Dengue and falciparum malaria co-infection in travelers returning from Burkina Faso:Report of two cases in Northeastern Italy

Rationale: Malaria and dengue are the most prevalent vector-borne diseases in tropical countries. Plasmodium parasite and dengue virus(DENV) concurrent infection is possible and often under-recognized in geographical areas where these infections are both endemic.Patients concern and diagnosis: We describe the first two cases of Plasmodium falciparum and DENV-3 co-infection in travelers returning to northeastern Italy from Burkina Faso during 2013-2014.Interventions: Malaria infection in both patients was treated with mefloquine. Due to the persistence of symptoms despite of the antimalaria treatment, dengue was also investigated;the treatment of dengue was symptomatic.Outcomes: The patients were discharged in good general condition.Lessons: The need for surveillance of potential malaria and dengue co-infection in travelers returning to Europe from endemic areas is highlighted, as infection with Plasmodium does not exclude arboviral co-infection.

Association of ABO blood group and Plasmodium falciparum malaria in Dore Bafeno Area,Southern Ethiopia

Objective:To assess the distribution of ABO blood group and their relationship with Plasmodium falciparum(P.falciparum) malaria among febrile outpatients who sought medical attention at Dore Bafeno Health Center,Southern Ethiopia.Methods:A total of 269 febrile outpatients who visited Dore Bafeno Health Center,Southern Ethiopia,were examined for malaria and also tested for ABO blood groups in January 2010.The blood specimens were collected by finger pricking,stained with Geimsa,and examined microscopically.Positive cases of the parasitemia were counted.CareStart^(TM) Malaria PflPv Combo was also used to test the blood specimens for malaria.ABO blood groups were determined by agglutination test using ERYCLONE antisera.Data on socio-demographic characteristics and treatment status of the participants were also collected.Chi-square and ANOVA tests were used to assess the difference between frequencies and means,respectively.Results:Out of a total of 269 participants,178(66.2%) febrile patients were found to be infected with Plasmodium parasites,among which 146(54.3%),28(10.4%),and 4(1.5%) belonged to P.falciparum,P.vivax,and mixed infections,respectively.All febrile patients were also tested for ABO blood groups and 51.3%,23.5%,21.9%and 3.3%were found to be blood types of 0,A,B and AB,respectively.Both total malaria infection and P.falciparum infection showed significant association with blood types(P<0.05).The proportion of A or B but not 0 phenotypes was higher(P<0.05) in individuals with P.falciparum as compared with non-infected individuals.The chance of having P.falciparum infection in patients with blood groups A,B and AB was 2.5,2.5 and 3.3times more than individuals showing blood 0 phenotypes,respectively.The mean P.falciparum malaria parasitemia for blood groups A,B,AB,and 0 were 3 744/μ L,1 805/ μ L,5 331/μ L,and1 515/μ L,respectively(P<0.01).Conclusions:The present findings indicate that individuals of blood groups A,B and AB are more susceptible to P.falciparum infection as compared with individuals of blood group O.Nevertheless,further in depth studies are required to clearly establish the role that ABO blood group plays in P.falciparum malaria.

A Comparative Study of Dihydroartemisin in Compounds in Treatment of Uncomplicated Falciparum Malaria in Kampong of Cambodia

Objective: To compare the safety and efficacy of two compounds of dihydroartemisinin(DHA) -Artekin and Artekin (T) in the treatment of uncomplicated falciparum malaria. Methods:The regimen of 8-tablet for 2 days of Artekin and Artekin (T) were applied to 100 patients with uncomplicated falciparum malaria, who were randomly divided into two groups. Each group contained 50 cases. The cure rate, the mean parasites clearance time, the mean fever clearance and side-effects were observed to assess the safety and efficacy of the compounds used. Results: The mean parasites clearance time was 31. 7±9.0 hours in the Artekin group and 32. 8±8. 8 hours in Artekin (T) group respectively; the mean fever clearance time was 12. 7±7. 2 hours in Artekin group and 16. 5±7. 9 hours in Artekin (T) group; there were no recrudescence case in both groups within the 28 days of follow-up, the cure rates in Artekin group and Artekin (T) groups were 100%. It indicated that the tolerability of both compounds were very good, the side-effects such as nausea, abdominal pain were mild and self-limited. Conclusion: The study preliminarily indicated that the DHA and PQ compounds were of high efficacy, rapid acting and low toxici-ty. Artekin is very promising as a cheap, simple, effective treatment for multi-resistance malaria in Cambodia.

