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.

Post-traumatic stress disorder, food insecurity, and social capital after the 2017 coastal El Niño flooding among mothers from Piura, Peru: A mixed method study.

In order to understand the impacts in the post-disaster scenario of the 2017 El Niño events in the Piura region-Peru, we examined post-traumatic stress disorder (PTSD), food insecurity (FI), and social capital (SC) across three-time points in mothers in highly affected areas. In the Piura, Castilla, and Catacaos districts, we studied mothers combining mixed-method assessments at three (June-July 2017), eight and 12 months after the flooding. Each outcome was measured with the PTSD-Checklist-Civilian (PCL-C), the Household-Food-Insecurity-Access-Scale (HFIAS), the Adapted-Social-Capital-Assessment-Tool (SASCAT) surveys. In-depth interviews at the first evaluation were also conducted. At the first evaluation, 38.1% (n = 21) of 179 mothers reported PTSD; eight months and one year after the flooding, it dropped to 1.9% and virtually zero, respectively. Severe FI also declined over time, from 90.0% three months after the flooding to 31.8% eight months after, to 13.1% one year after. Conversely, high-cognitive SC was increased three months after the flooding (42.1%) and much greater levels at eight and 12 months after (86.7% and 77.7%, respectively). High levels of PTSD and severe FI three months after the flooding consistently decreased to nearly zero one-year post-disaster. High levels of high-cognitive SC may have helped mothers to recover from PTSD and FI in Piura.

Phylogenetic congruence of Plasmodium spp. and wild ungulate hosts in the Peruvian Amazon.

Malaria parasites are known to infect a variety of vertebrate hosts, including ungulates. However, ungulates of Amazonia have not been investigated. We report for the first time, the presence of parasite lineages closely related to Plasmodium odocoilei clade 1 and clade 2 in free-ranging South American red-brocket deer (Mazama americana; 44.4%, 4/9) and gray-brocket deer (Mazama nemorivaga; 50.0%, 1/2). We performed PCR-based analysis of blood samples from 47 ungulates of five different species collected during subsistence hunting by an indigenous community in the Peruvian Amazon. We detected Plasmodium malariae/brasilianum lineage in a sample from red-brocket deer. However, no parasite DNA was detected in collared peccary (Pecari tajacu; 0.0%, 0/10), white-lipped peccary (Tayassu pecari; 0.0%, 0/15), and tapir (Tapirus terrestris; 0.0%, 0/11). Concordant phylogenetic analyses suggested a possible co-evolutionary relationship between the Plasmodium lineages found in American deer and their hosts.

Network Profile: Improving Response to Malaria in the Amazon through Identification of Inter-Community Networks and Human Mobility in Border Regions of Ecuador, Peru, and Brazil.

Objectives: Understanding human mobility's role on 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. Design: A community-level network survey. Setting: We collect data on community connectivity along three river systems in the Amazon basin: the Pastaza river corridor spanning the Ecuador-Peru border; and the Amazon and Javari river corridors spanning the Brazil-Peru border. Participants: We interviewed key informants in Brazil, Ecuador, and Peru, including from indigenous communities: Shuar, Achuar, Shiwiar, Kichwa, Ticuna, and Yagua. Key informants are at least 18 years of age and are considered community leaders. Primary outcome: Weekly, community-level malaria incidence during the study period. Methods: We measure community connectivity across the study area using a respondent driven sampling design. Forty-five communities were initially selected: 10 in Brazil, 10 in Ecuador, and 25 in Peru. Participants were recruited in each initial node and administered a survey to obtain data on each community's mobility patterns. Survey responses were ranked and the 2-3 most connected communities were then selected and surveyed. This process was repeated for a third round of data collection. Community network matrices will be linked with eadch country's malaria surveillance system to test the effects of mobility on disease risk. Findings: To date, 586 key informants were surveyed from 126 communities along the Pastaza river corridor. Data collection along the Amazon and Javari river corridors is ongoing. Initial results indicate that network sampling is a superior method to delineate migration flows between communities. Conclusions: Our study provides measures of mobility and connectivity in rural settings where traditional approaches are insufficient, and will allow us to understand mobility's effect on malaria transmission.

"We usually see a lot of delay in terms of coming for or seeking care": an expert consultation on COVID testing and care pathways in seven low- and middle-income countries.

