190 research outputs found

    Parenting interventions for male young offenders: a review of the evidence on what works

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    Approximately one in four incarcerated male young offenders in the UK is an actual or expectant father. This paper reviews evidence on the effectiveness of parenting interventions for male young offenders. We conducted systematic searches across 20 databases and consulted experts. Twelve relevant evaluations were identified: 10 from the UK, of programmes for incarcerated young offenders, and two from the US, of programmes for young parolees. None used experimental methods or included a comparison group. They suggest that participants like the courses, find them useful, and the interventions may improve knowledge about, and attitudes to, parenting. Future interventions should incorporate elements of promising parenting interventions with young fathers in the community, for example, and/or with older incarcerated parents. Young offender fathers have specific developmental, rehabilitative, and contextual needs. Future evaluations should collect longer-term behavioural parent and child outcome data and should use comparison groups and, ideally, randomization

    Determinants of success in national programs to Eliminate Lymphatic Filariasis: A perspective identifying essential elements and research needs

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    The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was launched in 2000. To understand why some national programs have been more successful than others, a panel of individuals with expertise in LF elimination efforts met to assess available data from programs in 8 countries. The goal was to identify: 1) the factors determining success for national LF elimination programs (defined as the rapid, sustained reduction in microfilaremia/antigenemia after repeated mass drug administration [MDA]): 2) the priorities for operational research to enhance LF elimination efforts. Of more than 40 factors identified, the most prominent were 1) initial level of LF endemicity: 2) effectiveness of vector mosquitoes; 3) MDA drug regimen: 4) population compliance. Research important for facilitating program success was identified as either biologic (i.e., [1] quantifying differences in vectorial capacity; [2] identifying seasonal variations affecting LF transmission) or programmatic (i.e., [1] identifying quantitative thresholds, especially the population compliance levels necessary for success, and the antigenemia or microfilaremia prevalence at which MDA programs can stop with minimal risk of resumption of transmission; [2] defining optimal drug distribution strategies and timing; [3] identifying those individuals who are "persistently noncompliant" during MDAs, the reasons for this non-compliance and approaches to overcoming it). While addressing these challenges is important, many key determinants of program success are already clearly understood; operationalizing these as soon as possible will greatly increase the potential for national program success

    High-throughput Plasmodium falciparum hrp2 and hrp3 gene deletion typing by digital PCR to monitor malaria rapid diagnostic test efficacy

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    Most rapid diagnostic tests for Plasmodium falciparum malaria target the Histidine-Rich Proteins 2 and 3 (HRP2, HRP3). Deletions of the hrp2 and hrp3 genes result in false negative tests and are a threat for malaria control. A novel assay for molecular surveillance of hrp2/hrp3 deletions was developed based on droplet digital PCR (ddPCR). The assay quantifies hrp2, hrp3, and a control gene with very high accuracy. The theoretical limit of detection was 0.33 parasites/microL. The deletion was reliably detected in mixed infections with wild-type and hrp2-deleted parasites at a density of >100 parasites/reaction. For a side-by-side comparison with the conventional nested PCR (nPCR) assay, 248 samples were screened in triplicate by ddPCR and nPCR. No deletions were observed by ddPCR, while by nPCR hrp2 deletion was observed in 8% of samples. The ddPCR assay was applied to screen 830 samples from Kenya, Zanzibar/Tanzania, Ghana, Ethiopia, Brazil, and Ecuador. Pronounced differences in the prevalence of deletions were observed among sites, with more hrp3 than hrp2 deletions. In conclusion, the novel ddPCR assay minimizes the risk of false-negative results (i.e. hrp2 deletion observed when the sample is wild type), increases sensitivity, and greatly reduces the number of reactions that need to be run

    Toll-like receptor polymorphisms and cerebral malaria: <it>TLR2 </it>Ξ”22 polymorphism is associated with protection from cerebral malaria in a case control study

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    <p>Abstract</p> <p>Background</p> <p>In malaria endemic areas, host genetics influence whether a <it>Plasmodium falciparum</it>-infected child develops uncomplicated or severe malaria. TLR2 has been identified as a receptor for <it>P. falciparum</it>-derived glycosylphosphatidylinositol (GPI), and polymorphisms within the TLR2 gene may affect disease pathogenesis. There are two common polymorphisms in the 5' un-translated region (UTR) of TLR2, a 22 base pair deletion in the first unstranslated exon (Ξ”22), and a GT dinucleotide repeat in the second intron (GTn).</p> <p>Methods</p> <p>These polymorphisms were examined in a Ugandan case control study on children with either cerebral malaria or uncomplicated malaria. Serum cytokine levels were analysed by ELISA, according to genotype and disease status. In vitro TLR2 expression was measured according to genotype.</p> <p>Results</p> <p>Both Ξ”22 and GTn polymorphisms were highly frequent, but only Ξ”22 heterozygosity was associated with protection from cerebral malaria (OR 0.34, 95% confidence intervals 0.16, 0.73). In vitro, heterozygosity for Ξ”22 was associated with reduced pam3cys inducible TLR2 expression in human monocyte derived macrophages. In uncomplicated malaria patients, Ξ”22 homozygosity was associated with elevated serum IL-6 (<it>p </it>= 0.04), and long GT repeat alleles were associated with elevated TNF (<it>p </it>= 0.007).</p> <p>Conclusion</p> <p>Reduced inducible TLR2 expression may lead to attenuated pro-inflammatory responses, a potential mechanism of protection from cerebral malaria present in individuals heterozygous for the TLR2 Ξ”22 polymorphism.</p

