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.

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.

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.

Impact of Malakit intervention on perceptions, knowledge, attitudes, and practices related to malaria among workers in clandestine gold mines in French Guiana: results of multicentric cross-sectional surveys over time.

BACKGROUND: Clandestine gold miners remain key hosts for malaria in French Guiana (FG) and contribute to imported malaria cases in Suriname and Brazil. The Malakit intervention, implemented in FG borders with Suriname and Brazil, provided gold miners with training on malaria and kits for self-diagnosis and self-treatment. Having shown a likely impact on malaria transmission, Suriname has now implemented it in routine care for cross-border moving populations. However, a decrease in malaria transmission is frequently associated with a decrease in risk perception, knowledge, and good practices regarding malaria. This study aims to describe the evolution of the perceptions, knowledge, attitudes, and practices (KAP) related to malaria among clandestine gold miners between 2015 and 2019, and to estimate the impact of Malakit on the FG/Suriname border. METHODS: The primary outcome was the overall KAP score over time and among participants and not participants in the Malakit intervention. A propensity score matching analysis and an inverse probability of treatment weighing analysis were used to estimate the Average Treatment effect on the Treated and the Average Treatment Effect of Malakit, respectively. RESULTS: Perception and knowledge scores were significantly lower in 2019 compared to 2015 (- 0.27 and - 0.23 points, respectively, p < 0.001) while attitude and practice scores were higher (+ 0.16 and + 0.47 points, respectively, p < 0.001). The overall KAP score was significantly higher among participants in Malakit with both propensity score matching (+ 0.72 points, 95%IC [0.29; 1.15]) and inverse probability of treatment weighting analysis (+ 0.70 points, 95%IC [0.34; 1.05]). CONCLUSION: A decrease in perception and knowledge about malaria but an improvement of attitudes and practices as the incidence of malaria decreased are observed. The Malakit intervention seems to have a significant positive impact on the overall KAP related to malaria. The integration of this strategy into malaria control programmes could help to improve the KAP, even in areas where malaria is nearly eliminated, through optimal training and health empowerment. Trial registration ClinicalTrials.gov registration number: NCT03695770.

Implementation of a novel malaria management strategy based on self-testing and self-treatment in remote areas in the Amazon (Malakit): confronting a-priori assumptions with reality.

BACKGROUND: A novel strategy to combat malaria was tested using a methodology adapted to a complex setting in the Amazon region and a hard-to-reach, mobile community. The intervention strategy tested was the distribution, after training, of malaria self-management kits to gold miners who cross the Surinamese and Brazilian borders with French Guiana to work illegally in the remote mining sites in the forest of this French overseas entity. MAIN TEXT: This article aims at presenting all process and implementation outcomes following the Conceptual Framework of Implementation Fidelity i.e. adherence, including content and exposure, and moderators, comprising participant responsiveness, quality of delivery, facilitation strategies, and context. The information sources are the post-intervention survey, data collected longitudinally during the intervention, a qualitative study, data collected during an outreach mission to a remote gold mining site, supervisory visit reports, in-depth feedback from the project implementers, and videos self-recorded by facilitators based on opened ended questions. As expected, being part of or close to the study community was an essential condition to enable deliverers, referred to as "facilitators", to overcome the usual wariness of this gold mining population. Overall, the content of the intervention was in line with what was planned. With an estimated one third of the population reached, exposure was satisfactory considering the challenging context, but improvable by increasing ad hoc off-site distribution according to needs. Participant responsiveness was the main strength of the intervention, but could be enhanced by reducing the duration of the process to get a kit, which could be disincentive in some places. Regarding the quality of delivery, the main issue was the excess of information provided to participants rather than a lack of information, but this was corrected over time. The expected decrease in malaria incidence became a source of reduced interest in the kit. Expanding the scope of facilitators' responsibilities could be a suitable response. Better articulation with existing malaria management services is recommended to ensure sustainability. CONCLUSIONS: These findings supplement the evaluation outcomes for assessing the relevance of the strategy and provide useful information to perpetuate and transfer it in comparable contexts. TRIAL REGISTRATION: ClinicalTrials.gov.  NCT03695770 . 10/02/2018 "Retrospectively registered".

