1,721,082 research outputs found
Artemisinin-based combination therapies (ACTs): best hope for malaria treatment but inaccessible to the needy!
No full textArtemisinin-based combination therapies (ACTs) are the best anti-malarial drugs available now. Artemisinin enhances efficacy and has the potential of lowering the rate at which resistance emerges and spreads. Under low transmission intensity, ACTs have an additional public health benefit of reducing the overall malaria transmission and studies are urgently needed to investigate modalities of attaining similar benefits under high transmission. Despite being recommended by WHO since 2001, overall deployment of ACT has been slow. Limiting factors are high cost, limited knowledge and public awareness on the concept of combination therapy (CT) and ACT in particular, limited knowledge on safety of ACTs in pregnancy, operational issue such as inappropriate drug use, lack of suitable drug formulations, lack of post-marketing surveillance (PMS) systems, and the imbalance between demand and supply. Through concerted efforts of multilateral organizations, the local scientific community with involvement of policy-makers progress has been on several fonts leading to improved ACT uptake rates in the last 2 years. Of 43 countries that had adopted ACT by February 2005, 18 (42%) adopted the policy in 2004. Preference to co-formulated Coartem has led to a surge in its demand with consequent shortage. Alternative ways for increased production of ACTs are urgently needed otherwise most policies will remain adopted on paper. Despite limitations, opportunities are opening up for effective malaria control. Insecticides, insecticide-treated nets (ITNs) and ACTs are proven efficacious controls available that should be accessed by many. Substantial funding is now available for biomedical malaria research and for policy implementation. While the Global Fund is the financial engine behind the scaling up of ACT uptake, delays in cash flow after grant approval has led to many countries adopting ACT in 2004 but only few (nine) implementing it. Clear policies on granted funds and minimal politics within funding agencies might improve the situation. Increased interest in drug development together with the public and private sector partnership have led to new anti-malarials, some less expensive and therefore affordable by poor malaria endemic countries. Dihydroartemisinin-piperaquine (Artekin) has a cost advantage over other ACTs (USD 1 for an adult treatment) making it a potential best candidate for deployment in Africa. Part of available funds should be invested into capacity building and strengthening (personnel, resources and infrastructure) of institutions in malaria endemic countries. This will create enabling environment and a critical mass of scientists and public health experts to spearhead ACT policy implementation. Active involvement of scientists from malaria endemic countries in recent International Scientific Forums like the Malaria in Pregnancy Working Group and the Consortium on ACT Implementation is the best way forward to emulate
The contribution of microscopy to targeting antimalarial treatment in a low transmission area of Tanzania.
Get PDFBACKGROUND: There is a need for improved targeting of antimalarial treatment if artemisinin combination therapy is to be successfully introduced in Africa. This study aimed to explore why malaria slides are requested and how their results guide treatment decisions in an area of low transmission of P. falciparum. METHODS: Outpatients attending a district hospital in a highland area of Tanzania were studied over a 3-week period. Clinical and social data were collected from patients who had been prescribed an antimalarial or sent for a malaria slide. Hospital slides were re-read later by research methods. RESULTS: Of 1,273 consultations 132(10%) were treated presumptively for malaria and 214(17%) were sent for a malaria slide; only 13(6%) of these were reported positive for P. falciparum but 96(48%) of the 201 slide-negative cases were treated for malaria anyway. In a logistic regression model, adults (OR 3.86, P < 0.01), a history of fever (OR1.72, P = 0.03) and a longer travel time to the clinic (OR 1.77 per hour travelled, P < 0.01) independently predicted the request for a malaria slide. Only a history of a cough predicted (negatively) the prescription of an antimalarial with a negative slide result (OR 0.44, P < 0.01). The sensitivity and specificity of hospital slide results were 50% and 96% respectively. CONCLUSION: Progress in targeting of antimalarials in low malaria transmission settings is likely to depend on consistent use of malaria microscopy and on the willingness of health workers to be guided by negative slide results. Further studies are needed to identify how this can be achieved
Amodiaquine and artemether-lumefantrine select distinct alleles of the Plasmodium falciparum mdr1 gene in Tanzanian children treated for uncomplicated malaria.
