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PubMedDate not supplied

Natural infections of Leishmania peruviana in animals in the Peruvian Andes.

Evidence that domestic dogs may act as reservoir hosts for cutaneous leishmaniasis in the Peruvian Andes is provided by the isolation, for the first time, from naturally infected dogs of parasites identified (by isoenzymes) as Leishmania peruviana. Leishmania parasites were isolated from nasal aspirates or biopsies from 5 (1.8%) of 279 asymptomatic dogs samples in endemic villages of the Peruvian Andes. In addition, Leishmania (Viannia) infections were identified in 15 (5.4%) of 276 nasal samples by the polymerase chain reaction (PCR) using subgenus-specific primers. Further circumstantial evidence for a reservoir role for dogs comes from the finding of a relatively high dog blood index among the sandfly vectors collected inside houses (29% for Lutzomyia peruensis and 17% for Lu. verrucarum). Possible wild mammal reservoir hosts for Andean cutaneous leishmaniasis were also detected in endemic villages. At least 8 species were identified among the 1266 small mammals trapped. Leishmania parasites were isolated from blood or skin biopsies taken from 2 (2.6%) of 78 Didelphis albiventris and 6 (1.2%) of 511 Phyllotis andinum. Three isolates were identified by isoenzymes as L. peruviana, and the other 5 were identified by PCR as Leishmania (Viannia) species. Leishmania (Viannia) infections were also identified by PCR directly on skin biopsies taken from 2 (2.8%) of 72 D. albiventris, 1 (0.2%) of 499 P. andinum, and 4 (2.6%) of 153 Akodon sp.

Animals↗

PubMed1998

Changing biocultural perspectives on health in the Andes.

New directions toward biocultural approaches to health and illness in Andean peoples have emerged since the original Health in the Andes volume was published in 1981. The reformulation of these perspectives was stimulated in part by the growth of political-economic perspectives in Andean ethnography and by critiques of medical ecology by critical medical anthropologists. This paper provides a brief history of changing biocultural perspectives on Andean health, and contrasts two projects dealing with Andean biology and health carried out in the 1960s and 1980s in the District of Nuñoa in Southern Peru. The recent Nuñoa research provides one example of a more critical biocultural approach that attempts to integrate perspectives from ecology and anthropological political economy. The utility of the approach is explored through the Nuñoa case study, which focused on the reproduction of illness and poverty in Andean households in contexts of social and economic change. Findings of this research are compared with recent work in the Andes to illustrate how a more critical biocultural perspective can better articulate with the diversity of approaches in medical anthropology and Andean health studies.

Anthropology, Cultural↗

PubMedDate not supplied

Subduction and collision processes in the Central Andes constrained by converted seismic phases.

The Central Andes are the Earth's highest mountain belt formed by ocean-continent collision. Most of this uplift is thought to have occurred in the past 20 Myr, owing mainly to thickening of the continental crust, dominated by tectonic shortening. Here we use P-to-S (compressional-to-shear) converted teleseismic waves observed on several temporary networks in the Central Andes to image the deep structure associated with these tectonic processes. We find that the Moho (the Mohorovicić discontinuity--generally thought to separate crust from mantle) ranges from a depth of 75 km under the Altiplano plateau to 50 km beneath the 4-km-high Puna plateau. This relatively thin crust below such a high-elevation region indicates that thinning of the lithospheric mantle may have contributed to the uplift of the Puna plateau. We have also imaged the subducted crust of the Nazca oceanic plate down to 120 km depth, where it becomes invisible to converted teleseismic waves, probably owing to completion of the gabbro-eclogite transformation; this is direct evidence for the presence of kinetically delayed metamorphic reactions in subducting plates. Most of the intermediate-depth seismicity in the subducting plate stops at 120 km depth as well, suggesting a relation with this transformation. We see an intracrustal low-velocity zone, 10-20 km thick, below the entire Altiplano and Puna plateaux, which we interpret as a zone of continuing metamorphism and partial melting that decouples upper-crustal imbrication from lower-crustal thickening.

Journal Article↗

PubMed2002

Andes virus infection of cynomolgus macaques.

