Risk behaviors and STI prevalence among people with HIV in El Salvador.

To date, there are no studies from El Salvador among people with HIV to inform prevention programs. We conducted a study in El Salvador in 2008 among people with HIV using audio computer-assisted interviews on risk behaviors and access to health care. Blood was tested for syphilis and herpes simplex type 2 (HSV-2). Active syphilis was defined as RPR titer ≥1:8. Genital specimens were tested for other sexually transmitted infections (STI) by PCR. We evaluated factors associated with unprotected sex with last stable partner of HIV-negative or unknown status among those reporting a stable partner. A total of 811 HIV-positive individuals participated: 413 men and 398 women. Prevalence of Chlamydia and gonorrhea was low (≤1%), while prevalence of other STI was high: Mycoplasma genitalium (14%), syphilis (15% seropositivity, active syphilis 3%) and HSV-2 (85%). In multivariate analysis, disclosing HIV status to partner (OR 0.2, 95% CI: 0.1-0.3, p<0.001), participation in HIV support groups (OR 0.3, 95% CI: 0.1-0.8, p=0.01), easy access to condoms (OR 0.4, 95% CI: 0.2-0.9, p=0.04) were protective factors for unprotected sex. Reporting a casual partner in the last 12 months (OR 3.6, 95% CI: 1.5-8.5, p=0.004). and having an STI (OR 2.6, 95% CI:1.3-5.5, p=0.02) were associated with an increased odds of unprotected sex. Prevention interventions among HIV-positives in El Salvador should focus on increasing condom access, promoting HIV disclosure and couples testing and reducing the number of partners. The positive role of support groups should be used to enhance behavioral change.

Availability of HIV care in Central America.

Central America is an area with a growing human immunodeficiency virus (HIV) epidemic, but with marked limitations in its health care infrastructure. Estimated adult HIV infection rates range from 0.20% in Nicaragua to 2.01% in Belize. Hospitals and clinicians with experience in HIV care exist mainly, if not only, in capital cities and principal economic centers. Nationally sponsored social security systems in each country consistently offer a wider range of services than do ministry of health systems. Estimated access to the social security system ranges from 0% in Belize and 10% of the population in Honduras to 95% in Costa Rica. Combination antiretroviral therapy is not available through the ministries of health and zidovudine is only sporadically available for prevention of perinatal transmission. Combination therapy is available through the social security system in the countries of Guatemala, Panama, and Costa Rica only. A wide variety of antiretroviral agents are available through private pharmacies in all countries except Belize. With the exception of Costa Ricans, most people with HIV infection in Central America have limited access to HIV-specific health services and limited or no access to antiretroviral agents.

The Onchocerciasis Elimination Program for the Americas: a history of partnership.

The decision in 1987 by the pharmaceutical firm Merck & Co. to provide Mectizan (ivermectin) free of charge to river blindness control programs has challenged the international public health community to find effective ways to distribute the drug to rural populations most affected by onchocerciasis. In the Americas, PAHO responded to that challenge by calling for the elimination of all morbidity from onchocerciasis from the Region by the year 2007 through mass distribution of ivermectin. Since 1991, a multinational, multiagency partnership (consisting of PAHO, the endemic countries, nongovernmental development organizations, the Centers for Disease Control and Prevention in Atlanta, Georgia, as well as academic institutions and funding agencies) has developed the political, financial, and technical support needed to move toward the realization of that goal. This partnership is embodied in the Onchocerciasis Elimination Program for the Americas (OEPA), which is supported by the River Blindness Foundation (RBF) and now by the Carter Center. OEPA was conceived as a means of maintaining a regional initiative to eliminate what is otherwise a low priority disease. Since its inception in 1993, the OEPA has provided more than US$ 2 million in financial, managerial, and technical assistance to stimulate and/or support programs in Brazil, Colombia, Ecuador, Guatemala, Mexico, and Venezuela, so as to take full advantage of the Merck donation. Now halfway into a five-year, US$ 4 million grant provided through the Inter-American Development Bank, the OEPA's capacity to support the regional initiative is assured through 1999.

