Blastocistosis y urticaria, una asociación poco conocida

Introducción: Globalmente, Blastocystis spp. es el protozoo más frecuentemente encontrado en las heces de humanos y otros animales. En Cuba, la Encuesta Nacional de Parasitismo Intestinal de 2009 demostró que la infección por Blastocystis spp. era la parasitosis más prevalente. La asociación entre blastocistosis y urticaria ha sido reportada de manera creciente en la literatura internacional. Esa asociación, poco conocida entre los profesionales de la salud cubanos, no ha sido estudiada en nuestro país. Objetivos: Describir la asociación entre blastocistosis y urticaria. Métodos: Mediante búsqueda electrónica en las bases de datos PubMed, Medline y Google Scholar, se realizó una revisión de los artículos publicados durante el período 2003-2023 sobre las evidencias y los mecanismos de asociación entre blastocistosis y urticaria. Puntualmente, también fueron consultados monografías y artículos originales fechados con anterioridad al intervalo mencionado. Resultados: Se expone y analiza, con un enfoque académico y asistencial, la información actualizada sobre los temas seleccionados. Conclusiones: Evidencias epidemiológicas, clínicas y terapéuticas demuestran asociación entre la infección por Blastocystis spp. y el desarrollo de urticaria. Trabajos recientes, insuficientes aún, describen los mecanismos que explicarían esa asociación. Algunos de esos mecanismos son similares a los relacionados con el desarrollo de lesiones urticarianas en el curso de otras infecciones parasitarias. Por ese motivo, el diagnóstico y tratamiento de lesiones urticarianas de posibles etiologías parasitarias debe hacerse desde un enfoque que tenga en cuenta no solo las condiciones socioeconómicas y sanitarias comunes que las propician, sino también el posible efecto potenciador de los mecanismos de las de una causa sobre los de otras.

Introduction: Globally, Blastocystis spp. is the protozoan most frequently found in the feces of humans and other animals. In Cuba, the 2009 National Survey of Intestinal Parasitism demonstrated that infection by Blastocystis spp. was the most prevalent parasitism. The association between blastocystosis and urticaria has been increasingly reported in the international literature. This association, little known among Cuban health professionals, has not been studied in our country. Objectives: To describe the mechanisms of the association between blastocystosis and urticaria. Methods: Through an electronic search in PubMed, Medline and Google Scholar databases, a review was carried out of the articles published during the period 2003-2023 on the evidence and mechanisms of association between blastocystosis and urticaria. Purposely, monographs and original articles dated prior to the aforementioned interval were also consulted. Results: Updated information on the selected topics is presented and analyzed with an academic and healthcare approach. Conclusions: Epidemiological, clinical and therapeutic evidence demonstrates an association between infection by Blastocystis spp. and the development of urticaria. Recent works, still insufficient, describes the mechanisms that would explain this association. Some of these mechanisms are similar to those related to the development of urticarial lesions during other parasitic infections. For this reason, the diagnosis and treatment of urticarial lesions of possible parasitic etiologies must be done from an approach that takes into account not only the common socioeconomic and health conditions that promote them, but also the possible enhancing effect of the mechanisms of those of a cause on those of others.

Educación para la salud en la prevención y control de la geohelmintosis: avances y desafíos / Health education for the prevention and control of soil transmitted helminth infection: advances and challenges

El vocablo geohelmintosis designa las infecciones producidas por nematodos que parasitan al humano al ponerse en contacto con superficies húmedas y cálidas contaminadas con sus huevos y larvas. Estas parasitosis, por sus prevalencias, encabezan el listado de enfermedades desatendidas. Experiencias nacionales e internacionales evidencian que las intervenciones dirigidas a atenuar estas parasitosis requieren de estrategias adecuadas a las condiciones y peculiaridades de cada localidad, en las que las acciones de educación para la salud desempeñan un papel protagónico. El presente estudio tuvo como objetivo revisar lo publicado sobre educación para la salud en la prevención y control de las geohelmintosis y, hasta donde la información lo permitió, exponer sus avances y desafíos. La revisión incluyó artículos, libros e informes técnicos publicados fundamentalmente en el periodo 1990-2015, disponibles en las bases de datos y sitios web de Scielo, BVS, PubMed, Scopus, Redalyc y otros buscadores electrónicos. En este trabajo se expone, con un enfoque académico, social y salubrista, la información actualizada sobre los temas seleccionados. Los resultados evidenciaron que la prevención y control de las geohelmintosis requieren ser abordados desde enfoques interdisciplinarios, intersectoriales e interprogramáticos. En consecuencia, las acciones de educación para la salud con ese fin demandan de la integración de factores tales como voluntad política, disponibilidad de recursos humanos y materiales, así como una adecuada estructuración de los sistemas de salud. Además, los retos relacionados con el diagnóstico, tratamiento, prevención y control de las geohelmintosis deben ser asumidos de forma dinámica y holística, no solo porque estas parasitosis encabezan la lista de prevalencias de las enfermedades desatendidas, sino también porque constituyen importantes problemas de salud en diferentes áreas del mundo subdesarrollado

[Immunization with Leishmania amazonensis subgenomic libraries protects BALB/c mice against the challenge]. / Inmunización con subgenoteca de leishmania amazonensis protege contra el reto a ratones BALB/c.

