The fluvial architecture of the Amazonian neighborhood of Belen, Peru

BackgroundPeru is one of the Latin American countries with the highest malaria burden, mainly due to Plasmodium vivax infections. However, little is known about P. vivax transmission dynamics in the Peruvian Amazon, where most malaria cases occur. The genetic diversity and population structure of P. vivax isolates collected in different communities around Iquitos city, the capital of the Peruvian Amazon, was determined.MethodsPlasmodium vivax population structure was determined by multilocus genotyping with 16 microsatellites on 159 P. vivax infected blood samples (mono-infections) collected in four sites around Iquitos city. The population characteristics were assessed only in samples with monoclonal infections (n = 94), and the genetic diversity was determined by calculating the expected heterozygosity and allelic richness. Both linkage disequilibrium and the genetic differentiation (θ) were estimated.ResultsThe proportion of polyclonal infections varied substantially by site (11% - 70%), with the expected heterozygosity ranging between 0.44 and 0.69; no haplotypes were shared between the different populations. Linkage disequilibrium was present in all populations (IAS 0.14 - 0.61) but was higher in those with fewer polyclonal infections, suggesting inbreeding and a clonal population structure. Strong population differentiation (θ = 0.45) was found and the Bayesian inference cluster analysis identified six clusters based on distinctive allele frequencies.ConclusionThe P. vivax populations circulating in the Peruvian Amazon basin are genetically diverse, strongly differentiated and they have a low effective recombination rate. These results are in line with the low and clustered pattern of malaria transmission observed in the region around Iquitos city.

Wild meat represents a vital source of micro- and macronutrients for forest-dwelling people; however, city dwellers with access to animal protein from different animals may also consume large amounts of wild meat as part of their customs and traditions, to diversify their diets, to maintain connections to their rural kin, and to access meat without having to pay the high prices of domestic meat in the city. The aggregate urban and rural demand for wild meat consumption demonstrates a great risk for overhunting highly preferred and vulnerable species and degrading already fragile Amazonian ecosystems and the food security of people in rural areas. We assessed the effects of socioeconomics factors on wild meat consumption in the city of Iquitos in the Peruvian Amazon. We conducted 1548 interviews with consumers across the city of Iquitos and collected socioeconomic and wild meat consumption data. We used a double hurdle model to estimate simultaneously the probability of a consumer eating wild meat each week and their consumption rate based on 10 variables. In final parsimonious models, monthly income, location in the city (district and distance to market), amount of education, and amount of time spent in Iquitos were all important factors determining consumption rate. We predicted that consumption rates would vary across the city and in some areas would be as high as >7kg·person-1·year-1. The spatial distribution of wild meat consumption showed that people in newer, rapidly growing parts of the city consumed more wild meat and were therefore more dependent on sustainable supply chains. We recommend that consumers who have very high predicted consumption rates may be useful targets for conservation efforts to reduce that consumption, such as culturally relevant, informal educational programs. In our study, these people migrated from rural areas and live along the Iquitos-Nauta Road and are wealthy consumers in downtown Iquitos.

Background. Human T-cell lymphotropic virus type 1 (HTLV-1) is responsible for tropical spastic paraparesis and HTLV-1-associated leukemia/lymphoma. The infection is endemic in some areas of Peru, but its prevalence in the Peruvian Amazon is not well established. We aimed to assess the seroprevalence of HTLV-1 infection in pregnant women in the Peruvian Amazon. Moreover, we performed a systematic literature review and meta-analysis of the seroprevalence of HTLV infection in Peru. (2) Methods. This is a prospective cross-sectional study involving pregnant women attending health centers in the city of Iquitos, Peru, in May and June 2019. The presence of antibodies against HTLV-1 was assessed using ELISA (HTLV I + II ELISA recombinant v.4.0, Wiener lab, Rosario, Argentina). Positive cases were confirmed by Western Blot and HTLV-1 proviral load. (3) Results. The study included 300 pregnant women with a mean age of 26 years (standard deviation [SD] 6.4). Five patients were diagnosed with HTLV-1 infection (prevalence 1.7%, 95% confidence interval (CI) 0.7% to 3.8%). Pregnant women with HTLV-1 infection were discretely younger (mean age 22.6 [SD 22.6] vs. 26.8 [SD 6.3]; p = 0.128). None of the five women had been transfused, and all were asymptomatic. Two (40%) also had a positive serology for Strongyloides, but larvae were not detected in any of the parasitological stool studies. The systematic review component identified 40 studies, which showed that the prevalence of HTLV infection in the general population was 2.9% (95% CI 1.2% to 5.3%) and in women of childbearing age, 2.5% (95% CI 1.2% to 4.0%). (4) Conclusion. The prevalence of HTLV-1 in the Peruvian Amazon basin is about 1.7%, indicating an endemic presence. Screening for HTLV-1 in prenatal care is warranted.