BACKGROUND: Rapid diagnostic testing may support improved treatment of COVID patients. Understanding COVID testing and care pathways is important for assessing the impact and cost-effectiveness of testing in the real world, yet there is limited information on these pathways in low-and-middle income countries (LMICs). We therefore undertook an expert consultation to better understand testing policies and practices, clinical screening, the profile of patients seeking testing or care, linkage to care after testing, treatment, lessons learnt and expected changes in 2023. METHODS: We organized a qualitative consultation with ten experts from seven LMICs (India, Indonesia, Malawi, Nigeria, Peru, South Africa, and Zimbabwe) identified through purposive sampling. We conducted structured interviews during six regional consultations, and undertook a thematic analysis of responses. RESULTS: Participants reported that, after initial efforts to scale-up testing, the policy priority given to COVID testing has declined. Comorbidities putting patients at heightened risk (e.g., diabetes) mainly relied on self-identification. The decision to test following clinical screening was highly context-/location-specific, often dictated by local epidemiology and test availability. When rapid diagnostic tests were available, public sector healthcare providers tended to rely on them for diagnosis (alongside PCR for Asian/Latin American participants), while private sector providers predominantly used polymerase chain reaction (PCR) tests. Positive test results were generally taken at 'face value' by clinicians, although negative tests with a high index of suspicion may be confirmed with PCR. However, even with a positive result, patients were not always linked to care in a timely manner because of reluctance to receiving care or delays in returning to care centres upon clinical deterioration. Countries often lacked multiple components of the range of therapeutics advised in WHO guidelines: notably so for oral antivirals designed for high-risk mild patients. Severely ill patients mostly received corticosteroids and, in higher-resourced settings, tocilizumab. CONCLUSIONS: Testing does not always prompt enhanced care, due to reluctance on the part of patients and limited therapeutic availability within clinical settings. Any analysis of the impact or cost-effectiveness of testing policies post pandemic needs to either consider investment in optimal treatment pathways or constrain estimates of benefits based on actual practice.

"We usually see a lot of delay in terms of coming for or seeking care": an expert consultation on COVID testing and care pathways in low- and middle-income countries.

Background: Rapid diagnostic testing may support improved treatment of COVID patients. Understanding COVID testing and care pathways is important for assessing the impact and cost-effectiveness of testing in the real world, yet there is limited information on these pathways in low-and-middle income countries (LMICs). We therefore undertook an expert consultation to better understand testing policies and practices, clinical screening, the profile of patients seeking testing or care, linkage to care after testing, treatment, lessons learnt and expected changes in 2023 in LMICs. Methods: We organized a qualitative consultation with ten experts from seven LMICs identified through purposive sampling. We conducted structured interviews during six regional consultations, and undertook a thematic analysis of the responses to our questions. Results: Participants reported that, after initial efforts to scale-up testing (which often encountered delays), the policy priority given to COVID testing has declined. Comorbidities putting patients at heightened risk (e.g., diabetes) mainly relied on self-identification. The decision to test following clinical screening was highly context- and location-specific, often dictated by local epidemiology and test availability. When rapid diagnostic tests were available, public sector healthcare providers tended to rely on them for diagnosis, while private sector providers predominantly used polymerase chain reaction (PCR) tests. Positive test results were generally taken at 'face value' by clinicians, although negative tests with a high index of suspicion may be confirmed with PCR. However, even with a positive result, patients were not always linked to care in a timely manner because of reluctance to receiving care or delays in returning to care centres upon clinical deterioration. Countries often lacked multiple components of the range of therapeutics advised in WHO guidelines: notably so for oral antivirals designed for high-risk mild patients. Severely ill patients mostly received corticosteroids and, in higher-resourced settings, tocilizumab. Conclusions: Testing does not always prompt enhanced care, due to reluctance on the part of patients and limited therapeutic availability within clinical settings. Any analysis of the impact or cost-effectiveness of testing policies post pandemic needs to either consider investment in optimal treatment pathways or constrain estimates of benefits based on actual practice.

Identifying gaps on health impacts, exposures, and vulnerabilities to climate change on human health and wellbeing in South America: a scoping review.

There is an important gap in regional information on climate change and health, limiting the development of science-based climate policies in South American countries. This study aims to identify the main gaps in the existing scientific literature on the impacts, exposure, and vulnerabilities of climate change on population health. A scoping review was performed guided by four sub-questions focused on the impacts of climate change on physical and mental health, exposure and vulnerability factors of population to climate hazards. The main findings showed that physical impacts mainly included infectious diseases, while mental health impacts included trauma, depression, and anxiety. Evidence on population exposure to climate hazards is limited, and social determinants of health and individual factors were identified as vulnerability factors. Overall, evidence on the intersection between climate change and health is limited in South America and has been generated in silos, with limited transdisciplinary research. More formal and systematic information should be generated to inform public policy. Funding: None.

