canadians. In Central and South America, differences between predicted and observed prevalences were <1.0 percent except in Honduras and Guyana. Some Caribbean countries had a predicted prevalence identical to the observed one, but there were outliers. Overall,predicted prevalence was 0.93 percent and observed prevalence 0.64 percent; two-thirds of this difference was attributed to Brazil. Although it was not possible to adjust to the confounding effects of sexual behavior and cofactors of transmission (such as sexually transmitted infections) because of the lack of nationally representative data for each and every country, a number of arguments reviewed in the paper suggest that confounders cannot explain all this association and that differential susceptibility might be an important determinant of steady-state HIV prevalence (AU)

Control externo de la calidad del diagnostico serologico del dengue en laboratorios de paises de las Americas, 1996-2001 / Quality control of the serological diagnosis of dengue in laboratories throughout the Americas, 1996-2001

Objective. To report the results from participating laboratories for four external quality control proficiency tests of dengue serological diagnosis that were carried out in the Region of the Americas in the period of 1996-2001. Methods. External quality control proficiency tests of dengue serological diagnosis were carried out in 1996-1997, 1998-1999, 2000-2001. Panels made up of 20 serum samples (12 of them positive for dengue IgM antibodies) were sent to participating laboratories in the Region. The sera were negative for HIV antibodies, hepatitis C virus antibodies, and hepatitis B surface antigen. The sera were stored at -20 degrees C until they were sent in refrigerated shipments to the participating laboratories. THe presence of IgM antibodies was determined through IgM-capture enzyme-linked immunosorbent assay (ELISA), while the IgG antibody titer was determined by hemagglutination inhibition or by IgG ELISA. The results of the IgM antibody testing that differed from those of the reference center were considered discordant. The IgG antibody titer was considered discordant when the results differed by two dilutions or more with respect to the reference center's results. Results. A total of 27 laboratories received a total of 59 serum panels over the 1996-2001 period, and the results from testing 54 of those panels (91.5 percent) were sent back in. Of the total of 1, 080 sera samples from those 54 panels, the results from 95.6 percent of the IgM antibody tests were concordant with the results from the reference center. With 47 of the 54 panels (87.0 percent) the participating laboratories' agreement with the reference center's results for the IgM antibody testing was 90.0 percent or higher. The laboratories sent back results from a total of 27 IgG antibody titer tests, and 22 of them (81.5 percent) coincided with those from the reference center. Considering the IgM antibody testing results from the four periods, the findings from 22 of the participating laboratories coincided with those from the reference center for at least 90 percent of the samples, and 13 of the laboratories were in complete concordance with the reference center. Conclusions. The majority of the participating laboratories showed an excellent level of performance in detecting dengue IgG and IgM antibodies. However, the deficiencies found in some instances confirm the need for continuing to improve laboratory diagnosis of dengue in the Region of the Americas (AU)

A standard method for measuring blood pressure in the Americas

Hypertension, or high blood pressure, is a silent but dangerous disease affecting an estimated 140 million men and women of all ethnic backgrounds in the Americas. This condition results in disability and millions of premature deaths each year from stroke and heart disease, heart failure, and kidney failure. It is estimated that strokes, heart attacks, and kidney failures resulting from hypertension comprise more than half the mortality in the Americas. These diseases cause untold suffering and lead to major social impacts, economic losses, and reduced productivity in every nation in the Western Hemisphere (AU)

Rapid changes in lifestyle make increased physical activity a priority for the Americas

The health benefits of regular participation in sports and aerobic fitness have been well recognized for more than 30 years. However, over the past decade new scientific evidence has shown that physical activity need not be strenuous to be beneficial to health. In fact, 30 minutes of moderate-intensity physical activity every day or on most days of the week provides important health benefits. This modest but regular amount of activity can greatly reduce or prevent the risk of cardiovascular disease, type 2 diabetes, osteoporosis, colon cancer, and breast cancer. Regular, moderate phyical activity, including daily activities such as climbing stairs, brisk walking, and biking, can reduce stress, alleviate depression and anxiety, enhance self-esteem, and increase mental alertness. Moreover, school-age children who are regularly active demonstrate enhanced school performance and a better sense of personal and social responsibility than those who are more sedentary (AU)

More need for the "old" in new public health research in the Americas

Research on the health of older adults in Latin America and the Caribbean has been neglected in epidemiology and public health. This is of grave concern since dramatic changes in fertility and mortality rates in recent decades ensure a rapid aging of the population in the Western Hemisphere. Persons 60 and older in Latin America and the Caribbean now make up 8 percent of the total population; by the middle of this century that figure will grow to 22 percent. In absolute numbers, the population of older persons will total over 180 million by 2050. In the coming decades we expect to find poorer health status and grater disability in the cohorts of persons who survived childhood and adult diseases. That higher survival rate is due to more public health interventions and less to an improvement in their socioeconomic status. Therefore, policy-makers in Latin America and the Caribbean need to understand the correlation among different gradients of poverty, access to health care, social networks, and health in old age (AU)

What do we do about the problem of overweight and obesity in the Americas?

