Histoplasmosis: Epidemiology in Latin America

Histoplasmosis is a frequent health problem in Latin American countries, but the fact that it is not a reportable disease prevents reliable estimates of its real incidence and impact on public health. Epidemiologic and clinical data remain patchy in general, and in some countries the information available is very limited. Histoplasmosis has a significant public health impact in susceptible populations such as immunosuppressed individuals, in whom the disease is associated with poor outcomes. Limited availability of diagnostic tools in many regions of Latin America is an additional problem, as many patients are already severely ill by the time of the diagnosis. Efforts are therefore necessary to ensure early diagnosis and appropriate treatment, limit the severity of the disease manifestations, and reduce morbidity and mortality. This paper reviews important aspects of the epidemiology of histoplasmosis, the most clinically significant endemic mycosis in Latin America.     

Visceral Leishmaniasis and HIV Coinfection in Latin America

Visceral leishmaniasis (VL) is an endemic zoonotic disease in Latin America caused by Leishmania (Leishmania) infantum, which is transmitted by sand flies from the genus Lutzomyia. VL occurs in 12 countries of Latin America, with 96% of cases reported in Brazil. Recently, an increase in VL, primarily affecting children and young adults, has been observed in urban areas of Latin America. The area in which this spread of VL is occurring overlaps regions with individuals living with HIV, the number of whom is estimated to be 1.4 million people by the World Health Organization. This overlap is suggested to be a leading cause of the increased number of reported VL-HIV coinfections. The clinical progression of HIV and L. infantum infections are both highly dependent on the specific immune response of an individual. Furthermore, the impact on the immune system caused by either pathogen and by VL-HIV coinfection can contribute to an accelerated progression of the diseases. Clinical presentation of VL in HIV positive patients is similar to patients without HIV, with symptoms characterized by fever, splenomegaly, and hepatomegaly, but diarrhea appears to be more common in coinfected patients. In addition, VL relapses are higher in coinfected patients, affecting 10% to 56.5% of cases and with a lethality ranging from 8.7% to 23.5% in Latin America, depending on the study. With regards to the diagnosis of VL, parasitological tests of bone marrow aspirates have proven to be the most sensitive test in HIV-infected patients. Serologic tests have demonstrated a variable sensitivity according to the method and antigens used, with the standard tests used for diagnosing VL in Latin America displaying lower sensitivity. For this review, few articles were identified that related to VL-HIV coinfections and originated from Latin America, highlighting the need for improving research within the regions most greatly affected. We strongly support the formation of a Latin American network for coinfections of Leishmania and HIV to improve the consistency of research on the current situation of VL-HIV coinfections. Such a network would improve the collection of vital data and samples for better understanding of the clinical manifestations and immunopathogenic aspects of VL in immunosuppressed patients. Ultimately, a concerted effort would improve trials for new diagnostic methodologies and therapeutics, which could accelerate the implementation of more specific and effective diagnosis as well as public policies for treatments to reduce the impact of VL-HIV coinfections on the Latin American population.     

The gamut of progressive pulmonary paracoccidioidomycosis

Paracoccidioidomycosis is an important Latin American endemy. The lung is the portal of entrance of the infection and the lesions are confined to this organ in, at least, 30 per cent of the progressive cases. Twelve case histories of patients with the progressive pulmonary form are presented in order to illustrate the repetitious clinical manifestations but the large variety of radiological presentations. The mycologic diagnosis is also emphasized.Pesquisador I-B do CNPqBolsista do CNPq     

Geographic patterns of genome admixture in Latin American Mestizos

The large and diverse population of Latin America is potentially a powerful resource for elucidating the genetic basis of complex traits through admixture mapping. However, no genome-wide characterization of admixture across Latin America has yet been attempted. Here, we report an analysis of admixture in thirteen Mestizo populations (i.e. in regions of mainly European and Native settlement) from seven countries in Latin America based on data for 678 autosomal and 29 X-chromosome microsatellites. We found extensive variation in Native American and European ancestry (and generally low levels of African ancestry) among populations and individuals, and evidence that admixture across Latin America has often involved predominantly European men and both Native and African women. An admixture analysis allowing for Native American population subdivision revealed a differentiation of the Native American ancestry amongst Mestizos. This observation is consistent with the genetic structure of pre-Columbian populations and with admixture having involved Natives from the area where the Mestizo examined are located. Our findings agree with available information on the demographic history of Latin America and have a number of implications for the design of association studies in population from the region.     

