RESUMEN
BACKGROUND: Chagas disease (CD) continues to be a neglected infectious disease with one of the largest burdens globally. Despite the modest cure rates in adult chronic patients and its safety profile, benznidazole (BNZ) is still the drug of choice. Its current recommended dose is based on nonrandomized studies, and efficacy and safety of the optimal dose of BNZ have been scarcely analyzed in clinical trials. METHODS/DESIGN: MULTIBENZ is a phase II, randomized, noninferiority, double-blind, multicenter international clinical trial. A total of 240 patients with Trypanosoma CD in the chronic phase will be recruited in four different countries (Argentina, Brazil, Colombia, and Spain). Patients will be randomized to receive BNZ 150 mg/day for 60 days, 400 mg/day for 15 days, or 300 mg/day for 60 days (comparator arm). The primary outcome is the efficacy of three different BNZ therapeutic schemes in terms of dose and duration. Efficacy will be assessed according to the proportion of patients with sustained parasitic load suppression in peripheral blood measured by polymerase chain reaction. The secondary outcomes are related to pharmacokinetics and drug tolerability. The follow-up will be 12 months from randomization to end of study participation. Recruitment was started in April 2018. CONCLUSION: This is a clinical trial conducted for the assessment of different dose schemes of BNZ compared with the standard treatment regimen for the treatment of CD in the chronic phase. MULTIBENZ may help to clarify which is the most adequate BNZ regimen in terms of efficacy and safety, predicated on sustained parasitic load suppression in peripheral blood. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03191162. Registered on 19 June 2017.
Asunto(s)
Enfermedad de Chagas/tratamiento farmacológico , Enfermedades Desatendidas/parasitología , Nitroimidazoles/uso terapéutico , Tripanocidas/uso terapéutico , Trypanosoma cruzi/aislamiento & purificación , Adulto , Cuidados Posteriores , Argentina/epidemiología , Brasil/epidemiología , Estudios de Casos y Controles , Enfermedad de Chagas/parasitología , Enfermedad Crónica , Colombia/epidemiología , Método Doble Ciego , Femenino , Humanos , Masculino , Nitroimidazoles/farmacocinética , Carga de Parásitos/estadística & datos numéricos , Seguridad , España/epidemiología , Resultado del Tratamiento , Tripanocidas/farmacocinética , Trypanosoma cruzi/genéticaRESUMEN
INTRODUCCIÓN En Argentina nacen por año 800-1000 niños infectados por Trypanosoma cruzi por vía congénita. El diagnóstico de referencia actual implica un seguimiento hasta los 10 meses de vida, período en el cual hay una pérdida del 50-75% de los casos por no concurrencia a control, por diferentes motivos. A su vez, los niños diagnosticados y tratados antes del año de vida tienen una posibilidad de éxito del 99%. OBJETIVOS Evaluar una técnica de serología (ELISA) para detectar anticuerpos (Ac) Antisana (shed acute phase antigen), aplicable en los primeros meses de vida del niño y de fácil implementación en el nivel de atención primaria de salud. MÉTODOS Se obtuvieron muestras de 177 madres y sus hijos en tres períodos según la edad del niño A) <3 meses de vida, B) 3-7 meses, C) ≥10 meses. Se analizaron las muestras por las técnicas patrón oro (PO) y por ELISA-SAPA en 64 binomios que completaron el seguimiento. RESULTADOS De 96 madres analizadas, el 64,6% fueron reactivas para Ac anti-SAPA. Entre los 84 niños con seguimiento completo, se observó una tasa de transmisión congénita de 4,8% por técnicas PO. Se analizaron 64 niños por ELISA-SAPA, y del análisis comparativo con las técnicas PO la asignación de infección fue concordante en 57 casos (85,9%) y en 7 casos (14,1%) fue discordante. Se incluyó un caso de infección congénita, detectado a la edad de 10 días por micrométodo y con ELISA-SAPA reactivo. Entre los casos de no coincidencia SAPA-PO hubo 2 falsos positivos, 4 dudosos no infectados y 1 reactivo no concluyente por serología convencional a los 10 meses. No se observó ningún falso negativo por ELISA-SAPA (caso infectado no detectado). Los casos dudosos y falsos positivos eran niños de 3-4 meses con madres con alta carga de Ac anti-SAPA, por lo que se plantea revisar ciertos parámetros en la aplicación de la técnica.d DISCUSIÓN La técnica ELISA-SAPA mostró resultados promisorios para su aplicación a edades tempranas y en el nivel de atención primaria de salud.
