Intestinal parasitic infections and atopic dermatitis among Venezuelan Warao Amerindian pre- school children.

BACKGROUND: We evaluated the influence of intestinal parasitic infection on food sensitization associated to the severity of Atopic Dermatitis (AD) in a group of Warao Amerindian pre- school children. METHODS: Feces examinations were performed in fresh stool specimens. Diagnosis of AD was done according to Hannifin and Rajka criteria and SCORAD index. Skin prick tests (SPT) were performed using extracts of cow's milk (CM), hen's egg (HE), Dermatophagoides pteronyssinus and Dermatophagoides farinae . Serum CM and HE-IgE levels (ELISA) were measured. Quantikine (R&D systems) assays were used for the determination of IL-13, TNF-α IL-6, and sCD23 in supernatants of CM- and HE- whole blood stimulated samples. RESULTS: Atopic Dermatitis was reported in 23% of the children. It was significantly (p < 0.0001) associated toward both CM and HE- SPT positivity (p < 0.001). Giardia duodenalis infection (37%) was associated to the presence of AD (p = 0.005) and to a significant increase in the levels of CM stimulated TNF-α (p=0.006), IL-13 (p = 0.01), sCD23 (p = 0.001), CM-IgE (p = 0.012) and CM-SPT (p < 0.0001). Similarly, G. duodenalis infection was particularly associated with the increase on the levels of HE-stimulated TNF-α (p = 0.001), sCD23 (p = 0.001), HE-IgE levels (p = 0.002) and HE-SPT (p = 0.001). CONCLUSION: Gut inflammation caused by G. duodenalis may enhance food allergic reactivity contributing to the manifestation of AD in these children. However, other environmental factors (not considered in this work) as well as an atopic background among the Warao population would also contribute to the presence of AD.

Evaluación de la posible asociación entre la presencia de parásitos intestinales y Helicobacter pylori en población infantil de la etnia Warao, Venezuela / Evaluation of the possible association between the presence of intestinal parasites and Helicobacter pylori in children of ethnic Warao

Las infecciones por microorganismos gastrointestinales constituyen hoy en día una de las principales causas de morbilidad y mortalidad en países en vías de desarrollo. Nos planteamos como objetivo evaluar la posible asociación entre la presencia de parásitos intestinales y la infección por Helicobacter pylori, y el comportamiento de anticuerpos séricos y secretores en una población infantil de la etnia Warao del Edo. Delta Amacuro, Venezuela. La presencia de parásitos se determinó por examen microscópico directo de las heces. Los niveles séricos de IgE total, IgG anti H. pylori e IgA anti Giardia duodenalis; y los secretores IgA total y específica a G. duodenalis y H. pylori en muestra de saliva, se determinaron utilizando el método de ELISA. El 65% de los niños estaban parasitados por protozoarios, observándose un 47% de poliparasitismo. Encontramos una mayor seroprevalencia de H. pylori en el grupo de niños no parasitados (46%) comparado con los parasitados (25%) (P<0,05). Sin embargo, los niños seropositivos a H. pylori y parasitados con G. duodenalis mostraron niveles séricos de IgE total mayores que los no parasitados (P<0,01); en contraparte, los niveles de IgA secretora total y especifica a H. pylori y G. duodenalis estaban disminuidos (P<0,05). Es posible que la respuesta inflamatoria generada por Giardia pueda aumentar los niveles de IgE total y disminuir la respuesta de IgA secretora favoreciendo la instauración de la infección por H. pylori.

The infections for gastrointestinal microorganisms represent nowadays one of the major reasons of morbidity and mortality in developing countries. We had evaluated both, the possible association between the presence of intestinal parasites and infection by Helicobacter pylori, and the production of serum and salivary antibodies in Amerindian Warao children from the Orinoco Delta, Venezuela. The prevalence of parasites was determined by faecal examination. The levels of serum antibodies (total IgE, specific anti- H. pylori IgG and anti G. duodenalis IgA) and salivary antibodies (total and specific IgA to G. duodenalis and H. pylori), was determined by ELISA. 65% of the child population was parasitized by protozoos, and a 47% of polyparasitism was observed. We found a major seroprevalence of H. pylori in the group of children not parasitized (46 %) compared with the parasitized ones (25 %) (P<0.05). Nevertheless, the seropositive children to H. pylori and parasitized with G. duodenalis showed levels of total IgE higher than the non parasitized ones (P<0.01); in contrast, levels of total and specific secretory IgA to H. pylori and G. duodenalis were decreased (P<0.05). It is possible that the inflammatory response generated by G. duodenalis infection may increase levels of total IgE and diminish secretory IgA response favoring the establishment of infection by H. pylori.

