Management of imported malaria in Europe

The ring-stage of Plasmodium falciparum observed in RBCs of hospitalized malaria patients

Raman spectra of the blood samples obtained directly from hospitalized malaria patients with Plasmodium falciparum (P. falciparum) in the ring-stage were analyzed. Changes observed in the Raman band intensities of the infected patients compared to healthy volunteers are the result of parasite activity inside red blood cells. The obtained spectra were discussed by analyzing differences in particular spectral regions by evaluating changes in the band intensity ratios as well as using PCA analysis. The alterations of erythrocyte membranes caused by parasite penetration are visible by a reduced I1130/I1075 intensity ratio expressing the lowering of the amount of domains arranged in trans conformation. The I2930/I2850 ratio, which is a measure of modifications in structures of membrane proteins and lipids, in infected red blood cells increases, which is caused by malaria protein export to the erythrocyte membrane and expresses the membrane disarrangement. In the pyrrole ring vibration region, the ν4 band marker of the oxygenated-Hb shows at 1371 cm(-1) whereas the ν4 band at 1353 cm(-1) related to the deoxygenated-Hb is observed for malaria patients and is characterized by a higher intensity in infected erythrocytes. The amide I analysis shows the modifications in the secondary structure composition in the infected RBCs. We found that the P. falciparum infection leads to a decrease in the α-helical content and a concurrent increase in undefined (random-coil) structures. It was observed that the Raman spectra changes are also the result of the hemozoin formation process. In the pyrrole ring stretching vibration region, the increase of 1220 cm(-1) (deoxyHb) as against 1248 cm(-1) (oxyHb) may be considered as a signal of hemozoin formation in the RBCs. Relatively intense band patterns at 1560 cm(-1) and also at 1570 cm(-1) and 1552 cm(-1) may be due to the hemozoin that is formed according to parasite activity. The results of medical diagnostic tests had not presented changes in patient RBC parameters. A significant reduction in WBC count was noticed along with a decrease in neutrophil and platelet count when compared with the control group. Although no change is observed in the overall picture of the erythrocytes, pathological changes are evident in the Raman spectrum.

Intravenous Artesunate for the Treatment of Severe and Complicated Malaria in the United States: Clinical Use Under an Investigational New Drug Protocol

BACKGROUND

Quinidine gluconate, the only U.S. Food and Drug Administration-approved treatment for life-threatening malaria in the United States, has a problematic safety profile and is often unavailable in hospitals.

OBJECTIVE

To assess the safety and clinical benefit of intravenous artesunate as an alternative to quinidine.

DESIGN

Retrospective case series.

SETTING

U.S. hospitals.

PATIENTS

102 patients aged 1 to 72 years (90% adults; 61% men) with severe and complicated malaria. Patients received 4 weight-based doses of intravenous artesunate (2.4 mg/kg) under a treatment protocol implemented by the Centers for Disease Control and Prevention between January 2007 and December 2010. At baseline, 35% had evidence of cerebral malaria, and 17% had severe hepatic impairment. Eligibility required the presence of microscopically confirmed malaria, need for intravenous treatment, and an impediment to quinidine.

MEASUREMENTS

Clinical and laboratory data from each patient's hospital records were abstracted retrospectively, including information from baseline through a maximum 7-day follow-up, and presented before a physician committee to evaluate safety and clinical benefit outcomes.

RESULTS

7 patients died (mortality rate, 6.9%). The most frequent adverse events were anemia (65%) and elevated hepatic enzyme levels (49%). All deaths and most adverse events were attributed to the severity of malaria. Patients' symptoms generally improved or resolved within 3 days, and the median time to discharge from the intensive care unit was 4 days, even for patients with severe liver disease or cerebral malaria. More than 100 concomitant medications were used, with no documented drug-drug interactions.

LIMITATION

Potential late-presenting safety issues might occur outside the 7-day follow-up.

CONCLUSION

Artesunate was a safe and clinically beneficial alternative to quinidine.

Simultaneous diagnosis of severe imported Plasmodium falciparum malaria and HIV: report of three cases

The increasing number of travellers to and from areas where considerable overlap between high malaria transmission and elevated prevalence of human immunodeficiency virus (HIV) infection exists, augment the probability that returning travellers to non-endemic countries might present with both infections. The presence of such co-infection can increase the severity of malaria episodes and also can change the progression of HIV infection. This article describes three travellers returning from malaria-endemic areas that had simultaneous diagnosis of severe Plasmodium falciparum malaria and HIV infection. Despite the severe forms of malaria and HIV co-infection, all patients responded successfully to anti-malarial treatment. Malaria and HIV interact with one another, with HIV infection increasing parasite burden, clinical severity and risk of complications of malaria; malaria seems to create an immunological interaction favourable to HIV spread and replication, with impact in progression to AIDS. The presence of malaria and HIV co-infection also poses other challenges related to treatment response, level of care and possible interactions of drugs. The authors recommend that all patients with fever returning from malaria endemic areas should be screened both for malaria and HIV infection.

Imported malaria in pregnant women: A retrospective pooled analysis

BACKGROUND

Data on imported malaria in pregnant women are scarce.

METHOD

A retrospective, descriptive study of pooled data on imported malaria in pregnancy was done using data from 1991 to 2014 from 8 different collaborators in Europe, the United States and Japan. National malaria reference centres as well as specialists on this topic were asked to search their archives for cases of imported malaria in pregnancy. A total of 631 cases were collated, providing information on Plasmodium species, region of acquisition, nationality, country of residence, reason for travel, age, gestational age, prophylactic measures and treatment used, as well as on complications and outcomes in mother and child.

