Community engagement in mobile and hard-to-reach populations: a community-based intervention for malaria elimination in a tri-national region of the Guiana Shield.

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.

CUREMA project: a further step towards malaria elimination among hard-to-reach and mobile populations.

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.

Clinical and parasitological features of Leishmania infection among gold miners in the Oiapoque basin, an international Brazil-French Guiana border.

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.

Core principles of Malakit intervention for transferability in other contexts.

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.

Kinetics of glucose-6-phosphate dehydrogenase (G6PD) activity during Plasmodium vivax infection: implications for early radical malaria treatment.

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 < 80% at D1 or D3 showed normal activity at D14. Sex and reticulocyte count were statistically associated with G6PD activity variation. In the whole sample (n = 210), no patient had severe G6PD deficiency (< 10%) and only three between 10 and 30%, giving a G6PD deficiency prevalence of 1.4%. Among the 100 patients from group 1 and 2, 30 patients (26.5%) were lost to follow-up before primaquine initiation. CONCLUSIONS: In patients treated for P. vivax infection, G6PD activity did not vary over time. Therefore, G6PD activity on D1 instead of D14 could be used for primaquine dose-adjustment. This could allow earlier radical treatment with primaquine, that could have a public health impact by decreasing early recurrences and patients lost to follow-up before primaquine initiation. This hypothesis needs to be confirmed in larger prospective studies.

Detection of Anaplasma and Ehrlichia bacteria in humans, wildlife, and ticks in the Amazon rainforest.

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.

Cooperation for malaria control and elimination in the Guiana Shield.

The Guiana Shield, a small region of South America, is currently one of the main hotspots of malaria transmission on the continent. This Amazonian area is characterised by remarkable socioeconomic, cultural, health, and political heterogeneity and a high degree of regional and cross-border population mobility, which has contributed to the increase of malaria in the region in the past few years. In this context, regional cooperation to control malaria represents both a challenge and an indispensable initiative. This Viewpoint advocates for the creation of a regional cooperative mechanism for the elimination of malaria in the Guiana Shield. This strategy would help address operational and political obstacles to successful technical cooperation in the region and could contribute to reversing the regional upsurge in malaria incidence through creating a functional international control and elimination partnership.

Migration in French Guiana: Implications in health and infectious diseases.

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.

Social determinants of health among people working on informal gold mines in French Guiana: a multicentre cross-sectional survey.

INTRODUCTION: Social determinants of health, such as living and working conditions, economical and environmental context and access to care, combine to impact the health of individuals and communities. In French Guiana (FG), the persons working in informal artisanal and small-scale gold mining in the rainforest are a particularly vulnerable population which lives in precarious conditions and far from the health system. Previous studies have demonstrated their high morbidity due to infectious diseases. This study aims to describe the social determinants of health in this specific population. METHODS: This international multicentre cross-sectional survey included people working on the informal FG gold mines at the crossing points located at both borders with Suriname and Brazil. After collecting written informed consent, a structured questionnaire was administered. RESULTS: From September to December 2022, 539 gold miners were included. These poorly educated migrants, mainly from Brazil (99.1%) did not have access to drinkable water (95.4%), lived in close contact with wild fauna by hunting, eating bushmeat or being bitten and were exposed to mercury by inhalation (58.8%) or ingestion (80.5%). They report frequent accidents (13.5%) and chronic treatment interruptions (26.6% of the 11.9% reporting chronic treatment). Half of them considered themselves in good health (56.4%). CONCLUSION: This study shows a singular combination of adverse exposures of gold miners working in FG such as zoonoses, heavy metal poisoning, aggression of wild fauna. For ethical as well as public health reasons, actions towards health equity must be considered at different levels: individual, community, environmental, systemic and global level. As end users of minerals, we must assume our responsibilities for the well-being of the extractors by including health in political decisions to engage together in global health. TRIAL REGISTRATION NUMBER: NCT05540470.

From an interventional study to a national scale-up: lessons learned from the Malakit strategy at the French Guiana-Suriname border.