Asunto(s)
Atención Primaria de Salud , Trypanosoma cruzi , Enfermedad de Chagas , Diagnóstico PrecozRESUMEN
El objetivo del presente estudio es efectuar el análisis del impacto de la vigilancia en sus diferentes modalidades en el control de la infección por T. cruzi y la densidad vectorial (Triatoma infestans). Material y métodos: El trabajo fue desarrollado en el Departamento de Capayán, en la provincia de Catamarca, Argentina. Se seleccionaron aleatoriamente 5 comunidades rurales y 3 comunidades peri-urbanas para desarrollar el estudio. Indicadores utilizados: a) infestación domiciliaria en los meses 24, 48 y 96; y b) Infección por T.cruzi de menores de 14 años. Resultados: Se observa persistencia de triatomineos durante el periodo de seguimiento y cuando se comparan los datos del estudio de base (2007) con los obtenidos en el año 2009 y 2012 existe significancia estadística (p <0.04) entre áreas. Se capturaron 1.89 insectos/intradomicilio en áreas con vigilancia activa versus 5.21 insectos/intradomicilio en áreas donde la misma no existió. Se demuestra la existencia de infecciones recientes en niños menores de 4 años e hijos de mujeres negativas para T. cruzi en áreas sin vigilancia activa (3 niños). Conclusión: En la presente investigación se demuestra el impacto de la vigilancia activa en sus diferentes modalidades por la no existencia de casos nuevos vectoriales en el período de seguimiento. (AU)
The aim of this study is to perform the analysis of the impact of surveillance in its various forms in the control of infection by T. cruzi and vector density (Triatoma infestans). Material and Methods: The work was developed in the Department of Capayán, in the Province of Catamarca, Argentina. Eight rural communities were selected to develop the study. Indicators used: a) house infestation in 24 months, 48 and 96; b) T. cruzi infection in children under 14 years. Results: Persistence of triatomine It is observed during the monitoring period as the baseline study (2007) thus obtained in 2009 compared to 2012 there is statistical significance (p <0.04) between areas. 1.89 insect / intradomicile were captured in areas with active surveillance versus 5.21 insect/intradomicile in areas where it did not exist. The existence of recent infections in children under four years of negative women and children for T. cruzi in areas without active surveillance (3 children) is demonstrated. Conclusion: In this research, the impact of active surveillance in its various forms by Vector exists no new cases in the follow-up period shown. (AU)
Asunto(s)
Humanos , Niño , Adolescente , Trypanosoma cruzi , Enfermedad de Chagas/epidemiología , Control de Vectores de las Enfermedades , Monitoreo Epidemiológico , Argentina , Saneamiento de Viviendas , Programas Nacionales de SaludRESUMEN
BACKGROUND:The role of trypanocidal therapy in patients with established Chagas' cardiomyopathy is unproven.METHODS:We conducted a prospective, multicenter, randomized study involving 2854 patients with Chagas' cardiomyopathy who received benznidazole or placebo for up to 80 days and were followed for a mean of 5.4 years. The primary outcome in the time-to-event analysis was the first event of any of the components of the composite outcome of death, resuscitated cardiac arrest, sustained ventricular tachycardia, insertion of a pacemaker or implantable cardioverter-defibrillator, cardiac transplantation, new heart failure, stroke, or other thromboembolic event.RESULTS:The primary outcome occurred in 394 patients (27.5%) in the benznidazole group and in 414 (29.1%) in the placebo group (hazard ratio, 0.93; 95% confidence interval [CI], 0.81 to 1.07; P=0.31). At baseline, a polymerase-chain-reaction (PCR) assay was performed on blood samples obtained from 1896 patients; 60.5% had positive results for Trypanosoma cruzi on PCR. The rates of conversion to negative PCR results (PCR conversion) were 66.2% in the benznidazole group and 33.5% in the placebo group at the end of treatment, 55.4% and 35.3%, respectively, at 2 years, and 46.7% and 33.1%, respectively, at 5 years or more (P<0.001 for all comparisons)...