RESULTS

Datasets from some sources were incomplete. The predominant Plasmodium species was P. falciparum (78.5% of cases). Among the 542 cases where information on the use of chemoprophylaxis was known, 464 (85.6%) did not use chemoprophylaxis. The main reason for travelling was "visiting friends and relatives" VFR (57.8%) and overall, most cases of malaria were imported from West Africa (57.4%). Severe anaemia was the most frequent complication in the mother. Data on offspring outcome were limited, but spontaneous abortion was a frequently reported foetal outcome (n = 14). A total of 50 different variants of malaria treatment regimens were reported.

CONCLUSIONS

Imported cases of malaria in pregnancy are mainly P. falciparum acquired in sub-Saharan Africa. Malaria prevention and treatment in pregnant travellers is a challenge for travel medicine due to few data on medication safety and maternal and foetal outcomes. International, collaborative efforts are needed to capture standardized data on imported malaria cases in pregnant women.

Artemisinin-based combination therapy in the treatment of uncomplicated malaria: review of recent regulatory experience at the European Medicines Agency

Malaria remains a major public health challenge with almost half of the world's population exposed to the risk of contracting the illness. Prompt, effective and well tolerated treatment remains one of the cornerstones in the disease management, with artemisinin-based combination therapy the recommended option for non-severe malaria in endemic areas with predominant Plasmodium falciparum infections.Recent experience has been obtained at the European Medicines Agency with regulatory approval of two such antimalarial fixed combination products. For these cases, two different regulatory pathways were applied. As such, the present contribution describes this experience, emphasising main differences and applicability offered by these regulatory choices.

Hydroxychloroquine in children with interstitial (diffuse parenchymal) lung diseases

Hydroxychloroquine (HCQ) is one of the drugs frequently used for the treatment of interstitial lung disease (ILD) in children (chILD). This use is off-label and studies to analyze the effect and safety of HCQ in chILD are lacking. Therefore, a literature research on the usage of chloroquine (CQ) and HCQ in these conditions was done. Eighty-five case reports and small series in the period from 1984 to 2013 were identified in which children with different diagnoses of ILD were treated with CQ or HCQ, sometimes in combination with other medication including steroids. A favorable response to HCQ or CQ was reported in 35 cases, whereas in the other cases the effect was negative or not clear. The dose of HCQ used was between 5 and 10 mg/kg body weight/day (bw/d). No pharmacokinetic studies have been done. The side effect profile in children seemed to be similar to that in adults. Most often gastrointestinal symptoms were reported. Three patients were found developing retinal changes during the treatment with CQ, whereas in none of the patients treated with HCQ retinal changes were reported. Based on retrospective case reports and small series likely to be reported with bias, the use of HCQ in chILD might be classified as safe. As no prospective data on efficacy and safety of HCQ in chILD are available, systematic collection is necessary. This may be achieved by web-based registers like the European Management Platform for Childhood Interstitial Lung Diseases. Prospective and controlled investigations of HCQ in patients with chILD are mandatory.

Parasitic infections in travelers and immigrants: part I protozoa

ABSTRACT 

The growth in international commerce, travel and migration contribute to the global emergence of certain parasitic infections. Importation of vectors and food products may contribute to the emergence of protozoan infections in nonendemic countries. Infections such as malaria are potentially fatal, especially in nonimmune patients, and outcome depends largely on timely diagnosis and treatment. Diagnosis/management of imported parasitic infections may be complex especially as some patients may have underlying immunosuppressive conditions such as HIV infection. Major challenges concern the development of improved diagnostic techniques, safer/more effective drug therapies and identification of biological markers of progression and response to treatment. Imported parasitic diseases which may be transmitted vertically or through blood transfusion/organ donation could become a public health priority in the near future. Climate change may affect arthropod distribution and facilitate the spread of protozoan vector-borne diseases. The first part of this review focuses on protozoan infections in travelers and immigrants.

Imported malaria in portugal 2000-2009: a role for hospital statistics for better estimates and surveillance

Background. Although eradicated in Portugal, malaria keeps taking its toll on travelers and migrants from endemic countries. Disease notification is mandatory but is compromised by underreporting. Methods. A retrospective study on malaria hospitalizations for 10 consecutive years (2000–2009) was conducted. Data on hospitalizations and notifications were obtained from Central Administration of Health System and Health Protection Agency, respectively. For data selection ICD-9 CM and ICD-10 were used: codes 084^*, 647.4, and B50–B54. Variables were gender, age, agent and origin of infection, length of stay (LOS), lethality, and comorbidities. Analysis included description, hypothesis testing, and regression. Results. There were 2003 malaria hospitalizations and 480 notified hospitalized cases, mainly in young male adults. P. falciparum was the main agent of infection acquired mainly in sub-Saharan Africa. Lethality was 1.95% and mean LOS was 8.09 days. Older age entailed longer LOS and increased lethality. Discussion. From 2000 to 2009, there were 2003 malaria hospitalizations with decreasing annual incidence, these numbers being remarkably higher than those notified. The national database of diagnosis related groups, reflecting hospitalizations on NHS hospitals, may be an unexplored complementary source for better estimates on imported malaria.

Perioperative considerations of the patient with malaria

Purpose

Malaria is a life-threatening infectious disease caused by the Plasmodium parasite. Increased global travel has resulted in an escalation in the number of imported cases seen in developed countries. Patients with malaria may present for surgery in both endemic and non-endemic countries. This article reviews the perioperative considerations when managing patients with malaria.

