Le paludisme en France : métropole et outre-mer

Prevention and management of infectious and tropical diseases in kidney transplant recipients residing in European outermost and overseas territories

BACKGROUND

The European Union encompasses 30 outermost and overseas countries and territories (OCTs). Despite a recent increasing activity of renal transplantation in these territories, many patients still undergo transplantation in continental Europe, with follow-up care coordinated between health professionals from both their transplant center and their home region. Each territory has its unique infectious epidemiology which must be known to ensure appropriate care for kidney transplant recipients (KTRs).

AIMS

This paper proposes a pragmatic approach to optimize pre-transplant check-up and to provide an overview of the specific epidemiological features of each region. It offers practical algorithms to help practitioners in managing infected KTR living in these territories. This work advocates for increased collaborative research among European OCTs.

Accuracy of SD Malaria Ag P.f/Pan® as a rapid diagnostic test in French Amazonia

Background

French Guiana (FG) is a French overseas territory where malaria is endemic. The current incidence rate is 0.74‰ inhabitants, and Plasmodium vivax is widely predominating even though Plasmodium falciparum is still present due to imported cases mainly from Africa. In FG, rapid diagnostic test (SD Malaria Ag P.f/Pan®) is based on the detection of pan-pLDH, PfHRP2, and PfHRP3 antigens, while in South America, the share of deletion of PfHRP2 gene is significantly increasing. Accordingly, the study questions the reliability of RDTs in the Amazonian context.

Methods

The study is retrospective. It is conducted over 4 years and analysed 12,880 rapid diagnostic tests (RDTs) compared to concomitant Blood Film Tests (BFTs) sampled for malaria diagnosis.

Results

The global assessment of the accuracy of SD Malaria Ag P.f/Pan® in the diagnostic of malaria shows both Positive and Negative Predictive Values (PPV and NPV) higher than 95%, except for PPV in the diagnosis of malaria to P. falciparum (88%). Overall, the concordance rate between RDT and BFT (positive/positive; negative/negative) was 99.5%. The PPV of the RDT in the follow-up of patients diagnosed with P. falciparum was the lowest during the first 28 days. The PPV of the RDT in the follow-up of patients diagnosed with P. vivax was the lowest during the first 21 days. The global sensitivity of SD Malaria Ag P.f/Pan® test was, on average, 96% (88.2–100) for P. falciparum and 93% (90.6–94.2) for P. vivax. The global specificity was 99.8% (99.5–100) for all included species.

Conclusion

SD Malaria Ag P.f/Pan® is a reliable rapid test used for the first-line diagnosis in remote healthcare centres. The test results should be interpreted in the light of patient’s recent medical history and the date of arrival to FG.

Changes in malaria epidemiology in France and worldwide, 2000-2015

In 2015, 212 million new cases of malaria were reported, causing 429,000 deaths. The World Health Organization (WHO) estimated a 41% decrease in the number of new cases worldwide between 2000 and 2015. The number of deaths from malaria fell by 62% worldwide and by 71% in Africa. In mainland France, malaria is mainly imported by travelers or migrants from endemic areas, in particular sub-Saharan Africa (95%). In France, the number of imported malaria cases, mainly due to Plasmodium falciparum (85%), was estimated at about 82,000 for the period 2000-2015. Over the same period, 6,468 cases of malaria were reported in the French armed forces, of which 2,430 cases (37.6%) were considered as imported because occurring outside of endemic areas. The number of malaria cases also fell between 2000 and 2015 in Mayotte and French Guiana, a malaria transmission zone. Mayotte has entered the elimination of malaria with less than 15 cases per year. In French Guiana, between 300 and 500 cases have been reported annually in recent years. The decline in morbidity and mortality is usually attributed to vector control measures and improved access to effective treatments. However, the Anopheles mosquitoes that transmit the disease have developed resistance against most insecticides. Similarly, malaria parasites have developed resistance against most of the antimalarial drugs used as prevention or treatment, even the latest marketed combinations such as artemisinin-based combination therapies.

K13-Propeller Polymorphisms in Plasmodium falciparum Isolates from Patients in Mayotte in 2013 and 2014

Plasmodium falciparum isolates were collected from 29 malaria patients treated with artemether-lumefantrine in Mayotte in 2013 and 2014. Twenty-four cases (83%) consisted of imported malaria. Seventeen percent of the isolates presented mutations in one of the six K13-propeller blades (N490H, F495L, N554H/K, and E596G). A total of 23.8% of the isolates from the Union of Comoros showed K13-propeller polymorphisms. Three of the 18 isolates (16.7%) from Grande Comore showed polymorphisms (N490H, N554K, and E596G).

Malaria on the Guiana Shield: a review of the situation in French Guiana

In a climate of growing concern that Plasmodium falciparum may be developing a drug resistance to artemisinin derivatives in the Guiana Shield, this review details our current knowledge of malaria and control strategy in one part of the Shield, French Guiana. Local epidemiology, test-treat-track strategy, the state of parasite drug resistance and vector control measures are summarised. Current issues in terms of mobile populations and legislative limitations are also discussed.

Objective sampling design in a highly heterogeneous landscape - characterizing environmental determinants of malaria vector distribution in French Guiana, in the Amazonian region

Background

Sampling design is a key issue when establishing species inventories and characterizing habitats within highly heterogeneous landscapes. Sampling efforts in such environments may be constrained and many field studies only rely on subjective and/or qualitative approaches to design collection strategy. The region of Cacao, in French Guiana, provides an excellent study site to understand the presence and abundance of Anopheles mosquitoes, their species dynamics and the transmission risk of malaria across various environments. We propose an objective methodology to define a stratified sampling design. Following thorough environmental characterization, a factorial analysis of mixed groups allows the data to be reduced and non-collinear principal components to be identified while balancing the influences of the different environmental factors. Such components defined new variables which could then be used in a robust k-means clustering procedure. Then, we identified five clusters that corresponded to our sampling strata and selected sampling sites in each stratum.

Results

We validated our method by comparing the species overlap of entomological collections from selected sites and the environmental similarities of the same sites. The Morisita index was significantly correlated (Pearson linear correlation) with environmental similarity based on i) the balanced environmental variable groups considered jointly (p = 0.001) and ii) land cover/use (p-value << 0.001). The Jaccard index was significantly correlated with land cover/use-based environmental similarity (p-value = 0.001).

Conclusions

The results validate our sampling approach. Land cover/use maps (based on high spatial resolution satellite images) were shown to be particularly useful when studying the presence, density and diversity of Anopheles mosquitoes at local scales and in very heterogeneous landscapes.