Research in animal reproduction: An analysis of the contribution made by Latin America

In an analysis carried out on the proceedings of the last two international congresses on animal reproduction and artificial insemination (1980 and 1984), a total of 944 papers presented were classified according to sex and species of the experimental animal, reproductive event studied, and country of origin. Latin America was found to be responsible for almost 10% of presentations, with Venezuela and Mexico making up half that total. The bovine species was the most studied both by Latin American countries (51.1%) and in general (42.7%). Approximately 15% of the Latin American contribution was concerned with goat studies versus 3.4% in general. Overall, the female was studied twice as much as the male. Fertility and estrous cycle were the reproductive events most studied both in general (36.3% and 31.6%, respectively) and by Latin American authors (27.2% and 33.3%, respectively). Latin American research concentrated on two main aspects: the effect of environment on reproduction and reproductive efficiency (25.8% and 13.7% of the total, respectively).     

Ethnic Differences in Correlates of Obesity between Latin‐American and Black Women

Objective: To date, no studies have examined dietary intake, physical activity, and body image in a large sample of Latin‐American and black women recruited using the same methodology. The aim of this study was to examine three potential correlates of obesity (dietary intake, body image, and physical activity) in a large sample of Latin‐American and black women across the weight spectrum. Research Methods and Procedures: Participants were black (n = 271) and Latin‐American (n = 234) adult women who completed a 24‐hour dietary recall and physical activity and body image questionnaires. Results: After controlling for BMI, education, marital status, and number of children, black women consumed more kilocalories, dietary fat (grams), and percent calories from fat than Latin‐American women, who consumed more carbohydrates (grams) and dietary fiber (total and soluble). Black women engaged in more sedentary behavior than Latin‐American women. Although Latin‐American women weighed less than black women, they perceived their current body image as heavier and reported greater body image dissatisfaction than black women. Black women also reported a higher ideal body image than Latin‐American women. Discussion: The combined effect of a diet higher in calories and fat, increased sedentary behavior, and more accepting body image could account for higher rates of obesity among black women. Future studies should further explore cultural attitudes and beliefs related to weight that could provide information for the development of culturally competent obesity interventions.     

The Prevalence,Correlates, Detection and Control of Diabetes among Older People in Low and Middle Income Countries. A 10/66 Dementia Research Group Population-Based Survey

Background

Little is known of the epidemiology of diabetes among older people in low and middle income countries. We aimed to study and compare prevalence, social patterning, correlates, detection, treatment and control of diabetes among older people in Latin America, India, China and Nigeria.

Methods

Cross-sectional surveys in 13 catchment area sites in nine countries. Diagnosed diabetes was assessed in all sites through self-reported diagnosis. Undiagnosed diabetes was assessed in seven Latin American sites through fasting blood samples (glucose > = 7mmol/L).

Results

Total diabetes prevalence in catchment sites in Cuba (prevalence 24.2%, SMR 116), Puerto Rico (43.4%, 197), and urban (27.0%, 125), and rural Mexico (23.7%, 111) already exceeds that in the USA, while that in Venezuela (20.9%, 100) is similar. Diagnosed diabetes prevalence varied very widely, between low prevalences in sites in rural China (0.9%), rural India (6.6%) and Nigeria (6.0%). and 32.1% in Puerto Rico, explained mainly by access to health services. Treatment coverage varied substantially between sites. Diabetes control (40 to 61% of those diagnosed) was modest in the Latin American sites where this was studied. Diabetes was independently associated with less education, but more assets. Hypertension, central obesity and hypertriglyceridaemia, but not hypercholesterolaemia were consistently associated with total diabetes.