Definition of hyperparasitemia in severe falciparum malaria should be updated

Hyperparasitemia is one criterion of severe falciparum malariaby World Health Organization(WHO)for more than two decades[1].Although there is a correlation between density of parasittemiaand severity of malaria,some individuals with high parasite countsmay not be severely ill,whereas others with low parasitemia mayhave ultimately fatal infections.Hyperparasitemia(more than 5%

Indicators of fatal outcome in severe Plasmodium falciparum malaria:a study in a tertiary-care hospital in Thailand

Objective:To illustrate the clinical features and investigate the indicators associated with a fatal outcome in adult patients with severe Plasmodium falciparum malaria admitted to the Hospital for Tropical Diseases,Bangkok,Thailand.Methods:We studied 202 adult malaria patients admitted to the Intensive Care Unit.A total of 43 clinical variables were identified by univariate and logistic regression analyses,to eliminate confounding factors.Results:Regarding the statistical methods,only 6 variables-jaundice,cerebral malaria,metabolic acidosis,body mass index,initial respiratory rate,and white blood cell count-were significant indicators of death, with adjusted odds ratios(95%CI) of 15.2(2.1-32.3).4.3(2.3-12.6),3.3(2.3-5.7),2.4(1.9-3.5),2.2 (1.5-2.6),and 1.7(1.2-3.1),respectively.Conclusions:Our study found that jaundice,cerebral malaria,metabolic acidosis,body mass index,initial respiratory rate and white blood cell count were indicators of fatal outcome in severe Plasmodium falciparum malaria.Further studies on the fatal indicators in severe malaria need to be compared with data from different geographical areas,to construct practical measures to address potentially fatal indicators in different settings.

Hemozoin triggers tumor necrosis factor alpha-mediated release of lysozyme by human adherent monocytes:new evidences on leukocyte degranulation in P.falciparum malaria

Objective:Avidly phagocytosed hemozoin(malarial pigment) alters several functions of human monocytes and stimulates generation of several cytokines.Recently,we showed that phagocytosis of hemozoin by human monocytes increases expression and activity of matrix metalloproteinase-9,a proteolytic enzyme available in specific gelatinase granules,which contain several enzymes including lysozyme.Present work investigated active lysozyme release after phagocytosis of hemozoin and its dependence on production of tumor necrosis factor alpha. Methods:After phagocytosis of hemozoin,hemozoin-containing trophozoites or control meals(opsonized nonparasitized red blood cells and latex particles),monocyte supematants were monitored for 2 hours,in presence of blocking anti-human tumor necrosis factor alpha antibodies or recombinant human tumor necrosis factor alpha cytokine in selected experiments.Lysozyme release was evaluated by a specific spectrometric assay measuring lysozyme activity after coincubation of cell supematants with suspensions of Mycrococcus Lysodeikticus,while levels of soluble tumor necrosis factor alpha were analyzed by specific enzyme-linked immunodsorbent assay. Results:Levels of lysozyme activity and soluble tumor necrosis factor alpha protein were increased in hemozoin in-or trophozoites-laden monocytes supematants.Phagocytosis per se(control meals) also increased lysozyme release,but levels were significantly lower than those obtained after phagocytosis of hemozoin or trophozoites. Interestingly,all effects on lysozyme release observed after phagocytosis were abrogated by blocking anti-human tumor necrosis factor alpha antibodies,while they were mimicked by recombinant human tumor necrosis factor alpha cytokine.Conclusions:Present work shows that phagocytosis of hemozoin promotes monocyte degranulation and enhances active lysozyme release.The effect requires tumor necrosis factor alpha mediation.