Setting-up a cross-border action-research project to control malaria in remote areas of the Amazon: describing the birth and milestones of a complex international project (Malakit).

BACKGROUND: In French Guiana, gold miners working illegally represents a major reservoir of malaria. This mobile population, mainly of Brazilian descent, enters the French Guianese forest from neighbouring countries, Suriname and Brazil. A complex and innovative intervention was piloted as a cooperation with the three involved countries involved to control malaria in this specific population. The principle was that health workers called "facilitators" provide the participants with a self-diagnosis and self-treatment kit along with adequate training and material to rapidly manage an episode of malaria symptoms on their own, when they find themselves isolated from health care services. METHODS: This paper describes the design, development, content of the intervention and players' organization of this multi-country project, the opportunities and constraints encountered, and the lessons learnt at this stage. RESULTS: The choice not to implement the usual "Test and Treat" approach within the community is mainly driven by regulatory reasons. The content of medical messages tends to balance the tension between thoroughness, accuracy and efficacy. The wide range of tools developed through a participatory approach was intended to cope with the challenges of the literacy level of the target population. Despite the difficulties encountered due to language, regulation differences and distance between partners, cooperation was fruitful, due to the complementary of stakeholders, their involvement at all important stages and regular face-to-face meetings. DISCUSSION AND CONCLUSION: This experience shows the feasibility of an ambitious project of action-research in a border malaria context, involving several countries and with a mobile and undocumented population. It reveals some factors of success which may be transferable in analogous settings.

Zika Virus Seroprevalence in Urban and Rural Areas of Suriname, 2017.

In 2015-2016, a Zika virus (ZIKV) outbreak occurred in the Americas. In 2017, we conducted a ZIKV serosurvey in Suriname in which 770 participants were recruited from 1 urban area and 2 rural villages in the tropical rainforest. All collected samples were tested for presence of ZIKV antibodies using a ZIKV immunoglobulin G enzyme-linked immunosorbent assay and a virus neutralization assay. We found that 35.1% of the participants had neutralizing antibodies against ZIKV. In 1 remote village in the rainforest, 24.5% of the participants had neutralizing antibodies against ZIKV, suggesting that ZIKV was widely spread across Suriname.

Malakit: an innovative pilot project to self-diagnose and self-treat malaria among illegal gold miners in the Guiana Shield.

BACKGROUND: Illegal gold miners in French Guiana, a French overseas territory ('département') located in Amazonia, often carry malaria parasites (up to 46.8%). While the Guiana Shield Region aims at malaria elimination, the high prevalence of Plasmodium in this hard-to-reach population in conjunction with frequent incorrect use of artemisinin-based anti-malarials could favour the emergence of resistant parasites. Due to geographical and regulatory issues in French Guiana, usual malaria control strategies cannot be implemented in this particular context. Therefore, new strategies targeting this specific population in the forest are required. METHODS: Numerous discussions among health institutions and scientific partners from French Guiana, Brazil and Suriname have led to an innovative project based on the distribution of kits for self-diagnosis and self-treatment of Plasmodium infections. The kit-distribution will be implemented at "resting sites", which are areas across the border of French Guiana regularly frequented by gold miners. The main objective is to increase the appropriate use and complete malaria treatment after a positive malaria diagnosis with a rapid test, which will be evaluated with before-and-after cross-sectional studies. Monitoring indicators will be collected from health mediators at the time of kit distribution and during subsequent visits, and from illegal gold miners themselves, through a smartphone application. The project funding is multisource, including Ministries of Health of the three countries, WHO/PAHO, and the European Union. RESULTS: This project will start in April 2018 as a 18 month pilot study led by the Clinical Investigation Centre of Cayenne. Results should be available at the end of 2019. DISCUSSION: This innovative approach may have several limitations which should be taken into account, as potential side effects, kit misuse or resale, declarative main criteria, or no Plasmodium vivax curative treatment. Close monitoring is thus needed. CONCLUSIONS: This project may be the best available solution to a specific and important public health challenge in the Guiana Shield. If the use of self-diagnosis and self-treatment approach is effective, this strategy could be sustained by health institutions in the region.

