963 resultados para Tropical medicine


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OBJECTIVES: To describe temporal trends in baseline clinical characteristics, initial treatment regimens and monitoring of patients starting antiretroviral therapy (ART) in resource-limited settings. METHODS: We analysed data from 17 ART programmes in 12 countries in sub-Saharan Africa, South America and Asia. Patients aged 16 years or older with documented date of start of highly active ART (HAART) were included. Data were analysed by calculating medians, interquartile ranges (IQR) and percentages by regions and time periods. Not all centres provided data for 2006 and 2005 and 2006 were therefore combined. RESULTS: A total of 36,715 patients who started ART 1996-2006 were included in the analysis. Patient numbers increased substantially in sub-Saharan Africa and Asia, and the number of initial regimens declined, to four and five, respectively, in 2005-2006. In South America 20 regimes were used in 2005-2006. A combination of 3TC/D4T/NVP was used for 56% of African patients and 42% of Asian patients; AZT/3TC/EFV was used in 33% of patients in South America. The median baseline CD4 count increased in recent years, to 122 cells/microl (IQR 53-194) in 2005-2006 in Africa, 134 cells/microl (IQR 72-191) in Asia, and 197 cells/microl (IQR 61-277) in South America, but 77%, 78% and 51%, respectively, started with <200 cells/microl in 2005-2006. In all regions baseline CD4 cell counts were higher in women than men: differences were 22cells/microl in Africa, 65 cells/microl in Asia and 10 cells/microl in South America. In 2005-2006 a viral load at 6 months was available in 21% of patients Africa, 8% of Asian patients and 73% of patients in South America. Corresponding figures for 6-month CD4 cell counts were 74%, 77% and 81%. CONCLUSIONS: The public health approach to providing ART proposed by the World Health Organization has been implemented in sub-Saharan Africa and Asia. Although CD4 cell counts at the start of ART have increased in recent years, most patients continue to start with counts well below the recommended threshold. Particular attention should be paid to more timely initiation of ART in HIV-infected men.

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OBJECTIVES: To examine the accuracy of the World Health Organization immunological criteria for virological failure of antiretroviral treatment. METHODS: Analysis of 10 treatment programmes in Africa and South America that monitor both CD4 cell counts and HIV-1 viral load. Adult patients with at least two CD4 counts and viral load measurements between month 6 and 18 after starting a non-nucleoside reverse transcriptase inhibitor-based regimen were included. WHO immunological criteria include CD4 counts persistently <100 cells/microl, a fall below the baseline CD4 count, or a fall of >50% from the peak value. Virological failure was defined as two measurements > or =10 0000 copies/ml (higher threshold) or > or =500 copies/ml (lower threshold). Measures of accuracy with exact binomial 95% confidence intervals (CI) were calculated. RESULTS: A total of 2009 patients were included. During 1856 person-years of follow up 63 patients met the immunological criteria and 35 patients (higher threshold) and 95 patients (lower threshold) met the virological criteria. Sensitivity [95% confidence interval (CI)] was 17.1% (6.6-33.6%) for the higher and 12.6% (6.7-21.0%) for the lower threshold. Corresponding results for specificity were 97.1% (96.3-97.8%) and 97.3% (96.5-98.0%), for positive predictive value 9.5% (3.6-19.6%) and 19.0% (10.2-30.9%) and for negative predictive value 98.5% (97.9-99.0%) and 95.7% (94.7-96.6%). CONCLUSIONS: The positive predictive value of the WHO immunological criteria for virological failure of antiretroviral treatment in resource-limited settings is poor, but the negative predictive value is high. Immunological criteria are more appropriate for ruling out than for ruling in virological failure in resource-limited settings.

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Rapid diagnostic tests (RDT) are sometimes recommended to improve the home-based management of malaria. The accuracy of an RDT for the detection of clinical malaria and the presence of malarial parasites has recently been evaluated in a high-transmission area of southern Mali. During the same study, the cost-effectiveness of a 'test-and-treat' strategy for the home-based management of malaria (based on an artemisinin-combination therapy) was compared with that of a 'treat-all' strategy. Overall, 301 patients, of all ages, each of whom had been considered a presumptive case of uncomplicated malaria by a village healthworker, were checked with a commercial RDT (Paracheck-Pf). The sensitivity, specificity, and positive and negative predictive values of this test, compared with the results of microscopy and two different definitions of clinical malaria, were then determined. The RDT was found to be 82.9% sensitive (with a 95% confidence interval of 78.0%-87.1%) and 78.9% (63.9%-89.7%) specific compared with the detection of parasites by microscopy. In the detection of clinical malaria, it was 95.2% (91.3%-97.6%) sensitive and 57.4% (48.2%-66.2%) specific compared with a general practitioner's diagnosis of the disease, and 100.0% (94.5%-100.0%) sensitive but only 30.2% (24.8%-36.2%) specific when compared against the fulfillment of the World Health Organization's (2003) research criteria for uncomplicated malaria. Among children aged 0-5 years, the cost of the 'test-and-treat' strategy, per episode, was about twice that of the 'treat-all' (U.S.$1.0. v. U.S.$0.5). In older subjects, however, the two strategies were equally costly (approximately U.S.$2/episode). In conclusion, for children aged 0-5 years in a high-transmission area of sub-Saharan Africa, use of the RDT was not cost-effective compared with the presumptive treatment of malaria with an ACT. In older patients, use of the RDT did not reduce costs. The question remains whether either of the strategies investigated can be made affordable for the affected population.