Asunto(s)
Cardiomiopatía Chagásica , Enfermedad de ChagasRESUMEN
Treatment for Chagas disease with currently available medications is recommended universally only for acute cases (all ages) and for children up to 14 years old. The World Health Organization, however, also recommends specific antiparasite treatment for all chronic-phase Trypanosoma cruzi-infected individuals, even though in current medical practice this remains controversial, and most physicians only prescribe palliative treatment for adult Chagas patients with dilated cardiomyopathy. The present opinion, prepared by members of the NHEPACHA network (Nuevas Herramientas para el Diagnóstico y la Evaluación del Paciente con Enfermedad de Chagas/New Tools for the Diagnosis and Evaluation of Chagas Disease Patients), reviews the paradigm shift based on clinical and immunological evidence and argues in favor of antiparasitic treatment for all chronic patients. We review the tools needed to monitor therapeutic efficacy and the potential criteria for evaluation of treatment efficacy beyond parasitological cure. Etiological treatment should now be mandatory for all adult chronic Chagas disease patients.
Asunto(s)
Cardiomiopatía Chagásica/tratamiento farmacológico , Manejo de la Enfermedad , Nifurtimox/uso terapéutico , Nitroimidazoles/uso terapéutico , Tripanocidas/uso terapéutico , Adolescente , Adulto , Anticuerpos Antiprotozoarios/sangre , Cardiomiopatía Chagásica/inmunología , Cardiomiopatía Chagásica/parasitología , Cardiomiopatía Chagásica/patología , Niño , Enfermedad Crónica , Esquema de Medicación , Humanos , Guías de Práctica Clínica como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Trypanosoma cruzi/efectos de los fármacos , Trypanosoma cruzi/patogenicidad , Trypanosoma cruzi/fisiologíaRESUMEN
Genetic diversity of Trypanosoma cruzi may play a role in pathogenesis of Chagas disease forms. Natural populations are classified into 6 Discrete Typing Units (DTUs) Tc I-VI with taxonomical status. This study aimed to identify T. cruzi DTUs in bloodstream and tissue samples of Argentinean patients with Chagas disease. PCR-based strategies allowed DTU identification in 256 clinical samples from 239 Argentinean patients. Tc V prevailed in blood from both asymptomatic and symptomatic cases and Tc I was more frequent in bloodstream, cardiac tissues and chagoma samples from immunosuppressed patients. Tc II and VI were identified in a minority of cases, while Tc III and Tc IV were not detected in the studied population. Interestingly, Tc I and Tc II/VI sequences were amplified from the same skin biopsy slice from a kidney transplant patient suffering Chagas disease reactivation. Further data also revealed the occurrence of mixed DTU populations in the human chronic infection. In conclusion, our findings provide evidence of the complexity of the dynamics of T. cruzi diversity in the natural history of human Chagas disease and allege the pathogenic role of DTUs I, II, V and VI in the studied population.