Within the last two decades the prevalence of obesity in the developed world has moved from single digits to near 20 percent. Even more alarming is that within the same time frame the prevalence of overweight in the developing world has exceeded that in the developed countries, with. for example, rates of up to 30 percent in adult females being reported in the Caribbean. This disproportionate increase in the developing world is expected to accelerate even further since individuals, health care providers, and planners have been slow to either recognize or react to the problem. Individuals have been blinded by cultural factors that interpret obesity as desirable and a sign of wealth and economic success. Many planners lack sufficient financial resources and personnel-and, most importantly, adequate local data with which to influence public policy decisions. Clinicians have been coached in the model of acute care, and they operate in environments ill suited to handling chronic, lifestyle-related diseases.

Ensuring safe blood in the Americas

This issue will deal not only with blood banks as the places where blood is collected and processed, but also with the whole spectrum of transfusion medicine. Blood has a special place in the culture of our civilizations as symbolizing strength and the vital force of life. Its use in forms that may seem macabre to us now found its way into many ancient rituals. All physicians regard blood with some awe since so far there is no substitute for it, and its transfusion may be regarded as the first organ transplant ... Most of the blood collected in Latin America and the Caribbean is still through replacemrnt donation. Although this practice is being strongly discouraged, it is easy to see its genesis. There must be few more gratifying feelings than that of giving one's own blood not to go into some great amorphous pool but to help someone who is known and loved. We have seen increased promotion of standards and norms for blood banks in the countries and sustained efforts to rationalize the large number of blood banks that are currently operating under a large number of different schemes in the countries. Because there is increased screening of blood, the number of transfusional infections has ben reduced, and this has been documented very clearly in the case of Chagas' disease. I have been pleased to see the emphasis placed on education, even by distance, and the dissemination of both technical and popular information (AU)

Promoting quality blood services in the Region of the Americas

Over the past several years, great progress has been made in the safety of blood transfusion available in the Region of the Americas. The screening of blood units for infectious markers has increased. Of the 5.9 million units of blood collected in Latin America and the Caribbean in 1997, 68 1666 (1.1 percent) were not screened for human immunodeficiency virus (HIV); 77 095 (1.3 percent) for hepatitis B, and 343 858 (5.8 percent) for hepatitis C. The corresponding figures for 2001 are 6338 (0.09 percent) for HIV, 8797 (0.13 percent) for hepatitis B, and 60 112 (0.88 percent) for hepatitis C, despite the fact that the number of units collected that year had increased to 6.8 million. The units not screened for HIV came from five countries, two of which test over 99 percent of the blood collected and another two at least 85 percent. Sixteen countries do not have universal screening for hepatitis C. Of these, five do not test for hepatitis C at all. The quality of screening also appears to have improved in the Region. Training activities, development of standard operating procedures, implementation of quality standards, and the use of appropriate testing kits contribute to better laboratory performance. Nevertheless, there are still many challenges ahead in terms of achieving desired levels of safety and availability of blood (AU)

Estudio de factores socioculturales relacionados con la donacion voluntaria de sangre en las Americas / A study of sociocultural factors related to voluntary blood donation in the Americas

Objective. To obtain baseline data for countries of the Americas on knowledge, attitudes, and practices related to voluntary blood donation as well as on the current level and quality of services that blood banks provide to donors. Methods. The study was conducted in 15 countries in the Americas: Argentina, Bolivia, Colombia, Costa Rica, Cuba, the Dominican Republic, Ecuador, El Salvador, Guatemala, Jamaica, Nicaragua, Panama, Paraguy, Peru, and Venezuela. Technical cooperation for the study came from the Pan American Health Organization. A qualitative formative methodology was applied, utilizing interviews with donors, health workers, and members of the general public; direct observation; focus groups; knowledge tests; and a review of documents. Results. Information was generated on people's knowledge of donation; their beliefs, perceptions, attitudes, and motivations; and their barriers to donating. Knowledge was also gained as to the best means for disseminating messages supporting voluntary donation. Conclusions. This information will serve as a foundation for designing a strategy in the countries of the Americas that is aimed at establishing and building the loyalty of voluntary blood donors. This strategy can support the implementation of changes needed in the care of donors, and it can also help in motivating donors to regularly return to donate blood (AU)