Scaling-up an experimental intervention is always a challenge. On the border between French Guiana, Brazil and Suriname, an interventional study demonstrated the effectiveness of distributing self-diagnosis and self-treatment kits (Malakits) to control malaria in mobile and hard-to-reach populations. Its integration into the Suriname's National Malaria Elimination Plan after a 2-year experiment faced numerous challenges, including human resources to cope with the additional workload of coordinators and to maintain the motivation of community health workers. The economic recession in Suriname, the Covid pandemic, and logistical issues also hampered the scale-up. Finally, thanks to the commitment of stakeholders in Suriname and French Guiana, the integration of Malakit distribution into the Surinamese national programme was proved possible.

Determination of different social groups' level of knowledge about malaria in a multicultural Amazonian cross-border context.

BACKGROUND: A steady decline in the number of cases of malaria was observed in the 2000s in French Guiana. This enabled regional health policies to shift their public health goal from control to elimination. To include inhabitants in this strategy, the main objective of this study was to describe knowledge about malaria, and related attitudes and practices in persons living in the French Guiana border. METHODS: We conducted a survey in people over 15 years old living in the twelve neighbourhoods of Saint-Georges de l'Oyapock with the highest malaria incidence. It comprised a 147-item questionnaire which collected data on socio-demographic characteristics and included a Knowledge Attitude and Practices survey on malaria. Knowledge-related data were studied using exploratory statistical methods to derive summary variables. A binary variable assessing level of knowledge was proposed and then assessed using exploratory approaches. RESULTS: The mean age of the 844 participants was 37.2 years [15.8], the male/female sex ratio was 0.8. In terms of nationality, 485 (57.5%) participants were Brazilian and 352 (41.7%) French. One third (305, 36.1%) spoke Brazilian Portuguese as their native language, 295 (34.9%) the Amerindian language Palikur, 36 (4.3%) French. The symptoms of malaria and prevention means were poorly known by 213 (25.2%) and 378 (44.8%) respondents, respectively. A quarter (206, 24.4%) did not know that malaria can be fatal. Overall, 251 people (29.7%) had an overall poor level of knowledge about malaria. Being under 25 years old, living in a native Amerindian neighbourhood, having an Amerindian mother tongue language, having risk behaviours related to gold mining were significantly associated with a poor level of knowledge. CONCLUSIONS: This study is the first to describe the poor level of knowledge about malaria in populations living in the malaria endemic border area along the Oyapock river in French Guiana. Results will allow to reinforce, to diversify and to culturally adapt prevention messages and health promotion to increase their effectiveness with a view to quickly reaching the goal of malaria elimination through empowerment.

COVID-19 and Vaccination: Knowledge, Attitudes and Practices of People Working on Illegal Gold Mining Sites in French Guiana.

INTRODUCTION: French Guiana is a French territory bordering Brazil and Suriname where the COVID-19 pandemic has severely strained the French Guianese health system. The people working on illegal gold mining sites in French Guiana, also known as garimpeiros, are mainly of Brazilian origin. Their health conditions are precarious, they live under the radar of the surveillance system and therefore, assessment of their health is quite challenging.. The objective of this study was to describe their knowledge, attitudes and practices regarding COVID-19 and vaccination against this infection. METHODS: We conducted an international multicenter cross-sectional survey between 1 March 2022 and 30 April 2022 in French Guiana and Suriname, using a structured questionnaire. RESULTS: Eighty persons were included, 95.0% of whom were Brazilian. Most had good general knowledge of COVID-19. Antibiotic prophylaxis had been practiced by 10.0% of participants. Forty-three people thought they had been infected with COVID-19 (53.8%). Self-medication was frequent, often with antibiotics (32.6%, mostlychloroquine, ivermectin or azithromycin) and most had not consulted a physician for symptoms of COVID-19. A majority (62.5%) had received at least one dose of vaccine. Those who were ever tested for COVID-19 were the most likely to be vaccinated (PR = 1.98, p = 0.009). CONCLUSIONS: Garimpeiros have a good level of knowledge about COVID-19 but the high consumption of antibiotics raises concerns about the selection of resistant bacteria. The vaccination rate was higher than that of the Guianese population. The most vaccinated individuals were those who had already taken a COVID test suggesting that these individuals had more exposure to the disease, were more health conscious, or had easier access to health centers.

[Overview of infectious and non-infectious diseases in French Guiana in 2022]. / Panorama des pathologies infectieuses et non infectieuses de Guyane en 2022.