Peruvian ornamental fish industry is based on the trade of wild-caught Amazonian species, which are exported to several countries. Throughout the ornamental fish value chain, fish are exposed to different stressors, which enhance their susceptibility to pathogens. Major emerging viral diseases in ornamental fish may result in trade restrictions. Therefore, it is important for authorities to monitor the health status of ornamental fish populations. The aim of this study was to detect the presence of the genera Megalocytivirus and Ranavirus in five ornamental fish species from the Peruvian Amazon. A total of 600 wild-caught ornamental fish of five species were collected from ornamental fish wholesale facilities in the city of Iquitos, Peru, between June and September 2022. The samples included the species Hyphessobrycon erythrostigma , Corydoras splendens , Carnegiella strigata , Pterophylum scalare and Ancistrus temminckii and were analyzed by quantitative PCR (qPCR) and histopathology. The qPCR results did not detect Megalocytivirus and Ranavirus. In addition, histopathology revealed the presence of monogenoids and Piscinoodinium sp. in the gills and metacercarial cysts in the liver. Furthermore, histopathological examination revealed an unusual finding of Ichthyophthirius sp. in the esophagus of A. temminckii . The results showed that Megalocytivirus and Ranavirus were not detected during the sampling periods in at least five wild-caught ornamental fish species from the Peruvian Amazon and there are no histopathological lesions related to Megalocytivirus-infected fish. Finally, we advise that additional monitoring is necessary to detect the occurrence of the World Organization for Animal Health (WOAH) listed diseases in ornamental fish and develop strategies that ensure surveillance plans to consider the wide variety of Amazonian fish species in the ornamental fish trade, as well as the presence of disease-susceptible ornamental fish species.

The present study aims to report zoonotic parasites in Hoplosternum littorale (Hancock, 1828), acquired in a fish market in the Peruvian Amazon. Forty specimens of H. littorale with an average size of 12.3 ± 2.5cm and weight 58.3 ± 10g were acquired in the "Santa Clara" Market, in the city of Iquitos, Loreto-Peru. Fish samples were taken alive, placed in plastic bags with water, and transported to the laboratory of "Parasitologia y Sanidad Acuicola" of "Instituto de Investigaciones de la Amazonia Peruana" in Iquitos, Peru for analyses. Two groups of endoparasites were identified: Trematoda, with specimens of Clinostomum sp. parasitizing the musculature and skin, and Nematoda, with specimens of Eustrongylides sp. parasitizing the intestine. The findings of the present study constitute a health risk in the event of accidental ingestion of any of these parasites. Socialization campaigns on the dangers of raw or undercooked fish consumption should be implemented by the competent authorities to guarantee the health of the Amazonian population.

In the Americas, as in much of the rest of the world, the dengue virus vector Aedes aegypti is found in close association with human habitations, often leading to high population densities of mosquitoes in urban settings. In the Peruvian Amazon, this vector has been expanding to rural communities over the last 10–15 years, but to date, the population genetic structure of Ae. aegypti in this region has not been characterized. To investigate the relationship between Ae. aegypti gene flow and human transportation networks, we characterized mosquito population structure using a panel of 8 microsatellite markers and linked results to various potential mechanisms for long-distance dispersal. Adult and immature Ae. aegypti (>20 individuals per site) were collected from Iquitos city and from six neighboring riverine communities, i.e., Nauta, Indiana, Mazan, Barrio Florida, Tamshiaco, and Aucayo. FST statistics indicate significant, but low to moderate differentiation for the majority of study site pairs. Population structure of Ae. aegypti is not correlated with the geographic distance between towns, suggesting that human transportation networks provide a reasonable explanation for the high levels of population mixing. Our results indicate that Ae. aegypti gene flow among sub-populations is greatest between locations with heavy boat traffic, such as Iquitos-Tamshiaco and Iquitos-Indiana-Mazan, and lowest between locations with little or no boat/road traffic between them such as Barrio Florida-Iquitos. Bayesian clustering analysis showed ancestral admixture among three genetic clusters; no single cluster was exclusive to any site. Our results are consistent with the hypothesis that human transportation networks, particularly riverways, are responsible for the geographic spread of Ae. aegypti in the Peruvian Amazon. Our findings are applicable to other regions of the world characterized by networks of urban islands connected by fluvial transport routes.