    O029: Reporting and case management of bloodborne pathogen exposures among health care workers in Tanzania

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    Introduction: In sub-Saharan Africa, bloodborne pathogens exposure (BPE) is a serious risk to health care workers (HCW). Reporting BPE is necessary for effective post-exposure prophylaxis (PEP), an important element of workplace safety in health facilities. Limited data are available on factors associated with BPE reporting among HCW. Methods: We conducted a cross-sectional study assessing experiences of occupational BPE, history of BPE reporting, and use of PEP among health care workers at three public hospitals in Tanzania. From August to November 2012, HCW were interviewed using Audio-Computer Assisted Self-Interview. All HCW at risk for BPE were invited to participate. Factors associated with reporting BPE were identified using logistic regression. Results: Of the 1,102 eligible HCW, 973 (88%) completed the interview. Of these, 690 (71%) were female and 387 (40%) were nurses. Of 357 HCW who had a BPE in the past 6 months, 120 (34%) reported it. Among these 120 reported exposures, 93 (78%) HCW reported within 2 hours of exposure, 98 (82%) received pre- and post-HIV test counseling, and 70 (58%) were offered PEP; 68 (97%) of these 70 HCWs completed PEP. Independent risk factors associated with reporting BPE were being female (adjusted odds ratio (AOR)=2.0 [95% confidence interval (CI) 1.2-3.5), having ever-received BPE training (AOR=2.0, CI 1.2-3.5), knowledge that HCW receive PEP at another facility (AOR=2.6, CI 1.5-4.4) and HIV testing within the past year (AOR=2.3, CI 1.2-4.4). Conclusion: Despite the significant proportion of HCW with a recent BPE, only one in three reported it. Our results highlight the importance of appropriate and continuous training on the prevention and reporting of occupational exposures to increase acceptance of HIV testing after BPE. Disclosure of interest: None declared

    Lymphangiogenesis and Lymphatic Remodeling Induced by Filarial Parasites: Implications for Pathogenesis

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    Even in the absence of an adaptive immune system in murine models, lymphatic dilatation and dysfunction occur in filarial infections, although severe irreversible lymphedema and elephantiasis appears to require an intact adaptive immune response in human infections. To address how filarial parasites and their antigens influence the lymphatics directly, human lymphatic endothelial cells were exposed to filarial antigens, live parasites, or infected patient serum. Live filarial parasites or filarial antigens induced both significant LEC proliferation and differentiation into tube-like structures in vitro. Moreover, serum from patently infected (microfilaria positive) patients and those with longstanding chronic lymphatic obstruction induced significantly increased LEC proliferation compared to sera from uninfected individuals. Differentiation of LEC into tube-like networks was found to be associated with significantly increased levels of matrix metalloproteases and inhibition of their TIMP inhibitors (Tissue inhibitors of matrix metalloproteases). Comparison of global gene expression induced by live parasites in LEC to parasite-unexposed LEC demonstrated that filarial parasites altered the expression of those genes involved in cellular organization and development as well as those associated with junction adherence pathways that in turn decreased trans-endothelial transport as assessed by FITC-Dextran. The data suggest that filarial parasites directly induce lymphangiogenesis and lymphatic differentiation and provide insight into the mechanisms underlying the pathology seen in lymphatic filariasis

    Midgut Barrier Imparts Selective Resistance to Filarial Worm Infection in Culex pipiens pipiens