Schistosoma haematobium and Plasmodium falciparum coinfection with protection against Plasmodium falciparum malaria in Nigerian children

Objective:Malaria remains the single leading killer of children in sub - Sahara Africa and Schistosomiasis is considered to be second to malaria in global importance.Co - infection of malaria and urinary schistosomiasis has been reported to exacerbate disease morbidity such as anaemia.In different part of the globe,the co - infection between malaria and schistosomiasis provides some protections on the infected persons.The protective effect of this co - infection elucidated immunologically using cytokines is lacking in our locality.Methods:Urine and blood samples obtained from the 160 volunteers were subjected to standard parasitological techniques for diagnosis of urinary schistosomiasis and malaria respectively.Blood samples collected from these volunteers comprising 80 children with schistosomiasis and malaria and the 80 children who had malaria only were subjected to cytokines concentration determination using commercial standard enzyme linked immunosorbent assay kits(Abeam,UK).Results:Eighty participants with co - infection had a mean malarial parasitaemia of 662±201.1μL while the 80 participants with only P.falciparum malaria had a mean malarial parasiteamia of 5943±3270.7μL.Also the volunteers had mean haemoglobin of 11.2 g/dL for co - infected individuals and 5.7 g/dL for participants with single infection of malaria.The serum cytokine levels of the children with S. haematobium and P.falciparum and only P.falciparum infection are as follows;interleukin - 4(16.6 pg/ mL versus 5.2 pg/mL),IL - 5(501.3 pg/mL versus 357.5 pg/mL);IL -8(2 550 pg/mL versus 309 pg/mL),IL - 10(273 pg/mL versus 290 pg/mL),TNF -α(25 pg/mL versus 290 pg/mL) and IFN -γ(21.9 pg/mL versus 2.5 pg/mL).The TNF -α/IL - 10 ratio is 7 for the children with co - infection while those with only P.falciparum malaria infection had a TNF -α/IL - 10 ratio of 0.9.Conclusion:We conclude that the elevated IL - 4,IL - 5,IL - 8 and IFN -γconcentration induced by schistosomiasis altered the Th1/Th 2 profile and protected the children against the morbidity and severity of malaria attack among the children with co - infection.

Higher production of tumor necrosis factor alpha in hemozoin-fed human adherent monocytes is dependent on lipidic component of malarial pigment:new evidences on cytokine regulation in Plasmodium falciparum malaria

Objective:To investigate whether the increase of tumor necrosis factor alpha is dependent on lipidic component of malarial pigment.Methods:Adherent human monocytes were fed for 3 hours with different meals(native hemozoin;lipid free hemozoin;and control latex particles),then tumor necrosis factor alpha was monitored in cell supernatants up to 48 hours through western blotting or specific enzyme-linked immunoadsorbent assay.In selected experiments,unfed monocytes were treated with different doses of 15(S,R)-hydroxy-6,8,11,13-eicosatetraenoic acid or 4-hydroxynonenal instead of phagocytosis.Results:Hemozoin-fed monocytes produced higher levels of tumor necrosis factor alpha than unstimulated and latex-fed cells, while lipid-free hemozoin did not reproduce these results.Additionally,hemozoin effects were mimicked dose-dependently by 15(S,R)-hydroxy-6,8,11,13-eicosatetraenoic acid,but not by 4-hydroxynonenal.Conclusions:Present data suggest an essential role for lipids in hemozoindependent enhanced release of tumor necrosis factor alpha from monocytes,and 15(S,R)hydroxy -6,8,11,13-eicosatetraenoic acid could be one possible specific mediator.

Changing trends in prevalence of different Plasmodium species with dominance of Plasmodium falciparum malaria infection in Aligarh(India)

Objective:To determine the prevalence of malaria in Aligarh and analyze species dominance in different years over a decade.Methods:Diagnosis of malaria was done using microscopy as gold standard,rapid antigen detection assays and quantitative buffy coat(QBC) assays.Giemsa stained blood smear examination was done,thick and thin films were examined for presence of different Plasmodium spp.Rapid antigen detection assays employing detection of HRP-2 and parasite lactate dehydrogenase antigen(pLDH) by immunochromatography was done in patients whose blood smear found to be negative by conventional Giemsa slide examination.QBC was done in cases where there is strong clinical suspicion of malaria with blood smear negative,in patients with chronic malaria,splenomegaly,or in those patients who had inadequate treatment and for post-treatment follow up.Results:Plasmodium vivax and Plasmodium falciparum were only species detected in our hospital.Overall prevalence of malaria in Aligarh was found to be 8.8%.The maximum prevalence of 20.1%was observed in year 2008 and lowest 2.3%in 2002. Conclusions:High prevalence of malaria is observed in this part of country with dominance of both species particularly Plasmodium falciparum should be monitored and factors accounting for occurrence should be studied to employ effective control measures.