IntroductionHerein, we tested the hypothesis that Asymptomatic P. vivax (Pv) infected individuals (Asym) feature different epidemiological, clinical and biochemical characteristics, as well as hematological parameters, potentially predictive of clinical immunity in comparison to symptomatic Pv infected individuals (Sym).MethodologyBetween 2018 - 2021, we conducted 11 population screenings (PS, Day 0 (D0)) in 13 different riverine communities around Iquitos city, in the Peruvian Amazon, to identify Pv Sym and Asym individuals. A group of these individuals agreed to participate in a nested case - control study to evaluate biochemical and hematological parameters. Pv Asym individuals did not present common malaria symptoms (fever, headache, and chills), had a positive/negative microscopy result, a positive qPCR result, reported no history of antimalarial treatment during the last month, and were followed-up weekly until Day 21 (D21). Control individuals, had a negative malaria microscopy and qPCR result, no history of antimalarial treatment or malaria infections during the last three years, and no history of comorbidities or chronic infections.ResultsFrom the 2159 individuals screened during PS, data revealed a low but heterogeneous Pv prevalence across the communities (11.4%), where most infections were Asym (66.7%) and submicroscopic (82.9%). A total of 29 Asym, 49 Sym, and 30 control individuals participated in the nested case - control study (n=78). Ten of the individuals that were initially Asym at D0, experienced malaria symptoms during follow up and therefore, were included in the Sym group. 29 individuals remained Asym throughout all follow-ups. High levels of eosinophils were found in Asym individuals in comparison to Sym and controls.ConclusionFor the first-time, key epidemiological, hematological, and biochemical features are reported from Pv Asym infections from the Peruvian Amazon. These results should be considered for the design and reshaping of malaria control measures as the country moves toward malaria elimination.

This paper presents a surrealist urban political ecology of cannibal capitalism beyond the city, through the case of the Iquitos-Nauta highway in the Peruvian Amazon. Inaugurated in 2005 after decades of corrupt construction, the highway has catalyzed a chaotic fusion of unplanned urban processes and paralegal extractive industries erupting from and surging back into the city of Iquitos. Armed mafias seize tracts of land and sell off lots to landless migrants; deforestation opens access to white sand mined for the concrete of the city; battery chicken farms abut nature reserves and exclusive resorts; spiritual tourists drink hallucinogenic plant medicines down the road from the municipal dump. All bisected by the howling speed and mangled flesh of the road itself. Drawing on extensive field research, I interpret the highway as a paradigmatic example of extended urbanization in response to the conceptual conundrum of how to grasp the structuring logic of this process without abstracting from the complexities of its disjunctive fragmentation. Cannibal capitalism is identified as the violent dynamic animating extended urbanization, which undermines the conditions of its own expanded reproduction, while surrealist modalities of montage, ethnography and psychogeography are deployed to convey the apocalyptic morphology of the expanding urban fabric.

Economic returns from forest conversion in the Peruvian Amazon

These data are the foundation of the analyses and results published in the article “Spatio-temporal patterns of Mauritia flexuosa fruit extraction in the Peruvian Amazon: Implications for conservation and sustainability” (Horn et al., 2018) [1]. Here we include data on the volume of M. flexuosa fruit arriving in the city of Iquitos, Peru from the surrounding region. This includes the amount of fruit (in sacks and kg), the date of entry into Iquitos, the point of embarkation (watershed and coordinates), the method of transportation and the point of entry into Iquitos. Data is provided in a number of formats, including data tables, Google Earth KML files and summary tables by watershed and/or month.

This study aimed to determine the psychosocial factors associated with delayed test-seeking among tuberculosis patients. The duration of symptoms before seeking medical care was assessed by interview for 108 newly diagnosed pulmonary tuberculosis patients in the city of Iquitos in the Peruvian Amazon, which has high tuberculosis incidence. Beliefs associated with test-seeking behavior and delay was assessed in these patients. The median delay from symptom onset to seeking diagnostic testing was 61 days (inter-quartile range 30-91 days). The belief that tuberculosis is curable was associated with a 100% longer test-seeking delay; the perception that tuberculosis was common was associated with a 57% longer delay; male gender was associated with a 48% longer delay; and education less than complete secondary schooling was associated with a 44% longer delay. In conclusion, current health promotion activities that emphasize tuberculosis curability and high prevalence may paradoxically increase test-seeking delay and therefore require prospective evaluation.

