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Abstract Background In most countries engaged on the last mile towards malaria elimination, residual transmission mainly persists among vulnerable populations represented by isolated and mobile (often cross-border) communities. These populations are sometimes involved in informal or even illegal activities. In regions with Plasmodium vivax transmission, the specific biology of this parasite poses additional difficulties related to the need for a radical treatment against hypnozoites to prevent relapses. Among hard-to-reach communities, case management, a pillar of elimination strategy, is deficient: acute malaria attacks often occur in remote areas, where there is limited access to care, and drugs acquired outside formal healthcare are often inadequately used for treatment, which typically does not include radical treatment against P. vivax. For these reasons, P. vivax circulation among these communities represents one of the main challenges for malaria elimination in many non-African countries. The objective of this article is to describe the protocol of the CUREMA study, which aims to meet the challenge of targeting malaria in hard-to-reach populations with a focus on P. vivax. Results CUREMA is a multi-centre, international public health intervention research project. The study population is represented by persons involved in artisanal and small-scale gold mining who are active and mobile in the Guiana Shield, deep inside the Amazon Forest. The CUREMA project includes a complex intervention composed of a package of actions: (1) health education activities; (2) targeted administration of treatment against P. vivax after screening against G6PD deficiency to asymptomatic persons considered at risk of silently carrying the parasite; (3) distribution of a self-testing and self-treatment kit (malakit) associated with user training for self-management of malaria symptoms occurring while in extreme isolation. These actions are offered by community health workers at settlements and neighbourhoods (often cross-border) that represent transit and logistic bases of gold miners. The study relies on hybrid design, aiming to evaluate both the effectiveness of the intervention on malaria transmission with a pre/post quasi-experimental design, and its implementation with a mixed methods approach. Conclusions The purpose of this study is to experiment an intervention that addresses both Plasmodium falciparum and P. vivax malaria elimination in a mobile and isolated population and to produce results that can be transferred to many contexts facing the same challenges around the world.

Abstract To eliminate malaria, all populations must be included. For those who are not reached by the health care system, specific interventions must be tailor-made. An innovative Malakit strategy, based on the distribution of self-diagnosis and self-treatment kits, has been evaluated in the Suriname-French Guiana- Amapá (Brazil) region. The results showed effectiveness and good acceptability. The Malakit intervention is complex and has many components. Its transferability requires adaptation to other populations and regions, while retaining the main features of the intervention. This article provides the keys to adapting, implementing and evaluating it in other contexts facing residual malaria in hard-to-reach and/or mobile populations. The process of transferring this intervention includes: diagnosis of the situation (malaria epidemiology, characteristics of the population affected) to define the relevance of the strategy; determination of the stakeholders and the framework of the intervention (research project or public health intervention); adaptation modalities (adaptation of the kit, training, distribution strategy); the role of community health workers and their need for training and supervision. Finally, evaluation needs are specified in relation to prospects for geographical or temporal extension. Malaria elimination is likely to increasingly involve marginalized people due to climate change and displacement of populations. Evaluation of the transferability and effectiveness of the Malakit strategy in new contexts will be essential to increase and refine the evidence of its value, and to decide whether it could be an additional tool in the arsenal recommended in future WHO guidelines.

Abstract Background Plasmodium vivax relapses due to dormant liver hypnozoites can be prevented with primaquine. However, the dose must be adjusted in individuals with glucose-6-phosphate-dehydrogenase (G6PD) deficiency. In French Guiana, assessment of G6PD activity is typically delayed until day (D)14 to avoid the risk if misclassification. This study assessed the kinetics of G6PD activity throughout P. vivax infection to inform the timing of treatment. Methods For this retrospective monocentric study, data on G6PD activity between D1 and D28 after treatment initiation with chloroquine or artemisinin-based combination therapy were collected for patients followed at Cayenne Hospital, French Guiana, between January 2018 and December 2020. Patients were divided into three groups based on the number of available G6PD activity assessments: (i) at least two measurements during the P. vivax malaria infection; (ii) two measurements: one during the current infection and one previously; (iii) only one measurement during the malaria infection. Results In total, 210 patients were included (80, 20 and 110 in groups 1, 2 and 3, respectively). Data from group 1 showed that G6PD activity remained stable in each patient over time (D1, D3, D7, D14, D21, D28). None of the patients with normal G6PD activity during the initial phase (D1–D3) of the malaria episode (n = 44) was categorized as G6PD-deficient at D14. Patients with G6PD activity