Reactividad alérgica a Anisakis simplex y su asociación con asma bronquial en niños escolares del estado Nueva Esparta, Venezuela / Anisakis simplex allergic reactivity and its association with bronchial asthma in scholar children from Nueva Esparta state, Venezuela

La reactividad alérgica frente a Anisakis simplex se ha convertido en un problema de salud pública en muchos países del mundo. En Venezuela, se ha reportado la presencia de mamíferos marinos infectados y se ha evidenciado la presencia del parásito en pescados de consumo masivo procedentes de las zonas costeras de oriente y occidente del país. No obstante, la importancia de este helminto en el desarrollo y severidad de patologías alérgicas no ha sido evaluada en el país. El objetivo de este estudio fue evaluar la reactividad alérgica al An. simplex en un grupo de 144 niños del estado de Nueva Esparta, así como su posible relación con la severidad de asma bronquial y rinitis alérgica. Todos los niños fueron evaluados utilizando un cuestionario socioeconómico validado y modificado de Graffar y un cuestionario validado según los criterios de ARIA (International Consensus Report) para rinitis alérgica, GINA (WHO/NIH Global Initiative for Asthma) para asma bronquial y Hannifin para dermatitis atópica, respectivamente. Se realizaron encuestas para evaluar las principales fuentes de alergenos a los cuales se expone la población de estudio. Se realizó la evaluación física de los niños y se practicaron pruebas cutáneas, así como pruebas de funcionalismo pulmonar. Encontramos un alto porcentaje (45%) de niños con pruebas de piel positiva al An. simplex. Se observó una mayor prevalencia y severidad, de asma y rinitis en aquellos niños con pruebas de piel positivas a An. simplex. Dado que ha sido previamente reportada la reactividad cruzada entre Ascaris lumbricoides y An. simplex, es importante considerar que la alta reactividad encontrada frente al An. simplex pueda deberse a la co-infección por Ascaris. De igual forma, la sensibilización frente a An. simplex, ya sea especifica o por reactividad cruzada existe, lo que sugiere que las autoridades locales deben considerar ciertas medidas preventivas, para evitar el consumo de pescados crudos o posiblemente parasitados con este helminto, que podrían exacerbar la patología respiratoria.

Allergic reactivity to Anisakis simplex has become in a health problem in many parts of the World. In Venezuelan coasts, it has been found infecting marine mammals and also different parasites fishes commonly consumed by human. However, the association of this helminth with the development and severity of allergic reactivity has not been previously evaluated in Venezuela. The aim of this study was to evaluate the allergic reactivity to An. simplex in a group 144 children from Nueva Esparta, state, and its possible relation with bronquial asthma and rhinitis allergic severity. All children were evaluated using a validated socioeconomic questionnaire modified by Graffar, and a validate questionnaire according to ARIA (International Consensus Report) for allergic rhinitis, GINA (WHO/NIH Global Initiative for Asthma) for bronquial asthma and Hannifin for atopic dermatitis. Surveys were performed in order to evaluate the main sources of allergens to which the study population exposes itself. Children physical evaluation and skin prick test were performed, as well as pulmonary function test. We found a high percentage (45%) of children with positive skin prick test to An. simplex. Moreover, a greatest prevalence and severity of asthma and rhinitis, was observed in those children with positive skin prick test to An. simplex. Since it has been reported the presence of the crossed reactivity between Ascaris lumbricoides and An. simplex, it’s important to consider that the high reactivity found to An. simplex might be due to the Co-infection with A. lumbricoides. Nevertheless, the sensibilization to An. simplex, due by specific or by crossed reactivity exists, and it should be considered by local health authorities in order to prevent the exacerbation of the respiratory pathologies mediated by the consumption of fresh fishes potentially infected.

Secretory IgA antibody responses in Venezuelan children infected with Giardia duodenalis.

We standardized and evaluated an ELISA technique for the detection of total and specific anti-Giardia duodenalis secretory IgA antibodies (sIgA). Samples of saliva and serum of 161 Venezuelan schoolchildren were analysed. After stool examination, 66 children were diagnosed to be infected with Giardia duodenalis, 22 with other protozoa, and 73 non-parasitized. The mean (+ 2 SD) values of secretory IgA in the non-parasitized group was considered as the criterion of positivity. The levels of total and specific anti-Giardia sIgA were significantly higher in children with Giardia compared with the group with other protozoa (p < 0.01) and the non-parasitized group (p < 0.001). The ELISA technique developed showed values of sensitivity and specificity of 74 and 94 per cent, respectively, a predictive value of 92 per cent for positive samples and 80 per cent for negative samples. Specific anti-Giardia IgA serum levels showed a low sensitivity (57 per cent) and a predictive value for negative samples (53 per cent). Our results suggest that secretory anti-Giardia IgA levels measured in saliva samples may reflect local intestinal IgA responses elicited by these parasites. Thus, determinations of the levels of sIgA anti-Giardia could be a useful diagnostic tool for giardiasis in children.