Therapeutic plasma exchange in the treatment of complicated Plasmodium falciparum malaria: A case report

Severe falciparum malaria is associated with multiple organ dysfunction and a high rate of fatal outcome. Malaria is a world‐wide disease in tropical areas through the bites of vector mosquitoes. Parasitic protozoans introduced by the mosquito's saliva to the blood travel to the liver then mature and reproduce. In humans, malaria is caused by Plasmodium falciparum, P. malariae, P. ovale, P. vivax, and P. knowlesi, and P. falciparum causes most deaths. Typical malaria symptoms include fever, chills, fatigue, headache, nausea, and vomiting. In severe cases, it can cause jaundice, seizures, coma, or death. Jaundice, caused by intravascular hemolysis is a usual complication of malaria, especially in patients with P. falciparum infection. The use of exchange transfusion in malaria is not currently advocated by the Centers of Disease Control and Prevention (CDC) of the United States of America. The role of therapeutic plasma exchange as an adjunctive therapy in malaria has not been widely discussed in the literature. Here, we present a 23‐year‐old patient with jaundice, acute renal failure, and cerebral involvement who was successfully treated with plasma exchange and hemodialysis.     

Halofantrine in the treatment of acute malaria: A multi-centre study in 268 patients

Summary

The clinical efficacy and tolerability of halofantrine, a new antimalarial schizontocide, was studied in a multi-centre trial involving 268 patients ranging in age from 6 months to 58 years. The patients were suffering from acute uncomplicated malaria due to either P.vivax or P. falciparum. Patients were treated orally with 3 doses of halofantrine hydrochloride, 500?mg/6-hourly in adults or 8?mg/kg body weight 6-hourly in children. The overall cure rate was 96.9%. The mean fever clearance time for different species was as follows: P. vivax — 39.1 hours, P. falciparum — 43.2 hours, mixed infection — 60.0 hours, and the mean parasitaemia clearance times were 47.7, 55.1 and 72.0 hours, respectively. Recrudescence was reported in 11 (4.1%) patients, although all of them were parasite-free on Day 7 post-treatment. No haematological or biochemical abnormalities were noted. The drug was very well tolerated and no significant side-effects were reported. Halofantrine was found to be highly effective in acute malaria and offers an important alternative to existing medications.     

2019年苏州市输入性恶性疟2例

对苏州市2019年报告的2例输入性恶性疟病例的基本信息、流行病学史以及诊治过程资料进行收集、整理和分析。结果显示,苏州市输入性疟疾不仅在劳务输出人群中高发,在探亲访友人群中也存在感染风险,尤其是儿童感染风险应引起重视。     

One step forward,two steps back: Tensions between malaria elimination and improved malaria surveillance in the Solomon Islands

The Solomon Islands experienced, between 2010, an apparent meteoric fall in the level of malaria incidence and prevalence [1]. Thanks ostensibly to the efforts of bilateral and multilateral partners and donors, annual parasite incidence (API) fell from 70 to 40 per 1,000 population. With such dramatic progress, international efforts were hailed as dramatic successes and showcased as progress towards malaria elimination and eradication, Yet, paradoxically, the true caseload of malaria in the Solomon Islands has revealed a situation that calls for more, rather than less, support.     

输入性疟疾90例临床特征分析

目的了解输入性疟疾的临床特点,抗疟疾药治疗效果,为临床诊治提供参考依据。方法对2008年1月至2018年6月笔者所在医院感染病科收住的90例非洲务工疟疾患者的临床表现、实验室检查、治疗方案进行回顾性分析。结果 90例患者均有发热现象,伴畏寒寒战84例,贫血30例,脾肿大24例。出现并发症57例,其中急性肝损害18例,急性血管内溶血15例,急性肾衰竭6例,脑型疟疾9例,肺病变9例。血小板减少有66例,其中严重减少18例,淋巴细胞减少60例,出现黄疸者共63例,以间接胆红素升高为主,ALT升高42例。血检疟原虫阳性率57例,其中间日疟15例,恶性疟18例,分型不详24例,根据情况选用不同抗疟药物治疗,所有病例最终均有效控制症状。结论输入性疟疾临床症状典型,有急性肝损害、急性血管内溶血、急性肾衰竭、脑型疟疾及肺病变等常见并发症。血检疟原虫阳性率较高。血小板减少较普遍且较严重,淋巴细胞比例严重减少者病情重。肾损害比例高。常用抗疟药物能有效控制症状。     

Development of vaccines for Plasmodium vivax malaria

Plasmodium vivax continues to cause significant morbidity outside Africa with more than 50% of malaria cases in many parts of South and South-east Asia, Pacific islands, Central and South America being attributed to P. vivax infections. The unique biology of P. vivax, including its ability to form latent hypnozoites that emerge months to years later to cause blood stage infections, early appearance of gametocytes before clinical symptoms are apparent and a shorter development cycle in the vector makes elimination of P. vivax using standard control tools difficult. The availability of an effective vaccine that provides protection and prevents transmission would be a valuable tool in efforts to eliminate P. vivax. Here, we review the latest developments related to P. vivax malaria vaccines and discuss the challenges as well as directions toward the goal of developing highly efficacious vaccines against P. vivax malaria.     