The Lancet Countdown South America: increasing health opportunities by identifying the gaps in health and climate change research.

South America is experiencing the effects of climate change, including extreme weather events and changes in temperature and precipitation patterns. These effects interact with existing social vulnerabilities, exacerbating their impact on the health and wellbeing of populations. This viewpoint highlights four main messages from the series, which presented key gaps from five different perspectives of health and climate. First, there is an overall need for local analyses of priority topics to inform public policy, which include national and sub-national evidence to adequately strengthen responses and preparedness for climate change hazards and address relevant social vulnerabilities in South American countries. Second, research in health and climate is done in silos and the intersection is not clear in terms of responsibility and leadership; therefore, transdisciplinary research and action are key. Third, climate research, policies, and action need to be reflected in effective funding schemes, which until now are very limited. For adaptation and mitigation policies to be effective, they need a robust and long-term funding scheme. Finally, climate action is a big opportunity for healthier and more prosperous societies in South America, taking the advantage of strategic climate policies to face the challenges of climate change and tackle existing social inequities.

Contributing factors for self-reported HIV in male Peruvian inmates: results of the 2016 prison census.

Introduction: Worldwide, prisons are high-risk settings for the transmission of infectious diseases such as HIV. There is a need to understand the health conditions of prisoners to improve and implement timely strategies for HIV diagnosis and control. Hence, we aimed to identify factors associated with self-reported HIV (srHIV) among Peruvian inmates. Methods: This study is a secondary data analysis of the First Peruvian Prison Census conducted in 2016. We estimated the prevalence of srHIV in prisoners who were male at birth and the association of srHIV with other social conditions, criminal records, and prevalent health conditions. Nested models identified a multivariable parsimonious model for factors associated with srHIV and yielding prevalence ratios adjusted by the included parameters. Results: The census surveyed 71,087 male inmates of whom 0.4% reported srHIV (n = 305), and 82% of whom were receiving antiretroviral treatment (n = 220). In our final multivariable model, srHIV was independently associated with age between 36 and 55 years old vs. >55 years old [parsimonious prevalence ratio (pPR) = 1.98, 95% CI, 0.96-4.08], having a stable partner out of prison (pPR = 1.64, 95% CI, 1.24-2.19), being homosexual (pPR = 4.16, 95% CI, 2.50-6.90), self-report of prevalent tuberculosis co-infection (pPR = 2.55, 95% CI, 1.82-3.58), self-report of prevalent sexually transmitted infections (pPR = 34.49, 95% CI, 24.94-47.70), and self-report of prevalent illicit drug use 30 days before the survey (pPR = 1.91, 95% CI, 1.43-2.56). Conclusion: Self-reported HIV is associated with multiple social, health and prison risks among Peruvian inmates. Deeply understanding these factors would help to design HIV prevention and control strategies in Peruvian prisons.

Reflections on the impact and response to the Peruvian 2017 Coastal El Niño event: Looking to the past to prepare for the future.

Climate-related phenomena in Peru have been slowly but continuously changing in recent years beyond historical variability. These include sea surface temperature increases, irregular precipitation patterns and reduction of glacier-covered areas. In addition, climate scenarios show amplification in rainfall variability related to the warmer conditions associated with El Niño events. Extreme weather can affect human health, increase shocks and stresses to the health systems, and cause large economic losses. In this article, we study the characteristics of El Niño events in Peru, its health and economic impacts and we discuss government preparedness for this kind of event, identify gaps in response, and provide evidence to inform adequate planning for future events and mitigating impacts on highly vulnerable regions and populations. This is the first case study to review the impact of a Coastal El Niño event on Peru's economy, public health, and governance. The 2017 event was the third strongest El Niño event according to literature, in terms of precipitation and river flooding and caused important economic losses and health impacts. At a national level, these findings expose a need for careful consideration of the potential limitations of policies linked to disaster prevention and preparedness when dealing with El Niño events. El Niño-related policies should be based on local-level risk analysis and efficient preparedness measures in the face of emergencies.

X-Chromosome Association Study in Latin American Cohorts Identifies New Loci in Parkinson's Disease.