The present study aims to report the occurrence of Eustrongylides sp. in some neotropical fish species commercialized in the Peruvian Amazonia. Samples of young farmed Arapaima gigas were collected from a fish farmer; young Brachyplatystoma tigrinum were acquired from a fish exporter and samples of adult specimens of Acestrorhynchus falcirostris, Pseudoplatystoma punctifer, Cichla monoculus, Hoplias malabaricus, Hydrolycus scomberoides, Raphiodon vulpinus, and Serrasalmus rhombeus were acquired from a fish market of Iquitos, Loreto-Peru. Samples were transported to the "Laboratorio de Parasiología y Sanidad Acuícola" from "Instituto de Investigaciones de la Amazonía Peruana" located in Iquitos, Peru. Larvae L4 of Eustrongylides sp. were found in the host body, in the muscle, and in the visceral cavity of studied fish species. Notorious damages were reported in young A. gigas (lumps in the muscle, inflammation and severe redness of the skin) and in young B. tigrinum (perforation of the abdominal cavity), while in adult specimens of the remaining species, no external damage was reported. The presence of Eustrongylides sp. in various fish species collected in the city of Iquitos-Peru contributes to the distribution of this parasite in the Peruvian Amazon, reporting it, for the first time in this country. Its presence in the muscle of various fish species commercialized in fish markets, warm a possible public health concern and implications for their marketability in the city of Iquitos, Peru.

BackgroundCharacterizing the parasite dynamics and population structure provides useful information to understand the dynamic of transmission and to better target control interventions. Despite considerable efforts for its control, vivax malaria remains a major health problem in Peru. In this study, we have explored the population genetics of Plasmodium vivax isolates from Iquitos, the main city in the Peruvian Amazon, and 25 neighbouring peri-urban as well as rural villages along the Iquitos-Nauta Road.Methodology/ ResultsFrom April to December 2008, 292 P. vivax isolates were collected and successfully genotyped using 14 neutral microsatellites. Analysis of the molecular data revealed a similar proportion of monoclonal and polyclonal infections in urban areas, while in rural areas monoclonal infections were predominant (p = 0.002). Multiplicity of infection was higher in urban (MOI = 1.5–2) compared to rural areas (MOI = 1) (p = 0.003). The level of genetic diversity was similar in all areas (He = 0.66–0.76, p = 0.32) though genetic differentiation between areas was substantial (PHIPT = 0.17, p<0.0001). Principal coordinate analysis showed a marked differentiation between parasites from urban and rural areas. Linkage disequilibrium was detected in all the areas ( = 0.08–0.49, for all p<0.0001). Gene flow among the areas was stablished through Bayesian analysis of migration models. Recent bottleneck events were detected in 4 areas and a recent parasite expansion in one of the isolated areas. In total, 87 unique haplotypes grouped in 2 or 3 genetic clusters described a sub-structured parasite population.Conclusion/SignificanceOur study shows a sub-structured parasite population with clonal propagation, with most of its components recently affected by bottleneck events. Iquitos city is the main source of parasite spreading for all the peripheral study areas. The routes of transmission and gene flow and the reduction of the parasite population described are important from the public health perspective as well for the formulation of future control policies.

To identify potential zoonotic reservoirs of pathogenic leptospires in the Peruvian Amazon basin, wild mammals were trapped from July 1997 to December 1998 near the city of Iquitos. After extraction of nucleic acids from animal kidneys, DNA of pathogenic leptospires was identified by polymerase chain reaction (PCR) assays using one of two primer sets, one amplifying a region of the 23S rRNA gene, and the other amplifying a gene fragment specific for Leptospira spp (G1/G2 primers). Overall, 29% (40 of 136) of the mammals tested showed evidence of renal infection by Leptospira spp., including 20% (13 of 64) of the rodents, 39% (20 of 51) of the marsupials, and 35% (7 of 20) of the chiropterans (bats). Marsupials and chiropterans were implicated as more significant reservoir hosts of leptospires pathogenic to humans than previously recognized.

This work has included the results of the study of the effects on the basic learning of the Peruvian Amazon language called Ikitu, in Spanish-speaking children, in primary level educational institutions in the city of Iquitos. A mobile application called Quimaya has been generated, which can serve as an educational tool to learn the contents of the initial level adapted to the Ikitu culture and language. Educational institutions have been chosen from the rural area of the city of Iquitos, considering the complex accessibility to native communities settled in the Peruvian Amazon. In coordination with the management of the schools, 2 classrooms of first and second grade of primary have been selected, at random 2 groups have been formed, the first control group, the second to perform tests and measurements. An important criterion has been that none of the children knew or were related to the language or Ikitu people. Favourable results have been achieved with regard to learning the basic level of the Ikitu language.