The Onchocerciasis elimination program for the Americas: a history of partnership

The decision in 1987 by the pharmaceutical firm Merck & Co. to provide Mectizan (ivermectin) free of charge to river blindness control programs has challenged the international public health community to find effective ways to distribute the drug to rural populations most affected by onchocerciasis. In the Americas, PAHO responded to that challenge by calling for the elimination all morbidity from onchocerciasis from the region by the year 2007 through mass distribution of ivermectin. Since 1991, a multinational, multiagency partnership (consisting of PAHO, the endemic countries, nongovernmental development organizations, the Centers for Disease Control and Prevention in Atlanta, Georgia, as well as academic institutions and funding agencies) has developed the political, financial, and technical support needed to move toward the realization of that goal. This partnership is embodied in the Onchocerciasis Elimination Program for the Americas (OEPA), which is supported by the River Blindness Foundation (RBF) and now by the Carter Center, OEPA was conceived as a means of maintaining a regional initiative to eliminate what is otherwise a low priority disease. Since its inception in 1993, the OEPA has provided more than US$ 2 million in financial, managerial, and technical assistance to stimulate and/or support programs in Brazil, Colombia, Ecuador, Guatemala, Mexico, and Venezuela, so as to take full advantage of the Merck donation, Now halfways into a five-year, US$ 4 million grant provided through the Inter-American Development Bank, the OEPA's capacity to support the regional initiative is assured through 1999 (AU)

The onchocerciasis elimination program for the Americas: a history of partnership / Programa de Eliminación de la Oncocercosis para las Américas: historia de solidaridad

The decision in 1987 by the pharmaceutical firm Merck & Co. to provide Mectizan (ivermectin) free of charge to river blindness control programs has challenged the international public health community to find effective ways to distribute the drug to rural populations most affected by onchocerciasis. In the Americas, PAHO responded to that challenge by calling for the elimination of all morbidity from onchocerciasis from the Region by the year 2007 through mass distribution of ivermectin. Since 1991, a multinational, multiagency partnership (consisting of PAHO, the endemic countries, nongovernmental development organizations, the Centers for Disease Control and Prevention in Atlanta, Georgia, as well as academic institutions and funding agencies) has developed the political, financial, and technical support needed to move toward the realization of that goal. This partnership is embodied in the Onchocerciasis Elimination Program for the Americas (OEPA), which is supported by the River Blindness Foundation (RBF) and now by the Carter Center. OEPA was conceived as a means of maintaining a regional initiative to eliminate what is otherwise a low priority disease. Since its inception in 1993, the OEPA has provided more than US$2 million in financial, managerial, and technical assistance to stimulate and/or support programs in Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela, so as to take full advantage of the Merck donation. Now halfway into a five-year, US$ 4 million grant provided through the Inter-American Development Bank, the OEPA's capacity to support the regional initiative is assured through 1999

La decisión tomada en 1987 por la Merck & Co., fabricante de productos farmacéuticos, de proveer Mectizan® (ivermectina) gratuitamente a los programas de control de la oncocercosis ha obligado a la comunidad sanitaria internacional a buscar formas de distribuir el medicamento a las poblaciones rurales que se ven más afectadas por la enfermedad. En las Américas, la OPS respondió al reto con un llamado a eliminar de la Región toda morbilidad por oncocercosis para el año 2007 mediante la distribución de ivermectina al público. Desde 1991, una alianza multinacional de diversas entidades (la OPS, países con oncocercosis endémica, agencias de desarrollo no gubernamentales, los Centros para el Control y la Prevención de Enfermedades en Atlanta, Georgia, instituciones académicas y agencias de financiamiento) ha generado el apoyo político, económico y técnico necesario para tratar de alcanzar esa meta. Esta alianza está representada por el Programa de Eliminación de la Oncocercosis en las Américas (OEPA), subvencionado por la Fundación Ceguera de los Ríos y actualmente por el Centro Carter. El OEPA se creó como iniciativa de alcance regional destinada a eliminar una enfermedad que no merece atención prioritaria. Desde su aparición en 1993, el OEPA ha aportado más de US$ 2 millones en ayuda económica, administrativa y técnica para fomentar y subvencionar programas en Brasil, Colombia, Ecuador, Guatemala, México y Venezuela, logrando así aprovechar al máximo la donación de la Merck & Co. Ahora que hemos llegado a la mitad de una subvención de 5 años y US$ 4 millones aportada por el Banco Interamericano de Desarrollo, se sabe que el OEPA tiene la capacidad para apoyar la iniciativa regional hasta fines de 1999

Autoantibodies and inmunocomplexes in Chagas' disease / Autoanticuerpos e inmunocomplejos en la enfermedad de Chagas

The presence of an autoimmune process mediated by antibodies in Chagas'disease was evaluated by studying EVI antibodies, immune complexes (Clq binding) and anti-DNA antibodies in serum samples from patients with Chagasic infection (Group I), Chagasic infection and Chagasic cardiomyopathy (Group II) and normal Venezuelan blood back donors (Group III). The study was performed on both single serum samples and those obtained longitudinally. With simgle samples the incidence of positivity for EVI antibodies was higher in Group II patients (87.5%) than in Group I (66.6%). However, with the serum samples from a longitudinal study the incidence of patients with persistently positive EVI antibodies was the same in both groups (43%). No relationship coul be established between the incidence of EVI antibodies and eiter the clinical status or the detection of circulating parasites by xenodiagnosis. The immunoglobulin fraction carryng the EVI antibodies was identified as IgG.Higher values of circulating immune comlexes were found in serum samples from patients with Chagasic cardiomyopathy. However no patient from the longitudinal study showed a persistently high Clq binding activity. The levels of anti-DNA antibodies were not different between the groups studied. It was concluded that no evidence was found to link the presence of EVI or other auto-reactive antibodies with heart damage in Chagas'disease

Longitudinal study of immune response in human Chagas' disease.