Molecular Profile of Malaria Drug Resistance Markers of Plasmodium falciparum in Suriname.

In Suriname, an artesunate monotherapy therapeutic efficacy trial was recently conducted to evaluate partial artemisinin resistance emerging in Plasmodium falciparum We genotyped the PfK13 propeller domain of P. falciparum in 40 samples as well as other mutations proposed to be associated with artemisinin-resistant mutants. We did not find any mutations previously associated with artemisinin resistance in Southeast Asia, but we found fixed resistance mutations for chloroquine (CQ) and sulfadoxine-pyrimethamine. Additionally, the PfCRT C350R mutation, associated with reversal of CQ resistance and piperaquine-selective pressure, was present in 62% of the samples. Our results from neutral microsatellite data also confirmed a high parasite gene flow in the Guiana Shield. Although recruiting participants for therapeutic efficacy studies is challenging in areas where malaria endemicity is very low due to the low number of malaria cases reported, conducting these studies along with molecular surveillance remains essential for the monitoring of artemisinin-resistant alleles and for the characterization of the population structure of P. falciparum in areas targeted for malaria elimination.

Population movements and the HIV cascade in recently diagnosed patients at the French Guiana -Suriname border.

Border areas are particular "hot spots" generating high levels of HIV vulnerability and facing great challenges to control epidemics. The objective of this study is to describe the sociodemographic, clinical and biological profiles of newly HIV diagnosed people at the French Guiana - Suriname border, to construct an HIV care cascade and compare it with the Surinamese one. HIV-patients aged over 15 years newly diagnosed in western French Guiana in 2011 and 2012 were included in a retrospective cohort study. Patients were identified using different sources (n = 121). The male-to-female ratio was 0.8, 85% of the patients were of foreign origin, 72% were undocumented migrants, 21% were living in Suriname and 48% had baseline CD4 cell counts <200 cells/mm3. After one year, 34% were lost to follow-up, 54% received treatment, 34% had controlled viremia and 6% died. We observed a disappointing HIV cascade, like that of Suriname, requiring to develop a coordinated healthcare offer on both sides of the border. Targeted efforts through a bi-national collaboration are needed to address the specific issues of cross-border patients to reach the 90*3 UNAIDS's diagnosis, link to care and treatment targets and better control the local epidemic.

Yellow fever in a traveller returning from Suriname to the Netherlands, March 2017.

A Dutch traveller returning from Suriname in early March 2017, presented with fever and severe acute liver injury. Yellow fever was diagnosed by (q)RT-PCR and sequencing. During hospital stay, the patient's condition deteriorated and she developed hepatic encephalopathy requiring transfer to the intensive care. Although yellow fever has not been reported in the last four decades in Suriname, vaccination is recommended by the World Health Organization for visitors to this country.

Prevalence of Plasmodium spp. in illegal gold miners in French Guiana in 2015: a hidden but critical malaria reservoir.