Source

A literature review of anesthesia, perioperative care, and malaria-related articles was performed using the MEDLINE^®, EMBASE™, and Web of Science databases to identify relevant articles published in English during 1945-2014. Of the 303 articles matching the search criteria, 265 were excluded based on title and abstract. Eleven of the remaining 38 articles were relevant to anesthesia/perioperative care, and 27 articles were identified as having direct relevance to critical care medicine.

Principal findings

The majority of imported malaria cases are caused by the falciparum species, which is associated with the greatest degree of morbidity and mortality. Various organ systems may be impacted as a consequence of changes in the structure and function of parasitized erythrocytes. Preoperative assessment should focus on establishing the species of malaria, the severity of disease, assessing the degree of end-organ impairment, and initiating treatment of malaria prior to surgery. Intravenous artesunate is the treatment of choice for severe falciparum malaria. Quinine is a second-line agent but has a narrow therapeutic index and particularly hazardous side effects. Intraoperatively, attention should focus on fluid management, dynamics of cerebral blood flow, and avoidance of hypoglycemia. Postoperative care of severe cases should ideally take place in a critical care unit as there may be ongoing requirements for multi-organ support, including renal replacement therapy, ventilation, and/or inotropic support. The safety of neuraxial anesthesia has not been well studied in the setting of malaria.

Conclusions

Malaria remains one of the most devastating infectious diseases worldwide. Multiple organ systems can be impacted as a consequence of changes in structure and function of parasitized erythrocytes. Safe perioperative management requires a sound knowledge of all these potential system effects.

Efficacy and safety of artemisinin combination therapy (ACT) for non-falciparum malaria: a systematic review

Background

Artemisinin combination therapy (ACT) is recommended as first-line treatment for uncomplicated Plasmodium falciparum malaria, whereas chloroquine is still commonly used for the treatment of non-falciparum species (Plasmodium vivax, Plasmodium ovale and Plasmodium malariae). A more simplified, more uniform treatment approach across all malaria species is worthwhile to be considered both in endemic areas and for malaria as an imported condition alike.

Methods

A PROSPERO-registered systematic review to determine the efficacy and safety of ACT for the treatment of non-falciparum malaria was conducted, following PRISMA guidelines. Without language restrictions, Medline/PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, LILACS, Biosis Previews and the African Index Medicus were searched for studies published up to November 2014.

Results

The literature search identified 986 reports; 40 publications were found eligible for inclusion, all of them on non-falciparum malaria in endemic areas. Most evidence was available for P. vivax (n = 35). Five clinical trials in total were identified evaluating ACT for P. ovale, P. malariae and Plasmodium knowlesi. Most ACT presentations have high efficacy against P. vivax parasites; artemisinin-based combinations have shorter parasite and fever clearance times compared to chloroquine. ACT is as effective as chloroquine in preventing recurrent parasitaemia before day 28. Artemisinin-based combinations with long half-lives show significantly fewer recurrent parasitaemia up to day 63. The limited evidence available supports both the use of chloroquine and an ACT for P. ovale and P. malariae. ACT seems to be preferable for optimal treatment of P. knowlesi.

Conclusion

ACT is at least equivalent to chloroquine in effectively treating non-falciparum malaria. These findings may facilitate development of simplified protocols for treating all forms of malaria with ACT, including returning travellers. Obtaining comprehensive efficacy and safety data on ACT use for non-falciparum species particularly for P. ovale, P. malariae and P. knowlesi should be a research priority.

Trial registration

CRD42014009103

Electronic supplementary material

The online version of this article (doi:10.1186/1475-2875-13-463) contains supplementary material, which is available to authorized users.

Haemolysis associated with the treatment of malaria with artemisinin derivatives: a systematic review of current evidence

BACKGROUND

Artemisinin derivatives are the mainstay of antimalarial treatment, both for uncomplicated malaria and for severe disease. Artemisinins are known for their rapid onset of action, good tolerability, and safety. However, besides the sporadic but worrying reports of delayed parasite clearance after treatment with artemisinins, there have been an increasing number of reports of acute haemolytic anaemia following their use and the safety of this class of antimalarials is being questioned.

METHODS

In this systematic review, all reports of patients experiencing haemolysis following the use of artemisinins for the treatment of malaria were identified and collated into an electronic database. Summary statistics were calculated to characterize the epidemiology and clinical features of this safety concern related to artemisinin derivatives.

RESULTS

A total of 37 patients were identified suffering from haemolysis following the treatment of severe malaria with artemisinin derivatives. Thirty-one cases had received intravenous artesunate, while the remaining cases were attributed to other parenteral or oral regimens of artemisinin derivatives. The majority of patients were returning travellers (n=30), and six clinical cases had been reported in paediatric patients. The median onset of haemolysis was 15 (interquartile range (IQR) 13-15) days after the initiation of treatment for the 'delayed-onset' pattern and 17 (IQR 13-22) days for the 'persistent' haemolysis pattern. The median reduction in haemoglobin due to haemolysis was 6 g/dl (IQR 4-8 g/dl). The estimated proportion of patients suffering from severe malaria experiencing haemolysis after treatment with artemisinin derivatives was 13% (95% confidence interval 9-18%), and 73% of these (i.e., 9% of the total population) required blood transfusions. No fatal outcome has been reported in the literature to date.

CONCLUSIONS

Haemolysis is commonly associated with the class of artemisinin drugs when used for the treatment of severe malaria. Potential causes of this safety issue are discussed. Although no deaths attributed to haemolysis have been reported so far, this safety issue may lead to life-threatening anaemia and is particularly worrying for regions where safe blood products are not readily available.