Asunto(s)
Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/parasitología , Enfermedades Endémicas , Trypanosoma cruzi/clasificación , Trypanosoma cruzi/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Argentina/epidemiología , Cardiomiopatía Chagásica/epidemiología , Cardiomiopatía Chagásica/parasitología , Cardiomiopatía Chagásica/fisiopatología , Enfermedad de Chagas/fisiopatología , Niño , Preescolar , ADN Protozoario/análisis , ADN Protozoario/genética , Femenino , Variación Genética , Genotipo , Corazón/parasitología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Filogenia , Reacción en Cadena de la Polimerasa , Trypanosoma cruzi/aislamiento & purificación , Adulto JovenRESUMEN
Argentina has a high incidence of hemolytic uremic syndrome (HUS); 12.2 cases per 100,000 children younger than 5 years old were reported in 2002. Shiga toxin (Stx)-producing Escherichia coli (STEC) is the primary etiologic agent of HUS, and STEC O157 is the predominant serogroup isolated. The main objective of the present work was to establish the phenotypic and genotypic characteristics of the STEC strains in general isolated from Argentine children during a prospective study and the clonal relatedness of STEC O157:H7 strains using subtyping techniques. One hundred and three STEC strains isolated from 99 children were included. The phenotypic and genotypic features were established, and a polymerase chain reaction-restriction fragment length polymorphism (PCRRFLP) was performed to determine stx2 variants. The clonal relatedness of E. coli O157 isolates was established by phage typing and pulsed-field gel electrophoresis (PFGE). The 103 STEC strains belonged to 18 different serotypes, and 59% were of serotype O157:H7. Stx2 was identified in 90.3%, and stx1 in 9.7%. Among the 61 STEC O157 strains, 93.4% harbored the stx2/stx2vh-a genes; PT4 (39.3%) and PT2 (29.5%) were the predominant phage types. Using PFGE with the enzyme XbaI, a total of 41 patterns with at least 80% similarity were identified, and seven clusters with identical profiles were established. Some of the clusters were further split by PFGE using BlnI as the second enzyme. Isolates with indistinguishable PFGE patterns were with one exception also indistinguishable by phage typing and stx genotyping. These findings confirmed that some isolates were genetically related. However, no epidemiological linkages were identified. STEC strains with different genotypes and belonging to diverse serotypes were isolated in Argentina. Some STEC O157 strains could not be distinguished by applying subtyping techniques such as PFGE and phage typing.
Asunto(s)
ADN Bacteriano/análisis , Diarrea/microbiología , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/clasificación , Síndrome Hemolítico-Urémico/microbiología , Toxinas Shiga/biosíntesis , Argentina/epidemiología , Tipificación de Bacteriófagos , Preescolar , Análisis por Conglomerados , Diarrea/epidemiología , Brotes de Enfermedades , Electroforesis en Gel de Campo Pulsado , Infecciones por Escherichia coli/epidemiología , Escherichia coli O157/aislamiento & purificación , Escherichia coli O157/metabolismo , Genotipo , Síndrome Hemolítico-Urémico/epidemiología , Humanos , Lactante , Recién Nacido , Fenotipo , Polimorfismo de Longitud del Fragmento de Restricción , Estudios Prospectivos , Serotipificación , Toxinas Shiga/aislamiento & purificaciónRESUMEN
Congenital transmission of Trypanosoma cruzi infection in Argentina has being increasing its relative importance with control of vectorial and transfusional transmission growth. It is for this reason that vertical transmission is seen, in the future, as a continuous source of infected newborns, even with vectorial and transfusional transmission completely controlled. Preventing vertical transmission of T.cruzi is not possible, but it can be precociously detected, permitting mother and child to be incorporated into the medical attention system, and so allowing the newborns treatment with practically 100% efficacy. It is estimated that between 800 and 1700 children infected with T. cruzi by congenital transmission are born in Argentina, per year. The implementation of an early strategy of detection for an effective and opportune treatment acquires great relevance as a Public Health measure.
