612 research outputs found

    Malaria caused by \u3ci\u3ePlasmodium vivax\u3c/i\u3e: recurrent, difficult to treat, disabling, and threatening to life — averting the infectious bite preempts these hazards

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    The maxim ‘an ounce of prevention is worth a pound of cure’ finds few better demonstrations than with malaria caused by Plasmodium vivax. Thoroughly neglected over the past 60 years, the chemotherapy of this complex infection has been dangerous and ineffective until the present. Work is at last being done, but seeing that translate to real improvements at the periphery of care delivery will take years of deliberate effort. In the meantime, patients face substantial risk of debilitating, threatening, and fatal courses of illness associated with a diagnosis of vivax malaria. For some of the most vulnerable to such outcomes — pregnant women and infants — repeated attacks of acute vivax malaria from a single infectious anopheline bite is now not preventable. One of the few measures than can be immediately applied with rigor is vector control, thereby effectively preventing as many of these difficult and dangerous infections as possible. This commentary emphasizes the dire consequences of infection by P. vivax and the real difficulty of dealing with them. That, in turn, emphasizes the many benefits to be derived by preventing them in the first place

    Letters to the Editor

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    Our colleague Dr. Meshnick has proposed that our Society change its name. He expresses the view that “Hygiene” may not represent the membership and the work we conduct. He suggests, “The American Society of Tropical Medicine and Global Health.” I don’t know what “Global Health” means, but I do understand “Hygiene” and argue its relevance to diseases of the tropics and our Society

    Resurgent Malaria at the Millennium: Control Strategies in Crisis

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    Completion of the Panama Canal in 1914 marked the beginning of an era of vector control that achieved conspicuous success against malaria. In 1955 the World Health Organization (WHO) adopted the controversial Global Eradication Campaign emphasising DDT (dichlorodiphenyltrichloroethane) spraying in homes. The incidence of malaria fell sharply where the programme was implemented, but the strategy was not applied in holoendemic Africa. This, along with the failure to achieve eradication in larger tropical regions, contributed to disillusionment with the policy. The World Health Assembly abandoned the eradication strategy in 1969. Aresurgence of malaria began at about that time and today reaches into areas where eradication or control had been achieved. A global malaria crisis looms. In 1993 the WHO adopted a Global Malaria Control Strategy that placed priority in control of disease rather than infection. This formalises a policy that emphasises diagnosis and treatment in a primary healthcare setting, while de-emphasising spraying of residual insecticides. The newpolicy explicitly stresses malaria in Africa, but expresses the intent to bring control programmes around the world into line with the strategy. This review raises the argument that a global control strategy conceived to address the extraordinary malaria situation in Africa may not be suitable elsewhere. The basis of argument lies in the accomplishments of the Global Eradication Campaign viewed in an historical and geographical context. Resurgent malaria accompanying declining vector control activities in Asia and the Americas suggests that the abandonment of residual spraying may be premature given the tools now at hand. The inadequacy of vector control as the primary instrument of malaria control in holoendemic Africa does not preclude its utility in Asia and the Americas

    Letters to the Editor

    Get PDF
    Our colleague Dr. Meshnick has proposed that our Society change its name. He expresses the view that “Hygiene” may not represent the membership and the work we conduct. He suggests, “The American Society of Tropical Medicine and Global Health.” I don’t know what “Global Health” means, but I do understand “Hygiene” and argue its relevance to diseases of the tropics and our Society

    Elimination Therapy for the Endemic Malarias

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    Most malaria diagnosed outside endemic zones occurs in patients experiencing the consequences of what was likely a single infectious bite by an anopheline mosquito. A single species of parasite is nearly always involved and expert opinion on malaria chemotherapy uniformly prescribes species- and stage-specific treatments. However the vast majority of people experiencing malaria, those resident in endemic zones, do so repeatedly and very often with the involvement of two or more species and stages of parasite. Silent forms of these infections—asymptomatic and beyond the reach of diagnostics—may accumulate to form substantial and unchallenged reservoirs of infection. In such settings treating only the species and stage of malaria revealed by diagnosis and not others may not be sensible or appropriate. Developing therapeutic strategies that address all species and stages independently of diagnostic evidence may substantially improve the effectiveness of the control and elimination of endemic malaria

    Malaria caused by \u3ci\u3ePlasmodium vivax\u3c/i\u3e: recurrent, difficult to treat, disabling, and threatening to life — averting the infectious bite preempts these hazards