Azadirachta indica extract–artesunic acid combination produces an increased cure rate of Plasmodium berghei-infected mice

Context: Available artemisinin-combination therapies (ACTs) are expensive. Various traditional herbal remedies for malaria involve plants, proven scientifically to have antiplasmodial effects, e.g., Azadirachta indica A. Juss. (Meliaceae).

Objective: Combination of an artemisinin-based compound and a medicinal herb extract will provide an indigenous alternative/herb-based ACT.

Materials and methods: The in vivo schizontocidal activity of the crude aqueous extract of 100, 500, and 1000?mg/kg of A. indica fresh leaves (NCE) and 6, 15, and 20?mg/kg of artesunic acid were determined, alone and in combination, while keeping the dose of artesunic acid constant at 15?mg/kg, using the Peter’s 4-day suppressive test and Swiss albino mice. The ED₅₀ was calculated from the dose-response relationships. Percentage survival and cure were also determined.

Results: The average yield of two extractions of NCE was 8.33?±?1.67%. Combination of 1000?mg/kg of NCE and 15?mg/kg of artesunic acid, produced a significant reduction of parasitemia (96.87%), compared to 20?mg/kg of artesunic acid alone (68.14%). The combination had an ED₅₀ of 0.58?mg/kg while that of artesunic acid alone was 8.814?mg/kg. The combinations of NCE with artesunic acid produced a cure, although the artesunic acid did not produce a cure in 30?d.

Discussion: NCE increased the activity of artesunic acid in terms of reduction in parasitemia, and increased survival time and cure rate.

Conclusion: The combination of an artemisinin and aqueous extract of neem leaf is possible, providing a potentiated reduction of parasitemia, and increased cure rate.     

Novel therapies for the prevention of malaria

Background: Malaria continues to exact a huge toll on the health of residents of endemic countries. Thus, new approaches to prevention and treatment are needed. Objective: To provide an update on novel therapies for the prevention of malaria. Methods: Systematic MEDLINE search from 1956 to 2008 using the search term ‘malaria’ (with the subheadings ‘intermittent preventive treatment’, ‘mass drug administration’, ‘chemotherapy’, ‘artemisinin-based combination therapy’ and ‘home-based management of malaria’). Conclusions: Chemoprophylaxis is used as a short-term protective measure for non-immune visitors to malaria-endemic countries. However, in malaria-endemic areas, chemoprophylaxis has not been implemented widely because of concerns related to sustainability, cost-effectiveness, appropriate delivery systems and development of drug resistance. Intermittent preventive treatment, a novel approach to malaria control, has the potential to provide some of the benefits of sustained chemoprophylaxis without some of its drawbacks.     

Genetic diversity of VAR2CSA ID1-DBL2Xb in worldwide Plasmodium falciparum populations: Impact on vaccine design for placental malaria

In placental malaria (PM), sequestration of infected erythrocytes in the placenta is mediated by an interaction between VAR2CSA, a Plasmodium falciparum protein expressed on erythrocytes, and chondroitin sulfate A (CSA) on syncytiotrophoblasts. Recent works have identified ID1-DBL2Xb as the minimal CSA-binding region within VAR2CSA able to induce strong protective immunity, making it the leading candidate for the development of a vaccine against PM. Assessing the existence of population differences in the distribution of ID1-DBL2Xb polymorphisms is of paramount importance to determine whether geographic diversity must be considered when designing a candidate vaccine based on this fragment. In this study, we examined patterns of sequence variation of ID1-DBL2Xb in a large collection of P. falciparum field isolates (n = 247) from different malaria-endemic areas, including Africa (Benin, Senegal, Cameroon and Madagascar), Asia (Cambodia), Oceania (Papua New Guinea), and Latin America (Peru). Detection of variants and estimation of their allele frequencies were performed using next-generation sequencing of DNA pools. A considerable amount of variation was detected along the whole gene segment, suggesting that several allelic variants may need to be included in a candidate vaccine to achieve broad population coverage. However, most sequence variants were common and extensively shared among worldwide parasite populations, demonstrating long term persistence of those polymorphisms, probably maintained through balancing selection. Therefore, a vaccine mixture including such stable antigen variants will be putatively applicable and efficacious in all world regions where malaria occurs. Despite similarity in ID1-DBL2Xb allele repertoire across geographic areas, several peaks of strong population differentiation were observed at specific polymorphic loci, pointing out putative targets of humoral immunity subject to positive immune selection.