A genomic library of Leishmania amazonensis in expression vector of eukaryote cells (pEF1HisA, pEF1HisB, pEF1HisC) was prepared. Also two subgenomic libraries having each 500 clones approximately were created and BALB/c mice were immunized with 50 mg/0,1 mL of DNA from each. Two immunizations were administered intramuscularly at 15-day interval. Groups of control mice were immunized with DNA from empty plasmid pEF1His, with soluble parasite antigen (100 mg/0,1 mL) and saline solution. The size of lesions was measured for 12 weeks and at the end of the experiment, the parasite load at lesion sites was determined by plaque microtitration method. In mice immunized with subgenomic library DNAI and with soluble antigens,the size of lesions was controlled, which reached an statistical difference (p< 0,05) in relation to the rest of groups whose lesions increased. The parasite load found in lesion sites confirmed the previous results; the number of promastigots was significantly lower in those mice already protected. It was concluded that in subgenomic library DNA1 there should be genes or gene fragments whose in vivo expression induces protective immune response against the challenge in the murine model used.

[Knowledge, believes and practices of physicians from Cienfuegos in relation to intestinal amebiasis: results of an intervention]. / Conocimientos, creencias y prácticas de medicos de Cienfuegos en relación con la amebiasis intestinal: resultados de una intervención.

In a study conducted in the province of Cienfuegos, it was proved by using immunological and biomolecular tools that intestina amebiasis in that province was an overdimensioned health problem. A survey on knowledge, perceptions and practices applied to those physicians related to the diagnosis, treatment and control of this parasitosis showed that the overdimensioning may be associated with an inadequate perception of the problem and with a marked lack of knowledge about important aspects of this entity. To contribute to the solution of the ovedimensioning and of its consequences, a set of actions were taken in that province. After a year, a second survey was done, whose results are published in this document, allowing to know about a significant improvement of the surveyed in almost all the evaluated cognitive and perceptual aspects (6.73 and 11.23 means of correct answers before and after the intervention, respectively).

[Importance of medical education in the diagnosis of toxoplasmosis in Cuba]. / Importancia de la educación médica en el diagnóstico de la toxoplasmosis en Cuba.

The results of the National Toxoplasmosis Reference Laboratory during 1999 and 2000 were processed and the evaluations on this topic were simultaneously analyzed among 51 professionals that attended the First National Workshop held at "Pedro Kouri" Institute of Tropical Medicine at that time. Of 3 672 orders, 3 171 (86.3%) did not have the reason for serology, 36.1% had no place of origin and only 301 cases (8.1%) were indicated the matched serum. On analyzing the main causes leading to make this test, 13.5% corresponded to repeated abortions, which is not accepted at present as a clinical manifestation in the course of the disease. Coincidentally, when some professionals were evaluated through a survey about the basic aspects related to this parasitosis, only 31.3% were able to obtain satisfactory marks. Most of the mistakes were observed in the interpretation of the laboratory results.

Significant and transitory control of lesions development in mice immunized with a genomic library of Leishmania amazonensis

DNA from a genomic library of Leishmania amazonensis and from pcDNA3 plasmid were used to immunize BALB/c mice. Three immunizations at two weeks intervals were done, with 50µg/0.1ml of DNA. A control group was also injected with the same volume of saline solution. Afterward, all mice were challenged with infective promastigotes of the parasite, and the development of lesions was followed during 16 weeks by dorsoventral measures of the footpad. Mice previously immunized with the genomic library were capable of controlling lesions at a significant level, with major significance between 9 and 13 weeks post challenge.

[Antiamebic effect of metronidazole proved in a study conducted in Cienfuegos province]. / Eficacia antiamebiana del metronidazol demostrada en un estudio realizado en la provincia de Cienfuegos.

Three studies were conducted in Cienfuegos province to prove that intestinal amebiasis in Cuba could be an overestimated health problem. The first two studies showed two components of this overestimation: microscopical overdiagnosis and lack of knowledge about Entamoeba dispar, a non-pathogenic species, in most cases in which microscopical examination was correct. This paper reported the third study that showed the third component: the wrong belief that Entamoeba histolytica is resistant to metronidazole. Thirty-five individuals infected with one or both species of E-histolytica-E. dispar combination were given metronidazole at a dose of 250 mg three times daily for 10 days. Stool samples taken immediately after the treatment were tested by ENZYMEBA to detect one or both species and by a multiplex polymerase chain reaction procedure to determine the existing species. The results of these assays revealed that E. histolytica infection disappeared in all the cases, therefore, we may conclude that in Cienfuegos province and probably in the rest of the country, metronidazol remains an effective drug in the treatment of intestinal amebiasis

Respuesta humoral específica en ratones Balb/c inoculados con una librería genómica de expresión de Trypanosoma cruzi / Specific humoral response in Balb/c mice inoculated with a genome library of expression of Trypanosoma cruzi

A genomic expression library of Trypanosoma cruzi (T. cruzi) was made using plasmid pcDNA3 as a vector, with which male mice from the Balb/c isogenic line were intramuscullary inoculated. It was used a positive control group that was administered soluble antigens of T. cruzi. Other 2 groups received genomic and plasmid DNA, respectively. One group was not immunized. Weekly blood samples were obtained from all the animals until the fourth week and 2 weeks after reimmunization to study the response of specific antibodies against the microorganism antigens by an indirect immunoenzymatic assay (ELISA). It was observed a significant increase of specific antibodies in the animals reimmunized with 50 micrograms of the library, as well as in the group immunized with soluble antigens of T. cruzi.