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.

Lower Microscopy Sensitivity with Decreasing Malaria Prevalence in the Urban Amazon Region, Brazil, 2018-2021.

Malaria is increasingly diagnosed in urban centers across the Amazon Basin. In this study, we combined repeated prevalence surveys over a 4-year period of a household-based random sample of 2,774 persons with parasite genotyping to investigate the epidemiology of malaria in Mâncio Lima, the main urban transmission hotspot in Amazonian Brazil. We found that most malarial infections were asymptomatic and undetected by point-of-care microscopy. Our findings indicate that as malaria transmission decreases, the detection threshold of microscopy rises, resulting in more missed infections despite similar parasite densities estimated by molecular methods. We identified genetically highly diverse populations of Plasmodium vivax and P. falciparum in the region; occasional shared lineages between urban and rural residents suggest cross-boundary propagation. The prevalence of low-density and asymptomatic infections poses a significant challenge for routine surveillance and the effectiveness of malaria control and elimination strategies in urbanized areas with readily accessible laboratory facilities.

A snapshot of a representative Brazilian state of illegal mining in indigenous areas during the era of malaria elimination.

Malaria is a public health problem and the cases diagnosed in the capital of Roraima, Brazil, show potential to characterize the burden of the disease in the state. This study aimed to describe the epidemiological, clinical, and laboratory aspects of malaria cases diagnosed in Boa Vista. For this purpose, a descriptive, cross-sectional study was conducted in two health units in the city, with individuals diagnosed and who agreed to respond the questionnaire. Of the total of 206 participants, characterized as men, mixed-race, and young, 96% (198) reported participating in illegal mining activity. Among the group of miners, 66% (131) came from other states of Brazil or other countries. The mines were mainly located in the Yanomami territory in Roraima. Plasmodium vivax infection occurred in 74% (153) of participants. In the miner's group, hospitalizations for severe malaria, previous malaria attacks, and delays in treatment after the onset of symptoms were reported. Although 73% (145) of miners reported knowing how malaria was transmitted, only 54% (107) used mosquito nets or repellents. The use of Artecom and chloroquine by miners is not for the complete treatment but only to relieve symptoms for returning to gold mines, highlighting the importance of molecular surveillance to antimalarial resistance. Indigenous peoples are considered vulnerable to malaria and miners promotes the increase of malaria in Roraima Indigenous Lands. Therefore, access to diagnosis and treatment in Indigenous areas invaded by miners is imperative to confront this disease that ravages Indigenous communities and threatens public health on a large scale to achieve the goal of eliminating malaria in the state.

Lifestyles associated with malaria in pregnancy in northwest Colombia: a mixed study from Latin American critical epidemiology.

BACKGROUND: In the scientific literature on Malaria in Pregnancy (MiP), no studies have been conducted on lifestyles based on critical theory. The objective of this study was to analyse the lifestyles or singular processes of social determination of health in MiP in northwestern Colombia. METHODS: Mixed QUAN-QUAL convergent triangulation study. In the quantitative component, a psychometric evaluation and a cross-sectional design were conducted in 400 pregnant women to whom the Pender-Walker lifestyle scale and a survey on MiP prevention were applied. In the qualitative study, a critical ethnography was conducted with 46 pregnant women in whom their narratives and practices regarding lifestyles at home and healthcare were described. RESULTS: The frequency of MiP was 9%, and a higher occurrence of the disease was identified in those who did not control stagnant water (29%), did not use insecticide-treated net (16%) and went to the hospital (14%) or the microscopist (20%) when they had fever. This coincides with the presence of unhealthy lifestyles, little knowledge about malaria, and a low perception of the risk of getting sick, as well as meanings and experiences about MiP, maternity, and pregnancy that show a high clinical, cultural, and socioeconomic burden for the women studied. CONCLUSION: This epidemiological profile and the approach to lifestyles based on the postulates of critical theory in health evidence that pregnant women exposed to malaria suffer serious social, cultural and health injustices that are not possible to impact with the current health model of malaria control in Colombia guided by aetiopathogenic, biomedical, positivist and utilitarian theories.