Cortisol and uncomplicated Plasmodium falciparum malaria in an area of unstable malaria transmission in eastern Sudan

Objective:To investigate the levels of serum Cortisol in patients with uncomplicated Plasmodium falciparum(P.falciparum) malaria in an area of unstable malaria transmission in eastern Sudan. Methods:The concentrations of Cortisol were measured in sera of 25 patients with uncomplicated P.fylciparum malaria(at presentation,24 h and 7 d later) and 25 healthy volunteers using radioimmunoassay gamma counter.Results:There was no significant difference in mean(SD) of total Cortisol levels in patients with malaria in comparison with the control group;602.2(369.6) vs. 449.2(311.7) ng/mL,P=0.12.In patients with uncomplicated P.falciparum malaria,the mean(SD) presenting Cortisol levels were significantly higher in comparison to the levels on day 7;602.2 (369.6) vs.373.6(139.1) ng/mL,P=0.009.In the patients with uncomplicated P.falciparum malaria (on presentation) Cortisol levels were not correlated with initial temperature or the presenting parasitaemia.Conclusions:Thus,Cortisol levels were not significantly different between the patients and the controls.

Haemophagocytic lymphohistiocytosis secondary to Plasmodium falciparum malaria: Case report and review of the literature

Rationale:Haemophagocytic lymphohistiocytosis is a rare complication of malaria,which is often misdiagnosed.Patient concerns:A 30-year-old male was admitted to our department for persistent fever,which began after returning from a stay in Guinea-Conakry.The laboratory investigations revealed a pancytopenia and an elevated C-reactive protein.Peripheral smear examination showed Plasmodium falciparum,therefore confirming the diagnosis of malaria.The laboratory tests showed a worsening pancytopenia.Bone marrow aspiration and biopsy revealed images of hemophagocytosis.Diagnosis:The diagnosis of haemophagocytic lymphohistiocytosis complicating malaria infection was established.Interventions:The patient was treated with artemether-lumefantrine.No immunosuppressant treatment was delivered to the patient.He received antipyretic and antimalarial treatment only.Outcomes and lessons:We report a case of haemophagocytic lymphohistiocytosis trigged by malaria infection and we review all reported cases secondary to Plasmodium falciparum malaria by searching PubMed publications till October 2019.Haemophagocytic lymphohistiocytos secondary to malaria should be suspected even in non-severe cases of malaria.

Multiple splenic infarcts in acute Plasmodium vivax malaria:A rare case report

In tropical countries like India,malaria has been one of the most common parasitic illnesses leading to frequent hospitalization and causing major economic burden among the masses. Although Plasmodium vivax infection is considered to be benign,in contrast to Plasmodium, falciparum infection which is notorious for its severe splenic complications can occur frequently. Splenomegaly tends not to receive special attention,as it is not usually accompanied by any symptoms and can be gradually resolved via standard antimalarial therapy.Splenic infarction, although rarely attributable to malaria in an endemic region with high parasitemia,can be a rare presentation of this disease entity.

Effect of Primaquine on Gametocyte Carriage in the Case-Management of Uncomplicated Falciparum Malaria with Acts: Nigerian Perspective

Background: Drugs that kill or inhibit sexual stages of Plasmodium such as Primaqiune (PQ) could potentially amplify or synergize the impact of first line antimalarials by blocking transmission to mosquitoes. This study examined the effect of Primaquine on gametocyte carriage in the case management of uncomplicated falciparum malaria with artemisinin-based combination therapy (ACT) with the overall purpose of possibly recommending it as an adjunct drug for malaria control. Methods: A total of 181 patients with uncomplicated falciparum malaria, normal glucose-6-phosphate dehydrogenase (G6PD) enzyme levels, and haemoglobin levels ≥ 8 g/dL completed this two-arm randomized blinded clinical trial to test the efficacy of a single dose PQ (0.75 mg/kg) on falciparum gametocytaemia. 88 subjects were assigned to a standard 3-day course of Dihydroartemisinin-Piperaquine (DHP) alone (n = 88) while 93 others had DHP combined with a single dose of PQ on day 3 (n = 93). A 28-day follow-up schedule carried out in the outpatient clinic of a Primary health facility in Vom, Plateau State Nigeria where study participants were seen on days 1, 3, 7 and then weekly to assess the presence of asexual parasites and gametocytes by microscopy. A Kaplan-Meier analysis was employed to determine the survival function of gametocytes on day 3. The data was analyzed using Epi info version 7.1.5. Results: With a gametocyte prevalence of 27.1%, gametocyte carriage rate was lower in the PQ group due to higher probability of clearing gametocytes (Breslow test χ2 = 8.306, df = 1, p = 0.004) and significantly less likely to harbor gametocytes by day 7 when compared to the DHP-alone group (χ2 = 6.218, df = 1, p = 0.013). Conclusion: Addition of single-dose 0.75 mg/kg PQ was associated with reduced gametocyte carriage as a result of faster gametocyte clearance and lower incidence of gametocyte development in DHP-treated patients. PQ as gametocytocidal drug may be useful in combination with artemisinin-based combination therapy (ACT) regimen to clear gametocytes and thereby interrupt malaria transmission to mosquito vector more effectively than ACT alone.