[Protozoa and protozoan infections of humans in Central Europe]

This article is a condensed review of the medically relevant protozoa in Central Europe and the infections and diseases caused by them. Information is given on modes and sources of infection, organs involved in the disease, prevalence, diagnostics, therapy, and prophylaxis. Moreover, travel-associated infections with protozoa are briefly outlined.

Stability profiling of anti-malarial drug piperaquine phosphate and impurities by HPLC-UV, TOF-MS, ESI-MS and NMR

BACKGROUND

Piperaquine, 1,3-bis-[4-(7-chloroquinolyl-4)-piperazinyl-1]-propane, is an anti-malarial compound belonging to the 4-aminoquinolines, which has received renewed interest in treatment of drug resistant falciparum malaria in artemisinin-based combination therapy with dihydroartemisinin. The impurity profile of this drug product is paid an ever-increasing attention. However, there were few published studies of the complete characterization of related products or impurities in piperaquine phosphate bulk and forced degradation samples.

METHODS

The impurities in piperaquine phosphate bulk drug substance were detected by a newly developed gradient phase HPLC method and identified by TOF-MS and ESI-MS. The structures of impurities were confirmed by NMR. Forced degradation studies were also performed for the stability of piperaquine phosphate bulk drug samples and the specificity of the newly developed HPLC method. In silico toxicological predictions for these piperaquine phosphate related impurities were made by Toxtree® and Derek®.

RESULTS

Twelve impurities (imp-1-12) were detected and identified, of which eight impurities (imp-1, 2, 4, 6-10) were first proposed as new related substances. Based on TOF-MS/ESI-MS and NMR analysis, the structures of imp-2, 6 and 12 were characterized by their synthesis and preparation. The possible mechanisms for the formation of impurities were also discussed. These piperaquine phosphate related impurities were predicted to have a toxicity risk by Toxtree® and Derek®.

CONCLUSIONS

From forced degradation and bulk samples of piperaquine phosphate, twelve compounds were detected and identified to be piperaquine phosphate related impurities. Two of the new piperaquine phosphate related substances, imp-2 and imp-6, were identified and characterized as 4-hydroxy-7-chloro-quinoline and a piperaquine oxygenate with a piperazine ring of nitrogen oxide in bulk drug and oxidation sample, respectively. The MS data of imp-1, 2, 4, 6-10 were first reported. The in-silico toxicological prediction showed a toxicity risk for piperaquine related impurities by Toxtree® and Derek®.

Severe delayed autoimmune haemolytic anaemia following artesunate administration in severe malaria: a case report

Background

Parenteral artesunate is recommended as first-line therapy for severe and complicated malaria. Although its efficacy has been proven, long-term safety profile is still under evaluation. Several cases of delayed haemolytic anaemia occurred after initial clinical improvement and resolution of parasitaemia in non-immune travellers and children living in endemic areas. Reports have generated concern that this phenomenon might be related to the treatment itself, either by direct toxicity or immune-related mechanism. This is a report of the first case of autoimmune haemolytic anaemia following treatment of severe malaria initially managed with parenteral artesunate with strong indication for drug-immune related mechanism.

Case

A 17-year old Ivoirian female travelling in France presented with fever, headache and abdominal pain seven days after her arrival. Physical examination was indicative of septic shock while blood analysis showed normal haemoglobin level, but profound thrombocytopaenia and hyperlactataemia. Blood smear analysis showed Plasmodium falciparum infection with a parasitaemia of 0.8%. Severe malaria was diagnosed according to the WHO criteria. The patient was initially managed with artemether/lumefantrine combination and then parenteral artesunate for 48 hours. Empiric antibiotic course was also initiated with ceftriaxone, metronidazole, gentamycin, and then piperacillin and ciprofloxacin. At day 14, haemoglobin dropped to 4.6 g/dL with biologic features indicative of haemolysis (LDH 658 U/L, haptoglobin <0.15 g/L). At that time, parasitaemia was negative and other infections or hereditary disorders were excluded, while Coombs’ direct antiglobulin test was positive for IgG and C3d. Antinuclear antibodies were absent. Further investigations evidenced drug-induced antibodies related to artesunate. It was concluded a drug-mediated autoimmune haemolytic anaemia. A corticosteroids regimen was initiated at 1 mg/kg/day. Outcome was favourable and corticosteroids were progressively tapered during two months. At present the patient’s condition remains stable without recurrence of haemolytic anaemia.

Conclusion

This is the first case of delayed haemolytic anaemia related to artesunate with a strong indication for drug-immune related mechanism. Further research is warranted to better characterize this plausible cause of post-treatment haemolysis following parenteral artesunate administration in severe malaria patients.

Electronic supplementary material

The online version of this article (doi:10.1186/1475-2875-13-398) contains supplementary material, which is available to authorized users.

Randomized trial of artesunate-amodiaquine, atovaquone-proguanil, and artesunate-atovaquone-proguanil for the treatment of uncomplicated falciparum malaria in children

BACKGROUND

Artemisinin-based combination therapies (ACTs) are recommended for the treatment of acute uncomplicated falciparum malaria in many malaria-endemic countries. Despite the emergence of artemisinin resistance, few alternative non-ACTs, including atovaquone-proguanil, are currently available.

METHODS

Plasmodium falciparum-infected Cameroonian children ≤5 years old (n = 338) were randomly assigned to artesunate-amodiaquine, atovaquone-proguanil, or artesunate-atovaquone-proguanil treatment groups and followed for 28 days, according to the standard World Health Organization protocol. In vitro response to atovaquone and cytochrome b sequence of clinical isolates were determined.