Availability, safety, and quality of blood for transfusion in the Americas

Objectives. This article has two objectives: (1) to present for countries and territories of the Region of the Americas data on the number of blood donations, proportion of voluntary blood donors versus remunerated blood donors, coverage of screening for infectious agents, and separation of donated blood into its components and (2) to explore the relationships of those characteristics with economic and organizational factors in the countries and territories. Methods. We carried out comparative analyses using population and health information gathered annually by the Pan American Health Organization (PAHO) from national health officials from the countries in the Americas, as well as economic information (gross national product (GNP) per capita) obtained from publications of the World Bank. Results. There is a direct correlation between the availability of blood for transfusion and GNP per capita. Seven countries with a GNP per capita above US$ 10 000 per year account for 38 percent of the Regional population but 68 percent of the Regional blood donations. Voluntary blood donation is more common in the countries with better blood availability. There is no association between GNP per capita and coverage of screening for infectious agents. Nevertheless, of the six countries with a GNP per capita below US$ 1 000, only one of the six screens all units for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B surface antigen (HBsAg). Countries with a higher proportion of voluntary blood donors tend to have lower prevalence rates of infectious markers. Separation of blood into its components is also more common in countries with higher blood donation rates. Conclusions. The availability, safety, and quality of blood for transfusion in the Americas needs to be improved. As part of that effort, national policies and strategies must be put into place so that the resources already allocated for blood services are better utilized (AU)

El control de la calidad de los analisis inmunohematologicos en la Region de las Americas / Quality control of immunologic testing of blood in the Region of the Americas

Assuring the best quality in transfusion medicine necessarily involves exercising exhaustive control over the entire system and developing protocols for procedures and techniques, the reagents and equipment used, personnel training and so on. Additional guarantees can come from adequately organizing the work and perhaps automating processes in order to avoid errors. Another way to avoid errors in the laboratory is to register and continuosly analyze the mistakes that do occur, since that makes it necessary to change procedures in order to avoid repeating them. External quality control programs (EQCP) make it possible to perform a periodic overall assessment of the suitability of techniques, reagents, and training of personnel in relation to the valdity of the results obtained. By voluntarily participating in an EQCP, the blood center shows its commitment to the quality of care. In the Region of the Americas, the Pan American Health Organization's Immunohematology Quality Control Program has made it possible to objectively quantify the improvement attained in the formative level reached by participating blood banks in the four years the Program has been in operation (AU)

Overview of social inequalities in health in the Region of the Americas, using various methodological approaches

Over the past decade, according to several important indicators, health conditions have improved in the Region of the Americas. However, inequalities persist among the countries of the Region. This article has two primary objectives: 1) to provide some unbiased evidence on health inequalities among countries of the Region of the Americas and 2) to illustrate the application of some of the more frequently used methods for measuring inequalities, including effect measurements, population attributable risk, the slope index of inequality, the relative index of inequality, and the concentration index. Analyses have shown that there are great health disparities in the Region of the Americas. For example, residents of the poorest countries of the region live nearly 10 years less, on average, than do residents of the richest countries. If the other countries of the Americas had the same incidence of tuberculosis as does the subregion of North America (Bermuda, Canada, and the United States of America), there would be 76 percent fewer cases of this disease in the region. In the Americas, nearly 35 percent of deaths of infants under 1 year old are concentrated in the 20 percent of live births that occur in the group with the lowest income. As for maternal mortality in the Americas, fewer than 2 percent of maternal deaths occur in association with the 20 percent of live births in the group with the highest income. The analyses of health inequalities based on the use of various methods highlight the existence of important disparities among subregions and countries of the Americas that are not readily seen when using only the more-traditional methods for analyzing mortality and morbidity. There is also a need to incorporate the concepts of distribution and socioeconomic dimensions of health when interpreting a given situation. Using this approach will allow decisionmakers to target areas and populations that are in less-favorable conditions. A considerable body of aggregate data at the regional and country levels from routine information systems is already available-especially on morbidity, mortality, and other health-related factors-that can be used on a regular basis to analyze health inequalities. These kinds of analyses may be regarded as a first step toward the identification of health inequalities (AU)

Charting a future for health in the Americas: quadrennial report of the Director

Charting a Future for Health in the Americas describes the work of the Pan American Health Organization in recent years. The report opens with a disquisition on the significance of its title-how PAHO has had, and will continue to need, to chart and steer a steady course, dealing with and even capitalizing on changes along the way, in order to reach its goal: health in the Americas. With pointillistic highlights of the organization's century-long work in its major fields of responsibility, the report brings the accounting of its actions to the present. It describes the resources PAHO has employed and the impact its cooperation with member countries has had on assessing the regional health situation, enhancing health and human development, preventing and controlling diseases, promoting health, protecting the environment, and strengthening health systems and services. Morever, because of the stature it has attained, the organization has been able to strike alliances with other international agencies, nongovernmental organizations, and the private sector-and the story of their shared agenda is recounted here. This, then, is the latest in a series of reports of progress in public health throughout the Americas and, at the same time, of the work of an organization built to last (Back cover)