BACKGROUND: Sex differences in Parkinson's disease (PD) risk are well-known. However, the role of sex chromosomes in the development and progression of PD is still unclear. OBJECTIVE: The objective of this study was to perform the first X-chromosome-wide association study for PD risk in a Latin American cohort. METHODS: We used data from three admixed cohorts: (1) Latin American Research consortium on the Genetics of Parkinson's Disease (n = 1504) as discover cohort, and (2) Latino cohort from International Parkinson Disease Genomics Consortium (n = 155) and (3) Bambui Aging cohort (n = 1442) as replication cohorts. We also developed an X-chromosome framework specifically designed for admixed populations. RESULTS: We identified eight linkage disequilibrium regions associated with PD. We replicated one of these regions (top variant rs525496; discovery odds ratio [95% confidence interval]: 0.60 [0.478-0.77], P = 3.13 × 10-5 replication odds ratio: 0.60 [0.37-0.98], P = 0.04). rs5525496 is associated with multiple expression quantitative trait loci in brain and non-brain tissues, including RAB9B, H2BFM, TSMB15B, and GLRA4, but colocalization analysis suggests that rs5525496 may not mediate risk by expression of these genes. We also replicated a previous X-chromosome-wide association study finding (rs28602900), showing that this variant is associated with PD in non-European populations. CONCLUSIONS: Our results reinforce the importance of including X-chromosome and diverse populations in genetic studies. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Prevalence of and factors associated with childhood anaemia in remote villages of the Peruvian Amazon: a cross-sectional study and geospatial analysis.

BACKGROUND: Anaemia is a public health problem in Peru. In the Loreto region of the Amazon, ≥50% of children may be anaemic, although insufficient information exists for rural villages. METHODS: To generate more data about childhood anaemia in the Peruvian Amazon, haemoglobin was measured as part of a trachoma survey in 21 randomly selected villages. All children 1-9 y of age from 30 randomly selected households per village were recruited. Anaemia was classified according to the World Health Organization guidelines and a socio-economic status (SES) index was created for each household using principal component analysis. Spatial autocorrelation was determined using Moran's I and Ripley's K function. RESULTS: Of 678 children with complete haemoglobin data, 25.4% (95% confidence interval [CI] 21.2 to 30.1) had mild-or-worse anaemia and 22.1% (95% CI 15.6 to 30.3) had moderate-or-worse anaemia. Mild-or-worse anaemia was more common among children whose primary source of drinking water was surface water (prevalence ratio [PR] 1.26 [95% CI 1.14 to 1.40], p<0.001) and who were in the lowest SES tercile (PR 1.16 [95% CI 1.02 to 1.32], p=0.021). Moderate-or-worse anaemia was more common among boys (PR 1.32 [95% CI 1.09 to 1.60], p=0.005). No evidence of geospatial clustering was found. CONCLUSIONS: Remote villages of the Amazon would benefit from interventions for childhood anaemia and the poorest households would have the most to gain. Integrating anaemia screening into neglected tropical diseases surveys is an opportunity to use public health resources more efficiently.

The impact of sustained malaria control in the Loreto region of Peru: a retrospective, observational, spatially-varying interrupted time series analysis of the PAMAFRO program.

Background: Although malaria control investments worldwide have resulted in dramatic declines in transmission since 2000, progress has stalled. In the Amazon, malaria resurgence has followed withdrawal of Global Fund support of the Project for Malaria Control in Andean Border Areas (PAMAFRO). We estimate intervention-specific and spatially-explicit effects of the PAMAFRO program on malaria incidence across the Loreto region of Peru, and consider the influence of the environmental risk factors in the presence of interventions. Methods: We conducted a retrospective, observational, spatial interrupted time series analysis of malaria incidence rates among people reporting to health posts across Loreto, Peru between the first epidemiological week of January 2001 and the last epidemiological week of December 2016. Model inference is at the smallest administrative unit (district), where the weekly number of diagnosed cases of Plasmodium vivax and Plasmodium falciparum were determined by microscopy. Census data provided population at risk. We include as covariates weekly estimates of minimum temperature and cumulative precipitation in each district, as well as spatially- and temporally-lagged malaria incidence rates. Environmental data were derived from a hydrometeorological model designed for the Amazon. We used Bayesian spatiotemporal modeling techniques to estimate the impact of the PAMAFRO program, variability in environmental effects, and the role of climate anomalies on transmission after PAMAFRO withdrawal. Findings: During the PAMAFRO program, incidence of P. vivax declined from 42.8 to 10.1 cases/1000 people/year. Incidence for P. falciparum declined from 14.3 to 2.5 cases/1000 people/year over this same period. The effects of PAMAFRO-supported interventions varied both by geography and species of malaria. Interventions were only effective in districts where interventions were also deployed in surrounding districts. Further, interventions diminished the effects of other prevailing demographic and environmental risk factors. Withdrawal of the program led to a resurgence in transmission. Increasing minimum temperatures and variability and intensity of rainfall events from 2011 onward and accompanying population displacements contributed to this resurgence. Interpretation: Malaria control programs must consider the climate and environmental scope of interventions to maximize effectiveness. They must also ensure financial sustainability to maintain local progress and commitment to malaria prevention and elimination efforts, as well as to offset the effects of environmental change that increase transmission risk. Funding: National Aeronautics and Space Administration, National Institutes of Health, Bill and Melinda Gates Foundation.