Investigation of the Efficacy of Home-Based Oral Chloroquine Treatment among Under-Five Children with Plasmodium falciparum Malaria in Some Parts of Jos, Plateau State, Nigeria

Background: Nigeria is currently a malaria endemic country with an estimated 76% of her population at risk of contracting malaria [1]. According to a study in Nigeria, the first line of action mothers took when their children under 5 years have malaria showed that over 50% of them used non-prescription drugs they have at home or bought from pharmacy stores. And 60% of the most commonly used drugs for malaria treatment were chloroquine [2]. Many recent studies have demonstrated re-emergence of chloroquine-sensitive P. falciparum, suggesting a possible role in future malaria control [3]. Objective: The aim of this study was to investigate the effect of home-based oral chloroquine treatment among children under 5 years with Plasmodium falciparum malaria attending Jos University Teaching Hospital and OLA Hospital in Jos Metropolis. Method: This is a cross-sectional study of 93 malaria and non-malaria children. Malaria diagnosis was carried out using microscopical examination of Leishman’s stained thick and thin blood films, P. falciparum parasitemia was assessed by standard microscopy techniques and complete blood count was done using Beckman Coulter Analyzer. Results: The body temperature on admission was significantly lower (p &#730;C ± 0.07&#730;C) than in the three malaria groups. The mean body temperature of chloroquine treated children with malaria was significantly lower (p Conclusion: The results obtained in this study demonstrate that there was significant positive impact of chloroquine treatment on Plasmodium falciparum parasitemia and degree of anemia in children under 5 years with Plasmodium falciparum in Jos Metropolis.

Investigation of the effect of malaria and home-based oral chloroquine treatment on biochemical indices of P.falciparum malaria infection in children under 5 years in jos metropolis

Background:In Nigeria,malaria is a leading cause of hospital admission and death.The country accounts for highest malaria cases and deaths globally.About 25% of all malaria cases and deaths in the world occurs in Nigeria.In 2010,malaria was reported to account for 60% of all outpatient visits and responsible for 30% of all hospital admission of children under the age of five years leaving in Nigeria.Objective:The goal of this research work was to investigate the possible role of the state of protein nutrition,kidney and liver functions of the under 5 years children with P.falciparum malaria;the assessment of these biochemical parameters as possible indicator of P.falciparum infection in the studied subjects and the effect of home-based oral chloroquine treatment in these children leaving in Jos metropolis.Method:Total of 93 children within the age range of 1 to 59 months and leaving in Jos North,Central Nigeria were recruited for this cross-sectional study.Malaria parasite identification was done using microscopic examination of Leishman-stained thick and thin blood films while the complete blood count was carried out using Beckman Coulter Analyzer.Results:The serum albumin concentration of(37.63±0.82 g/L)obtained in the malaria-free children was higher than concentration of(34.07±1.90 g/L)obtained in the chloroquine treated children with malaria,but not different from those obtained in the untreated uncomplicated malaria(37.35±1.19 g/L)and untreated severe malaria(37.43±1.02 g/L)groups.The Serum globulin concentration of 35.09±1.95 g/L,obtained in the untreated simple malaria group was higher than 30.18±1.30 g/L in the control group,34.57±2.59 g/L in the untreated severe malaria group and chloroquine treated malaria with 30.71±2.38 g/L,respectively.Conclusion:This study suggests that the biochemical parameters of serum creatinine,serum albumin,total protein,and globulin,serum alkaline phosphatase,serum alanine aminotransferase and serum aspartate aminotransferase are not sensitive indicators of P.falciparum infection in studied children with malaria.It also demonstrated that involvement of liver and kidney or impairment of their functions could be ruled out in the pathogenesis of malaria in this group of children.These results further shows that there was no significant effect of first-line treatment with oral chloroquine on the studied biochemical parameters in the study population.