Asunto(s)
Humanos , Animales , Femenino , Embarazo , Recién Nacido , Enfermedad de Chagas/congénito , Enfermedad de Chagas/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Anticuerpos Antiprotozoarios/sangre , Argentina/epidemiología , Complicaciones Parasitarias del Embarazo/diagnóstico , Enfermedad de Chagas/diagnóstico , Enfermedad de Chagas/terapia , Estudios de Seguimiento , Transmisión Vertical de Enfermedad Infecciosa , Control de Insectos , Insectos Vectores , Trypanosoma cruziRESUMEN
Hantavirus pulmonary syndrome (HPS) has been documented in the Salta and Jujuy provinces of northern Argentina since 1991 and 1997, respectively, accounting for almost 50% of the cases of HPS reported in this country. Andes (AND) virus, specifically the AND virus Nort lineage, was previously associated with human disease in this region. Genetic analysis of viral medium RNA segments obtained from 18 HPS cases showed the existence of three AND virus Nort sublineages co-circulating in these two provinces. They showed a nucleotide sequence diversity of up to 11.1% between the sublineages. The putative site of infection of one of these cases (Sal3/97) was determined. A 100% nucleotide sequence identity was observed between the viral sequence found in patient Sal3/97 and in two virus-positive Oligoryzomys chacoensis captured in the same place where the case lived and worked. These results indicated the putative site of infection and identified this rodent species as the source of infection.
Asunto(s)
Síndrome Pulmonar por Hantavirus/epidemiología , Orthohantavirus/genética , Orthohantavirus/aislamiento & purificación , Argentina/epidemiología , Secuencia de Bases , Cartilla de ADN , Genotipo , Geografía , Orthohantavirus/clasificación , Síndrome Pulmonar por Hantavirus/virología , Humanos , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Different experimental approaches were evaluated for their ability to detect stx genes by PCR and identify Shiga toxin-producing Escherichia coli (STEC) in bovine fecal samples. One hundred and sixty fecal samples from steers in Argentina were processed by protocols that involved: (1) enrichment of fecal samples and DNA extraction using a commercially available kit (Protocol A); (2) plating on selective media after enrichment of the fecal sample followed by heat-lysis DNA extraction from the confluent growth zone (Protocol B); (3) analysis of individual colonies isolated from direct fecal culture on MacConkey agar and sorbitol MacConkey agar supplemented with cefixime and potassium tellurite (Protocol C), used as Gold Standard. PCR performed on bacteria from the confluent growth zone (Protocol B) proved to be the most sensitive methodology. In addition, enrichment for greater than 6h, enhanced sensitivity. Among eight STEC isolates, four were O8:H19 and four were stx2/eae-negative. An STEC isolate was characterized as O26:H11 with a stx1/eae/EHEC-hlyA genotype, often associated with human disease. Finally, no STEC O157 strains were isolated using these methods.
Asunto(s)
Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli/metabolismo , Reacción en Cadena de la Polimerasa/veterinaria , Toxina Shiga I/biosíntesis , Toxina Shiga II/biosíntesis , Animales , Argentina , Bovinos , ADN Bacteriano/química , ADN Bacteriano/genética , Farmacorresistencia Bacteriana , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/diagnóstico , Infecciones por Escherichia coli/microbiología , Heces/microbiología , Masculino , Antígenos O/sangre , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , Toxina Shiga I/genética , Toxina Shiga II/genética , VirulenciaRESUMEN
The province of Misiones reported 205 leishmaniasis cases during 1998, 98% of them from the locality of Puerto Esperanza. The reports of Puerto Esperanza Hospital (January to September 1998) for leishmaniasis were analysed (n: 129). The mainly reported lesion was the single cutaneous ulcer (97.2%), localized in the inferior limbs (72.5%), without any mucosa involvement. The results are consistent with the knowledge from other Argentinean leishmaniasis foci due to Leishmania (V.) braziliensis. The difference in incidence among sexes was not significant, leishmaniasis was reported in all age groups, and it was susceptible to the conventional treatment. The main focus was located in Km 1 neighbourhood, the transmission peak was during April 1998. The Montenegro skin test among general population (n: 205) did not show reactivity among asymptomatic people. The prevalent Phlebotominae species were Lutzomyia intermedia (79.7%) and Lu. whitmani (10.9%), among the 577 individuals belonging to 8 species collected. The Phlebotominae were abundant in peridomestic habitats of Km 1 neighbourhood, close to human dwellings, in places associated with residual primary forest and secondary vegetation. The results are discussed in the frame of surveillance and possible control strategies.