Results of Integrated Transmission Assessment Surveys for Lymphatic Filariasis and Malaria in Haiti, 2017-2022.

Haiti is endemic for lymphatic filariasis (LF) and malaria, two mosquito-transmitted parasitic diseases targeted for elimination. The World Health Organization recommends a transmission assessment survey (TAS-1) to determine if LF prevalence is significantly beneath putative transmission thresholds (<2% antigen prevalence in Haiti, where Culex is the primary vector for Wuchereria bancrofti) to stop mass drug administration (MDA). Repeated TASs (TAS-2 and TAS-3) are recommended at 2-3-year intervals during post-treatment surveillance. From 2017 to 2022, The Carter Center assisted the Haitian Ministry of Public Health and Population in conducting 15 TASs in 11 evaluation units (EUs) encompassing 54 of the country's 146 districts. Children 6-7 years old were assessed for circulating filarial antigen (CFA) by Filariasis Test Strip: n = 5,239 in TAS-1; n = 11,866 in TAS-2; and n = 1,842 in TAS-3, of whom eight (0.15%), 20 (0.17%), and eight (0.43%) tested positive, respectively. The number of positive results in children was less than the threshold in each EU. When available, participants (n = 16,663) were also tested for malaria by rapid diagnostic test, with 31 (0.19%) children testing positive for Plasmodium falciparum. Integrated TASs provided an efficient means to collect epidemiological data for LF and malaria in Haiti. Results indicated thresholds for stopping and maintaining the halt of MDA for LF have been achieved in all EUs, with the halt of MDA for 571,358 people in four districts and the first TAS-3 surveys conducted in Haiti. Investigations are needed to assess the potential of ongoing LF transmission, especially in areas where CFA-positive samples were detected in TAS-3.

Malaria in areas under mining activity in the Amazon: A review.

Deforestation and high human mobility due to mining activities have been key to the increase in malaria cases in the Americas. Here, we review the epidemiological and control aspects of malaria in the Amazon mining areas. Epidemiological evidence shows: 1) a positive correlation between illegal mining activity and malaria incidence, mostly in the Amazon region; 2) most Brazilian miners are males aged 15-29 years who move between states and even countries; 3) miners do not fear the disease and rely on medical care, diagnosis, and medication when they become ill; 4) illegal mining has emerged as the most reported anthropogenic activity within indigenous lands and is identified as a major cause of malaria outbreaks among indigenous people in the Amazon; and 5) because mining is largely illegal, most areas are not covered by any healthcare facilities or activities, leading to little assistance in the diagnosis and treatment of malaria. Our review identified five strategies for reducing the malaria incidence in areas with mining activities: 1) reviewing legislation to control deforestation and mining expansion, particularly in indigenous lands; 2) strengthening malaria surveillance by expanding the network of community health agents to support rapid diagnosis and treatment; 3) reinforcing vector control strategies, such as the use of insecticide-treated nets; 4) integrating deforestation alerts into the national malaria control program; and 5) implementing multi-sectoral activities and providing prompt assistance to indigenous populations. With this roadmap, we can expect a decrease in malaria incidence in the Amazonian mining areas in the future.

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.

Towards malaria elimination: a reflection about digital notification modules to improve malaria cases notification speed and follow-up in the Brazilian Amazon region.

