Chagas disease: a Latin American health problem becoming a world health problem.

Political repression and/or economic stagnation stimulated the flow of migration from the 17 Latin American countries endemic for Chagas disease to developed countries. Because of this migration, Chagas disease, an autochthonous disease of the Continental Western Hemisphere is becoming a global health problem. In 2006, 3.8% of the 80,522 immigrants from those 17 countries to Australia were likely infected with Trypanosoma cruzi. In Canada in 2006, 3.5% of the 156,960 immigrants from Latin America whose country of origin was identified were estimated to have been infected. In Japan in 2007, there were 80,912 immigrants from Brazil, 15,281 from Peru, and 19,413 from other South American countries whose country of origin was not identified, a portion of whom may have been also infected. In 15 countries of Europe in 2005, excluding Spain, 2.9% of the 483,074 legal Latin American immigrants were estimated to be infected with T. cruzi. By 2008, Spain had received 1,678,711 immigrants from Latin American endemic countries; of these, 5.2% were potentially infected with T. cruzi and 17,390 may develop Chagas disease. Further, it was estimated that 24-92 newborns delivered by South American T. cruzi infected mothers in Spain may have been congenitally infected with T. cruzi in 2007. In the USA we estimated that 1.9% of approximately 13 million Latin American immigrants in 2000, and 2% of 17 million in 2007, were potentially infected with T. cruzi. Of these, 49,157 and 65,133 in 2000 and 2007 respectively, may have or may develop symptoms and signs of chronic Chagas disease. Governments should implement policies to prevent donations of blood and organs from T. cruzi infected donors. In addition, an infrastructure that assures detection and treatment of acute and chronic cases as well as congenital infection should be developed.

Congenital Chagas disease: estimating the potential risk in the United States.

Economic hardship and/or political turmoil stimulated migration of Trypanosoma cruzi-infected population from Latin American countries to the United States and Europe; originating cases of Chagas disease were transmitted through blood, organ donation, and vertical transmission. Hispanic immigrant women of reproductive age in the United States coming from Chagas disease-endemic countries accounted for 2,384,644, and 5,841,538 in 1990 and 2000, respectively. Considering the prevalence rates for T. cruzi infection in their country of origin and the risk of newborns from infected mothers to acquire congenital infection as 1.33% and 5%, we estimated that the number of T. cruzi-infected newborns was 85-318 in 1990 and 166-638 in 2000. Diagnosis of infection in the mother and newborns at risk is needed. A high rate of cure is achieved, almost 100%, when the offspring is treated early. Health authorities, professional associations, physicians, and Hispanic groups should pay more attention to the subject.

Prevention of blood-borne diseases in Bolivia, 1993-2002.

This report shows the outcome of a coordinated effort by locals, foreign institutions, and an international agency, from 1996-2002, aimed at preventing transmission of blood-borne diseases in Santa Cruz, Bolivia. From 2001-2002, testing the donor pool for HIV prevented transfusion of 32 infected units and 29 infections. With 100% screening coverage, 196 hepatitis B virus (HBV)-infected units were discarded, and 177 infections of HBV were prevented between 1999 and 2002. Incomplete screening for hepatitis C virus (HCV) may have tainted nine units of blood and generated eight HCV infections in 1999. On the other hand, 600 units infected with HCV were discarded, and 540 HCV infections were prevented between 1999 and 2002. Screening for Chagas disease prevented transfusion of 10,661 tainted units and 2,133 infections from 1999 to 2002. From 1996-2002, the investment was US$1,108,000.

Epidemiology of Chagas disease in non endemic countries: the role of international migration

Human infection with the protozoa Trypanosoma cruzi extends through North, Central, and South America, affecting 21 countries. Most human infections in the Western Hemisphere occur through contact with infected bloodsucking insects of the triatomine species. As T. cruzi can be detected in the blood of untreated infected individuals, decades after infection took place; the infection can be also transmitted through blood transfusion and organ transplant, which is considered the second most common mode of transmission for T. cruzi. The third mode of transmission is congenital infection. Economic hardship, political problems, or both, have spurred migration from Chagas endemic countries to developed countries. The main destination of this immigration is Australia, Canada, Spain, and the United States. In fact, human infection through blood or organ transplantation, as well as confirmed or potential cases of congenital infections has been described in Spain and in the United States. Estimates reported here indicates that in Australia in 2005-2006, 1067 of the 65,255 Latin American immigrants (16 per 1000) may be infected with T. cruzi, and in Canada, in 2001, 1218 of the 131,135 immigrants (9 per 1000) whose country of origin was identified may have been also infected. In Spain, a magnet for Latin American immigrants since the 2000, 5125 of 241,866 legal immigrants in 2003 (25 per 1000), could be infected. In the United States, 56,028 to 357,205 of the 7,20 million, legal immigrants (8 to 50 per 1000), depending on the scenario, from the period 1981-2005 may be infected with T. cruzi. On the other hand, 33,193 to 336,097 of the estimated 5,6 million undocumented immigrants in 2000 (6 to 59 per 1000) could be infected. Non endemic countries receiving immigrants from the endemic ones should develop policies to protect organ recipients from T. cruzi infection, prevent tainting the blood supply with T. cruzi, and implement secondary prevention...