Conclusions

Diabetes prevalence is already high in most sites. Identifying undiagnosed cases is essential to quantify population burden, particularly in least developed settings where diagnosis is uncommon. Metabolic risk factors and associated lifestyles may play an important part in aetiology, but this requires confirmation with longitudinal data. Given the high prevalence among older people, more population research is indicated to quantify the impact of diabetes, and to monitor the effect of prevention and health system strengthening on prevalence, treatment and control.     

Population genetic analysis of cat populations from Mexico, Colombia, Bolivia, and the Dominican Republic: Identification of different gene pools in Latin America

In this paper we identify new genetic profiles of eight Latin American cat populations. In addition, we combine data from the present study and previously published data on 70 other American and European populations to discuss (1) the points of introduction of mutant alleles for cat coat phenotypes from Europe into Latin America, (2) the heterozygosity levels at these loci in the current Latin American cat populations, (3) the level of genetic heterogeneity among Latin American cat populations, and how this compares with levels found in North American and European cat populations, and (4) how many different cat gene pools are currently present in Latin America. We also include in our purview historical records of human migrations from Europe to and within the Americas. Our analyses clearly support the view that the current genetic profiles and structuring of cat populations in Latin America can be largely explained by the historical migration patterns of humans. This work is dedicated to the memory of Dr Roy Robinson. May he rest in peace.     

Immigrant political socialization as bridging and boundary work: mapping the multi-layered incorporation of Latin American immigrants in Toronto

We present a longitudinal map of three overlapping organizational trajectories developed by Latin American immigrants in the city of Toronto. We propose the concept of bridging and boundary work to specify how new (1) intersectional political identities and organizational agendas are constituted by Latin American feminist women and artists in the interstice of (2) country-of-origin and (3) mainstream pan-ethnic organizations. Boundary work occurs as activists with intersectional priorities carve out a distinct political agenda; the ‘out-group’ relations based on a shared sectoral focus constitute bridging work. Tracing changes in the local and transnational political opportunity structures, we consider how negotiations over resources, representation and agendas between these three Latin American organizational forms generate multi-directional political learning and socialization and the coexistence of different Latin American political cultures. We define political socialization as in-group and out-group encounters between political cultures understood as civic toolkits or ways of doing politics.     

Reduction in morbidity and mortality from childhood diarrhoeal disease after species A rotavirus vaccine introduction in Latin America - a review

Countries in Latin America were among the first to implement routine vaccination against species A rotavirus (RVA). We evaluate data from Latin America on reductions in gastroenteritis and RVA disease burden following the introduction of RVA vaccine. Published literature was reviewed to identify case-control studies of vaccine effectiveness and population-based studies examining longitudinal trends of diarrhoeal disease reduction after RVA vaccine introduction in Latin American countries. RVA vaccine effectiveness and impact on gastroenteritis mortality and hospitalization rates and RVA hospitalization rates are described. Among middle-income Latin American countries with published data (Mexico, Brazil, El Salvador and Panama), RVA vaccine contributed to a gastroenteritis-associated mortality reduction of 22-41%, a gastroenteritis-associated hospitalization reduction of 17-51% and a RVA hospitalization reduction of 59-81% among children younger than five years of age. In Brazil and El Salvador, case-control studies demonstrated that a full RVA vaccination schedule was 76-85% effective against RVA hospitalization; a lower effectiveness of 46% was seen in Nicaragua, the only low-income country with available data. A growing body of literature offers convincing evidence of "real world" vaccine program successes in Latin American settings, which may be expanded as more countries in the region include RVA vaccine in their immunization programs.     

Human T-cell lymphotropic virus type I and adult T-cell leukemia/lymphoma outside Japan and the Caribbean Basin

Ninety-six patients with the diagnosis of adult T-cell leukemia/lymphoma (ATLL) were identified in countries outside Japan and the Caribbean Basin. Seventy-four of these patients were initially diagnosed in the United States; 25 of 52 patients whose places of birth were known had been born in the United States. The detection of 14 patients born in the southeastern United States, all black, indicates a group deserving particular attention for studies of human T-cell lymphotropic virus type I (HTLV-I), a suspected etiologic agent in most cases of ATLL. Although geographic clustering of ATLL in areas endemic for HTLV-I, particularly southwest Japan and the Caribbean Basin, is a dramatic feature of this disease, a review of the literature indicates that HTLV-I-associated ATLL probably occurs sporadically in a much wider distribution, the disease being diagnosed in native-born African, Chinese, European, and Latin American patients. A registry for ATLL cases is suggested, to assist in the identification of risk factors for this disease and, at the same time, improve case definitions and early diagnosis.     