BACKGROUND: Health information systems (HIS) are a pivotal element in epidemiological surveillance. In Brazil, malaria persists as a public health challenge, with 99% of its occurrences concentrated in the Amazon region, where cases are reported through the HIS Sivep-Malaria. Recent technological advancements indicate that case notifications can be expedited through more efficient systems with broader coverage. The objective of this study is to analyse opportunities for notification within Sivep-Malaria and explore the implementation of mobile electronic devices and applications to enhance the performance of malaria case notifications and use. METHODS: This descriptive study analyses data on malaria-positive cases in the Brazilian Amazon from 2004 to 2022. Malaria Epidemiological Surveillance System (Sivep-Malaria) data were used. The Brazilian Amazon region area is approximately 5 million km2 across nine different states in Brazil. Data entry opportunities were assessed by considering the time difference between the 'date of data entry' and the 'date of notification.' Descriptive statistics, including analyses of means and medians, were conducted across the entire Amazon region, and for indigenous population villages and gold mining areas. RESULTS: Between 2004 and 2022, 6,176,878 new malaria cases were recorded in Brazil. The average data entry opportunity throughout the period was 17.9 days, with a median of 8 days. The most frequently occurring value was 1 day, and 99% of all notifications were entered within 138 days, with 75.0% entered within 20 days after notification. The states with the poorest data entry opportunities were Roraima and Tocantins, with averages of 31.3 and 31.0 days, respectively. For indigenous population villages and gold mining areas, the median data entry opportunities were 23 and 15 days, respectively. CONCLUSIONS: In malaria elimination, where surveillance is a primary strategy for evaluating each reported case, reducing notification time, enhancing data quality and being able to follow-up cases through computerized reports offer significant benefits for cases investigation. Technological improvements in Sivep-Malaria could yield substantial benefits for malaria control in Brazil, aiding the country in achieving disease elimination and fulfilling the Sustainable Development Goals.

Physical durability and insecticidal activity of long-lasting insecticidal nets in Cruzeiro do Sul, Brazil.

Vector control is one of the principal strategies used for reducing malaria transmission. Long-lasting insecticidal bed nets (LLINs) are a key tool used to protect populations at risk of malaria, since they provide both physical and chemical barriers to prevent human-vector contact. This study aimed to assess the physical durability and insecticidal efficacy of LLINs distributed in Cruzeiro do Sul (CZS), Brazil, after 4 years of use. A total of 3000 LLINs (PermaNet 2.0) were distributed in high malaria risk areas of CZS in 2007. After 4 years of use, 27 'rectangular' LLINs and 28 'conical' LLINs were randomly selected for analysis. The evaluation of physical integrity was based on counting the number of holes and measuring their size and location on the nets. Insecticidal efficacy was evaluated by cone bioassays, and the amount of residual insecticide remaining on the surface of the LLINs was estimated using a colorimetric method. After 4 years of use, physical damage was highly prevalent on the rectangular LLINs, with a total of 473 holes detected across the 27 nets. The upper portion of the side panels sustained the greatest damage in rectangular LLINs. The overall mosquito mortality by cone bioassay was < 80% in 25/27 rectangular LLINs, with panel A (at the end of the rectangular bednet) presenting the highest mortality (54%). The overall mean insecticide concentration was 0.5 µg/sample, with the bednet roof containing the highest average concentration (0.61 µg/sample). On the conical LLINs, 547 holes were detected, with the bottom areas sustaining the greatest damage. The cone bioassay mortality was < 80% in 26/28 of the conical LLINs. The mean insecticide concentration was 0.3 µg/sample. After 4 years of use, the insecticidal efficacy of the LLINs was diminished to below acceptable thresholds.

Study protocol: improving response to malaria in the Amazon through identification of inter-community networks and human mobility in border regions of Ecuador, Peru and Brazil.

INTRODUCTION: Understanding human mobility's role in malaria transmission is critical to successful control and elimination. However, common approaches to measuring mobility are ill-equipped for remote regions such as the Amazon. This study develops a network survey to quantify the effect of community connectivity and mobility on malaria transmission. METHODS: We measure community connectivity across the study area using a respondent driven sampling design among key informants who are at least 18 years of age. 45 initial communities will be selected: 10 in Brazil, 10 in Ecuador and 25 in Peru. Participants will be recruited in each initial node and administered a survey to obtain data on each community's mobility patterns. Survey responses will be ranked and the 2-3 most connected communities will then be selected and surveyed. This process will be repeated for a third round of data collection. Community network matrices will be linked with each country's malaria surveillance system to test the effects of mobility on disease risk. ETHICS AND DISSEMINATION: This study protocol has been approved by the institutional review boards of Duke University (USA), Universidad San Francisco de Quito (Ecuador), Universidad Peruana Cayetano Heredia (Peru) and Universidade Federal Minas Gerais (Brazil). Results will be disseminated in communities by the end of the study.