Higher-Dose Primaquine to Prevent Relapse of Plasmodium vivax Malaria

Background:In most of the Americas,the recommended treatment to prevent relapse of Plasmodium vivax malaria is primaquine at a total dose of 3.5 mg per kilogram of body weight,despite evidence of only moderate efficacy.Methods:In this trial conducted in Brazil,we evaluated three primaquine regimens to prevent relapse of P.vivax malaria in children at least 5 years of age and in adults with microscopy-confirmed P.vivax monoinfection.All the patients received directly observed chloroquine for 3 days(total dose,25 mg per kilogram).Group 1 received a total primaquine dose of 3.5 mg per kilogram(0.5 mg per kilogram per day)over 7 days with unobserved administration;group 2 received the same regimen as group 1 but with observed administration;and group 3 received a total primaquine dose of 7.0 mg per kilogram over 14 days(also 0.5 mg per kilogram per day)with observed administration.We monitored the patients for 168 days.

Severe thrombocytopaenia in patients with vivax malaria compared to falciparum malaria:a systematic review and metaanalysis

Background:Plasmodium vivax is the most geographically widespread species among human malaria parasites.Immunopathological studies have shown that platelets are an important component of the host innate immune response against malaria infections.The objectives of this study were to quantify thrombocytopaenia in P.vivax malaria patients and to determine the associated risks of severe thrombocytopaenia in patients with vivax malaria compared to patients with P.falciparum malaria.Main body:A systematic review and meta-analysis of the available literature on thrombocytopaenia in P.vivax malaria patients was undertaken.Relevant studies in health-related electronic databases were identified and reviewed.The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed.Fifty-eight observational studies(n=29664)were included in the current review.Severe thrombocytopaenia(<50000/mm3)to very severe thrombocytopaenia(<20000/mm3)was observed in 10.1%of patients with P.vivax infection.A meta-analysis of 11 observational studies showed an equal risk of developing severe/very severe thrombocytopaenia between the patients with P.vivax malaria and those with P.falciparum malaria(OR:1.98,95%CI:0.92-4.25).This indicates that thrombocytopaenia is as equally a common manifestation in P.vivax and P.falciparum malaria patients.One study showed a higher risk of developing very severe thrombocytopaenia in children with severe P.vivax malaria than with severe P.falciparum malaria(OR:2.80,95%CI:1.48-5.29).However,a pooled analysis of two studies showed an equal risk among adult severe cases(OR:1.19,95%CI:0.51-2.77).This indicates that the risk of developing thrombocytopaenia in P.vivax malaria can vary with immune status in both children and adults.One study reported higher levels of urea and serum bilirubin in patients with P.vivax malaria and severe thrombocytopaenia compared with patients mild thrombocytopaenia or no thrombocytopaenia,(P<0.001 in all comparisons).A pooled analysis of two other studies showed a similar proportion of bleeding episodes with thrombocytopaenia in severe P.vivax patients and severe P.falciparum patients(P=0.09).This implied that both P.vivax and P.falciparum infections could present with bleeding episodes,if there had been a change in platelet counts in the infected patients.A pooled analysis of another two studies showed an equal risk of mortality with severe thrombocytopaenia in both P.vivax and P.falciparum malaria patients(OR:1.16,95%CI:0.30-4.60).However,due to the low number of studies with small sample sizes within the subset of studies that provided clinically relevant information,our confidence in the estimates is limited.Conclusion:The current review has provided some evidence of the clinical relevance of severe thrombocytopaenia in P.vivax malaria.To substantiate these findings,there is a need for well designed,large-scale,prospective studies among patients infected with P.vivax.These should include patients from different countries and epidemiological settings with various age and gender groups represented.