The reality of scientific research in Latin America; an insider’s perspective

There is tremendous disparity in scientific productivity among nations, particularly in Latin America. At first sight, this could be linked to the relative economic health of the different countries of the region, but even large and relatively rich Latin American countries do not produce a good level of science. Although Latin America has increased the number of its scientists and research institutions in recent years, the gap between developed countries and Latin American countries is startling. The prime importance of science and technology to the development of a nation remains unacknowledged. The major factors contributing to low scientific productivity are the limited access to grant opportunities, inadequate budgets, substandard levels of laboratory infrastructure and equipment, the high cost and limited supply of reagents, and inadequate salaries and personal insecurity of scientists. The political and economic instability in several Latin America countries results in a lack of long-term goals that are essential to the development of science. In Latin America, science is not an engine of the economy. Most equipment and supplies are imported, and national industries are not given the incentives to produce these goods at home. It is a pity that Latin American society has become accustomed to expect new science and technological developments to come from developed countries rather than from their own scientists. In this article, we present a critical view of the Latin American investigator’s daily life, particularly in the area of biomedicine. Too many bright young minds continue to leave Latin America for developed countries, where they are very successful. However, we still have many enthusiastic young graduates who want to make a career in science and contribute to society. Governments need to improve the status of science for the sake of these young graduates who represent the intellectual and economic future of their countries.     

Whither Latin America? Trends and challenges of science in Latin America

Science in Latin America has experienced vigorous growth in the past decade, as demonstrated by the fact that the Latin American share of the world's scientific publications increased from 1.8% in 1991-1995 to 3.4% in 1999-2003. Significant growth has also taken place in the numbers of PhDs in science and engineering (S&E) awarded in Latin American countries in recent years, including those in the natural sciences. Importantly, albeit at different rates, growth has been verified in almost all countries in the region, indicating a general effort to promote the development of S&E. In most research fields, however, the recognition or relative impact of Latin American science, as measured by the average number of citations received by published articles (CpP), is still below world averages and much lower than in developed nations. We show that average CpP values for a set of 34 representative developing and developed countries correlate significantly with gross expenditure in research and development (GERD), with gross domestic product (GDP) per capita and with the number of researchers per million inhabitants (RpM). Among those countries, Latin American nations present some of the lowest average values of CpP (<6), GERD (< or =1% of GDP) and RpM (<2,000). We also examined recent trends in scientific activity in Latin America, with focus on the natural sciences and on biochemistry and molecular biology (BMB). In terms of citation scores, publications in BMB compare favorably to those in other research fields within Latin America. At the same time, however, Latin American BMB is one of the areas for which relative impact--compared to developed nations or normalized to world averages--is lowest. These observations clearly indicate the need to establish effective policies to increase competitiveness in terms of the quality and international recognition of Latin American natural sciences in general, and BMB in particular, as opposed to merely increasing the absolute numbers of publications or the numbers of PhDs awarded in the region.     

Birth Outcomes of Latin Americans in Two Countries with Contrasting Immigration Admission Policies: Canada and Spain

Background

We delved into the selective migration hypothesis on health by comparing birth outcomes of Latin American immigrants giving birth in two receiving countries with dissimilar immigration admission policies: Canada and Spain. We hypothesized that a stronger immigrant selection in Canada will reflect more favourable outcomes among Latin Americans giving birth in Canada than among their counterparts giving birth in Spain.

