Malaria: an update on treatment of adults in non-endemic countries

Recent Progress in the Development of Diagnostic Tests for Malaria

The impact of malaria on global health has continually prompted the need to develop effective diagnostic strategies. In malaria endemic regions, routine diagnosis is hampered by technical and infrastructural challenges to laboratories. These laboratories lack standard facilities, expertise or diagnostic supplies; thus, therapy is administered based on clinical or self-diagnosis. There is the need for accurate diagnosis of malaria due to the continuous increase in the cost of medication, and the emergence and spread of drug resistant strains. However, the widely utilized Giemsa-stained microscopy and immunochromatographic tests for malaria are liable to several drawbacks, including inadequate sensitivity and false-positive outcomes. Alternative methods that offer improvements in performance are either expensive, have longer turnaround time or require a level of expertise that makes them unsuitable for point-of-care (POC) applications. These gaps necessitate exploration of more efficient detection techniques with the potential of POC applications, especially in resource-limited settings. This minireview discusses some of the recent trends and new approaches that are seeking to improve the clinical diagnosis of malaria.

Automated erythrocytapheresis for severe falciparum malaria

We describe a case of severe falciparum malaria with hyperparasitaemia. Treatment with automated erythrocytapheresis, in conjunction with parenteral artesunate, produced a rapid and sustained fall in parasite burden. Several poor prognostic features were present at admission. Despite the development of a severe headache with abnormal cerebrospinal fluid parameters and transient pulmonary oedema, a complete recovery was observed. Erythrocytapheresis can be considered in selected cases where facilities exist and has theoretical and practical advantages over traditional methods of red cell exchange transfusion. The paucity of systematic or trial evidence convincingly demonstrating a benefit in terms of morbidity or mortality has limited its application. However, the lack of robust trial data should not in itself invalidate considering this therapeutic option in the appropriate context.

Developing and testing a high-fidelity simulation scenario for an uncommon life-threatening disease: severe malaria

Background. Severe malaria is prevalent globally, yet it is an uncommon disease posing a challenge to education in nonendemic countries. High-fidelity simulation (sim) may be well suited to teaching its management. Objective. To develop and evaluate a teaching tool for severe malaria, using sim. Methods. A severe malaria sim scenario was developed based on 5 learning objectives. Sim sessions, conducted at an academic center, utilized METI ECS mannequin. After sim, participants received standardized debriefing and completed a test assessing learning and a survey assessing views on sim efficacy. Results. 29 participants included 3rd year medical students (65%), 3rd year EM residents (28%), and EM nurses (7%). Participants scored average 85% on questions related to learning objectives. 93% felt that sim was effective or very effective in teaching severe malaria, and 83% rated it most effective. All respondents felt that sim increased their knowledge on malaria. Conclusion. Sim is an effective tool for teaching severe malaria in and may be superior to other modalities.

Early treatment of imported falciparum malaria in the intermediate and intensive care unit setting: an 8-year single-center retrospective study

INTRODUCTION

Imported falciparum malaria is characterized by a broad spectrum of potentially life-threatening complications that may arise even after initiation of appropriate antimalarial drug therapy. Hence, at Heidelberg University Hospital, all patients with newly diagnosed falciparum malaria are initially treated in the intermediate care unit (IMC) or intensive care unit (ICU). The present study was undertaken to evaluate critically the benefit of this strategy, which includes daily consultation with senior specialists in tropical medicine.

METHODS

We conducted a retrospective cohort study at the 14-bed combined IMC/ICU of a 1,685-bed university hospital. A cohort of 122 patients with imported falciparum malaria admitted from 1 January 1996 to 31 December 2003 was included.

RESULTS

Thirty-four patients (27.9%) developed complications, defined according to the current World Health Organization classification. Most patients (80.3%) studied did not take the recommended chemoprophylaxis against malaria. The majority of patients (89.3% [n = 109]) could be adequately treated in the IMC. Life-threatening complications requiring ICU support occurred in 13 patients (10.7%). All complications were successfully managed. Fifty-five patients (45.1%) fulfilling recently published criteria for outpatient treatment had an excellent therapeutic response and did not require ICU support.

CONCLUSION

This retrospective evaluation demonstrated favourable therapeutic results in hospitalized patients with imported falciparum malaria. Both initial treatment in the medical IMC/ICU and close collaboration between intensivists and specialists in tropical medicine may improve disease outcome among affected patients. Prospective studies are needed to confirm these preliminary findings.

Stroke in central nervous system infections

Background

Stroke subtypes and etiology may differ between developing and developed countries. Infections are a relatively common cause of stroke in tropical regions.

Objective

To review the main infectious diseases associated with stroke.

Discussion

Prevalence of stroke in HIV patients is around 1%. Pathogenic mechanisms include HIV vasculopathy, vasculitis, cardioembolism, acquired hypercoagulability, and the effect of opportunistic infections. Treatment with protease inhibitors has been associated with premature atherosclerotic vascular disease. Emerging viral infections that are associated with stroke include viral hemorrhagic fevers, Japanese encephalitis, dengue, and West Nile virus. Vasculitis involving perforating vessels of the brain is a cerebrovascular complication of tuberculous meningitis. Small, medium, and large arteries of the anterior circulation can be involved. A progressive intracranial arteriopathy afterLeptospira interrogansinfection has been described, which involves the large intracranial arteries. Cerebrovascular complications of mycosis are associated with large vessel vasculitis, direct vessel damage by invasion or embolization, and subarachnoid hemorrhage due to mycotic aneurysm rupture. Pathological findings of cerebral malaria include diffuse cerebral edema, perivascular ring hemorrhages, white matter necrosis, parenchyma petechial hemorrhages, occlusion of brain vessels, and sequestration of infected erythrocytes in cortical and perforating arteries. Stroke can occur in subarachnoid neurocysticercosis and the lesions in such cases consist mostly of deep lacunar infarctions resulting from endarteritis of small penetrating arteries. Cardiac arrhythmias, congestive heart failure, apical aneurysm, and mural thrombus are the conditions that predispose patients with American trypanosomiasis to cardioembolism. Gnathostoma spinigerum infestation is a cause of hemorrhagic stroke in Asia.

Conclusion

Infectious and tropical diseases should be included in the differential diagnoses of stroke.

Selective ambulatory management of Plasmodium falciparum malaria in paediatric refugees

BACKGROUND

Plasmodium falciparum (Pf) malaria is a leading cause of childhood mortality and morbidity. In developed countries, it is widely recommended that even patients with uncomplicated Pf malaria are hospitalised for at least 24 h, whereas ambulatory treatment is usual for uncomplicated infections in developing countries. This observational study assessed the safety of selective admission of paediatric refugees with Pf malaria in Australia.

METHODS

Data were collected on African humanitarian refugee children (<16 years of age) presenting with malaria between February 2005 and April 2006. Children were treated as outpatients if they fulfilled specific criteria devised to maximise the safety of outpatient management of this potentially life-threatening condition.

RESULTS

Ninety paediatric refugees were infected with P falciparum, of whom 56 were treated as outpatients. Of the 34 children admitted to hospital, four had parasite loads > or =4%. Most children were treated with oral atovaquone-proguanil. Eighty eight patients attended follow-up; all were compliant and none reported side-effects. One infant failed treatment and was subsequently readmitted; he did not meet criteria for severe malaria on either occasion and had been initially treated as an inpatient.

CONCLUSIONS

Using this protocol, outpatient management of refugee children with Pf malaria appears safe, with minimal complication and treatment failure rates. This approach has rationalised management of paediatric malaria in this carefully selected population and substantially reduced utilisation of hospital resources.