BACKGROUND: Malaria is endemic in French Guiana, an overseas territory of France on the Guiana Shield. Since 2005, notified malaria cases are decreasing. However, new data show that malaria affects many Brazilian gold miners working illegally in French Guiana, the majority of whom are not counted in official data. In addition, one major concern is the usual practice of improper self-treatment in this mining population, raising fear of the development of anti-malarial resistance. This prospective study, conducted in 2015, aimed to estimate the prevalence of Plasmodium spp. in illegal gold miners working in French Guiana. METHODS: The recruitment of gold miners was carried out in resting sites along the French Guiana-Suriname border, where they go for supplies, medical care or leisure. After recording agreement, three malaria diagnostic methods were performed: rapid diagnostic test, microscopy and PCR. RESULTS: Among 421 persons recruited in the study, malaria prevalence, detected by nested-PCR, was 22.3 % (CI [18.3-26.3], n = 94/421) of which 84 % were asymptomatic. CONCLUSIONS: This significant malaria reservoir in a mobile and illegal population with difficult access to a health care system raises the threat of artemisinin resistance and puts the population of the Guiana Shield at risk of new transmission foci while countries of the region aim at malaria elimination. Even though French legislation may hamper dealing with this population, France must face the reality of malaria in illegal gold miners in order to meet its commitment to malaria elimination.

Acceptability and Feasibility of Provision of COVID-19 Services by Community Health Workers to Remote Gold Mining Communities in Suriname.

Gold mining communities in the Amazon region typically have limited access to public health services. In Suriname, the Ministry of Health Malaria Program (MoH-MP) works with community health workers (CHWs), people from mining communities without a formal medical degree, to provide malaria diagnostic and treatment services. During the COVID-19 pandemic, the MoH-MP trained 21 of these CHWs in COVID-19 outreach and testing, using rapid antigen tests for symptomatic persons in their communities; afterward, a mixed methods research approach was used to investigate whether including COVID-19 services in the tasks of the CHWs was feasible and accepted among gold mining populations. Also, CHWs took part in active case detection missions to proactively offer COVID-19 testing to all inhabitants of specific mining areas, regardless of symptoms. In the 6 months of field implementation (May-October 2022), 1,300 persons were tested for COVID-19, among whom 28.7% were women. Eight percent tested positive. Of the 312 asymptomatic persons tested, 2.2% tested positive. Qualitative semi-structured interviews with the CHWs and quantitative pre- and postintervention surveys revealed that the communities appreciated the nearby and free COVID-19 testing opportunity. The intervention motivated individuals who otherwise would not have been tested to test for COVID-19. Twenty-nine percent of those who had tested at least once for COVID-19 reported that their most recent test was conducted through the services of the CHWs. The results suggest that integrating COVID-19 testing into other CHW services can lower health access barriers in difficult-to-reach populations in remote communities.

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.

Improving disseminated histoplasmosis diagnosis in HIV/AIDS patients in Suriname: The role of a urine lateral flow assay.

Histoplasmosis is a frequent cause of infections in people living with HIV/AIDS (PLWHA). This study introduces the application of a Histoplasma capsulatum urine antigen lateral flow assay (LFA) for diagnosing disseminated histoplasmosis in PLWHA in Suriname. The LFA's diagnostic accuracy was compared with the current diagnostic approach, aiming to assess whether this test resulted in improved early detection and management. Additionally, the prevalence of histoplasmosis among advanced stage HIV patients without clinical suspicion of infection was evaluated using the same LFA. In total, 98 patients were included in the study, of which 58 were classified as "possible disseminated histoplasmosis (DH)" based on clinical criteria and 40 as "controls". Of these possible DH cases, only 19 (32.7%) had a positive LFA. During the study, decisions for treatment were made without the treating physician being aware of the LFA result. Only 55% of the patients who started treatment for histoplasmosis based on clinical criteria had a positive LFA, and 21% of untreated patients had a positive LFA. This study shows that combining clinical signs with LFA results enhances diagnostic accuracy and is cost effective, resulting in better treatment decisions.

Operational Research to Support Rapid Evidence-Based Responses to Outbreaks: Learnings from COVID-19.