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We synthesized recombinant Echinococcus granulosus protoscolex recP29 antigen to be preliminarily assessed by ELISA and immunoblotting. RecP29-serology was carried out on 54 young patients with cystic echinococcosis (CE). Patients were classified into either cured (CCE) (n=40) or non-cured (NCCE) (n=14) CE patients. RecP29 ELISA showed a gradual decrease of antibody concentrations in all CCE cases that were initially (before treatment) seropositive to this antigen (25 out of 40) or that seroconverted following treatment. A complete seronegativity was reached within 3 years post-surgery in all of these cases. Conventional HCF ELISA yielded seronegativity in only 10% of initially recP29-seropositive CCE patients (P=0.086). Likewise, recP29 immunoblotting yielded seronegativity in 93% of 29 out of 40 initially recP29-immunoblot-positive CCE patients after 3 years follow-up, compared with 72% in the HCF immunoblotting (P=0.060). Eleven out of 14 NCCE patients were initially positive by recP29 ELISA, and 10 out of these maintained a marked anti-recP29 antibody reactivity until the endpoint of the follow-up period. All 14 NCCE cases were initially seropositive by recP29 immunoblotting, and 13 cases remained seropositive until the end of the study. Thus, recombinant P29 protein appears prognostically useful for monitoring those post-surgical CE cases with an initial seropositivity to this marker.

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OBJECTIVES Cotrimoxazole prophylactic treatment (CPT) prevents opportunistic infections in HIV-infected or HIV-exposed children, but estimates of the effectiveness in preventing malaria vary. We reviewed studies that examined the effect of CPT on incidence of malaria in children in sub-Saharan Africa. METHODS We searched PubMed and EMBASE for randomised controlled trials (RCTs) and cohort studies on the effect of CPT on incidence of malaria and mortality in children and extracted data on the prevalence of sulphadoxine-pyrimethamine resistance-conferring point mutations. Incidence rate ratios (IRR) from individual studies were combined using random effects meta-analysis; confounder-adjusted estimates were used for cohort studies. The importance of resistance was examined in meta-regression analyses. RESULTS Three RCTs and four cohort studies with 5039 children (1692 HIV-exposed; 2800 HIV-uninfected; 1486 HIV-infected) were included. Children on CPT were less likely to develop clinical malaria episodes than those without prophylaxis (combined IRR 0.37, 95% confidence interval: 0.21-0.66), but there was substantial between-study heterogeneity (I-squared = 94%, P < 0.001). The protective efficacy of CPT was highest in an RCT from Mali, where the prevalence of antifolate resistant plasmodia was low. In meta-regression analyses, there was some evidence that the efficacy of CPT declined with increasing levels of resistance. Mortality was reduced with CPT in an RCT from Zambia, but not in a cohort study from Côte d'Ivoire. CONCLUSIONS Cotrimoxazole prophylactic treatment reduces incidence of malaria and mortality in children in sub-Saharan Africa, but study designs, settings and results were heterogeneous. CPT appears to be beneficial for HIV-infected and HIV-exposed as well as HIV-uninfected children.

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Analysis of human serum reactivities to antigenic components of soluble Taenia solium metacestode proteins showed the predominant presence of determinants shared by T. solium, Echinococcus multilocularis and E. granulosus. Two polypeptides were demonstrated by SDS-PAGE and Western blot or enzyme-linked immunoelectrotransfer blot (EITB) assay to bind serum and CSF antibodies only from T. solium cysticercosis patients. These species-specific antigenic polypeptides focused between pH 4.6 and 3.9 after resolution by isoelectric focusing followed by EITB. The high species-specificity demonstrated by the present techniques offers the opportunity to confirm serologically an infection by T. solium metacestode.

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An immunoassay (double-antibody-sandwich-ELISA) was developed to detect circulating antigens (CAg) in patients with cystic (Echinococcus granulosus) echinococcosis. Echinococcus antigens derived from heterologous intermediate hosts were used to immunize rabbits and to purify the rabbit-IgG-fraction obtained by affinity-chromatography, thus avoiding major interference with host components. The purified rabbit anti-hydatid IgG was immunosorbed with bovine and human sera. One part of the resulting IgG served as coating agent in a double antibody sandwich-ELISA; the other part, coupled to alkaline phosphatase, as detecting conjugate. The specificity of the antibody reaction was demonstrated by immunoelectrophoresis. Sera of 21 patients with cystic echinococcosis were examined with this test system. In seven of the patients' sera CAg were detected in concentrations ranging between 310 ng and 680 ng protein per ml serum. Comparing pre- and postoperative serum samples obtained from nine patients operated on for cystic echinococcosis, four sera were found to be CAg-positive before and three after operation.