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    The maxim ‘an ounce of prevention is worth a pound of cure’ finds few better demonstrations than with malaria caused by Plasmodium vivax. Thoroughly neglected over the past 60 years, the chemotherapy of this complex infection has been dangerous and ineffective until the present. Work is at last being done, but seeing that translate to real improvements at the periphery of care delivery will take years of deliberate effort. In the meantime, patients face substantial risk of debilitating, threatening, and fatal courses of illness associated with a diagnosis of vivax malaria. For some of the most vulnerable to such outcomes — pregnant women and infants — repeated attacks of acute vivax malaria from a single infectious anopheline bite is now not preventable. One of the few measures than can be immediately applied with rigor is vector control, thereby effectively preventing as many of these difficult and dangerous infections as possible. This commentary emphasizes the dire consequences of infection by P. vivax and the real difficulty of dealing with them. That, in turn, emphasizes the many benefits to be derived by preventing them in the first place

    AN \u3ci\u3eIN VITRO\u3c/i\u3e MICRO-VOLUME PROCEDURE FOR RAPID MEASUREMENT OF ERYTHROCYTIC HEXOSE MONOPHOSPHATE SHUNT ACTIVITY

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    I. A radiometric micro-volume procedure for measurement of erythrocytic hexose monophosphate shunt (HMS) activity in intact cells in vitro is described. 2.The procedure is rapid, allowing 200 individual HMS determinations in a single experiment of 5 hr duration. 3. The procedure is reproducible, yielding HMS activity means insignificantly different (P \u3e 0.05) between replicate experiments. 4. A profile of sodium nitrite-induced HMS stimulation is reported: HMS was elevated 2-fold (P \u3c 0.001) between zero and 2.5mM NaN02; HMS elevation was more distinct (7-fold) between 2.5 and 5.0mM NaNO2; maximum activity (22-fold) was observed between 10 and 20mM NaN02; \u3e 20mM NaNO2 caused significant (P \u3c 0.001) diminution of HMS; glucose carbon recycling through the HMS occurred only with \u3e 2.5mM NaNO2 where this process contributed :::; 16% to total HMS activity

    Mefloquine Is Highly Efficacious against Chloroquine-Resistant \u3ci\u3ePlasmodium vivax\u3c/i\u3e Malaria and \u3ci\u3ePlasmodium falciparum\u3c/i\u3e Malaria in Papua, Indonesia

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    Background. During the period of 1996–1999, we prospectively monitored 243 Javanese adults and children after arriving in Papua, Indonesia, and microscopically documented each new case of malaria by active surveillance. Methods. In a randomized, open-label, comparative malaria treatment trial, 72 adults and 50 children received chloroquine for each incident case of malaria, and 74 adults and 47 children received mefloquine. Results. Among 975 primary treatment courses, the cumulative 28-day curative efficacies were 26% and 82% for chloroquine against Plasmodium falciparum malaria and Plasmodium vivax malaria, respectively. Mefloquine cure rates were far superior (96% against P. falciparum malaria and 99.6% against P. vivax malaria). Conclusions. Mefloquine is a useful alternative treatment for P. vivax malaria and P. falciparum malaria in areas such as Papua, where chloroquine is still recommended as the first-line therapeutic agent

    The clinical and public health problem of relapse despite primaquine therapy: case review of repeated relapses of \u3ci\u3ePlasmodium vivax\u3c/i\u3e acquired in Papua New Guinea

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    Background: Primaquine is the only drug available for preventing relapse following a primary attack by Plasmodium vivax malaria. This drug imposes several important problems: daily dosing over two weeks; toxicity in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency; partner blood schizontocides possibly impacting primaquine safety and efficacy; cytochrome P-450 abnormalities impairing metabolism and therapeutic activity; and some strains of parasite may be tolerant or resistant to primaquine. There are many possible causes of repeated relapses in a patient treated with primaquine. Case description: A 56-year-old Caucasian woman from New Zealand traveled to New Ireland, Papua New Guinea for two months in 2012. One month after returning home she stopped daily doxycycline prophylaxis against malaria, and one week later she became acutely ill and hospitalized with a diagnosis of Plasmodium vivax malaria. Over the ensuing year she suffered four more attacks of vivax malaria at approximately two-months intervals despite consuming primaquine daily for 14 days after each of those attacks, except the last. Genotype of the patient’s cytochrome P-450 2D6 alleles (*5/*41) corresponded with an intermediate metabolizer phenotype of predicted low activity. Discussion: Multiple relapses in patients taking primaquine as prescribed present a serious clinical problem, and understanding the basis of repeated therapeutic failure is a challenging technical problem. This case highlights these issues in a single traveler, but these problems will also arise as endemic nations approach elimination of malaria transmission
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