Andes virus (ANDV), a member of the genus Hantavirus, is a causative agent of hantavirus pulmonary syndrome (HPS) and is the only hantavirus known to be transmissible from person to person. HPS is found in North and South America and is often fatal. To test the virulence of ANDV in nonhuman primates, we exposed cynomolgus macaques to Andes virus, either intravenously or by aerosol. The monkeys did not manifest clinical disease but showed significant lymphocyte decreases between days 8 and 11 postexposure. All monkeys developed (1) both IgM and IgG antibodies against the viral nucleocapsid protein and (2) a neutralizing antibody response. By plaque assay, serum samples were negative for infectious virus, but by nonnested reverse transcriptase-polymerase chain reaction, viral S-segment genomes were detected in whole blood from 4 of 6 monkeys. This study is the first demonstration of infection of nonhuman primates by an HPS-causing virus.

Animals↗

PubMed2026

Digest: Speciation involves both barriers and bridges in the tropical Andes.

Mountains are important centers of biodiversity and studies of speciation. In particular, the north-south linear orientation of the Andes allows examination of how geographic isolation, elevation, and latitude influence divergence in closely related species such as Myioborus warblers (Parulidae), the focal taxa of this study. Traditional models of Andean speciation have emphasized allopatric divergence due to geographic barriers, but thanks to the limited sampling of hybrid zones and lack of genome-wide datasets in tropical taxa, we may have underestimated of the role of gene flow in shaping patterns of divergence in the region. Using ddRAD-seq genomic data, Céspedes Arias et al. (2026) demonstrated that geographic isolation and hybridization both contribute to the generation and maintenance of Andean warbler lineages. Their results revealed how complex patterns of genetic divergence, introgression, and isolation-by-distance contribute to the historical buildup of biodiversity in the Andes, challenging strictly isolationist models of mountain evolution.

Animals↗

PubMed2004

Quaternary Ice-Age dynamics in the Colombian Andes: developing an understanding of our legacy.

Pollen records from lacustrine sediments of deep basins in the Colombian Andes provide records of vegetation history, the development of the floristic composition of biomes, and climate variation with increasing temporal resolution. Local differences in the altitudinal distribution of present-day vegetation belts in four Colombian Cordilleras are presented. Operating mechanisms during Quaternary Ice-Age cycles that stimulated speciation are discussed by considering endemism in the asteraceous genera Espeletia, Espeletiopsis and Coespeletia. The floristically diverse lower montane forest belt (1000-2300 m) was compressed by ca. 55% during the last glacial maximum (LGM) (20 ka), and occupied the slopes between 800 m and 1400 m during that period. Under low LGM atmospheric pCO2 values, C4-dominated vegetation, now occurring below 2200 m, expanded up to ca. 3500 m. Present-day C3-dominated paramo vegetation is therefore not an analogue for past C4-dominated vegetation (with abundant Sporobolus lasiophyllus). Quercus immigrated into Colombia 478 ka and formed an extensive zonal forest from 330 ka when former Podocarpus-dominated forest was replaced by zonal forest with Quercus and Weinmannia. During the last glacial cycle the ecological tolerance of Quercus may have increased. In the ecotone forests Quercus was rapidly and massively replaced by Polylepis between 45 and 30 ka illustrating complex forest dynamics in the tropical Andes.

Altitude↗

PubMed1990

Antibody to HTLV-I in indigenous inhabitants of the Andes and Amazon regions in Colombia.

To explore the HTLV-I-carrying groups among the indigenous inhabitants in South America, a sero-epidemiological study on HTLV-I focusing on hinterland villages isolated from others in the Andes and Amazon regions was conducted. Five (2.9%) out of 171 subjects showed positive for HTLV-I antibody in the gelatin particle agglutination (PA) test. Two out of 5 positives with high antibody titer (greater than or equal to x 1024) in the PA test also showed a positive immunofluorescence (IF) test and anti-HTLV-I-specific protein products, p19, p24, p28, gp46, and p53 in sera by the Western blotting (WB) test. One of three negatives in the IF test showed positive antibodies to p19 and p24 by the WB test. Finally, two were confirmed as HTLV-I carriers and one was suspected of being a carrier. All three are Paez Indians from the central Andes; 53- and 34-year-old women and a 35-year-old man. The results show that HTLV-I carriers exist among isolated indigenous people in South America.

Adult↗

PubMed2025

Are We Witnessing a Speciation Continuum? Evidence From Current and Past Gene Flow in the Genus Oritrophium s.s. (Asteraceae) From the Tropical High Andes.