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OBJECTIVE In 2013, Mozambique adopted Option B+, universal lifelong antiretroviral therapy (ART) for all pregnant and lactating women, as national strategy for prevention of mother-to-child transmission of HIV. We analyzed retention in care of pregnant and lactating women starting Option B+ in rural northern Mozambique. METHODS We compared ART outcomes in pregnant ("B+pregnant"), lactating ("B+lactating") and non-pregnant-non-lactating women of childbearing age starting ART after clinical and/or immunological criteria ("own health") between July 2013 and June 2014. Lost to follow-up was defined as no contact >180 days after the last visit. Multivariable competing risk models were adjusted for type of facility (type 1 vs. peripheral type 2 health center), age, WHO stage and time from HIV diagnosis to ART. RESULTS Over 333 person-years of follow-up (of 243 "B+pregnant", 65″B+lactating" and 317 "own health" women), 3.7% of women died and 48.5% were lost to follow-up. "B+pregnant" and "B+lactating" women were more likely to be lost in the first year (57% vs. 56.9% vs. 31.6%; p<0.001) and to have no follow-up after the first visit (42.4% vs. 29.2% vs. 16.4%; p<0.001) than "own health" women. In adjusted analyses, risk of being lost to follow-up was higher in "B+pregnant" (adjusted subhazard ratio [asHR]: 2.77; 95% CI: 2.18-3.50; p<0.001) and "B+lactating" (asHR: 1.94; 95% CI: 1.37-2.74; p<0.001). Type 2 health center was the only additional significant risk factor for loss to follow-up. CONCLUSIONS Retaining pregnant and lactating women in option B+ ART was poor; losses to follow-up were mainly early. The success of Option B+ for prevention of mother-to-child transmission of HIV in rural settings with weak health systems will depend on specific improvements in counseling and retention measures, especially at the beginning of treatment. This article is protected by copyright. All rights reserved.

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The Institute of Tropical Medicine in Antwerp hereby presents the results of two pilot distance learning training programmes, developed under the umbrella of the AFRICA BUILD project (FP7). The two courses focused on evidence-based medicine (EBM): with the aim of enhancing research and education, via novel approaches and to identify research needs emanating from the field. These pilot experiences, which were run both in English-speaking (Ghana), and French-speaking (Mali and Cameroon) partner institutions, produced targeted courses for the strengthening of research methodology and policy. The courses and related study materials are in the public domain and available through the AFRICA BUILD Portal (http://www.africabuild.eu/taxonomy/term/37); the training modules were delivered live via Dudal webcasts. This paper assesses the success and difficulties of transferring EBM skills with these two specific training programmes, offered through three different approaches: fully online facultative courses, fully online tutor supported courses or through a blended approach with both online and face-to-face sessions. Key factors affecting the selection of participants, the accessibility of the courses, how the learning resources are offered, and how interactive online communities are formed, are evaluated and discussed.

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Acknowledgements This article was based on the first author’s PhD which was financed by the Malawi Health Research Capacity Strengthening Initiative. We thank Mr Patrick Naphini formerly of the Ministry of Health and Mrs Mafase Sesani at CHAM Secretariat for helping with the data. We also thank Mr Jacob Mazalale for useful comments on the article.

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Leishmaniaparasites cause a broad range of disease, with cutaneous afflictions being, by far, the most prevalent. Variations in disease severity and symptomatic spectrum are mostly associated to parasite species. One risk factor for the severity and emergence of leishmaniasis is immunosuppression, usually arising by coinfection of the patient with human immunodeficiency virus (HIV). Interestingly, several species ofLeishmaniahave been shown to bear an endogenous cytoplasmic dsRNA virus (LRV) of theTotiviridaefamily, and recently we correlated the presence of LRV1 withinLeishmaniaparasites to an exacerbation murine leishmaniasis and with an elevated frequency of drug treatment failures in humans. This raises the possibility of further exacerbation of leishmaniasis in the presence of both viruses, and here we report a case of cutaneous leishmaniasis caused byLeishmania braziliensisbearing LRV1 with aggressive pathogenesis in an HIV patient. LRV1 was isolated and partially sequenced from skin and nasal lesions. Genetic identity of both sequences reinforced the assumption that nasal parasites originate from primary skin lesions. Surprisingly, combined antiretroviral therapy did not impact the devolution ofLeishmaniainfection. TheLeishmaniainfection was successfully treated through administration of liposomal amphotericin B.

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Mode of access: Internet.