X-Chromosome Association Study in Latin American Cohorts Identifies New Loci in Parkinson Disease.

Sex differences in Parkinson Disease (PD) risk are well-known. However, it is still unclear the role of sex chromosomes in the development and progression of PD. We performed the first X-chromosome Wide Association Study (XWAS) for PD risk in Latin American individuals. We used data from three admixed cohorts: (i) Latin American Research consortium on the GEnetics of Parkinson's Disease (n=1,504) as discover cohort and (ii) Latino cohort from International Parkinson Disease Genomics Consortium (n = 155) and (iii) Bambui Aging cohort (n= 1,442) as replication cohorts. After developing a X-chromosome framework specifically designed for admixed populations, we identified eight linkage disequilibrium regions associated with PD. We fully replicated one of these regions (top variant rs525496; discovery OR [95%CI]: 0.60 [0.478 - 0.77], p = 3.13 × 10 -5 ; replication OR: 0.60 [0.37-0.98], p = 0.04). rs525496 is an expression quantitative trait loci for several genes expressed in brain tissues, including RAB9B, H2BFM, TSMB15B and GLRA4 . We also replicated a previous XWAS finding (rs28602900), showing that this variant is associated with PD in non-European populations. Our results reinforce the importance of including X-chromosome and diverse populations in genetic studies.

Correction: Diversity, distribution and natural Leishmania infection of sand flies from communities along the Interoceanic Highway in the Southeastern Peruvian Amazon.

[This corrects the article DOI: 10.1371/journal.pntd.0009000.].

Association of vision impairment and blindness with socioeconomic status in adults 50 years and older from Alto Amazonas, Peru.

OBJECTIVE: To determine the relationship between socioeconomic status (SES) and visual impairment (VI) or blindness in the rural Peruvian Amazon, hypothesizing that higher SES would have a protective effect on the odds of VI or blindness. METHODS: In this cross-sectional study of 16 rural communities in the Peruvian Amazon, consenting adults aged ≥ 50 years were recruited from ~30 randomly selected households per village. Each household was administered a questionnaire and had a SES score constructed using principal components analysis. Blindness and VI were determined using a ministry of health 3-meter visual acuity card. RESULTS: Overall, 207 adults aged ≥ 50 were eligible; 146 (70.5%) completed visual acuity screening and answered the questionnaire. Of those 146 participants who completed presenting visual acuity screening, 57 (39.0%, 95% CI 30.2-47.1) were classified as visually impaired and 6 (4.1%, 95% CI 0.9-7.3) as blind. Belonging to the highest SES tercile had a protective effect on VI or blindness (OR 0.29, 95% CI 0.09 to 0.91, p = 0.034), with a linear trend across decreasing levels of SES (p = 0.019). This observed effect remained significant regardless of how SES groups were assigned. CONCLUSION: Belonging to a higher SES group resulted in a lower odds of VI or blindness compared to those in the lowest SES group. The observation of a dose response provides confidence in the observed association, but causality remains unclear. Blindness prevention programs could maximize impact by designing activities that specifically target people with lower SES.

Antibody Banding Patterns on the Enzyme-Linked Immunoelectrotransfer Blot (EITB) Assay Clearly Discriminate Viable Cysticercosis in Naturally Infected Pigs.