Epidemiology of Chagas disease in non-endemic countries: the role of international migration.

Human infection with the protozoa Trypanosoma cruzi extends through North, Central, and South America, affecting 21 countries. Most human infections in the Western Hemisphere occur through contact with infected bloodsucking insects of the triatomine species. As T. cruzi can be detected in the blood of untreated infected individuals, decades after infection took place; the infection can be also transmitted through blood transfusion and organ transplant, which is considered the second most common mode of transmission for T. cruzi. The third mode of transmission is congenital infection. Economic hardship, political problems, or both, have spurred migration from Chagas endemic countries to developed countries. The main destination of this immigration is Australia, Canada, Spain, and the United States. In fact, human infection through blood or organ transplantation, as well as confirmed or potential cases of congenital infections has been described in Spain and in the United States. Estimates reported here indicates that in Australia in 2005-2006, 1067 of the 65,255 Latin American immigrants (16 per 1000) may be infected with T. cruzi, and in Canada, in 2001, 1218 of the 131,135 immigrants (9 per 1000) whose country of origin was identified may have been also infected. In Spain, a magnet for Latin American immigrants since the 2000, 6141 of 38,777 to 339,954 [corrected] legal immigrants in 2003 (25 per 1000), could be infected. In the United States, 56,028 to 357,205 of the 7,20 million, legal immigrants (8 to 50 per 1000), depending on the scenario, from the period 1981-2005 may be infected with T. cruzi. On the other hand, 33,193 to 336,097 of the estimated 5,6 million undocumented immigrants in 2000 (6 to 59 per 1000) could be infected. Non endemic countries receiving immigrants from the endemic ones should develop policies to protect organ recipients from T. cruzi infection, prevent tainting the blood supply with T. cruzi, and implement secondary prevention of congenital Chagas disease.

Safety of the blood supply in Latin America.

Appropriate selection of donors, use of sensitive screening tests, and the application of a mandatory quality assurance system are essential to maintain the safety of the blood supply. Laws, decrees, norms, and/or regulations covering most of these aspects of blood transfusion exist in 16 of the 17 countries in Latin America that are the subject of this review. In 17 countries, there is an information system that, although still incomplete (there are no official reports on adverse events and incidents), allows us to establish progress made on the status of the blood supply since 1993. Most advances originated in increased screening coverage for infectious diseases and better quality assurance. However, in 2001 to 2002, tainted blood may have caused infections in 12 of the 17 countries; no country reached the number of donors considered adequate, i.e., 5% of the population, to avoid blood shortages, or decreased significantly the number of blood banks, although larger blood banks are more efficient and take advantage of economies of scale. In those years, paid donors still existed in four countries and replacement donors made up >75% of the blood donors in another eight countries. In addition, countries did not report the number of voluntary donors who were repeat donors, i.e., the healthiest category. In spite of progress made, more improvements are needed.

Safety of blood supply in the Caribbean countries: role of screening blood donors for markers of hepatitis B and C viruses.

BACKGROUND: Blood transfusions carry risks of untoward reactions, including the transmission of infections, such as hepatitis B and C. Proper blood donor recruitment and selection, and adequate laboratory screening for infectious markers diminish the risk of transfusion-transmitted infections. OBJECTIVES: To estimate the potential risk of acquiring transfusion-transmitted infections by hepatitis B or hepatitis C in 24 Caribbean countries during the period of 1996 to 2003. STUDY DESIGN: Official national reports for 1996, 2000-2003 of the yearly number of blood donors, screening coverage, and prevalence of serological markers for infectious diseases were used to estimate the risk of patients receiving an HBV- or HCV-positive unit of blood, and of developing an infection after receiving a positive unit. Estimates of number of infections transmitted through transfusion and number of infections prevented by screening of blood were also obtained. RESULTS: During the period analyzed, HBV screening coverage among blood donors was 100% in all countries with the exception of Grenada (0% in 1996) and Saint Lucia (99.5% in 2002). For HCV, only 10 countries reported universal screening in 1996, while 15 did in 2003. The number of countries that did not screen any units for HCV decreased from 11 in 1996 to five in 2003. In general, high prevalence rates of HBV (10-75 per 1000 donors) and HCV (7-19.3 per 1000 donors) markers were found in the majority of countries. We estimated that 235 infections by HCV (1:12471 donations) and two infections by HBV (1:1465373) were transmitted through transfusion because of lack of screening. On the other hand, screening of blood for transfusion prevented 21 005 HCV and 22 100 HBV infections. CONCLUSIONS: Blood donor recruitment and coverage of screening for transfusion-transmitted infections, especially HCV, must be improved in the Caribbean countries.