Determining species boundaries is key for appropriately assessing biodiversity. However, the continuity of the speciation process makes delimiting species a difficult task, especially for recently diverged taxa. Furthermore, past introgression may leave traces that result in reticulate evolutionary patterns, challenging the estimation of species relationships. The fastest-evolving biodiversity hotspot on Earth is the Páramo. Its flora in the tropical high Andes is known for extraordinarily high species richness and endemism. However, the recent origin, fast diversification and complex taxonomy of many genera challenge species delimitation and phylogenetic reconstruction. In this study, we reconstructed phylogenetic relationships and addressed the role of introgression in the diversification of Oritrophium s.s. (Asteraceae) based on phylogenomic data. We combined genomic, phenotypic and ecological data to test species boundaries and compared trajectories across the speciation continuum within the taxonomically complex 'O. peruvianum group'. We found that historical introgression played an important role in the evolution of Oritrophium s.s., and many of the taxa within the 'O. peruvianum group' are at various stages of speciation. These results highlight the importance of testing for introgression to understand the diversification of recently evolved groups. Likewise, they suggest that heterogeneous speciation trajectories associated with geographic isolation and secondary contact, possibly during the Pleistocene, contributed to plant diversity in the tropical high Andes.

Genetic Speciation↗

PubMed2006

Bidirectional virus secretion and nonciliated cell tropism following Andes virus infection of primary airway epithelial cell cultures.

Hantavirus pulmonary syndrome (HPS) is an acute disease resulting from infection with any one of a number of New World hantaviruses. HPS has a mortality rate of 40% and, unlike many other severe respiratory diseases, often occurs in young, healthy adults. Infection is usually initiated after inhalation of rodent excreta containing virus particles, but human-to-human transmission has been documented. Postmortem tissue samples show high levels of viral antigen within the respiratory endothelium, but it is not clear how the virus can traverse the respiratory epithelium in order to initiate infection in the microvasculature. We have utilized Andes virus infection of primary, differentiated airway epithelial cells to investigate the ability of the virus to interact with and cross the respiratory epithelium. Andes virus infects the Clara and goblet cell populations but not the ciliated cells, and this infection pattern corresponds to the expression of beta(3) integrin, the viral receptor. The virus can infect via the apical or basolateral membrane, and progeny virus particles are secreted bidirectionally. There is no obvious cytopathology associated with infection, and beta(3) integrins do not appear to be critical for respiratory epithelial cell monolayer integrity. Our data suggest that hantavirus infection of the respiratory epithelium may play an important role in the early or prodrome phase of disease as well as serving as a source of virus involved in transmission.

Animals↗

PubMed2002

Acral paresthesias in the Andes and neurology at sea level.

BACKGROUND: Thirty-nine percent of permanent altitude dwellers in the Andes experience acral paresthesias. METHODS: Clinical examinations, sural nerve biopsies, and electrodiagnostic studies on peripheral nerves were performed on 15 men. Ten Cerro de Pasco (CP) natives living at 4,338 meters were biopsied. Three of these subjects had no burning feet/burning hands (BF/BH); three had BF/BH; and four had chronic mountain sickness (CMS), a maladaptation syndrome resulting from living in the Andes, all with BF/BH. Three patients with CMS were biopsied in Lima within hours after leaving CP. Two normal Lima natives were biopsied in Lima. Symptom scores for BF/BH and CMS score ratings were used. The nerves were assayed for Na+, K+ adenosine triphosphatase (ATPase), cytochrome oxidase (CO), substance P (SP), and endothelin (ET). RESULTS: Low ATPase was inversely related to symptom scores and CMS scores (p < 0.001). Patients with CMS biopsied in normoxia (Lima) had ATPase levels similar to those of controls. Nerve motor conduction velocities and sensory action potentials were normal. CO was inversely related to age (p < 0.03) and no relation of SP to any variable was found. ET levels were lower in sea level natives (p = 0.04). CONCLUSIONS: Acral paresthesias are associated with low ATPase in peripheral nerves. Lower ET levels of sea level natives likely reflect lowered release from vasa nervorum.

Adult↗

PubMed2002

First human isolate of Hantavirus (Andes virus) in the Americas.