Asunto(s)
Brotes de Enfermedades , Leishmaniasis Cutánea Difusa/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Antiprotozoarios/uso terapéutico , Argentina/epidemiología , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Pruebas Intradérmicas , Leishmaniasis Cutánea Difusa/tratamiento farmacológico , Leishmaniasis Cutánea Difusa/inmunología , Masculino , Meglumina/uso terapéutico , Antimoniato de Meglumina , Persona de Mediana Edad , Compuestos Organometálicos/uso terapéutico , PsychodidaeRESUMEN
The incidence of tegumentary leishmaniasis increased in October 1997, in an area close to Oran city, province of Salta. The leishmaniasis' epidemiology and the entomology of this outbreak were studied during June 1998 at Paraje Las Carmelitas and Río Blanco, places with high reported incidence. The prevalence of infection (Montenegro Skin Test reactive) was 171/1000 inhabitants in Paraje Las Carmelitas and 790/1000 in Río Blanco, while the rates of leishmaniasis' incidence (active ulcers) were 72/1000 and 790/1000. The prevalence differences among sex and age groups were not significant. The clinical and epidemiologic patterns were consistent with those reported in the area for Leishmania (Viannia) braziliensis. Lutzomyia intermedia was the prevalent species (96%) among 2577 Phlebotominae collected, Lu. shannoni, Lu. cortelezzii y Lu. migonei were also present. The results about distribution of prevalence by age, and spatial distribution of Phlebotominae supported deforestation-residual primary forest transmission hypotheses. Therefore, in Salta the epidemic outbreaks generated by extensive deforestation could be sustained and amplified because the human settlements are located close to the remaining primary forest "spots". Furthermore, in this scenario the risk of human-vector contact increases by the subsistence or recreational activities performed in secondary transitional forests, and the presence of domestic animals around the houses. The results are discussed in the frame of possible control strategies.
Asunto(s)
Leishmania braziliensis , Leishmaniasis Cutánea/epidemiología , Adolescente , Adulto , Animales , Argentina/epidemiología , Niño , Preescolar , Conservación de los Recursos Naturales , Brotes de Enfermedades , Reservorios de Enfermedades , Femenino , Humanos , Incidencia , Lactante , Insectos Vectores , Leishmania braziliensis/aislamiento & purificación , Leishmaniasis Cutánea/prevención & control , Leishmaniasis Cutánea/transmisión , Persona de Mediana Edad , Prevalencia , Psychodidae/fisiologíaRESUMEN
Factors related to the characteristics of Hantavirus pulmonary syndrome in Argentina are described. Factors from different scientific fields converge to form the syndrome's analytical framework. Some of these factors are the history of spatial occupation, work and production structures, human migration patterns, ethnic composition, reservoir dynamics and its relationship to the different circulating viruses, and human behavior. Furthermore, the multiple factors are expressed in three ecological frameworks, associated with three different geographical regions of Argentina: 1) Northwest; 2) Central ("wet Pampa"); and 3) South Andean. In order to understand the actual causality of health or disease as an interaction of many factors, research on the primary biological, social, and environmental determinants of diseases should attend to the complexity of variable relationships in each region. The multiple-factor convergence approach allows for the design of appropriate strategies to improve the population's health status. Therefore, strategies should be developed and transferred by multidisciplinary teams, while their sustainability should be assured by community participation beginning with the earliest steps of research onward.