Materials and Methods

We conducted a cross-sectional bi-national comparative study. We analyzed birth data of singleton infants born in Canada (2000–2005) (N = 31,767) and Spain (1998–2007) (N = 150,405) to mothers born in Spanish-speaking Latin American countries. We compared mean birthweight at 37–41 weeks gestation, and low birthweight and preterm birth rates between Latin American immigrants to Canada vs. Spain. Regression analysis for aggregate data was used to obtain Odds Ratios and Mean birthweight differences adjusted for infant sex, maternal age, parity, marital status, and father born in same source country.

Results

Latin American women in Canada had heavier newborns than their same-country counterparts giving birth in Spain, overall [adjusted mean birthweight difference: 101 grams; 95% confidence interval (CI): 98, 104], and within each maternal country of origin. Latin American women in Canada had fewer low birthweight and preterm infants than those giving birth in Spain [adjusted Odds Ratio: 0.88; 95% CI: 0.82, 0.94 for low birthweight, and 0.88; 95% CI: 0.84, 0.93 for preterm birth, respectively].

Conclusion

Latin American immigrant women had better birth outcomes in Canada than in Spain, suggesting a more selective migration in Canada than in Spain.     

AFLP analysis of African cassava (Manihot esculenta Crantz) germplasm resistant to the cassava mosaic disease (CMD)

Amplified fragment length polymophism was assessed in 20 land races and nine elite lines of cassava from Africa, resistant and susceptible to the cassava mosaic disease (CMD). Eleven accessions from a representative core collection from Latin America, previously studied by AFLPs, were included as a reference. AFLP data from all accessions was analyzed by both the unweighted pair group mean average (UPGMA) and multiple cluster analysis (MCA) methods of analysis. Genetic differentiation between clusters and the coefficient of genetic differentiation was also calculated. Results reveal a genetic divergence between African and Latin American accessions, although some overlap was found between them. African land races resistant to CMD, were also found to be genetically differentiated from susceptible land races and from resistant elite lines. AFLP analysis identified a considerable number of duplicates in the African accessions, suggesting a sizeable percentage of redundancy. A unique AFLP fragment, found in a relatively high frequency in African accessions, but absent in the Latin American accessions, was found to be associated with branching pattern by QTL mapping in an F1 progeny derived from African and Latin American parents. The likely source and the utility of the unique AFLP fragment in understanding the processes of genetic divergence in Africa is discussed. Received: 15 May 1999 / Accepted: 28 July 1999     

Neglect of a Neglected Disease in Italy: The Challenge of Access-to-Care for Chagas Disease in Bergamo Area

ObjectivesChagas disease (CD) represents a growing problem in Europe; Italy is one of the most affected countries but there is no national framework for CD and access-to-care is challenging. In 2012 Médecins Sans Frontières (MSF) started an intervention in Bergamo province, where many people of Latin American origin (PLAO) are resident. A new model-of-care for CD, initiated by Centre for Tropical Diseases of Sacro Cuore Hospital, Negrar (CTD), the NGO OIKOS and the Bolivian community since 2009 in the same area, was endorsed. Hereby, we aim to describe the prevalence of CD and the treatment management outcomes among PLAO screened from 1^st June 2012 to 30^th June 2013.MethodsRetrospective cohort study using routine program data. Screening sessions were done in Bergamo at OIKOS outpatient service and serological confirmation, staging and treatment for CD was offered at the CTD. MSF provided health education on CD, awareness generation prior to screening days, pre-test and post-test counselling through cultural mediators of Latin American origin.ResultsOf 1305 PLAO screened, 223(17%) had CD. Among 210 patients eligible for treatment, 102(49%) were lost-to-follow-up before treatment. The median delay from diagnosis to treatment was 4 months (range 0.7–16.6 months). Among 108 started on treatment, 63(58%) completed treatment, 36(33%) interrupted treatment, (33 for drug side-effects, two for patients decision and one due to pregnancy), 6(6%) were lost-to-follow-up and 3(3%) were on treatment at study censuring.ConclusionIn this first study focusing on process of care for CD in Italy, less than 30% of patients completed treatment with drop-outs along the cascade of care. There is an urgent need to involve affected communities and local regional health authorities to take part to this model-of-care, adapting it to the local epidemiology. The Italian health authorities should take steps in advocating for a change in the current paradigm.