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    Mosquitoes in the Culex pipiens complex thrive in temperate and tropical regions worldwide, and serve as efficient vectors of Bancroftian lymphatic filariasis (LF) caused by Wuchereria bancrofti in Asia, Africa, the West Indies, South America, and Micronesia. However, members of this mosquito complex do not act as natural vectors for Brugian LF caused by Brugia malayi, or for the cat parasite B. pahangi, despite their presence in South Asia where these parasites are endemic. Previous work with the Iowa strain of Culex pipiens pipiens demonstrates that it is equally susceptible to W. bancrofti as is the natural Cx. p. pipiens vector in the Nile Delta, however it is refractory to infection with Brugia spp. Here we report that the infectivity barrier for Brugia spp. in Cx. p. pipiens is the mosquito midgut, which inflicts internal and lethal damage to ingested microfilariae. Following per os Brugia exposures, the prevalence of infection is significantly lower in Cx. p. pipiens compared to susceptible mosquito controls, and differs between parasite species with <50% and <5% of Cx. p. pipiens becoming infected with B. pahangi and B. malayi, respectively. When Brugia spp. mf were inoculated intrathoracically to bypass the midgut, larvae developed equally well as in controls, indicating that, beyond the midgut, Cx. p. pipiens is physiologically compatible with Brugia spp. Mf isolated from Cx. p. pipiens midguts exhibited compromised motility, and unlike mf derived from blood or isolated from the midguts of Ae. aegypti, failed to develop when inoculated intrathoracically into susceptible mosquitoes. Together these data strongly support the role of the midgut as the primary infection barrier for Brugia spp. in Cx. p. pipiens. Examination of parasites recovered from the Cx. p. pipiens midgut by vital staining, and those exsheathed with papain, suggest that the damage inflicted by the midgut is subcuticular and disrupts internal tissues. Microscopic studies of these worms reveal compromised motility and sharp bends in the body; and ultrastructurally the presence of many fluid or carbohydrate-filled vacuoles in the hypodermis, body wall, and nuclear column. Incubation of Brugia mf with Cx. p. pipiens midgut extracts produces similar internal damage phenotypes; indicating that the Cx. p. pipiens midgut factor(s) that damage mf in vivo are soluble and stable in physiological buffer, and inflict damage on mf in vitro

    Parasite-Dependent Expansion of TNF Receptor II–Positive Regulatory T Cells with Enhanced Suppressive Activity in Adults with Severe Malaria

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    Severe Plasmodium falciparum malaria is a major cause of global mortality, yet the immunological factors underlying progression to severe disease remain unclear. CD4+CD25+ regulatory T cells (Treg cells) are associated with impaired T cell control of Plasmodium spp infection. We investigated the relationship between Treg cells, parasite biomass, and P. falciparum malaria disease severity in adults living in a malaria-endemic region of Indonesia. CD4+CD25+Foxp3+CD127lo Treg cells were significantly elevated in patients with uncomplicated (UM; nβ€Š=β€Š17) and severe malaria (SM; nβ€Š=β€Š16) relative to exposed asymptomatic controls (AC; nβ€Š=β€Š10). In patients with SM, Treg cell frequency correlated positively with parasitemia (rβ€Š=β€Š0.79, pβ€Š=β€Š0.0003) and total parasite biomass (rβ€Š=β€Š0.87, p<0.001), both major determinants for the development of severe and fatal malaria, and Treg cells were significantly increased in hyperparasitemia. There was a further significant correlation between Treg cell frequency and plasma concentrations of soluble tumor necrosis factor receptor II (TNFRII) in SM. A subset of TNFRII+ Treg cells with high expression of Foxp3 was increased in severe relative to uncomplicated malaria. In vitro, P. falciparum–infected red blood cells dose dependently induced TNFRII+Foxp3hi Treg cells in PBMC from malaria-unexposed donors which showed greater suppressive activity than TNFRIIβˆ’ Treg cells. The selective enrichment of the Treg cell compartment for a maximally suppressive TNFRII+Foxp3hi Treg subset in severe malaria provides a potential link between immune suppression, increased parasite biomass, and malaria disease severity. The findings caution against the induction of TNFRII+Foxp3hi Treg cells when developing effective malaria vaccines

    Long-Lived Antibody and B Cell Memory Responses to the Human Malaria Parasites, Plasmodium falciparum and Plasmodium vivax

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    Antibodies constitute a critical component of the naturally acquired immunity that develops following frequent exposure to malaria. However, specific antibody titres have been reported to decline rapidly in the absence of reinfection, supporting the widely perceived notion that malaria infections fail to induce durable immunological memory responses. Currently, direct evidence for the presence or absence of immune memory to malaria is limited. In this study, we analysed the longevity of both antibody and B cell memory responses to malaria antigens among individuals who were living in an area of extremely low malaria transmission in northern Thailand, and who were known either to be malaria naΓ―ve or to have had a documented clinical attack of P. falciparum and/or P. vivax in the past 6 years. We found that exposure to malaria results in the generation of relatively avid antigen-specific antibodies and the establishment of populations of antigen-specific memory B cells in a significant proportion of malaria-exposed individuals. Both antibody and memory B cell responses to malaria antigens were stably maintained over time in the absence of reinfection. In a number of cases where antigen-specific antibodies were not detected in plasma, stable frequencies of antigen-specific memory B cells were nonetheless observed, suggesting that circulating memory B cells may be maintained independently of long-lived plasma cells. We conclude that infrequent malaria infections are capable of inducing long-lived antibody and memory B cell responses
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