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Ambiente , Síndrome Pulmonar por Hantavirus/epidemiología , Orthohantavirus , Animales , Argentina/epidemiología , Demografía , Brotes de Enfermedades , Reservorios de Enfermedades , Orthohantavirus/clasificación , Síndrome Pulmonar por Hantavirus/transmisión , Síndrome Pulmonar por Hantavirus/virología , Promoción de la Salud , Humanos , Factores de Riesgo , Roedores/clasificaciónRESUMEN
Lutzomyia longipalpis is reported for the second time after 50 years in Misiones Province, Argentina. This insect is the vector of Leishmania (L.) chagasi, visceral leishmaniasis' parasite. The literature concerning the 16 visceral leishmaniasis cases in the country is reviewed. The cases were reported from Salta, Jujuy, Santiago del Estero and Chaco Provinces. Based on the clinical and entomo-epidemiological data two alternative hypotheses were evaluated: a) visceral leishmaniasis in Argentina is due to the visceralization of L. (V.) braziliensis or their variants, b) L (L.) chagasi remains in enzootic foci where the human contact is very unusual. Recommendations concerning the management of new cases have been made in order to confirm either one or both hypotheses. In consequence, the appropriate diagnosis and therapy could be arrived at according to the parasite actual identity, and the risk of outbreaks and mitigation measures could be estimated.
Asunto(s)
Insectos Vectores/fisiología , Leishmaniasis Visceral/epidemiología , Psychodidae/fisiología , Adulto , Animales , Argentina/epidemiología , Niño , Preescolar , Femenino , Humanos , Leishmaniasis Visceral/parasitología , MasculinoRESUMEN
OBJECTIVE: Determine the seroprevalence of Trypanosoma cruzi infection in Ushuaia, Argentina, which is the southernmost city in the world. METHODS: Serum samples were analyzed from 2,991 people, obtained between January 1995 and December 1996. The samples were processed using indirect hemagglutination and either enzyme-linked immunosorbent assay or indirect immunofluorescence. RESULTS: The general seroprevalence of T. cruzi infection was 6.8%. According to the residents' country of origin, prevalence was 41.1% among Bolivians, 5.0% among Argentines, and 0.9% among Chileans. The prevalence found in pregnant women was 5.9%; in compulsory examinations (such as for a job or for immigrants settling permanently in Argentina), it was 6.3%; and in examinations done based on clinical or epidemiological reasons to suspect infection with Chagas' disease, it was 30.8%. CONCLUSIONS: There is an alarming level of T. cruzi infection in this region, where the insect vector does not even exist. Given the risk of transmission congenitally and from blood transfusions, controls must be maintained on donated blood. In addition, follow-up of children of infected women should be strengthened so that these children receive early diagnosis and timely treatment of the infection.
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Anticuerpos Antiprotozoarios/análisis , Enfermedad de Chagas/epidemiología , Triatominae , Trypanosoma cruzi/inmunología , Adulto , Animales , Argentina/epidemiología , Bolivia/epidemiología , Enfermedad de Chagas/prevención & control , Niño , Chile/epidemiología , Estudios Transversales , Emigración e Inmigración , Ensayo de Inmunoadsorción Enzimática , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Pruebas de Hemaglutinación , Humanos , Masculino , Embarazo , Factores de Riesgo , Estudios Seroepidemiológicos , Reacción a la TransfusiónRESUMEN
The objective of this work was evaluate risk factors for acquiring cutaneous leishmaniasis in Salta, the region with the greatest indices of transmission in Argentina. A Case-cohort study was realized from June 1989 to December 1992. The procedures performed on cases and controls included: a) socio-demographic questionnaire; b) domestic and peridomestic environment description; c) physical exam of skin and nasal and oral mucosal; d) Montenegro Skin Test. Multivariate analysis showed a significant risk for factors outside the home (cattle management, hunting, sleeping at the work place) and while at home (sleeping outside of the bedroom, presence of three or more pigs in the yard and windows that cannot be locked in the closed position). This association allowed the identification of risk factors linked to the transmission of leishmaniasis in the home for the first time in Salta (Argentina).