Source of many myths, French Guiana represents an exceptional territory due to the richness of its biodiversity and the variety of its communities. The only European territory in Amazonia, surrounded by the Brazilian giant and the little-known Suriname, Ariane 6 rockets are launched from Kourou while 50% of the population lives below the poverty line. This paradoxical situation is a source of health problems specific to this territory, whether they be infectious diseases with unknown germs, intoxications or chronic pathologies.Some infectious diseases such as Q fever, toxoplasmosis, cryptococcosis or HIV infection are in common with temperate countries, but present specificities leading to sometimes different management and medical reasoning. In addition to these pathologies, many tropical diseases are present in an endemic and / or epidemic mode such as malaria, leishmaniasis, Chagas disease, histoplasmosis or dengue. Besides, Amazonian dermatology is extremely varied, ranging from rare but serious pathologies (Buruli ulcer, leprosy) to others which are frequent and benign such as agouti lice (mites of the family Trombiculidae) or papillonitis. Envenomations by wild fauna are not rare, and deserve an appropriate management of the incriminated taxon. Obstetrical, cardiovascular and metabolic cosmopolitan pathologies sometimes take on a particular dimension in French Guiana that must be taken into account in the management of patients. Finally, different types of intoxication are to be known by practitioners, especially due to heavy metals.European-level resources offer diagnostic and therapeutic possibilities that do not exist in the surrounding countries and regions, thus allowing the management of diseases that are not well known elsewhere.Thanks to these same European-level resources, research in Guyana occupies a key place within the Amazon region, despite a smaller population than in the surrounding countries. Thus, certain pathologies such as histoplasmosis of the immunocompromised patient, Amazonian toxoplasmosis or Q fever are hardly described in neighboring countries, probably due to under-diagnosis linked to more limited resources. French Guiana plays a leading role in the study of these diseases.The objective of this overview is to guide health care providers coming to or practicing in French Guiana in their daily practice, but also practitioners taking care of people returning from French Guiana.

Case Report: Acute Brucellosis Due to Brucella suis in a Brazilian Gold Miner Diagnosed in French Guiana.

A 29-year-old Brazilian illegal gold miner developed intermittent fever. Blood cultures were positive for Gram-negative coccobacilli and, after an initial misidentification by an automated identification system, the diagnosis of brucellosis caused by Brucella suis was confirmed. We hypothesize an association with domestic or wild swine exposure. The patient responded well to standard antibiotic therapy of brucellosis. We report the first case of human brucellosis on the Guiana Shield. This report underlines the importance of considering brucellosis in the presence of a fever of unknown origin, even in the Amazonian rainforest area, where several zoonotic diseases might be considered in the differential diagnosis of unexplained fever.

The Epidemiologic Transition in French Guiana: Secular Trends and Setbacks, and Comparisons with Continental France and South American Countries.

There are great variations between population subgroups, notably in poorer countries, leading to substantial inconsistencies with those predicted by the classical epidemiologic transition theory. In this context, using public data, we aimed to determine how the singular case of French Guiana fit and transitioned in the epidemiologic transition framework. The data show a gradual decline in infant mortality to values above 8 per 1000 live births. Premature mortality rates were greater but declined more rapidly in French Guiana than in mainland France until 2017 when they reascended in a context of political turmoil followed by the COVID-19 pandemic and strong reluctance to get vaccinated. Although infections were a more frequent cause of death in French Guiana, there is a marked decline and circulatory and metabolic causes are major causes of premature death. Fertility rates remain high (>3 live births per woman), and the age structure of the population is still pyramid-shaped. The singularities of French Guiana (rich country, universal health system, widespread poverty) explain why its transition does not fit neatly within the usual stages of transition. Beyond gradual improvements in secular trends, the data also suggest that political turmoil and fake news may have detrimentally affected mortality in French Guiana and reversed improving trends.

Emerging infectious diseases and new pandemics: dancing with a ghost! Lessons in inter- and transdisciplinary research in French Guiana, South America.