During the COVID-19 pandemic, the need for making testing readily available was recognized as an important factor for individuals to help make informed decisions, including to isolate or seek care, and for policymakers to control transmission. Toward this end, FIND and the Access to COVID-19 Tools Accelerator funded 16 rapid operational research studies and one implementation project in Africa, the Caribbean, and Asia evaluating the utility, acceptability, and feasibility of different community-based SARS-CoV-2 testing approaches. Here, we discuss common factors and challenges encountered during study implementation. We note six key factors essential for success: 1) collaboration and partnerships; 2) buy-in of local stakeholders, including communities; 3) access to affordable supplies; 4) flexible financing; 5) effective approval systems; and 6) a skilled and motivated workforce. We also note various challenges that must be addressed to fully capitalize on these success factors. In particular, ethics committees are often not well equipped to assess operational research during outbreaks. Outbreaks, especially of novel pathogens, are unpredictable, and transmission dynamics are even more likely to change if the pathogen is prone to frequent mutations, such as SARS-CoV-2. Research that aims to evaluate strategies for curbing transmission must hence be easily and swiftly adaptable. This requires flexibility from researchers, funders, staff conducting the studies, and ethics and other approval committees. International guidelines for evaluating operational research protocols in outbreaks are needed to provide timely evidence to enable informed decisions by individuals, communities, and policymakers, thereby reducing both the human and the economic impact of outbreaks.

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.

Evidence of an increased incidence of day 3 parasitaemia in Suriname: an indicator of the emerging resistance of Plasmodium falciparum to artemether.

The emerging resistance to artemisinin derivatives that has been reported in South-East Asia led us to assess the efficacy of artemether-lumefantrine as the first line therapy for uncomplicated Plasmodium falciparum infections in Suriname. This drug assessment was performed according to the recommendations of the World Health Organization in 2011. The decreasing number of malaria cases in Suriname, which are currently limited to migrating populations and gold miners, precludes any conclusions on artemether efficacy because adequate numbers of patients with 28-day follow-up data are difficult to obtain. Therefore, a comparison of day 3 parasitaemia in a 2011 study and in a 2005/2006 study was used to detect the emergence of resistance to artemether. The prevalence of day 3 parasitaemia was assessed in a study in 2011 and was compared to that in a study in 2005/2006. The same protocol was used in both studies and artemether-lumefantrine was the study drug. Of 48 evaluable patients in 2011, 15 (31%) still had parasitaemia on day 3 compared to one (2%) out of 45 evaluable patients in 2005/2006. Overall, 11 evaluable patients in the 2011 study who were followed up until day 28 had negative slides and similar findings were obtained in all 38 evaluable patients in the 2005/2006 study. The significantly increased incidence of parasite persistence on day 3 may be an indication of emerging resistance to artemether.

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.

Involving hard-to-reach populations is pivotal for the tailoring and implementation of an epidemiological study in cross-border communities of French Guiana and Suriname.

Background: Hard-to-reach, vulnerable and cross-border populations are often disproportionately affected by communicable diseases. Epidemiological data on viral hepatitis in French Guiana and Suriname are available for urban areas, but not for remote communities. The Maroni River, which separates FG and Suriname, is home to Tribal and Indigenous communities. Reaching these populations is challenging due to logistical constraints, cultural and language barriers, and mistrust of outsiders. Objectives: We aimed to conduct an epidemiological study of viral hepatitis [Maroni Hepatites Virales (MaHeVi)] in this remote and complex area. Here, we describe the operational hurdles and solutions required to achieve this. Methods: We undertook a preliminary assessment of the area with local community leaders and health workers to gain approval of MaHeVi, acceptance of blood sampling, and suggestions for adapting the study to cultural and logistical constraints. Anthropological assessments were conducted through focus groups and interviews with key individuals to assess knowledge, beliefs and risk factors for VH. Results: MaHeVi was well received by the local communities. The approval of the community leaders was crucial for the implementation and acceptance of the study. The main adaptations were hiring community health mediators to overcome cultural and language differences, using blotting paper instead of venipuncture for logistical and acceptability reasons, and adapting communication materials. Conclusion: Careful preparation and tailoring of the communication materials and research protocol have enabled the successful implementation of the study. This process could be replicated in this area and transferred to other complex contexts combining borders, logistical hurdles and populations requiring cultural adaptations.