RESULTS

Eight late failures and 16 failures (8 late and 8 early failures) were observed after artesunate-amodiaquine and atovaquone-proguanil therapies, respectively. Most late failures were due to reinfections. Artesunate-atovaquone-proguanil was not associated with any failure. After correction by genotyping, per-protocol analysis showed no difference in the efficacy of 3 drugs. However, the proportion of atovaquone-proguanil-treated patients with positive smears on day 3 was much higher (36.0%; P < .05) than that of the artesunate-amodiaquine (2.9%) and artesunate-atovaquone-proguanil (1.0%) groups. In vitro response and cytochrome b sequence did not indicate atovaquone resistance.

CONCLUSIONS

Atovaquone-proguanil was characterized by a slow blood schizontocidal action and resulted in early treatment failure in a few patients. Artesunate-atovaquone-proguanil was a highly effective alternative treatment.

CLINICAL TRIALS REGISTRATION

UMIN000003813.

Sensitivity of parasitological tests in imported Plasmodium vivax malaria in adults and impact of chemoprophylaxis and attack type

BACKGROUND

Plasmodium vivax is the second most common species among cases of imported malaria diagnosed in Europe. The objective of this study is to describe the sensitivity of the parasitological tests in imported P. vivax malaria, and the impact of chemoprophylaxis and attack type (primary infection or relapse).

METHODS

A retrospective study included the imported vivax malaria cases admitted in a French military hospital between 2001 and 2013. The reference diagnosis method was microscopy corrected by polymerase chain reaction (PCR). Thin and thick blood films examination, quantitative buffy coat (QBC) test, and a rapid diagnostic test (RDT) had been systematically performed. PCR had been carried out for ambiguous profiles.

RESULTS

Eighty-nine cases recorded from 78 patients were included, 65 of them having recently traveled to French Guyana. Forty-two patients had properly followed chemoprophylaxis. Forty-six cases were primary infections while 43 were relapses. The sensitivity was 91% for the thin blood smear, 96% for the concentration techniques (Giemsa thick blood smear and QBC test), and 76% for the RDT. The combination of the three conventional tools has an imperfect sensitivity, both for the positive diagnosis of malaria (96%) and for the diagnosis of vivax species (80%). In 4% of the cases, the positive diagnosis was established only by the PCR. The species identification was established in 20% by the PCR. The sensibility of thin blood smear and of RDT decreased significantly with full compliance of chemoprophylaxis or primary infection, whereas the decrease of sensibility of concentration techniques was not significant.

CONCLUSIONS

This study illustrates the difficulties encountered in vivax malaria diagnosis, especially in patients who properly followed chemoprophylaxis or with primary infection due to a lower parasitemia. It underlines the lack of sensitivity of RDT for P. vivax and emphasizes the need for systematically combining various diagnosis methods.

Challenges facing providers of imported malaria-related healthcare services for Africans visiting friends and relatives (VFRs)

Background

In many non-malarious countries, imported malaria disproportionately affects Africans visiting friends and relatives (VFRs). Most previous research has focused on understanding the knowledge, attitudes and practices of these travellers, but has not examined the quality of prevention, diagnosis and treatment services provided. The aim of this study was to understand the perspective of providers of malaria-related healthcare services to VFRs about factors impacting on the quality of these and to make recommendations about improvements.

Methods

Thirty semi-structured interviews were conducted with practice nurses providing pre-travel health advice (n = 10), general practitioners (GPs) (n = 10), hospital consultants (n = 3), and community pharmacists (n = 7) working in areas of London with large African communities and a relatively high burden of imported malaria. A thematic analysis of the results was undertaken.

Results

Time constraints in GPs’ surgeries and competing priorities, lack of confidence in issuing advice on mosquito avoidance, the cost of chemoprophylaxis and travel at short notice prevented the provision of adequate malaria prevention advice. Long GP waiting times, misdiagnoses, lack of disclosure by VFRs about recent travel, and the issue of where malaria treatment should be provided were raised as potential barriers to diagnosis and treatment.

Conclusions

Some issues raised by respondents are relevant to all travellers, irrespective of their reason for travel. The challenge for healthcare providers to reduce the burden of imported malaria in VFRs is to provide services of sufficient quality to persuade them to adopt these in preference to those with which they may be familiar in their country of birth. Although no single intervention will significantly lower the burden of imported malaria, addressing the issues raised in this research could make a significant impact.

Haemoglobin levels for population from Gambo, a rural area of Ethiopia, and their association with anaemia and malaria

BACKGROUND

Knowledge of appropriate reference intervals is critical not only to provide optimal clinical care, but also to enrol populations in medical research. The aim of this study was to generate normal ranges of laboratory values for haemoglobin among healthy Ethiopian adults and children and to determine if anaemia is a possible indicator of malaria in women and children in this area of Ethiopia.

METHODS

This study was carried out from January 2008 to May 2010. The reference sample population with malaria-negative consisted of 454 individuals, divided women, men and children. The malaria-infected sample population consisted of 117 individuals. The reference ranges were based on the guidelines from the Clinical and Laboratory Standards Institute. Haemoglobin concentration was determined by Hemo-Control EKF Diagnostic Analyser on whole blood. Testing for malaria-positive and negative infection was done by microscopy and by PCR.

RESULTS

The lower limits for adult haemoglobin range obtained from this population were slightly higher than those derived from other African populations, but were equal to those established by other studies in Ethiopia and the World Health Organization (WHO). Regarding children, the minimum values were lower than those obtained from different African populations and those established by WHO. The malaria-negative group had anaemia in 35.6% of cases and in the malaria-positive group in 70.9%. There was a stronger, statistically significant association between anaemia and malaria-positive samples than between anaemia and malaria-negative samples in women and both groups of children.

