Post-treatment haemolysis is common following oral artemisinin combination therapy of uncomplicated malaria in travellers

How to manage adult patients with malaria in the non-endemic setting

BACKGROUND

The diagnosis and management of malaria in non-endemic countries presents a continuing challenge. Plasmodium falciparum, which is capable of rapidly inducing severe and life-threatening multiorgan disease, is the species most frequently diagnosed in Europe and North America.

OBJECTIVES

To summarise the more relevant diagnostic findings and clinical features of malaria observed in non-endemic settings and to provide an update of the key management decision points using three illustrative clinical scenarios of uncomplicated and severe malaria.

SOURCES

The discussion is based on a relevant literature search spanning the last 20 years. Recommendations are based on available clinical guidelines including those of the WHO, observational studies conducted in non-endemic settings, and, when available, extrapolation from randomised studies from malaria-endemic settings.

CONTENT

The following topics are covered: diagnosis, including the use of molecular biology; clinical characteristics; management with a specific focus on complicated (severe) and uncomplicated malaria; and areas of resistance to available antimalarial drugs.

IMPLICATIONS

Malaria imported to non-endemic settings, especially P. falciparum malaria, is sometimes initially overlooked and the delayed diagnosis is responsible for every year of preventable deaths. This review aims to raise awareness of malaria outside endemic countries and to provide clinicians with a practical guide for efficient diagnosis and targeted therapy for the different species involved.

[Emergencies in infectious diseases]

This article aims to provide an overview of common and high-impact medical emergencies that require prompt and effective infectious diseases management. In the described clinical scenarios of malaria, sepsis, necrotizing fasciitis, and meningitis the authors have emphasized the crucial importance of rapid and accurate diagnosis, as well as appropriate treatment from the perspective of infectious diseases. All of these emergencies demand a high degree of clinical suspicion for accurate diagnosis. Some of them also necessitate the involvement of other medical disciplines, such as neurology in the case of meningitis or surgery for necrotizing fasciitis. Additionally, implementing the right empiric antibiotic regimen or, in the case of malaria, antiparasitic treatment is crucial for improving patient outcomes. As patients with these diagnoses may present at any outpatient department, and efficient and quick management is essential, a deep understanding of diagnostic algorithms and potential pitfalls is of the utmost importance.

Failure of artemether-lumefantrine therapy in travellers returning to Belgium with Plasmodium falciparum malaria: an observational case series with genomic analysis

BACKGROUND

Failure of artemisinin-based combination therapy is increasingly reported in patients with Plasmodium falciparum malaria in sub-Saharan Africa. We aimed to describe the clinical and genomic characteristics of recent cases of P. falciparum malaria failing artemether-lumefantrine in Belgium.

METHODS

Travel-related cases of malaria confirmed at the national reference laboratory of the Institute of Tropical Medicine, Antwerp, Belgium, were reviewed. All cases for which attending clinicians reported persistence (beyond Day 3 post-treatment initiation, i.e. early failure) or recrudescence (from Day 7 to 42, i.e. late failure) of P. falciparum parasites despite adequate drug intake were analysed. Both initial and persistent/recurrent samples were submitted to next generation sequencing to investigate resistance-conferring mutations.

RESULTS

From July 2022 to June 2023, eight P. falciparum cases of failure with artemether-lumefantrine therapy were reported (early failure = 1; late failure = 7). All travellers were returning from sub-Saharan Africa, most (6/8) after a trip to visit friends and relatives. PfKelch13 (PF3D7_1343700) mutations associated with resistance to artemisinin were found in two travellers returning from East Africa, including the validated marker R561H in the patient with early failure and the candidate marker A675V in a patient with late failure. Additional mutations were detected that could contribute to decreased susceptibility to artemisinin in another three cases, lumefantrine in six cases and proguanil in all eight participants. Various regimens were used to treat the persistent/recrudescent cases, with favourable outcome.

CONCLUSION

Within a 12-month period, we investigated eight travellers returning from sub-Saharan Africa with P. falciparum malaria and in whom artemether-lumefantrine failure was documented. Mutations conferring resistance to antimalarials were found in all analysed blood samples, especially against lumefantrine and proguanil, but also artemisinin. There is a pressing need for systematic genomic surveillance of resistance to antimalarials in international travellers with P. falciparum malaria, especially those experiencing treatment failure.

[Emergencies in infectious diseases]

This article aims to provide an overview of common and high-impact medical emergencies that require prompt and effective infectious diseases management. In the described clinical scenarios of malaria, sepsis, necrotizing fasciitis, and meningitis the authors have emphasized the crucial importance of rapid and accurate diagnosis, as well as appropriate treatment from the perspective of infectious diseases. All of these emergencies demand a high degree of clinical suspicion for accurate diagnosis. Some of them also necessitate the involvement of other medical disciplines, such as neurology in the case of meningitis or surgery for necrotizing fasciitis. Additionally, implementing the right empiric antibiotic regimen or, in the case of malaria, antiparasitic treatment is crucial for improving patient outcomes. As patients with these diagnoses may present at any outpatient department, and efficient and quick management is essential, a deep understanding of diagnostic algorithms and potential pitfalls is of the utmost importance.

Favorable outcome without corticosteroids during post-artesunate delayed hemolysis with positive direct antiglobulin test in severe imported Plasmodium falciparum malaria, France

OBJECTIVES

Positive direct antiglobulin tests (DATs) have been reported in cases of post-artesunate delayed hemolysis (PADH), but the causal role of auto-immune hemolysis remains unclear. We aimed to analyze a cohort of patients with PADH and DAT during severe malaria.

METHODS

We describe PADH and DAT results in a 7-year multi-center retrospective cohort of patients receiving artesunate for severe imported malaria.

RESULTS

Of 337 patients treated with artesunate, 46 (13.6%) had at least one DAT result within 30 days of treatment initiation, and 25/46 (54.3%) had at least one positive DAT. Among 40 patients with available data, 17 (42.5%) experienced PADH. Patient characteristics were similar for patients with a positive or negative DAT, and DAT positivity was not associated with PADH occurrence (P = 0.36). Among patients, 5/13 (38.5%) with a positive DAT after day 7 experienced PADH, compared to 10/13 (76.9%) of those with a negative DAT after day 7 (P = 0.11). Overall, 41% of patients required blood transfusions, and outcome was favorable without corticosteroids, even in cases of PADH.

CONCLUSIONS

DAT does not appear to be a marker of PADH, but rather an indirect marker of an immune-mediated mechanism. DAT positivity should not lead to the administration of systemic corticosteroids during PADH.