Noscapine shows antimalarial activity against Plasmodium falciparum 3D7,its clinical isolate Pf140/SS,and Plasmodium berghei ANKA

Objective:To evaluate the antimalarial activity of noscapine against Plasmodium falciparum 3D7 strain(Pf3D7),its clinical isolate(Pf140/SS),and Plasmodium berghei ANKA(PbA).Methods:Using ring-stage survival assay,phenotypic assessments,and SYBR-green-based fluorescence assay,the antimalarial activities of noscapine were assessed compared with dihydroartemisinin(DHA)in in vivo and in vitro studies.In addition,hemolysis and cytotoxicity tests were carried out to evaluate its safety.RT-PCR assay was also conducted to determine the effect of noscapine on papain-like cysteine protease Plasmodium falciparum falcipain-2(PfFP-2).Results:The antimalarial efficacy of noscapine against Pf3D7 and Pf140/SS was comparable to DHA,with IC50 values of(7.68±0.88)and(5.57±0.74)nM/mL,respectively,and>95%inhibition of PbA infected rats.Noscapine also showed a safe profile,as evidenced by low hemolysis and cytotoxicity even at high concentrations.Moreover,PfFP-2 expression was significantly inhibited in both noscapine-treated Pf3D7 and Pf140/SS(P<0.01).Conclusions:Noscapine has antimalarial properties comparable to standard antimalarial DHA with better safety profiles,which may be further explored as a therapeutic candidate for the treatment of malaria.

Insights into the elimination of vivax malaria in China

Background Malaria is caused by multiple parasitic species of the genus Plasmodium.Plasmodium vivax is the most geographically widespread and poses challenges in elimination due to its unique biological and epidemiological characteristics.The aim of study was to highlight the practices and experience targeting vivax malaria control and elimination in China.Main body P.vivax malaria was historically endemic in more than 70%of counties in China,with reported vivax malaria cases as high as 26 million a year.After around 70 years of effort,China was certified as malaria-free in June of 2021.The key insights into China’s vivax malaria control and elimination were offered,including radical cure strategies,comprehensive but adaptive strategies targeting species of Plasmodium and Anopheles,mass drug administration,and case-/focus-centred surveillance and response systems.Conclusion The complete global eradication of P.vivax and eventually malaria will be more difficult,and China’s practices and experience could be a valuable reference in this campaign.

Prolonged parasite clearance in a Chinese splenectomized patient with falciparum malaria imported from Nigeria

Background:The spleen plays a pivotal role in the rapid clearance of parasitized red blood cells in patients with falciparum malaria after artemisinin treatment.Prolonged parasite clearance can be found in patients who have had a splenectomy,or those with hemoglobin abnormalities and/or reduced immunity,which are all distinguishable from artemisinin resistance.This paper reports on a case of prolonged parasite clearance in a Chinese splenectomized patient with falciparum malaria imported from Nigeria.Case presentation:A 35-year-old Chinese male suffered 2 days of febrile illness after returning to Zhumadian city of Henan province from Nigeria on October 1,2014.The main symptoms were febrile,including the highest axillary temperature of 40℃,headache,and chills.A peripheral blood smear showed parasitemia(53913 asexual parasites/μl)of Plasmodium falciparum.The patient had not used any chemoprophylaxis against malaria in Nigeria when he worked there as a construction worker between 2009 and 2014.The patient had three episodes of malaria in Nigeria and had a splenectomy due to a traffic accident 8 years ago from the time he was admitted to hospital.The patient was orally administrated a total of 320 mg/2.56 g dihydroartemisinin-piperaquine for 2 days and intravenously administrated a total of 3000 mg artesunate for 18 days.The axillary temperature of the patient ranged between 37.0 and 37.7℃ from Day 0 to Day 3,and blood microscopy revealed falciparum malaria parasitemia(26674 asexual parasites/μl)on Day 3.The patient was afebrile on Day 4,falciparum malaria parasitemia was continuously present and then gradually decreased on the next days,and was negative on Day 21.The patient was cured and left hospital on Day 24 after no plasmodium falciparum was found in the blood on Day 21 to Day 23.No mutation was found in the K13 propeller gene when compared with the PF3D7_1343700 K13 propeller gene reference sequence.Conclusions:This is the first reported case in China of prolonged parasite clearance in a splenectomized patient with imported falciparum malaria.Artemisinin resistance should be distinguished when prolonged parasite clearance is found in a malaria patient who has had splenectomy.