Leishmaniasis visceral en América Latina y perspectivas terapéuticas

In Latin America, visceral leishmaniasis is caused by Leishmania infantum. In this geographical area, main vectors associated with transmission are Lutzomyia longipalpis and Lutzomyia evansi, with dogs being incriminated as the main reservoir involved in transmission of the disease. This pathology primarily affects children between 0 - 5 years, a highly susceptible population where socio-economic, environmental and nutritional factors affects the pathological outcome and increase the likelihood of vector-human contact. According to the World Health Organization (WHO) recommended treatment for Visceral Leishmaniasis is liposomal amphotericin B, a drug with a limited and variable availability between countries depending on market prices, which leaves pentavalent antimonial as the most widely used treatment despite the associated toxic effects. In the Americas, evidence on the efficacy of single-dose (monotherapy) and combination therapies as options for treating these parasites is required.La Leishmaniasis visceral es una enfermedad causada en América Latina por Leishmania infantum, en esta área geográfica los principales vectores asociados a la transmisión son Lutzomyia longipalpis y Lutzomyia evansi, siendo el perro uno de los principales reservorios incriminados en su transmisión. Es una patología que afecta principalmente a la población infantil entre los 0 a 5 años, donde los factores socioeconómicos, ambientales y nutricionales son determinantes en el contacto con el insecto vector y el desenlace patológico. Según la Organización Mundial de la Salud el tratamiento recomendando para esta patología es la Anfotericina B liposomal, sin embargo, la disponibilidad del medicamento por el costo varía entre los diferentes países, dejando antimoniales pentavalentes como opción más utilizada, pese a los efectos tóxicos asociados. En el continente americano se requiere evidencia de la eficacia de monoterapias de una solo dosis y terapias combinadas, como opciones para el tratamiento de estas parasitosis

Epidemiology of visceral leishmaniasis in children under five years in the municipality of San Andres de Sotavento, Córdoba (Colombia), 2012

Abstract: Objective: To determine the casuistry of visceral leishmaniasis in children under five years old from the municipality of San Andres de Sotavento in the department of Cordoba, Colombia. In particular, to relate the cases registered with the variables of age, sex, race, origin, physical status, treatment, hematologic evaluations and predisposing causes for presentation. Materials and methods: This was a descriptive, retrospective study. The analysis unit corresponded to the archives of the Secretariat of Health of Cordoba, which recorded a population of 278 medical records of patients with leishmaniasis in the study area. The sample consisted of 70 medical records of childrens under five years old with visceral leishmaniasis. The data collection was achieved through the use of chips adapted to the objectives of the study. Results: The study highlights the increased commitment to the group of 12 years, with 45.71% of the cases, 55.75% of predominance of males, and 94.29% of significance of the Indian race. The body condition of infected infants as a whole was assessed as fair and poor. The origin of children was related to the communities of Cerro Los Vidales, Tuchín, Guayacan, El Contento, Las Gardenias and Los Castillos. The evaluation of the treatment administered showed great desertion (85.71%) in the completion of the cycles. Hematic evaluations showed hematocrit, hemoglobin and platelet decreased, and increasing of the speed of sedimentation. The observations of the white cell count showed non normal white blood cell count greater than 80% for leukocytes, neutrophils and lymphocytes with moderate to monocytes, and minimum to basophils and eosinophils counts. Predisposing conditions for the presentation of visceral leishmaniasis were interesting, reported by the children responsible for a history of visceral leishmaniasis in the villages (71.4%), and family history (60.0%). The keeping of dogs as epidemiological risk factor is evidenced by the coexistence with the same (77.1%) in the home and report cases of the disease in the animal species. Conclusion: Leishmaniasis is considered a reemerging disease, and a growing public health problem worldwide, due to increased number of people affected as a result of increased exposure of humans to disease vectors

Ultrasensitive detection of toxocara canis excretory-secretory antigens by a nanobody electrochemical magnetosensor assay.

peer reviewedHuman Toxocariasis (HT) is a zoonotic disease caused by the migration of the larval stage of the roundworm Toxocara canis in the human host. Despite of being the most cosmopolitan helminthiasis worldwide, its diagnosis is elusive. Currently, the detection of specific immunoglobulins IgG against the Toxocara Excretory-Secretory Antigens (TES), combined with clinical and epidemiological criteria is the only strategy to diagnose HT. Cross-reactivity with other parasites and the inability to distinguish between past and active infections are the main limitations of this approach. Here, we present a sensitive and specific novel strategy to detect and quantify TES, aiming to identify active cases of HT. High specificity is achieved by making use of nanobodies (Nbs), recombinant single variable domain antibodies obtained from camelids, that due to their small molecular size (15kDa) can recognize hidden epitopes not accessible to conventional antibodies. High sensitivity is attained by the design of an electrochemical magnetosensor with an amperometric readout with all components of the assay mixed in one single step. Through this strategy, 10-fold higher sensitivity than a conventional sandwich ELISA was achieved. The assay reached a limit of detection of 2 and15 pg/ml in PBST20 0.05% or serum, spiked with TES, respectively. These limits of detection are sufficient to detect clinically relevant toxocaral infections. Furthermore, our nanobodies showed no cross-reactivity with antigens from Ascaris lumbricoides or Ascaris suum. This is to our knowledge, the most sensitive method to detect and quantify TES so far, and has great potential to significantly improve diagnosis of HT. Moreover, the characteristics of our electrochemical assay are promising for the development of point of care diagnostic systems using nanobodies as a versatile and innovative alternative to antibodies. The next step will be the validation of the assay in clinical and epidemiological contexts