CONCLUSIONS

The results from this study are a contribution in the definition of the haemoglobin parameters in African populations, which could be taken as standards for interpretation of laboratory results. The haemoglobin indices in adults from Gambo tended to be higher than other African populations and in children were lower than other studies in Africa. The results also suggest that anaemia is not useful as a supportive diagnostic criterion to monitor and evaluate malaria in women and children from Ethiopia, because a 29.1% of malaria cases will be not detected, because of not having anaemia.

Performance of rapid diagnostic tests for imported malaria in clinical practice: results of a national multicenter study

We compared the performance of four rapid diagnostic tests (RDTs) for imported malaria, and particularly Plasmodium falciparum infection, using thick and thin blood smears as the gold standard. All the tests are designed to detect at least one protein specific to P. falciparum (Plasmodium histidine-rich protein 2 (PfHRP2) or Plasmodium LDH (PfLDH)) and one pan-Plasmodium protein (aldolase or Plasmodium LDH (pLDH)). 1,311 consecutive patients presenting to 9 French hospitals with suspected malaria were included in this prospective study between April 2006 and September 2008. Blood smears revealed malaria parasites in 374 cases (29%). For the diagnosis of P. falciparum infection, the three tests detecting PfHRP2 showed high and similar sensitivity (96%), positive predictive value (PPV) (90%) and negative predictive value (NPV) (98%). The PfLDH test showed lower sensitivity (83%) and NPV (80%), despite good PPV (98%). For the diagnosis of non-falciparum species, the PPV and NPV of tests targeting pLDH or aldolase were 94-99% and 52-64%, respectively. PfHRP2-based RDTs are thus an acceptable alternative to routine microscopy for diagnosing P. falciparum malaria. However, as malaria may be misdiagnosed with RDTs, all negative results must be confirmed by the reference diagnostic method when clinical, biological or other factors are highly suggestive of malaria.

Accurate identification of the six human Plasmodium spp. causing imported malaria, including Plasmodium ovale wallikeri and Plasmodium knowlesi

Background

Accurate identification of Plasmodium infections in non-endemic countries is of critical importance with regard to the administration of a targeted therapy having a positive impact on patient health and management and allowing the prevention of the risk of re-introduction of endemic malaria in such countries. Malaria is no longer endemic in Italy where it is the most commonly imported disease, with one of the highest rates of imported malaria among European non-endemic countries including France, the UK and Germany, and with a prevalence of 24.3% at the University Hospital of Parma. Molecular methods showed high sensitivity and specificity and changed the epidemiology of imported malaria in several non-endemic countries, highlighted a higher prevalence of Plasmodium ovale, Plasmodium vivax and Plasmodium malariae underestimated by microscopy and, not least, brought to light both the existence of two species of P. ovale (Plasmodium ovale curtisi and Plasmodium ovale wallikeri) and the infection in humans by Plasmodium knowlesi, otherwise not detectable by microscopy.

Methods

In this retrospective study an evaluation of two real-time PCR assays able to identify P. ovale wallikeri, distinguishing it from P. ovale curtisi, and to detect P. knowlesi, respectively, was performed applying them on a subset of 398 blood samples belonging to patients with the clinical suspicion of malaria.

Results

These assays revealed an excellent analytical sensitivity and no cross-reactivity versus other Plasmodium spp. infecting humans, suggesting their usefulness for an accurate and complete diagnosis of imported malaria. Among the 128 patients with malaria, eight P. ovale curtisi and four P. ovale wallikeri infections were detected, while no cases of P. knowlesi infection were observed.

Discussion and conclusions

Real-time PCR assays specific for P. ovale wallikeri and P. knowlesi were included in the panel currently used in the University Hospital of Parma for the diagnosis of imported malaria, accomplishing the goal of adhering to the recommendations of the World Health Organization to countries that are malaria-free to include the improvement of the early diagnosis of all cases of imported malaria.

Global malaria connectivity through air travel

Background

Air travel has expanded at an unprecedented rate and continues to do so. Its effects have been seen on malaria in rates of imported cases, local outbreaks in non-endemic areas and the global spread of drug resistance. With elimination and global eradication back on the agenda, changing levels and compositions of imported malaria in malaria-free countries, and the threat of artemisinin resistance spreading from Southeast Asia, there is a need to better understand how the modern flow of air passengers connects each Plasmodium falciparum- and Plasmodium vivax-endemic region to the rest of the world.

Methods

Recently constructed global P. falciparum and P.vivax malaria risk maps, along with data on flight schedules and modelled passenger flows across the air network, were combined to describe and quantify global malaria connectivity through air travel. Network analysis approaches were then utilized to describe and quantify the patterns that exist in passenger flows weighted by malaria prevalence. Finally, the connectivity within and to the Southeast Asia region where the threat of imported artemisinin resistance arising is highest, was examined to highlight risk routes for its spread.

Results

The analyses demonstrate the substantial connectivity that now exists between and from malaria-endemic regions through air travel. While the air network provides connections to previously isolated malarious regions, it is clear that great variations exist, with significant regional communities of airports connected by higher rates of flow standing out. The structures of these communities are often not geographically coherent, with historical, economic and cultural ties evident, and variations between P. falciparum and P. vivax clear. Moreover, results highlight how well connected the malaria-endemic areas of Africa are now to Southeast Asia, illustrating the many possible routes that artemisinin-resistant strains could take.

Discussion

The continuing growth in air travel is playing an important role in the global epidemiology of malaria, with the endemic world becoming increasingly connected to both malaria-free areas and other endemic regions. The research presented here provides an initial effort to quantify and analyse the connectivity that exists across the malaria-endemic world through air travel, and provide a basic assessment of the risks it results in for movement of infections.

