Imported Malaria in Portugal: Prevalence of Polymorphisms in the Anti-Malarial Drug Resistance Genes pfmdr1 and pfk13

An overview of artemisinin-resistant malaria and associated Pfk13 gene mutations in Central Africa

Malaria caused by Plasmodium falciparum is one of the deadliest and most common tropical infectious diseases. However, the emergence of artemisinin drug resistance associated with the parasite's Pfk13 gene, threatens the public health of individual countries as well as current efforts to reduce malaria burdens globally. It is of concern that artemisinin-resistant parasites may be selected or have already emerged in Africa. This narrative review aims to evaluate the published evidence concerning validated, candidate, and novel Pfk13 polymorphisms in ten Central African countries. Results show that four validated non-synonymous polymorphisms (M476I, R539T, P553L, and P574L), directly associated with a delayed therapy response, have been reported in the region. Also, two Pfk13 polymorphisms associated to artemisinin resistance but not validated (C469F and P527H) have been reported. Furthermore, several non-validated mutations have been observed in Central Africa, and one allele A578S, is commonly found in different countries, although additional molecular and biochemical studies are needed to investigate whether those mutations alter artemisinin effects. This information is discussed in the context of biochemical and genetic aspects of Pfk13, and related to the regional malaria epidemiology of Central African countries.

Anti-malarial resistance in Mozambique: Absence of Plasmodium falciparum Kelch 13 (K13) propeller domain polymorphisms associated with resistance to artemisinins

BACKGROUND

Malaria remains one of the most serious public health problems in sub-Saharan Africa and Mozambique is the world's fourth largest contributor, with 4.7% of disease cases and 3.6% of total deaths due to malaria. Its control relies on the fight against the vector and treatment of confirmed cases with anti-malarial drugs. Molecular surveillance is an important tool for monitoring the spread of anti-malarial drug resistance.

METHODS

A cross-sectional study recruited 450 participants with malaria infection detected by Rapid Diagnostic Tests, from three different study sites (Niassa, Manica and Maputo) between April and August 2021. Correspondent blood samples were collected on filter paper (Whatman® FTA® cards), parasite DNA extracted and pfk13 gene sequenced using Sanger method. SIFT software (Sorting Intolerant From Tolerant) was used, predict whether an amino acid substitution affects protein function.

RESULTS

No pfkelch13-mediated artemisinin resistance gene mutation was detected in this study settings. However, non-synonymous mutations were detected at prevalence of 10.2%, 6% and 5% in Niassa, Manica and Maputo, respectively. Most (56.3%) of the reported non-synonymous mutations were due to substitution at the first base of the codon, 25% at the second base and 18.8% at the third base. Additionally, 50% of non-synonymous mutations showed a SIFTscore bellow cut off value of 0.05, therefore, they were predicted to be deleterious.

CONCLUSION

These results do not show an emergence of artemisinin resistance cases in Mozambique. However, the increased number of novel non-synonymous mutations highlights the relevance of increasing the number of studies focused on the molecular surveillance of artemisinin resistance markers, for its early detection.

HIV Infection Diagnosis in a Late Presenter Patient during a Severe Imported Falciparum Malaria: A Challenging

BACKGROUND: Malaria and HIV share the same epidemiological spreading and coinfection may be clinically challenging. In 2019, nearly all malaria cases reported by EU/EEA countries were imported. Severe falciparum malaria is a medical emergency often associated with poor outcome, even when treated with appropriate therapy. CASE PRESENTATION: Here, we described an unusual case of a late presenter HIV diagnosis made during the management of a severe falciparum malaria in an Italian traveler returning from Nigeria, who did not take antimalaria prophylaxis. Clinical course was complicated by the occurrence of several superinfections caused by deep immunosuppression, and bilateral subsegmental pulmonary embolism. CONCLUSION: Although critical conditions, malaria prompt diagnosis and treatment, along with HIV diagnosis and the successful treatment of occurred superinfection, resulted in a positive outcome.