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.

Characterisation of the merozoite thrombospondin related anonymous protein (MTRAP) of Plasmodium berghei as a transmission-blocking antigen.

BACKGROUND: Malaria is an infectious disease caused by protozoan parasites belonging to the genus Plasmodium. Human-to-human transmission depends on a mosquito vector; thus, the interruption of parasite transmission from humans to mosquitoes is an important approach in the fight against malaria. The parasite stages infectious to mosquitoes are the gametocytes, sexual stages that are ingested by the vector during a blood meal and transform into male and female gametes in the midgut. Immunity against sexual stage antigens expressed by gametocytes, gametes, and the zygote formed after fertilisation can interrupt the parasite sexual cycle in the mosquito. This transmission blocking immunity is mediated by specific antibodies ingested during the mosquito blood feed, inhibiting the parasite development in the midgut. Merozoite thrombospondin related anonymous protein (MTRAP) is a merozoite and gametocyte surface protein essential for gamete egress from erythrocytes and for parasite transmission to mosquitoes. OBJECTIVES: Here, we evaluated the potential of the P. berghei MTRAP to elicit antibodies with the ability to inhibit gamete fertilisation in vitro. METHODS: We expressed a soluble recombinant PbMTRAP and used it to immunise BALB/c mice. The transmission blocking activity of the anti-rPbMTRAP antibodies was tested through in vivo challenge experiments followed by in vitro conversion assays. FINDINGS: Immunisations with the rPbMTRAP induced a strong antibody response and the antibodies recognised the native protein by Western Blot and IFA. Anti-rPbMTRAP present in the blood stream of immunised mice partially inhibited gamete conversion into ookinetes. CONCLUSION: Our results indicate that antibodies to PbMTRAP may reduce but are not sufficient to completely block transmission.

Profiling the antibody response of humans protected by immunization with Plasmodium vivax radiation-attenuated sporozoites.

Malaria sterile immunity has been reproducibly induced by immunization with Plasmodium radiation-attenuated sporozoites (RAS). Analyses of sera from RAS-immunized individuals allowed the identification of P. falciparum antigens, such as the circumsporozoite protein (CSP), the basis for the RTS, S and R21Matrix-M vaccines. Similar advances in P. vivax (Pv) vaccination have been elusive. We previously reported 42% (5/12) of sterile protection in malaria-unexposed, Duffy-positive (Fy +) volunteers immunized with PvRAS followed by a controlled human malaria infection (CHMI). Using a custom protein microarray displaying 515 Pv antigens, we found a significantly higher reactivity to PvCSP and one hypothetical protein (PVX_089630) in volunteers protected against P. vivax infection. In mock-vaccinated Fy + volunteers, a strong antibody response to CHMI was also observed. Although the Fy- volunteers immunized with non-irradiated Pv-infected mosquitoes (live sporozoites) did not develop malaria after CHMI, they recognized a high number of antigens, indicating the temporary presence of asexual parasites in peripheral blood. Together, our findings contribute to the understanding of the antibody response to P. vivax infection and allow the identification of novel parasite antigens as vaccine candidates.Trial registration: ClinicalTrials.gov number: NCT01082341.

Effect of fluralaner on the biology, survival, and reproductive fitness of the neotropical malaria vector Anopheles aquasalis.