Immune response, clinical status, and reactivity to heart tissue were studied longitudinally for 1 year in 42 patients with Chagas' disease (South American trypanosomiasis). The patients were divided into two groups. Group 1 was composed of patients with chagasic infection with no evidence of heart disease. Group 2 patients had chagasic infection and cardiomyopathy. Humoral immune response to Trypanosoma cruzi was measured serologically, and cell-mediated immune responses to T. cruzi and rat heart antigens were evaluated by lymphoblastogenesis. Parasitemia was detected by xenodiagnosis. Serological tests for anti-T. cruzi antibodies were positive in all patients of both groups, and the titers were significantly higher in group 2. A change of titer during the study period was more frequently associated with a positive xenodiagnosis in both groups. Lymphoblastogenesis in response to T. cruzi antigen was positive at least once in all patients of both groups. When rat heart antigen was used, 44.4% of the patients in group 1 and 40.0% of those in group 2 were positive on at least one occasion. Xenodiagnosis revealed that 20% of the patients in group 1 and 50% of those in group 2 (P = 0.01) had detectable circulating parasites during the course of the study. Positive xenodiagnosis was associated with lower lymphoblastogenic responses to T. cruzi in group 1 patients, suggesting the presence of a regulatory or modulatory mechanism which is lost in patients with chagasic cardiomyopathy. No relationship between positive xenodiagnosis and positive lymphoblastogenesis in response to heart antigen could be established. In addition, no correlation was found between clinical heart disease and reactivity to rat heart tissue.

Comparative characterization of Venezuelan Trypanosoma cruzi stocks by electron microscopy, isoelectrofocusing and lectin typing.

The intraspecific variation among culture forms of 14 Venezuelan Trypanosoma cruzi stocks were examined by kDNA configuration, isoenzymes, and agglutination behaviour of lectins. The results have shown that in all of the stocks the central band of kDNA is present, showing that the stocks are parasites of the subgenus Schizotrypanum. By isoenzymes and lectin typing it has been found that the stocks belong to the isoenzyme group I and the lectin-type PNA which were already described for other Venezuelan stocks. The homogeneous results of intraspecific characterization contrast to those found in other countries in South America south of the Amazon basin and seem to be a further evidence that in countries north of the Amazon basin mainly on T. cruzi-type exists.

Vertebrate hosts and vectors of Trypanosoma rangeli in the Amazon Basin of Brazil.

A total of 46 Trypanosoma rangeli stocks were isolated from naturally infected mammals and triatomine vectors. Twenty-two stocks were from the common opossum (Didelphis marsupialis), one from the brown "4-eyed" opossum (Metachirus nudicaudatus), one from the anteater (Tamandua tetradactyla), one from the coati (Nasua nasua), seven from Rhodnius pictipes and 14 from Rhodnius robustus. Two stocks were also isolated from recently fed sandflies (Lutzomyia sp., Shannoni group). The stocks were identified as T. rangeli on the basis of natural or experimental salivary gland infections in Rhodnius, inoculative (anterior station) transmission to mice, morphological parameters in parasitemic mice and comparisons of isozyme profiles with a known stock of T. rangeli isolated from man. Three other trypanosome stocks from D. marsupialis, T. tetradactyla and the three-toed sloth (Bradypus tridactylus) were morphologically similar to T. rangeli in culture but had quite different isozyme profiles and were not identified. It is concluded that T. rangeli is widely distributed in Amazonas, Pará and Rondonia States of Brazil, and probably extends into other regions where R. pictipes and R. robustus are known to occur. R. pictipes is light-attracted into houses and occasionally transmits Chagas' disease to man. It is likely that T. rangeli is also occasionally transmitted to man in the Amazon basin.

El xenodiagnostico artificial en la enfermedad de Chagas. / Artificial xenodiagnosis in Chagas' disease

Se estudia una nueva tecnica de xenodiagnostico artificial, comparando la efectividad de diversos tipos de membranas y de anticoagulantes para favorecer la alimentacion, a temperatura ambiente, de ninfas de Rhodnius prolixus