Current challenges in travelers' malaria

Travel health providers are often confronted with complex scenarios when advising travelers on malaria prevention. Current challenges in prevention include malaria risk assessment, where a detailed itinerary and knowledge of malaria epidemiology are needed. Up-to-date information on the correct use, limitations, and drug interactions of current priority chemoprophylaxis agents (atovaquone/proguanil, mefloquine, doxycycline) is key. Another challenge is to identify and reach travelers who are most at risk of malaria, such as the traveler visiting friends and relatives. Posttravel, delays in presentation, diagnosis, and inappropriate treatment of malaria are key risk factors leading to death. Treatment of malaria is an emergency requiring expert in-patient management and referral to a center with adequate expertise. Artemisinin combination therapies are the drugs of choice for uncomplicated malaria. Complicated malaria is treated preferably with intravenous artesunate, and the supply and quality of this life-saving antimalarial in some settings can pose one of the most urgent challenges in travelers' malaria.

Clinical relevance of different biomarkers in imported plasmodium falciparum malaria in adults: a case control study

Background

For rapid initiation of anti-malarial treatment and prevention of complications, early diagnosis and risk stratification is important in patients with Plasmodium falciparum malaria. Routine laboratory values do not correlate well with disease severity. The aim of this study was to determine the diagnostic and prognostic value of several biomarkers related to inflammation; endothelial and cardiac dysfunction; coagulation, and haemolysis in imported P. falciparum malaria.

Methods

In a prospective case-control study, 79 adult travellers with both uncomplicated and complicated P. falciparum malaria were included between 2007 and 2011. Forty-one healthy subjects were included as controls. Blood samples were obtained within 24 hours after first consultation to assess routine laboratory values as well as markers related to inflammation (PAPP-A, copeptin, CRP), endothelial activation (MPO, elastase-2, endothelin-1, sICAM-1, sVCAM-1), cardiac function (NT-proBNP, MR-proANP), coagulation (fibrinogen, D-dimers, platelet count), and haemolysis (LDH). Prognostic performance was assessed using the receiver operating characteristic curve (area under the curve = AUROC).

Results

Twelve (15.2%) patients had severe P. falciparum malaria. In the patient group, significant thrombocytopaenia was found, all other markers but PAPP-A were significantly elevated. Diagnostic performance was best for CRP with an AUROC of 1.00, followed by MPO (0.99), D-dimers (0.98), elastase-2 (0.98), and sICAM-1 (0.98). Biomarker levels did not correlate well with disease severity.

Conclusion

The combination of travel history, fever prior to blood sampling, and CRP serum levels above or below 10.8 mg/l upon hospital admission, best discriminated between malaria patients and control persons. None of the biomarkers studied predicted the presence or the development of malaria complications, neither at the time of admission, nor during hospitalization.

Two cases of Plasmodium falciparum malaria in the Netherlands without recent travel to a malaria-endemic country

Recently, two patients of African origin were given a diagnosis of Plasmodium falciparum malaria without recent travel to a malaria-endemic country. This observation highlights the importance for clinicians to consider tropical malaria in patients with fever. Possible transmission routes of P. falciparum to these patients will be discussed. From a public health perspective, international collaboration is crucial when potential cases of European autochthonous P. falciparum malaria in Europe re considered.

Artesunate versus quinine in the treatment of severe imported malaria: comparative analysis of adverse events focussing on delayed haemolysis

BACKGROUND

Severe malaria is a potentially life-threatening infectious disease. It has been conclusively shown that artesunate compared to quinine is superior in antiparasitic efficacy and in lowering mortality showing a better short-term safety profile. Regarding longer-term effects, reports of delayed haemolysis after parenteral artesunate for severe malaria in returning travellers have been published recently. So far, delayed haemolysis has not been described after the use of parenteral quinine.

METHODS

In this retrospective study, all patients treated for severe malaria at the University Medical Centre Hamburg-Eppendorf were included between 2006 and 2012. The primary endpoint was the proportion of delayed haemolysis in patients treated with quinine versus those who received artesunate. As secondary endpoint, the proportion of any adverse event was assessed.

RESULTS

A total of 36 patients with severe malaria were included in the analysis. Of these, 16 patients contributed sufficient data to assess the endpoint delayed haemolysis. Twelve were treated primarily with intravenous quinine - with four patients having received intrarectal artesunate as an adjunct treatment - and five patients were treated primarily with artesunate. Five cases of delayed haemolysis could be detected - two in patients treated with quinine and intrarectal artesunate and three in patients treated with artesunate. No case of delayed haemolysis was detected in patients treated with quinine alone.While adverse events observed in patients treated with artesunate were limited to delayed haemolysis (three patients, 60%) and temporary deterioration in renal function (three patients, 60%), patients treated with quinine showed a more diverse picture of side effects with 22 patients (71%) experiencing at least one adverse event. The most common adverse events after quinine were hearing disturbances (12 patients, 37%), hypoglycaemia (10 patients, 32%) and cardiotoxicity (three patients, 14%).

CONCLUSIONS

This study provides further evidence on delayed haemolysis after artesunate and underlines the importance of a standardized follow-up of patients treated with artesunate for severe malaria.