In light of current international public health challenges, calls for inter- and transdisciplinary research are increasing, particularly in response to complex and intersecting issues. Although widely used under the One Health flag, it is still unclear how inter- and transdisciplinary science should be applied to infectious disease research, public health, and the different stakeholders. Here, we present and discuss our common scientific and biomedical experience in French Guiana, South America to conduct and enrich research in vector-borne and zoonotic infectious diseases, with the aim to translate findings to public health and political stakeholders. We highlight the successful progressive dissolution of disciplinary boundaries that go beyond One Health positive-driven assumptions and argue that specific local conditions, as well as strong support from research and medical institutions, have facilitated an emulsion toward inter- and transdisciplinary science. This argument is intended to improve responses to public health concerns in French Guiana and other countries and regions of the world.

The burden of COVID-19 in French Guiana: Vaccine-averted deaths, hospitalizations and costs.

Objectives: French Guiana, the least-vaccinated French territory, also has the lowest COVID-19 vaccination coverage in Latin America. We aimed to estimate how many deaths, hospitalizations and costs the vaccines had and could have avoided. Methods: We calculated the Number Needed to Vaccinate to prevent one death per year, 1 standard hospitalization, 1 Intensive Care Unit admission given the mean incidence numbers of the past 6 months, and divided the number of persons vaccinated to estimate how many deaths and hospitalizations had been avoided in French Guiana at that time. Results: The crude number needed to vaccinate to prevent one death per year, the crude number needed to vaccinate to prevent one hospitalization per 6 months were computed Based on our observed incidence and ICU admission rate, the crude number needed to vaccinate to prevent one ICU admission per 6 months.After 6 months with an incidence exceeding 400 per million inhabitants, and 148 observed deaths, we estimate that vaccination avoided 46 deaths (IC95%=43.5-48.7). If the number of vaccinated persons had reached the same proportion as mainland France, 141 deaths per year could have been prevented (IC95%=131.9-147.6).With 2085 hospitalization and 370 ICU admissions during the same period, we estimate that the current albeit low vaccination rate avoided 300 hospital (IC95%=280-313) and 77 (IC95%=72-81) ICU admissions. With the same vaccination rates as mainland France, we estimate that 900 hospitalizations and 231 ICU admissions would have been avoided.Similarly, there would have been 139 ICU admission (instead of 370). Conclusions: In sparsely populated French Guiana these numbers are quite substantial and framing the vaccine benefits and wasted opportunities using such concrete numbers may help convincing undecided persons to get vaccinated.

Automated and combined HIV, HBV, HCV, and syphilis testing among illegal gold miners in French Guiana using a standardized dried blood device.

Blood spotted onto filter paper can be easily collected outside healthcare facilities and shipped to a central laboratory for serological testing. However, dried blood testing generally requires manual processing for pre-analytical steps. In this study, we used a standardized blood collection device combined with an automated elution system to test illegal gold miners living in French Guiana for human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis. We included 378 participants, 102 females and 266 males, in three illegal gold mining resting sites. Blood collected on the Ser-Col device (Labonovum) was eluted using an automated system (SCAUT Ser-Col automation, Blok System Supply) and an automated analyzer (Alinity i, Abbott). Ser-Col results were compared to both plasma results, considered the gold standard, and to Dried blood Spot (DBS) results, considered the reference sampling method using dried blood. In plasma samples, two participants (0.5%) tested positive for HIV, six (1.5%) tested positive for hepatitis B surface antigen (HBsAg), eight were weakly positive for anti-HCV antibodies but negative for HCV RNA, and 47 tested positive for treponemal antibodies (12.4%), including 20 females (19.6%) and 27 males (9.8%, p= 0.010179). We observed a full concordance of Ser-Col and DBS results for HIV diagnosis compared to plasma results. Ser-Col and DBS samples tested positive in five HBsAg carriers and negative for one participant with a low HBsAg level in plasma (0.5 IU/mL). All participants tested negative for HCV in Ser-Col and DBS samples, including the eight participants who tested low positive for HCV antibodies and HCV RNA negative in plasma. Among syphilis seropositive participants, 41 (87.2%) and 40 (85.1%) tested positive for treponemal antibodies in Ser-Col and DBS samples, respectively. The Ser-Col method allows automated dried blood testing of HIV, HBV, HCV and syphilis with performances comparable to DBS. Automated approaches to test capillary blood transported on dried blood devices may facilitate large-scale surveys and improve testing of populations living in remote areas.

Contrasted life trajectories: reconstituting the main population exposomes in French Guiana.

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.