BACKGROUND: Reducing mosquito abundance or interfering with its ability to support the parasite cycle can help to interrupt malaria in areas of significant risk of malaria transmission. Fluralaner is a safe and effective drug for veterinary use indicated for the treatment against fleas and ticks which acts as an antagonist of chloride ion channels mediated by γ-aminobutyric acid (GABA), preventing the entry of these ions into the postsynaptic neuron, leading to hyperexcitability of the postsynaptic neuron of the central nervous system of arthropods. Fluralaner demonstrated insecticidal activity against different insect species. METHODS: The study aimed to evaluate the effects of fluralaner on the biology, survival, and reproductive fitness of Anopheles aquasalis. The following lethal concentrations (LC) were determined for An. aquasalis: LC5 = 0.511 µM; LC25 = 1.625 µM; LC50 = 3.237 µM. RESULTS: A significant decrease (P < 0.001) was evident in the number of eggs, larvae, and pupae in the group exposed to a sublethal dose of fluralaner when compared to a control group (without the drug). Using blood from dogs after administration of fluralaner, it was observed that the drug causes 100% mortality in An. aquasalis in less than 24 h after feeding; this effect remains even after 90 days in all samples. DISCUSSION: Fluralaner showed the same result for up to 60 days, and after that, there was a slight reduction in its effect, evidenced by a decrease in the percentage of dead females; however, still significant when compared to the control group. CONCLUSION: Fluralaner affects the biology and reduction of survival in An. aquasalis in a lasting and prolonged period, and its fecundity with lower dosages, is a strong candidate for controlling disease vectors.

Social determination of malaria in pregnancy in Colombia: a critical ethnographic study.

BACKGROUND: The meanings and experiences related to malaria in pregnancy (MiP) and its processes of social determination of health (PSDH) have not been reported in the world scientific literature. The objective was to understand the meanings and experiences of MiP, and to explain their PSDH in an endemic area from Colombia, 2022. METHODS: Critical ethnography with 46 pregnant women and 31 healthcare workers. In-depth and semi-structured interviews, focus group discussions, participant and non-participant observations, and field diaries were applied. A phenomenological-hermeneutic analysis, saturation and triangulation was carried out. The methodological rigor criteria were reflexivity, credibility, auditability, and transferability. RESULTS: At the singular level, participants indicated different problems in antenatal care and malaria control programmes, pregnant women were lacking knowledge about MiP, and malaria care was restricted to cases with high obstetric risk. Three additional levels that explain the PSDH of MiP were identified: (i) limitations of malaria control policies, and health-system, geographic, cultural and economic barriers by MiP diagnosis and treatment; (ii) problems of public health programmes and antenatal care; (iii) structural problems such as monetary poverty, scarcity of resources for public health and inefficiency in their use, lacking community commitment to preventive actions, and breach of institutional responsibilities of health promoter entity, municipalities and health services provider institutions. CONCLUSION: Initiatives for MiP control are concentrated at the singular level, PDSH identified in this research show the need to broaden the field of action, increase health resources, and improve public health programmes and antenatal care. It is also necessary to impact the reciprocal relationships of MiP with economic and cultural dimensions, although these aspects are increasingly diminished with the predominance and naturalization of neoliberal logic in health.

Assessing the impact of the "malaria supporters project" intervention to malaria control in the Brazilian Amazon: an interrupted time-series analysis.

BACKGROUND: In 2021, Brazil was responsible for more than 25% of malaria cases in the Americas. Although the country has shown a reduction of cases in the last decades, in 2021 it reported over 139,000 malaria cases. One major malaria control strategy implemented in Brazil is the "Malaria Supporters Project", which has been active since 2012 and is directed to municipalities responsible for most Brazil's cases. The objective of this study is to analyse the intervention effect on the selected municipalities. METHODS: An ecological time-series analysis was conducted to assess the "Malaria Supporters Project" effect. The study used data on Annual Parasitic Incidence (API) spanning the period from 2003 to 2020 across 48 intervention municipalities and 88 control municipalities. To evaluate the intervention effect a Prais-Winsten segmented regression model was fitted to the difference in malaria Annual Parasitic Incidence (API) between control and intervention areas. RESULTS: The intervention group registered 1,104,430 cases between 2012 and 2020, a 50.6% reduction compared to total cases between 2003 and 2011. In 2020 there were 95,621 cases, 50.4% fewer than in 2011. The number of high-risk municipalities (API > 50 cases/1000) reduced from 31 to 2011 to 17 in 2020. The segmented regression showed a significant 42.0 cases/1000 residents annual decrease in API compared to control group. CONCLUSIONS: The intervention is not a silver bullet to control malaria, but it has reduced API in locations with high malaria endemicity. Furthermore, the model has the potential to be replicated in other countries with similar epidemiological scenarios.