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Leishmaniasis Cutánea/epidemiología , Adolescente , Adulto , Argentina/epidemiología , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
Lutzomyia longipalpis is reported for the second time after 50 years in Misiones Province, Argentina. This insect is the vector of Leishmania (L.) chagasi, visceral leishmaniasis parasite. The literature concerning the 16 visceral leishmaniasis cases in the country is reviewed. The cases were reported from Salta, Jujuy, Santiago del Estero and Chaco Provinces. Based on the clinical and entomo-epidemiological data two alternative hypotheses were evaluated: a) visceral leishmaniasis in Argentina is due to the visceralization of L. (V.) braziliensis or their variants, b) L (L.) chagasi remains in enzootic foci where the human contact is very unusual. Recommendations concerning the management of new cases have been made in order to confirm either one or both hypotheses. In consequence, the appropriate diagnosis and therapy could be arrived at according to the parasite actual identity, and the risk of outbreaks and mitigation measures could be estimated.
RESUMEN
The incidence of tegumentary leishmaniasis increased in October 1997, in an area close to Oran city, province of Salta. The leishmaniasis epidemiology and the entomology of this outbreak were studied during June 1998 at Paraje Las Carmelitas and Río Blanco, places with high reported incidence. The prevalence of infection (Montenegro Skin Test reactive) was 171/1000 inhabitants in Paraje Las Carmelitas and 790/1000 in Río Blanco, while the rates of leishmaniasis incidence (active ulcers) were 72/1000 and 790/1000. The prevalence differences among sex and age groups were not significant. The clinical and epidemiologic patterns were consistent with those reported in the area for Leishmania (Viannia) braziliensis. Lutzomyia intermedia was the prevalent species (96
) among 2577 Phlebotominae collected, Lu. shannoni, Lu. cortelezzii y Lu. migonei were also present. The results about distribution of prevalence by age, and spatial distribution of Phlebotominae supported deforestation-residual primary forest transmission hypotheses. Therefore, in Salta the epidemic outbreaks generated by extensive deforestation could be sustained and amplified because the human settlements are located close to the remaining primary forest [quot ]spots[quot ]. Furthermore, in this scenario the risk of human-vector contact increases by the subsistence or recreational activities performed in secondary transitional forests, and the presence of domestic animals around the houses. The results are discussed in the frame of possible control strategies.
RESUMEN
The province of Misiones reported 205 leishmaniasis cases during 1998, 98
of them from the locality of Puerto Esperanza. The reports of Puerto Esperanza Hospital (January to September 1998) for leishmaniasis were analysed (n: 129). The mainly reported lesion was the single cutaneous ulcer (97.2
), localized in the inferior limbs (72.5
), without any mucosa involvement. The results are consistent with the knowledge from other Argentinean leishmaniasis foci due to Leishmania (V.) braziliensis. The difference in incidence among sexes was not significant, leishmaniasis was reported in all age groups, and it was susceptible to the conventional treatment. The main focus was located in Km 1 neighbourhood, the transmission peak was during April 1998. The Montenegro skin test among general population (n: 205) did not show reactivity among asymptomatic people. The prevalent Phlebotominae species were Lutzomyia intermedia (79.7
) and Lu. whitmani (10.9
), among the 577 individuals belonging to 8 species collected. The Phlebotominae were abundant in peridomestic habitats of Km 1 neighbourhood, close to human dwellings, in places associated with residual primary forest and secondary vegetation. The results are discussed in the frame of surveillance and possible control strategies.
RESUMEN
This work describes the epidemiological pattern of tegumentary leishmaniasis in an area north of Salta, Argentina. The prevalence and incidence were estimated by means of a cross-sectional study and two follow-up studies during two consecutive years. The Montenegro Skin Test (MST) was administered to 7336 subjects at baseline. The prevalence and incidence between 1990 and 1992 of infection (MST reactive) was 38 per mil persons and 4.5 per mil persons/year respectively. The prevalence and incidence of tegumentary leishmaniasis (presence of clinical signs) was 1.8 per mil and 0.8 per mil persons/year, respectively. A physical examination performed on 264 patients with MST reactive during three years revealed that 130 cases (49.2%) had some evident sign of infection (scar and/or lesion), with a clinical presentation compatible with leishmaniasis. Our study demonstrated that after the epidemic outbreak of 1985 the transmission in the study area returned to endemic levels in 1992, and also demonstrated the presence of the asymptomatic infection in the area.