La reforma del sector salud, descentralización, prevención y control de enfermedades transmitidas por vectores / Health system, decentralization, and the control of vector-borne disease

Con las nuevas macropolíticas mundiales, la salud en América Latina ha sufrido importante transición en direción a la decentralización, sin compatibilizar la salud pública con la lógica de las economías de mercado. Con esto, el control decentralizado de las enfermedades endémicas presenta dificultades políticas y operativas. Aunque la decentralización se justifica por los presupuestos teóricos, no hay tradición de este control en los niveles municipales, lo que dificulta la simple o burocrática transferencia de encargos para estos niveles. La falta de expertise, el turn-over político y la corrupción son dificultades adicionales, conllevando a una extinción de varias instituiciones y programas. La falta de efectividad en el enfrentamiento del dengue, de la malaria y de la enfermedad de Chagas son algunos ejemplos. Requierese una modernización con responsabilidad, con una transición compartida entre los niveles y garantizada por acciones continuadas. Sugierese mantener estructuras regionales para referência, consolidación epidemiológica, normatización, capacitación y supervisión, incluso con reserva técnica para acciones finalísticas supletivas.

Prevention of transfusional Trypanosoma cruzi infection in Latin America

Trypanosoma cruzi is a protozoan infection widely spread in Latin America, from Mexico in the north to Argentina and Chile in the south. The second most important way of acquiring the infection is by blood transfusion. Even if most countries of Latin America have law/decree/norms, that make mandatory the screening of blood donors for infectious diseases, including T. cruzi (El Salvador and Nicaragua do not have laws on the subject), there is usually no enforcement or it is very lax. Analysis of published serologic surveys of T. cruzi antibodies in blood donors done in 1993, indicating the number of donors and screening coverage for T. cruzi in ten countries of Central and South America indicated that the probability of receiving a potentially infected transfusion unit in each country varied from 1,096 per 10,000 transfusions in Bolivia, the highest, to 13.02 or 13.86 per 10,000 transfusions in Honduras and Venezuela respectively, where screening coverage was 100 per cent. On the other hand the probability of transmitting a T. cruzi infected unit was 219/10,000 in Bolivia, 24/10,000 in Colombia, 17/10,000 in El Salvador, and around 2-12/10,000 for the seven other countries. Infectivity risks defined as the likelihood of being infected when receiving an infected transfusion unit were assumed to be 20 per cent for T. cruzi. Based on this, estimates of the absolute number of infections induced by transfusion indicated that they were 832, 236, and 875 in Bolivia, Chile and Colombia respectively. In all the other countries varied from seven in Honduras to 85 in El Salvador. Since 1993, the situation has improved. At that time only Honduras and Venezuela screened 100 per cent of donors, while seven countries, Argentina, Colombia, El Salvador, Honduras, Paraguay, Uruguay and Venezuela, did the same in 1996. In Central America, without information from Guatemala, the screening of donors for T. cruzi prevented the transfusion of 1,481 infected units and the potential infection of 300 individuals in 1996. In the same year, in seven countries of South America, the screening prevented the transfusion of 36,017 infected units and 7, 201 potential cases of transfusional infection.

Tourism and emerging and re-emerging infectious diseases in the Americas: What physicians must remember for patient diagnosis and care