We isolated Andes virus (formal name: Andes virus [ANDV], a species in the genus Hantavirus), from serum of an asymptomatic 10-year-old Chilean boy who died 6 days later of hantavirus pulmonary syndrome (HPS). The serum was obtained 12 days after his grandmother died from HPS and 2 days before he became febrile. No hantavirus immunoglobulin (Ig) G or IgM antibodies were detected in the serum sample. After three blind passages, ANDV antigens were detected in Vero E6 cells by immunofluorescence assay and enzyme-linked immunosorbent assay, and ANDV RNA was detected by reverse transcription-polymerase chain reaction. A fragment of the virus genome showed 96.2% nucleotide identity with that of prototype ANDV. To our knowledge, this is the first isolation of any agent of hemorrhagic fever with HPS from a human and the first such isolation of hantavirus before symptoms of that syndrome or HPS began.

Animals↗

PubMed2003

Complete sequence of the genome of the human isolate of Andes virus CHI-7913: comparative sequence and protein structure analysis.

We report here the complete genomic sequence of the Chilean human isolate of Andes virus CHI-7913. The S, M, and L genome segment sequences of this isolate are 1,802, 3,641 and 6,466 bases in length, with an overall GC content of 38.7%. These genome segments code for a nucleocapsid protein of 428 amino acids, a glycoprotein precursor protein of 1,138 amino acids and a RNA-dependent RNA polymerase of 2,152 amino acids. In addition, the genome also has other ORFs coding for putative proteins of 34 to 103 amino acids. The encoded proteins have greater than 98% overall similarity with the proteins of Andes virus isolates AH-1 and Chile R123. Among other sequenced Hantavirus, CHI-7913 is more closely related to Sin Nombre virus, with an overall protein similarity of 92%. The characteristics of the encoded proteins of this isolate, such as hydrophobic domains, glycosylation sites, and conserved amino acid motifs shared with other Hantavirus and other members of the Bunyaviridae family, are identified and discussed.

Amino Acid Sequence↗

PubMed1997

Perspectives on the diagnosis, epizootiology, and control of the 1973 duck plague epizootic in wild waterfowl at Lake Andes, South Dakota.

An epizootic of duck plague occurred in early 1973 in a population of 163,500 wild waterfowl, primarily mallards (Anas platyrhynchos), wintering on Lake Andes and the nearby Missouri River in southeastern South Dakota (USA). The diagnosis was based on pathologic lesions and confirmed by virus isolation. Control measures included quarantine, attempts to reduce virus contamination of the area, dispersal of waterfowl, and monitoring of wild waterfowl populations for mortality. The epizootic resulted in documented mortality of 18% and estimated mortality of 26% of the waterfowl at risk. Prompt implementation of control measures might have limited mortality to approximately 8%. Losses during the epizootic were equivalent to 0.12% of the annual mortality in the North American 1996 fall population of 80,000,000 wild ducks. The most likely sources of the infection were free-flying wild mallard or American black duck (Anas rubripes) carriers from the upper midwestern or northeastern United States. Duck plague serum neutralization antibodies were demonstrated in 31% of 395 apparently healthy mallards sampled prior to dispersal of the flock at Lake Andes, suggesting that tens of thousands of potential duck plague carriers entered the wild waterfowl populations of all four major flyways. Consequently, the absence of major epizootics of duck plague in wild waterfowl in the subsequent two decades is evidence that substantial numbers of duck plague carriers can occur in wild waterfowl populations without resulting in epizootic mortalities. The failure to isolate duck plague virus from apparently healthy mallards sampled during the epizootic raises questions concerning the validity of conclusions regarding the status of duck plague in wild waterfowl based upon negative results of random surveys conducted in the absence of epizootics.

Animals↗

PubMedDate not supplied

Dust mites but not grass pollen are important sensitizers in asthmatic children in the Ecuadorian Andes.

Grass pollen is an important cause of asthma and rhinoconjunctivitis in Europe and the United States. In the high Andes however, the role this pollen plays in respiratory allergies is unknown. In this study, we tested the prevalence of grass pollen sensitization in comparison to other aeroallergens on 433 asthmatic children living in Quito, Ecuador (the Andes mountain range, 2,800 m above sea level). The skin prick test technique was used. We found that the least sensitizing allergens of all were grass pollen (12.2%) and molds (7.4%) with p < 0.0001. A clear predominance of sensitization to the house dust mite Dermatophagoides pteronyssinus (77.8%) and Dermatophagoides farinae (76.9%), in comparison to the other aeroallergens tested, in terms of sensitization (p = 0.00000) and papule size (p < 0.0002), was observed. The most highly sensitized group consisted of asthmatics between 5 and 15 years of age (D. pteronyssinus 90.7%, D. farinae 87.5%, dog hair 37.4%, cat hair 43%, grass pollen 15.9% and molds 9.9%). In the total study group, males were only more sensitive than females to D. pteronyssinus (82.1% vs. 71.6%, p = 0.0009). We concluded that in the group of asthmatic children studied, grass pollen showed a low capacity of sensitization, even though it is widely found all over our city. The most sensitizing allergens were D. pteronyssinus and D. farinae, followed by cat and dog hair.