A sticky situation: the unexpected stability of malaria elimination

Malaria eradication involves eliminating malaria from every country where transmission occurs. Current theory suggests that the post-elimination challenges of remaining malaria-free by stopping transmission from imported malaria will have onerous operational and financial requirements. Although resurgent malaria has occurred in a majority of countries that tried but failed to eliminate malaria, a review of resurgence in countries that successfully eliminated finds only four such failures out of 50 successful programmes. Data documenting malaria importation and onwards transmission in these countries suggests malaria transmission potential has declined by more than 50-fold (i.e. more than 98%) since before elimination. These outcomes suggest that elimination is a surprisingly stable state. Elimination's ‘stickiness’ must be explained either by eliminating countries starting off qualitatively different from non-eliminating countries or becoming different once elimination was achieved. Countries that successfully eliminated were wealthier and had lower baseline endemicity than those that were unsuccessful, but our analysis shows that those same variables were at best incomplete predictors of the patterns of resurgence. Stability is reinforced by the loss of immunity to disease and by the health system's increasing capacity to control malaria transmission after elimination through routine treatment of cases with antimalarial drugs supplemented by malaria outbreak control. Human travel patterns reinforce these patterns; as malaria recedes, fewer people carry malaria from remote endemic areas to remote areas where transmission potential remains high. Establishment of an international resource with backup capacity to control large outbreaks can make elimination stickier, increase the incentives for countries to eliminate, and ensure steady progress towards global eradication. Although available evidence supports malaria elimination's stickiness at moderate-to-low transmission in areas with well-developed health systems, it is not yet clear if such patterns will hold in all areas. The sticky endpoint changes the projected costs of maintaining elimination and makes it substantially more attractive for countries acting alone, and it makes spatially progressive elimination a sensible strategy for a malaria eradication endgame.

Impact of routine real-time PCR testing of imported malaria over 4 years of implementation in a clinical laboratory

In clinical laboratories, diagnosis of imported malaria is commonly performed by microscopy. However, the volume of specimens is generally low and maintaining proficiency in reading blood smears, particularly at the species level, is challenging in this setting. To address this problem, the Provincial Laboratory for Public Health (ProvLab) in Alberta, Canada, implemented real-time PCR for routine confirmation of all smear-positive samples in the province. Here we report our experience over a 4-year period (2008 to 2012) with this new diagnostic algorithm. While detection of Plasmodium falciparum by microscopy alone was accurate, real-time PCR served as an important adjunct to microscopy for the identification of non-falciparum species. In 18% of cases, the result was reported as non-falciparum or the species could not be identified by microscopy alone, and in all cases, the species was resolved by real-time PCR. In another 4% of cases, the species was misidentified by microscopy. To enhance surveillance for malaria, we integrated our demographic, clinical, and laboratory data into a new system developed by the Canadian Network for Public Health Intelligence, called the Malaria System for Online Surveillance (SOS). Using this application, we characterized our patient populations and travel history to identify risk factors associated with malaria infection abroad.

Imported malaria in Finland 2003-2011: prospective nationwide data with rechecked background information

BACKGROUND

Although described in several reports, imported malaria in Europe has not been surveyed nationwide with overall coverage of patients and individually rechecked background information. Plasmodium falciparum infections have been reported despite regularly taken appropriate chemoprophylaxis, yet the reliability of such questionnaire-based retrospective data has been questioned. This was the starting-point for conducting a prospective nationwide survey of imported malaria where compliance data was double-checked.

METHODS

Data was collected on all cases of imported malaria confirmed and recorded by the reference laboratory of Finland (population 5.4 million) from 2003 to 2011, and these were compared with those reported to the National Infectious Disease Register (NIDR). Background information was gathered by detailed questionnaires sent to the clinicians upon diagnosis; missing data were enquired by telephone of clinician or patient. Special attention was paid to compliance with chemoprophylaxis: self-reported use of anti-malarials was rechecked for all cases of P. falciparum.

RESULTS

A total of 265 malaria cases (average annual incidence rate 0.5/100,000 population) had been recorded by the reference laboratory, all of them also reported to NIDR: 54% were born in malaria-endemic countries; 86% were currently living in non-endemic regions. Malaria was mainly (81%) contracted in sub-Saharan Africa. Plasmodium falciparum proved to be the most common species (72%). Immigrants constituted the largest group of travellers (44%). Pre-travel advice was received by 20% of those born in endemic regions and 81% of those from non-endemic regions. Of those with P. falciparum, 4% reported regular use of appropriate chemoprophylaxis (mefloquine or atovaquone/proguanil or doxycycline for regions with chloroquine-resistant and atovaquone/proguanil or doxycycline for regions with mefloquine-resistant P. falciparum); after individual rechecking, however, it was found that none of them had been fully compliant.

CONCLUSIONS

Information on compliance with chemoprophylactic regimen cannot be relied on, and it should be rechecked if malaria is suspected. The results of the present study suggest that mefloquine, atovaquone/proguanil and doxycycline are effective as chemoprophylaxis against P. falciparum malaria, when taken conscientiously.

Artemisinin based combination therapy in travel medicine

A steadily increasing number of Western travellers are exposed to malaria. Also, numbers of migrants from malarious areas are increasing. Fast and effective treatment options are needed to ensure effective malaria treatment in these groups in the future. Artemisinin combinations are well tolerated and have shown high efficacy in malaria endemic areas. Since 2001, 42 malaria endemic countries, 23 of them in Africa, have adopted artemisinin based combination therapies recommended by WHO. An additional 14 countries are in the process of changing their malaria treatment policy. Studies in non-immune travellers confirm a rapid parasite clearance time and very low rate of side effects. Outpatient clinics and hospitals in non-endemic countries should have standard operating procedures for diagnosing and managing patients with malaria. In this setting, artemisinin combinations should be available for treatment of uncomplicated malaria as they are clearly superior to any other oral antimalarial in their fast reduction of parasite biomass and in decreasing clinical symptoms. Also, they are the drugs of choice for travellers who are advised to carry stand-by emergency treatment during their journey.