Emerging diseases are those which have shown an increased in humans over the last 20 years. Re-emerging diseases are those which have reappeared after a period of significant decrease in incidence. The etiological agents of these diseases in the Western Hemisphere are viroses (HIV, dengue, oroupuche, sabia, guanarito, or hanta), bacteria (Vibrio cholera, Borrellia burgdorferi, Legionella pneumofila, Escherichia coli O157:H7, or other bacteria with a new pattern of antibiotic resistence), or parasites (Cryptosporidia, Cyclosporidia or drug resistant Plasmodium falciparum). Due to the widespread geographical distribution of these infectious diseases in the Americas, and an increasing number of travellers (more than 87 milion persons within the region in 1997), there are many opportunities to contract an infection when travelling in developed or undeveloped countries. The infections may present with symptoms during the trip, or following the traveler's return to his or her place of origin. However, too often practicing physicians do not inquire about the travel history of their patients and, when they do, they often lack the information about diseases relevant to travelers. From the regional perspective, the emerging or reemerging agents that pose a higher risk to tourists or travelers are: 1) those that cause enteric infections; 2) sexually transmitted diseases; and 3) vector-borne diseases, including those present in ecotourism areas. Emerging and re-emerging diseases that physicians may encounter in their clinical practice while caring for travelers returning from different countries of the Western Hemisphere are briefly described (Lyme diseases, legionellosis, dengue, yellow fever, P. falciparum malaria, cyclosporidiosis and cryptosporidiosis). This report attempts to draw attention to the fact that new clinical and etiological entities are present in several geographical areas of the Americas; to place each of the these entities into an epidemiological context; and to end the misconception that only travel to poor coutries carries a risk of acquiring an infection. By knowing which infectious agents occur in each area and the incubation period of each disease, the treating physician can often patients sucessfully. Health care professionals must be aware of the organisms circulating in the region so that they have them in mind during their clinical practice.

Riesgo de la enfermedad de Chagas a traves de las transfusiones en las Americas / Risk of Chagas disease through transfusions in the Americas

La seguridad de la transfusión sanguínea tanto de la existencia en el país de leyes, decretos y/o reglamentos que normal la obtención, producción y uso de sangre y derivados y la decisión gubernamental de hacerlos cumplir, como de profesionales de salud capacitados para obtener sangre y producir hemoderivados imbuidos de los conceptos de garantía de calidad total en la obtención, producción y uso de los mismos. Con la excepción de El Salvador y Nicaragua, todos los países latinoamericanos poseían leyes, decretos y/o regulaciones que regían la producción y el uso de sangre en 1998. Las penurias económicas en América latina han estimulado la emigración a las zonas urbanas en las seis últimas décadas. Como consecuencia, más del 60 por ciento de la población vive actualmente en las ciudades, lo que aumenta la probabilidad de infección por T. cruzi en donantes de sangre. Mientras no se descarte la sangre de los donantes infectados, existirá la posibilidad de transmitir la infección por medio de la transfusión. Asimismo, la infección transfusional por T. cruzi es un problema potencial en los países desarrollados, ya que decenas de miles de latinoamericanos han emigrado a los Estados Unidos, Canadá, los países de Europa Occidental, Australia o Japón. Cuando no se lleva a cabo la serología para T. cruzi en los donantes, el riesgo de recibir una unidad infectada se incrementará cuanto mayor sea la prevalencia de la infección en la población de nonantes y el número de transfusiones recibidas por el receptor. En 1993, el riesgo mayor de recibir unidad infectada y de infectarse con T. cruzi estaba en Bolivia, seguido de Colombia, El Salvador y Paraguay. Como la cobertura de la serología para VIH fue casi universal, la probabilidad de recibir una unidad infectada o de infectarse, fue baja para todos los países. La probabilidad fue mayor para HVB, sobre todo en Bolivia, Nicaragua y Guatemala; y aún mayor para HVC, debido a la baja cobertura del tamizaje de donantes. En números absolutos, el país donde se trasnmitieron más casos potenciales de infección por T. cruzi fue Bolivia; mayor número de casos de HVC, en Colombia; y más casos de HVB, en Nicaragua. Sólo en dos países, Bolivia y Colombia, existiría el potencial de transmitir VIH por medio de la transfusión. Si bien la situación ha mejorado desde 1993, y al 100 por ciento de los donantes....

Riesgo de la enfermedad de Chagas a traves de las transfusiones en las Americas / Risk of Chagas disease through transfusions in the Americas

