16 research outputs found

    Early Exposure of Infants to GI Nematodes Induces Th2 Dominant Immune Responses Which Are Unaffected by Periodic Anthelminthic Treatment

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    We have previously shown a reduction in anaemia and wasting malnutrition in infants <3 years old in Pemba Island, Zanzibar, following repeated anthelminthic treatment for the endemic gastrointestinal (GI) nematodes Ascaris lumbricoides, hookworm and Trichuris trichiura. In view of the low intensity of worm infections in this age group, this was unexpected, and it was proposed that immune responses to the worms rather than their direct effects may play a significant role in morbidity in infants and that anthelminthic treatment may alleviate such effects. Therefore, the primary aims of this study were to characterise the immune response to initial/early GI nematode infections in infants and the effects of anthelminthic treatment on such immune responses. The frequency and levels of Th1/Th2 cytokines (IL-5, IL-13, IFN-γ and IL-10) induced by the worms were evaluated in 666 infants aged 6–24 months using the Whole Blood Assay. Ascaris and hookworm antigens induced predominantly Th2 cytokine responses, and levels of IL-5 and IL-13 were significantly correlated. The frequencies and levels of responses were higher for both Ascaris positive and hookworm positive infants compared with worm negative individuals, but very few infants made Trichuris-specific cytokine responses. Infants treated every 3 months with mebendazole showed a significantly lower prevalence of infection compared with placebo-treated controls at one year following baseline. At follow-up, cytokine responses to Ascaris and hookworm antigens, which remained Th2 biased, were increased compared with baseline but were not significantly affected by treatment. However, blood eosinophil levels, which were elevated in worm-infected children, were significantly lower in treated children. Thus the effect of deworming in this age group on anaemia and wasting malnutrition, which were replicated in this study, could not be explained by modification of cytokine responses but may be related to eosinophil function

    The development of TH2 responses from infancy to 4 years of age and atopic sensitization in areas endemic for helminth infections

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    BACKGROUND: Helminth infections and allergies are associated with TH(2) responses. Whereas the development of TH(2) responses and allergic disorders in pediatric populations has been examined in affluent countries, no or little data exist from low income regions of the world. The aim of this study is to examine factors influencing the development of TH(2) responses of children born in areas endemic for helminth infections and to relate these factors to atopic sensitization at 4 years of age. METHODS: Data were collected from pregnant mothers on helminth infections, education and socioeconomic status (SES). Total IgE, IL-5 in response to mitogen, and helminth antigens were measured in children at 2, 5, 12, 24 and 48 months of age. Skin prick testing (SPT) and allergen-specific IgE were determined at 4 years of age. RESULTS: Strong TH(2) responses were seen at 5 months of age and increased with time. Although maternal filarial infection was associated with helminth-antigen specific TH(2) responses, it was low maternal education or SES but not helminth infection, which was associated with the development of high total IgE and PHA-induced IL-5. At 4 years of age when allergen reactivity was assessed by SPT, the high general TH(2) responses did not translate into higher prevalence of SPT. The risk factor for SPT reactivity was low maternal education which decreased the risk of SPT positivity to allergens (adjusted OR, 0.32; 95% CI, 0.12 – 0.87) independently of maternal filarial infection which tended to reduce the child’s risk for being SPT positive (adjusted OR, 0.35; 95% CI, 0.07 – 1.70). CONCLUSIONS: In areas endemic for helminths, potent TH(2) responses were seen early in life, but did not translate into a higher SPT reactivity to allergens. Therefore, in many parts of the world TH(2) responses in general and IgE in particular cannot be used for diagnosis of allergic diseases

    The Hookworm Tissue Inhibitor of Metalloproteases (Ac-TMP-1) Modifies Dendritic Cell Function and Induces Generation of CD4 and CD8 Suppressor T Cells

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    Hookworm infection is a major cause of disease burden for humans. Recent studies have described hookworm-related immunosuppression in endemic populations and animal models. A Tissue Inhibitor of Metalloproteases (Ac-TMP-1) has been identified as one of the most abundant proteins released by the adult parasite. We investigated the effect of recombinant Ac-TMP-1 on dendritic cell (DC) and T cell function. Splenic T cells from C57BL/6 mice injected with Ac-TMP-1 showed reduced proliferation to restimulation with anti CD3 or bystander antigens such as OVA. Incubation of bone marrow-derived DCs with Ac-TMP-1 decreased MHC Class I and, especially, Class II expression but increased CD86 and IL-10 expression. Co-incubation of splenic T cells with DCs pulsed with Ac-TMP-1 induced their differentiation into CD4+ and, particularly, CD8+ CD25+Foxp3+ T cells that expressed IL-10. These cells were able to suppress proliferation of naïve and activated CD4+ T cells by TGF-Β-dependent (CD4+ suppressors) or independent (CD8+ suppressors) mechanisms. Priming of DCs with non-hookworm antigens, such as OVA, did not result in the generation of suppressor T cells. These data indicate that Ac-TMP-1 initiates the development of a regulatory response through modifications in DC function and generation of suppressor T cells. This is the first report to propose a role of suppressor CD8+ T cells in gastrointestinal helminthic infections