No full textThe artemisinin-based combination therapies artemether-lumefantrine (AL) and amodiaquine (AQ) plus artesunate have been adopted for treatment of Plasmodium falciparum malaria in many African countries. Molecular markers of parasite resistance suitable for surveillance have not been established for any of the component drugs in either of these combinations. We assessed P. falciparum mdr1 (Pfmdr1) alleles present in 300 Tanzanian children presenting with uncomplicated falciparum malaria, who were enrolled in a clinical trial of antimalarial therapy. Pfmdr1 genotype analysis was also performed with isolates from 182 children who failed AQ monotherapy and 54 children who failed AL treatment. Pfmdr1 alleles 86Y, 184Y, and 1246Y were more common among treatment failures in the AQ group than among pretreatment infections. The converse was found in the AL-treated group. Children presenting with the 86Y/184Y/1246Y Pfmdr1 haplotype and treated with AQ were significantly more likely to retain this haplotype if they were parasite positive during posttreatment follow-up than were children treated with AL (odds ratio, 33.25; 95% confidence interval, 4.17 to 1441; P, <0.001). We conclude that AL and AQ exert opposite within-host selective effects on the Pfmdr1 gene of P. falciparum
Putting the genie back in the bottle? Availability and presentation of oral artemisinin compounds at retail pharmacies in urban Dar-es-Salaam.
Get PDFBACKGROUND\ud
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Recently global health advocates have called for the introduction of artemisinin-containing antimalarial combination therapies to help curb the impact of drug-resistant malaria in Africa. Retail trade in artemisinin monotherapies could undermine efforts to restrict this class of medicines to more theoretically sound combination treatments.\ud
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METHODS\ud
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This paper describes a systematic search for artemisinin-containing products at a random sample of licensed pharmacies in Dar-es-Salaam, Tanzania in July 2005.\ud
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RESULTS\ud
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Nineteen different artemisinin-containing oral pharmaceutical products, including one co-formulated product, one co-packaged product, and 17 monotherapies were identified. All but one of the products were legally registered and samples of each product were obtained without a prescription. Packaging and labeling of the products seldom included local language or illustrated instructions for low-literate clients. Packaging and inserts compared reasonably well with standards recommended by the national regulatory authority with some important exceptions. Dosing instructions were inconsistent, and most recommended inadequate doses based on international standards. None of the monotherapy products mentioned potential benefits of combining the treatment with another antimalarial drug.\ud
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CONCLUSION\ud
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The findings confirm the widespread availability of artemisinin monotherapies that led the World Health Organization to call for the voluntary withdrawal of these drugs in malaria-endemic countries. As the global public health community gathers resources to deploy artemisinin-containing combination therapies in Africa, planners should be mindful that these drugs will coexist with artemisinin monotherapies in an already well-established market place. In particular, regulatory authorities should be incorporated urgently into the process of planning for rational deployment of artemisinin-containing antimalarial combination therapies
A possible role for proguanil-dapsone against SP-resistant P.falciparum?
Get PDFA two-armed trial was conducted in July 2000 in 4 villages near Muheza, Tanga Region, in Tanzania, asymptomatic children with P.falciparum parasitaemia > 200/ul (Mutabingwa et al. 2001 Trans Roy Soc Trop Med Hyg 95: 433-438). In one of the arms 188 children were treated with sulfadoxine-pyrimethamine and only 14.3% showed parasite clearance at day 7 (16.1% at day 14). The SP batch used was checked for good quality and the low clearance rate is indicative of one of the worst levels of SP resistance yet recorded in Africa. SP resistance in this area has increased from about 20% in 1995 (Trigg et all 1997 Acta Trop 63: 1865-189) to 45% in 1998/9 (Mutabingwa et al 2001 Lancet 358: 1218-1233) and is now 86
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Impact of El Niño and malaria on birthweight in two areas of Tanzania with different malaria transmission patterns.
No full textBACKGROUND: Malaria infection increases low birthweight especially in primigravidae. Malaria epidemics occur when weather conditions favour this vector borne disease. Forecasting using the El Niño Southern Oscillation (ENSO) may assist in anticipating epidemics and reducing the impact of a disease which is an important cause of low birthweight. The aim of the present study was to determine the impact of the malaria epidemic in East Africa during 1997-1998 on birthweights in two different areas of Tanzania and to explore ESNO's potential for forecasting low birthweight risk in pregnant women. METHOD: A retrospective analysis of birthweight differences between primigravidae and multigravidae in relation to malaria cases and rainfall for two different areas of Tanzania: Kagera, which experiences severe outbreaks of malaria, and Morogoro which is holoendemic. Birthweight and parity data and malaria admissions were collected over a 10-year period from two district hospitals in these locations. RESULTS: The risk of delivering a low birthweight baby in the first pregnancy increases approximately 5 months following a malaria epidemic. An epidemic of marked reduced birthweight in primigravidae compared with multigravidae occurred, related to the ENSO of 1997-1998. In Kagera this birthweight difference and the risk of low birthweight were significantly lower compared with Morogoro, except after the ENSO when the two areas had similar differences. No significant interaction was noted between secundigravidae and any of the risk periods. The results indicate that the pressure of malaria is much greater on pregnant women, especially primigravidae, living in the Morogoro location. CONCLUSIONS: Surveillance of birthweight differences between primigravidae and multigravidae is a useful indicator of malaria exposure
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