Enzyme-linked immunoelectrotransfer blot (EITB) detects antibodies against seven Taenia solium larvae antigens in three protein families (GP50, T24/42, and 8-kDa) with different structures and functions. EITB banding patterns against these antigens in pigs provide information about the course of infection and may discriminate viable cysticercosis. We analyzed the banding patterns and infection outcomes (presence of viable cysts, degenerated cysts, and any cysts) of 512 rural pigs. Banding patterns were grouped into homogenous classes using latent class analysis, and relationships with infection outcomes were assessed. Four classes were identified: 1 (n = 308, EITB-negative or positive for the GP50 family), 2 (n = 127, positive for GP50 (GP50 family), GP42-39 and GP24 (T24/42 family), but negative for 8-kDa antigens), 3 (n = 22, positive for GP50 and T24/42 antigens (GP42-39 and GP24), as well as to 8-kDa bands GP13, GP14, and GP18, but negative for GP21), and 4 (n = 55, positive for GP50 and T24/42 antigens, as well as to 8-kDa antigens GP21 and GP18 in combination). Pigs in classes 3 and 4 were more likely to have viable cysts (72.6% and 96.4%, respectively) than pigs in classes 1 and 2 (0.7% and 27.6%, respectively; p < 0.001). The number of infections with any cysts was higher in classes 3 and 4 (77.3% and 98.2%, respectively) and lower in classes 2 and 1 (34.7% and 4.9%, respectively; p < 0.001). Pigs with viable cysts represented >90% of pigs with any cysts in classes 3 and 4 (94.1% and 98.2%, respectively), while degenerated cysts were frequent among pigs with any cysts in classes 1, 3, and 2 (86.7%, 47.1%, and 43.2%, respectively; p < 0.001). EITB banding patterns strongly correlate with cysticercosis infection status in rural pigs, with classes 3 and 4 being more predictive of viable infections.

Quantitative Detection of Leishmania in Rhipicephalus microplus and Amblyomma sabanerae in the Peruvian Amazon Basin.

Leishmaniasis is a disease of public importance with a complex transmission cycle. A quantitative PCR was developed by using the small subunit of the ribosomal RNA gene (SSU rRNA) as a DNA target, which is conserved in all Leishmania species. A TaqMan ® probe was designed to have a high specificity. In all, 22 out of 23 (95.7%) ticks classified as R. microplus tested positive for Leishmania sp. The quantification was between 34.1 and 2197.1 parasites per tick in a range of 12 to 769 fg/uL. In addition, 9 out of 10 (90%) ticks classified as Amblyomma sabanerae tested positive for Leishmania sp. The quantification was between 448.6 and 5428.6 parasites per tick in a range of 157 to 1900 fg/µL. Leishmania sp. was identified in very high percentages in Rhipicephalus microplus and Amblyomma sabanerae from wild Pecari tajacu and Chelonoidis denticulata, in quantities of 34.1 and 5428.6 parasites per arthropod, and this could suggest that the ticks were parasitized by sucking blood from the animals from which they were collected. This is the first report about Leishmania parasites found in wild Rhipicephalus microplus and Amblyomma sabanerae, adding new information about the distribution and epidemiology of the parasite in sylvatic areas.

Impairment in Working Memory and Executive Function Associated with Mercury Exposure in Indigenous Populations in Upper Amazonian Peru.

The Matsigenka people living traditional lifestyles in remote areas of the Amazon rely on a fish-based diet that exposes them to methylmercury (MeHg) at levels that have been associated with decreased IQ scores. In this study, the association between Hg levels and working memory was explored using the framework of the Multicomponent Model. Working memory tasks were modified to fit the culture and language of the Matsigenka when needed and included measures for verbal storage (Word Span) visuospatial storage (Corsi Block Task) and a measure of executive functions, the Self-Ordered Pointing Task (SOPT). An innovation of the Trail Making Tests A & B (TMT A & B) was pilot tested as another potential measure of executive functions. The mean hair Hg levels of 30 participants, ages 12 to 55 years, from three different communities (Maizal, Cacaotal and Yomibato) was 7.0 ppm (sd = 2.40), well above the World Health Organization (WHO) limit for hair of 2.0 ppm and ranged from 1.8 to 14.2 ppm, with 98% of a broader sample of 152 individuals exceeding the WHO limit. Hair Hg levels showed significant associations with cognitive performance, but the degree varied in magnitude according to the type of task. Hg levels were negatively associated with executive functioning performance (SOPT errors), while Hg levels and years of education predicted visuospatial performance (Corsi Block accuracy). Education was the only predictor of Word Span accuracy. The results show that Hg exposure is negatively associated with working memory performance when there is an increased reliance on executive functioning. Based on our findings and the review of the experimental research, we suggest that the SOPT and the Corsi Block have the potential to be alternatives to general intelligence tests when studying remote groups with extensive cultural differences.