Incidence and prevalence of diabetes mellitus in the Americas

Objective: To present the incidence and prevalence of diabetes mellitus in the Americas as found through a review of published information on the subject. Methods: Data were obtained through a comprehensive review using the MEDLINE and BIREME bibliographical databases. In addition, government publications, conference reports, and meeting documents were identified by contacting government and nongovernmental organizations and other institutions. Incidence and prevalence rates were adjusted by age and sex, when possible, by the direct method using the world Segi population as the standard. The 95 percent confidence intervals were calculated using the Poisson distribution or the normal distribution. Results: Diabetes Mellitus represents a major public health problem in Latin America, and there is evidence that its prevalence is increasing in some countries. Conclusions: Given that most Latin American and Caribbean nations are experiencing a demographic transition, it is expected that the prevalence of diabetes will continue to increase rapidly in the near future. Despite the economic constraints faced by the countries of the Americas, there is a clear need for more efforts in the area of diabetes prevention and control (AU)

La equidad en materia de salud vista con enfoque etnico / Equity in health as seen from an ethnic focus

In this day and age, public policies that aim to improve equity cannot limit themselves to seeking greater access for all to the job market; the lack of equity is also reflected in unequal access to health services, to education, and to political representation. In order to understand and attempt to correct this unequal access, an approach is needed that takes into account all the sociodemographic factors that shape inequality in the Region of the Americas, most notably sex, ethnic origin, and race. This paper is the product of a request by the Member States of the Pan American Health Organization for PAHO to make known the influence that race, ethnic origin, and sex have on the state of health and on access to health care services. The paper examines how racial discrimination and other forms of intolerance, the low socioeconomic and educational level of certain ethnic and racial groups, and cultural beliefs exert a decisive influence on individuals' search for health care and their possibilities of enjoying good health. This subject is particularly important this year, when the United Nations is holding its World Conference against Racism, Racial Discrimination, Xenophobia and Related Intolerance (AU)

Brote de poliomielitis en Haiti y la Republica Dominicana debido a un virus derivado de la vacuna antipoliomielitica oral / Poliomyelitis outbreak caused by vaccine-derived virus in Haiti and the Dominican Republic

In October 2000, the Ministries of Helth of the Dominican Republic and Haiti notified two cases of acute flaccid paralyis (AFP) in rural areas, one of them in a 9-month-old female, and the other in a 2-year-old female, respectively. Stool samples that were obtained from these cases, which occured in July and August 2000, after a 9-year interruption of wild poliovirus circulation in the Western Hemisphere, revealed the presence of type 1 poliovirus. Genetic sequencing, which was later performed at the CEnters for Disease Control and Prevention, in Atlanta, Georgia, United States of America, revealed an atypical descendant of the virus used in the manufacture of the oral polio vaccine (OPV), but with 3 percent genetic divergence with respect to the parent strain. Normally, viral isolates that derive from vaccine components show 99.5 percent genetic agreement with the parent strain; in wild polioviruses, on the other hand, this agreement is usually less than 82.0 percent. Thus, the 3 percent genetic divergence detected in this study suggests that, in areas with low vaccine coverage, the virus used in the vaccine remained in circulation for at least two years, during which it recovered the neurovirulence and communicability of wild poliovirus type 1. This report describes the characteristics and results of the active search for cases of AFP that was sparked by the detection of the two index cases. It also looks at the public health implications of this outbreak for the entire Region of the Americas (AU)

El VIH y el sida en las Americas: una epidemia con muchas caras / HIV and AIDS in the Americas: an epidemic with many faces

This document presents data that was analyzed at a joint meeting of the Monitoring the AIDS Pandemic Network and the LAtin America and Caribbean Epidemiological Network for HIV/AIDS, held in Rio de Janiero from 4 to 5 November 2000, along with the final recommendations of that meeting. The report focuses on the diversity of the global HIV/AIDS pandemic, a diversity that is particularly evident in Latin America and the Caribbean. After providing an overall perspective on the epidemic in the Americas, the report describes the epidemic in different areas of the Americas: the Andean Subregion, Brazil, the Caribbean, Central America, Mexico, the Southern Cone, and North America. The problem of infections associated with HIV/AIDS is also addressed, especially tuberculosis, as well as other sexually transmitted infections. Also analyzed are achievements and challenges in preventing HIV infection, both in groups that are considered low risk (heterosexual adults) and those of high risk (men who have sex with men, intravenous drug users, young people, and marginalized populations). Other aspects analyzed are efforts to improve HIV surveillance, new antiretroviral agents and their impact, and the prevention of vertical transmission of HIV (AU)