La seguridad de la transfusión sanguínea tanto de la existencia en el país de leyes, decretos y/o reglamentos que normal la obtención, producción y uso de sangre y derivados y la decisión gubernamental de hacerlos cumplir, como de profesionales de salud capacitados para obtener sangre y producir hemoderivados imbuidos de los conceptos de garantía de calidad total en la obtención, producción y uso de los mismos. Con la excepción de El Salvador y Nicaragua, todos los países latinoamericanos poseían leyes, decretos y/o regulaciones que regían la producción y el uso de sangre en 1998. Las penurias económicas en América latina han estimulado la emigración a las zonas urbanas en las seis últimas décadas. Como consecuencia, más del 60 por ciento de la población vive actualmente en las ciudades, lo que aumenta la probabilidad de infección por T. cruzi en donantes de sangre. Mientras no se descarte la sangre de los donantes infectados, existirá la posibilidad de transmitir la infección por medio de la transfusión. Asimismo, la infección transfusional por T. cruzi es un problema potencial en los países desarrollados, ya que decenas de miles de latinoamericanos han emigrado a los Estados Unidos, Canadá, los países de Europa Occidental, Australia o Japón. Cuando no se lleva a cabo la serología para T. cruzi en los donantes, el riesgo de recibir una unidad infectada se incrementará cuanto mayor sea la prevalencia de la infección en la población de nonantes y el número de transfusiones recibidas por el receptor. En 1993, el riesgo mayor de recibir unidad infectada y de infectarse con T. cruzi estaba en Bolivia, seguido de Colombia, El Salvador y Paraguay. Como la cobertura de la serología para VIH fue casi universal, la probabilidad de recibir una unidad infectada o de infectarse, fue baja para todos los países. La probabilidad fue mayor para HVB, sobre todo en Bolivia, Nicaragua y Guatemala; y aún mayor para HVC, debido a la baja cobertura del tamizaje de donantes. En números absolutos, el país donde se trasnmitieron más casos potenciales de infección por T. cruzi fue Bolivia; mayor número de casos de HVC, en Colombia; y más casos de HVB, en Nicaragua. Sólo en dos países, Bolivia y Colombia, existiría el potencial de transmitir VIH por medio de la transfusión. Si bien la situación ha mejorado desde 1993, y al 100 por ciento de los donantes....(AU)

Inmunidad experimental en la tripanosomiasis americana (enfermedad de Chagas-Mazza) / Experimental immunity in the american trypanosomiasis (Chagas-Mazza disease)

Se describe en el presente trabajo el efecto de la presión sobre materiales antigénicos obtenidos a partir de las formas de cultivo del Tripanosoma Cruzi (Crithidias). El antígeno fue preparado en el refrigerador celular de Ribi-Sorvall, a temperatura menor de 10°C y en una atmosfera de gases inertes. Para el estudio de los antígenos se usó la fijación de complemento, la prueba intradérmica y la capacidad protectora en el ratón. La curva más típica de fijación de complemento fue obtenido con el sobrenadante del antígeno roto a menos de 10000 PSI. La reacción intradérmica más intensa se obtuvo con el sedimento del antígeno preparado a 20000 PSI. Los mejores resultados en cuanto a la capacidad protectora se obtuvieron con el homogeneizado total roto a una presión menor de 10000 PSI. El antígeno usado como vacuna demostró no ser tóxica para el ratón, conejo y humano. Los ratones vacunados e infectados con dosis altamente mortales de tripanosomas cruzi virulentos sobreviven entre el 85 al 100 por ciento. La supervivencia dependió tanto de la cantidad de vacuna suministrada como del número de Tripanosoma Cruzi virulentos utilizadas en la infección. Los ratones inmunizados e infectados mostraron una parasitemia más leve cuanto mayor fue la dosis de antígeno que recibieron. La histopatología de los ratones vacunados y no infectados no mostró grandes alteraciones en relación a los controles normales... (TRUNCADO)

Inmunidad experimental en la tripanosomiasis americana (enfermedad de Chagas-Mazza) / Experimental immunity in the american trypanosomiasis (Chagas-Mazza disease)

Se describe en el presente trabajo el efecto de la presión sobre materiales antigénicos obtenidos a partir de las formas de cultivo del Tripanosoma Cruzi (Crithidias). El antígeno fue preparado en el refrigerador celular de Ribi-Sorvall, a temperatura menor de 10°C y en una atmosfera de gases inertes. Para el estudio de los antígenos se usó la fijación de complemento, la prueba intradérmica y la capacidad protectora en el ratón. La curva más típica de fijación de complemento fue obtenido con el sobrenadante del antígeno roto a menos de 10000 PSI. La reacción intradérmica más intensa se obtuvo con el sedimento del antígeno preparado a 20000 PSI. Los mejores resultados en cuanto a la capacidad protectora se obtuvieron con el homogeneizado total roto a una presión menor de 10000 PSI. El antígeno usado como vacuna demostró no ser tóxica para el ratón, conejo y humano. Los ratones vacunados e infectados con dosis altamente mortales de tripanosomas cruzi virulentos sobreviven entre el 85 al 100 por ciento. La supervivencia dependió tanto de la cantidad de vacuna suministrada como del número de Tripanosoma Cruzi virulentos utilizadas en la infección. Los ratones inmunizados e infectados mostraron una parasitemia más leve cuanto mayor fue la dosis de antígeno que recibieron. La histopatología de los ratones vacunados y no infectados no mostró grandes alteraciones en relación a los controles normales... (TRUNCADO)(AU)