Abstract Tick-borne bacteria of the genera Ehrlichia and Anaplasma cause several emerging human infectious diseases worldwide. In this study, we conduct an extensive survey for Ehrlichia and Anaplasma infections in the rainforests of the Amazon biome of French Guiana. Through molecular genetics and metagenomics reconstruction, we observe a high indigenous biodiversity of infections circulating among humans, wildlife, and ticks inhabiting these ecosystems. Molecular typing identifies these infections as highly endemic, with a majority of new strains and putative species specific to French Guiana. They are detected in unusual rainforest wild animals, suggesting they have distinctive sylvatic transmission cycles. They also present potential health hazards, as revealed by the detection of Candidatus Anaplasma sparouinense in human red blood cells and that of a new close relative of the human pathogen Ehrlichia ewingii, Candidatus Ehrlichia cajennense, in the tick species that most frequently bite humans in South America. The genome assembly of three new putative species obtained from human, sloth, and tick metagenomes further reveals the presence of major homologs of Ehrlichia and Anaplasma virulence factors. These observations converge to classify health hazards associated with Ehrlichia and Anaplasma infections in the Amazon biome as distinct from those in the Northern Hemisphere.

Several countries of the Guiana Shield are aiming at the control and elimination of malaria in areas where Artisanal and Small-scale Gold Mining (ASGM) activities predominate, raising questions about how to strengthen community engagement to improve the effectiveness of health programs. The Curema project focuses its intervention on the mobile and hard-to-reach ASGM population, complementing the efforts of national programs in the Guiana Shield. The Curema intervention combines targeted drug administration for suspected Plasmodium vivax asymptomatic carriers, the Malakit distribution, and health education activities. The primary goals of this manuscript are to outline a pathway to foster community participation in the Curema project aimed at eliminating malaria. Thus, it presents a vision of the challenges that the AGSM community poses in terms of community participation for an asymptomatic problem; and highlights the community-based model and the Information, Education and Communication (IEC) components as foundations for participation. In addition, it also presents culturally sensitive IEC strategies designed through iterative and collaborative consultative processes and other bottom-up outreach activities. The community engagement approach facilitates adaptability and responsiveness in a complex, evolving context increasing the effectiveness of interventions.

Gold miners working illegally in mines live in poor health conditions related to their strenuous work and precarious housing. Therefore, they are at higher risk for infectious diseases. American tegumentary leishmaniasis (ATL) appears to be of great concern to the population living in the Guiana Shield region. Our aim was to describe their demographic characteristics, the clinical features of cutaneous leishmaniasis (CL), and the frequency of Leishmania infection in people working in illegal gold mines in French Guiana. A cross-sectional study was carried out from October to December 2019 in Oiapoque city, Amapá, Brazil. Indeed, many gold miners working in French Guiana are originally from Brazil, and from Oiapoque in particular. A total of 105 participants from 31 different mining sites in French Guiana were recruited. Suspected Leishmania infection was confirmed by the following: detection of kDNA in blood or the lesion site; detection of specific antibodies; or detection of IFN-γ release after blood incubation with leishmanial antigens (IGRA-Leish). Nine active CL cases, 38 healed ATL (hATL) and 58 cases with no history of ATL (noATL), were identified. Only half of the treated hATL (50.0%; n = 14) reported having been assisted by a health care unit and the others treated themselves. PCR-kDNA for Leishmania was positive in the blood of 100% of CL cases. Curiously, blood PCR-kDNA was positive in 13% of hATL patients and in 15.5% of noATL patients. The IGRA-Leish was positive in 60.5% of hATL and in 37.9% of noATL. In addition to scars suggestive of CL, 71% of hATL had laboratory evidence of Leishmania infection. Restriction fragment polymorphism (RFLP) of the hsp70 gene identified a sympatric circulation of L. (V.) guyanensis (n = 4), L. (V.) braziliensis (n = 1), L. (L.) amazonensis (n = 2), L. (V.) shawi (n = 1) and L. (V.) naiffi/shawi (n = 1). Taking the laboratory techniques and the clinical evaluations together, 76% (n = 80) of the 105 participants had evidence of Leishmania infection. These results suggests that illegal gold miners working in French Guiana are at high risk for infection with different species of Leishmania, but their illegal condition and remoteness make it difficult for them to access health services.