    Geohelminth Infections among Pregnant Women in Rural Western Kenya; a Cross-Sectional Study

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    In rural western Kenya, both malaria and intestinal infections with worms are common. Pregnant women are particularly vulnerable to infection with malaria, but the effect on pregnancy of intestinal infections with worms is not clear and may depend both on how heavy the worm infection is and on the type of worm. Additionally, it is not clear whether infections with worms may affect malaria infections. In this article, we begin to disentangle some of these issues. Intestinal infections with worms were diagnosed in three-quarters of 390 pregnant women in western Kenya who provided a stool sample. In these women, intestinal worm infections caused a modest decrease both in haemoglobin levels and indicators of nutritional status. Women in their second and third pregnancies who were diagnosed with one particular type of worm infection (Ascaris lumbricoides) were less likely to have malaria than other women in their second or third pregnancies who did not have this type of worm infection. Although our results suggest that it would be good advice to treat women with drugs for intestinal worm infections during their pregnancy in this area, the effect on maternal and infant health and malaria infection needs further study

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Significance Communicating in ways that motivate engagement in social distancing remains a critical global public health priority during the COVID-19 pandemic. This study tested motivational qualities of messages about social distancing (those that promoted choice and agency vs. those that were forceful and shaming) in 25,718 people in 89 countries. The autonomy-supportive message decreased feelings of defying social distancing recommendations relative to the controlling message, and the controlling message increased controlled motivation, a less effective form of motivation, relative to no message. Message type did not impact intentions to socially distance, but people’s existing motivations were related to intentions. Findings were generalizable across a geographically diverse sample and may inform public health communication strategies in this and future global health emergencies. Abstract Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

    Piloting the role of a pharmacist in a community palliative care multidisciplinary team: an Australian experience

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    <p>Abstract</p> <p>Background</p> <p>While the home is the most common setting for the provision of palliative care in Australia, a common problem encountered here is the inability of patient/carers to manage medications, which can lead to misadventure and hospitalisation. This can be averted through detection and resolution of drug related problems (DRPs) by a pharmacist; however, they are rarely included as members of the palliative care team. The aim of this study was to pilot a model of care that supports the role of a pharmacist in a community palliative care team. A component of the study was to develop a cost-effective model for continuing the inclusion of a pharmacist within a community palliative care service.</p> <p>Methods</p> <p>The study was undertaken (February March 2009-June 2010) in three phases. Development (Phase 1) involved a literature review; scoping the pharmacist's role; creating tools for recording DRPs and interventions, a communication and education strategy, a care pathway and evidence based patient information. These were then implemented in Phase 2. Evaluation (Phase 3) of the impact of the pharmacist's role from the perspectives of team members was undertaken using an online survey and focus group. Impact on clinical outcomes was determined by the number of patients screened to assess their risk of medication misadventure, as well as the number of medication reviews and interventions performed to resolve DRPs.</p> <p>Results</p> <p>The pharmacist screened most patients (88.4%, 373/422) referred to the palliative care service to assess their risk of medication misadventure, and undertook 52 home visits. Medication reviews were commonly conducted at the majority of home visits (88%, 46/52), and a variety of DRPs (113) were detected at this point, the most common being "patient requests drug information" (25%, 28/113) and "condition not adequately treated" (22%, 25/113). The pharmacist made 120 recommendations in relation to her interventions.</p> <p>Fifty percent of online survey respondents (10/20) had interacted 10 or more times with the pharmacist for advice. All felt that the pharmacist's role was helpful, improving their knowledge of the different medications used in palliative care. The six team members who participated in the focus group indicated that there were several benefits of the pharmacist's contributions towards medication screening and review.</p> <p>Conclusions</p> <p>The inclusion of a pharmacist in a community palliative care team lead to an increase in the medication-related knowledge and skills of its members, improved patients' medication management, and minimised related errors. The model of care created can potentially be duplicated by other palliative care services, although its cost-effectiveness was unable to be accurately tested within the study.</p
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