IntroductionAn innovative and community-based intervention is implemented in the Guiana Shield to eliminate malaria among people involved in artisanal and small-scale gold mining. The intervention consists of the distribution of malaria self-management kits to goldminers and the presumptive treatment for individuals at risk of carrying Plasmodium vivax hypnozoites. The intervention is possible owing to community health workers (CHWs) who are previously trained to master all intervention procedures, including health education activities and goldmining training. This study aimed to evaluate the training program provided to CHWs in terms of quality and effectiveness.MethodsA training-of-trainers program for CHWs has been developed based on the CDC framework. A mixed-method case study was implemented in two steps between February and March 2023. The evaluation was based on a knowledge survey, satisfaction test, observations, and semi-structured interviews. Quantitative and qualitative data were analyzed and triangulated.ResultsA total of 20 CHWs participated in the training and the first-step evaluation. For the second step, four semi-structured interviews were conducted. The Qualitative data showed that group dynamics and adaptations were central elements of a high-quality training program. Quantitative analysis found that CHWs’ satisfaction was elevated (> 4/5 overall), especially regarding format and learning results. Improvements in knowledge level demonstrated good effectiveness (pre-training vs. post-training, p

In French Guiana, life expectancy is between 2 and 3 years below that of France, reflecting differences in mortality rates that are largely sensitive to primary healthcare and thus preventable. However, because poverty affects half of the population in French Guiana, global measurements of life expectancy presumably conflate at least two distinct situations: persons who have similar life expectancies as in mainland France and persons living in precariousness who have far greater mortality rates than their wealthier counterparts. We thus aimed to synthesize what is known about statistical regularities regarding exposures and sketch typical French Guiana exposomes in relation to health outcomes. We conducted a narrative review on common exposures in French Guiana and made comparisons between French Guiana and mainland France, between rich and poor in French Guiana, and between urban and rural areas within French Guiana. The most striking fact this panorama shows is that being a fetus or a young child in French Guiana is fraught with multiple threats. In French Guiana, poverty and poor pregnancy follow-up; renouncing healthcare; wide variety of infectious diseases; very high prevalence of food insecurity; psychosocial stress; micronutrient deficiencies; obesity and metabolic problems; and frequent exposure to lead and mercury in rural areas constitute a stunningly challenging exposome for a new human being to develop into. A substantial part of the population’s health is hence affected by poverty and its sources of nutrition.

In French Guiana, more than a third of the population, and nearly half of the adults, are of foreign origin. This immigration is explained by the French standard of living, which is attractive to nationals of surrounding countries. Infectious diseases remain in the top 10 causes of premature death, often in the most precarious populations. In this context we aimed to synthesize the state of the knowledge regarding immigration and infectious diseases in French Guiana and the general implications that follow this diagnosis.For HIV, although the majority of patients are of foreign origin, estimates of the presumed date of infection based on CD4 erosion modelling and from molecular analyses suggest that the majority of transmissions in foreign-born individuals occur in French Guiana and that the Guiana shield has been a crossroad between Latin America and the Caribbean. Among key populations bridging these regions illegal gold miners are very mobile and have the greatest proportion B Caribbean HIV viruses. Gold miners have been a key vulnerable population for falciparum malaria and other tropical diseases such as leishmaniasis, leprosy, or leptospirosis. The complex history of migrations in French Guiana and on the Guiana Shield is also reflected in the fingerprinting of mycobacterium tuberculosis and the high incidence of tuberculosis in French Guiana, notably in immigrants, reflects the incidences in the countries of origin of patients. The high burden of infectious diseases in immigrants in French Guiana is first and foremost a reflection of the precarious living conditions within French Guiana and suggests that community-based proactive interventions are crucial to reduce transmission, morbidity, and mortality from infectious diseases.