Adolescent↗

PubMed2005

Illicit crops and armed conflict as constraints on biodiversity conservation in the Andes region.

Coca, once grown for local consumption in the Andes, is now produced for external markets, often in areas with armed conflict. Internationally financed eradication campaigns force traffickers and growers to constantly relocate, making drug-related activities a principal cause of forest loss. The impact on biodiversity is known only in general terms, and this article presents the first regional analysis to identify areas of special concern, using bird data as proxy. The aim of conserving all species may be significantly constrained in the Santa Marta and Perijá mountains, Darién, some parts of the Central Andes in Colombia, and between the middle Marañón and middle Huallaga valleys in Peru. Solutions to the problem must address the root causes: international drug markets, long-lasting armed conflict, and lack of alternative income for the rural poor.

Animals↗

PubMed2000

Genetic structure of Quechua-speakers of the Central Andes and geographic patterns of gene frequencies in South Amerindian populations.

A sample of 141 Quechua-speaking individuals of the population of Tayacaja, in the Peruvian Central Andes, was typed for the following 16 genetic systems: ABO, Rh, MNSs, P, Duffy, AcP1, EsD, GLOI, PGM1, AK, 6-PGD, Hp, Gc, Pi, C3, and Bf. The genetic structure of the population was analyzed in relation to the allele frequencies available for other South Amerindian populations, using a combination of multivariate and multivariable techniques. Spatial autocorrelation analysis was performed independently for 13 alleles to identify patterns of gene flow in South America as a whole and in more specific geographic regions. We found a longitudinal cline for the AcP1*a and EsD*1 alleles which we interpreted as the result of an ancient longitudinal expansion of a putative ancestral population of modern Amerindians. Monmonnier's algorithm, used to identify areas of sharp genetic discontinuity, suggested a clear east-west differentiation of native South American populations, which was confirmed by analysis of the distribution of genetic distances. We suggest that this pattern of genetic structures is the consequence of the independent peopling of western and eastern South America or to low levels of gene flow between these regions, related to different environmental and demographic histories.

Gene Frequency↗

PubMedDate not supplied

Body size, composition, and blood pressure of high-altitude Quechua from the Peruvian Central Andes (Huancavelica, 3,680 m).

Although much information is available about the effects of high altitude on physiological characteristics, less is know about its effect on body composition. In the present study, anthropometric and body composition variables were investigated in a sample of 77 adult Quechua males from the Peruvian Central Andes (Huancavelica, 3,680 m). The subjects are shorter in relation to body weight than other ethnic groups, whereas body proportions are macrocormic (indicating a long trunk relative to the lower extremities), with intermediate values of the acromial-iliac index. All skinfold thicknesses are low (approximately 15th percentiles of NHANES reference values for the triceps and subscapular skinfolds), but tend to be higher than in the other Quechua populations. Similar results are obtained when percentage fat is estimated. Somatotypes are dominant in mesomorphy with very low ectomorphy. Comparison with a sample of high-altitude Kirghiz (3,200 m), previously studied with the same methods, shows higher values in the Peruvian sample for all variables related to adiposity. The presence of low adiposity in the Quechua population could be associated with stresses of the high-altitude environment. Mean values of blood pressure are very low and there is no correlation with age.

Adipose Tissue↗

PubMed1995

Socioeconomic change and patterns of growth in the Andes.

Changes in the pattern of growth over a 20-year period are described for a combined rural and semi-urban population in the District of Nuñoa (Puno) in southern Peruvian Andes. Over the past two decades, Andean regions have experienced many socioeconomic changes, including the implementation of agrarian reform policies and increased integration into a market economy. Local changes in Nuñoa have included improved transportation networks, new markets, an expanded public school system, and improved health care facilities. Secular trends in stature and weight have been found to be associated with social and economic development throughout the developing world, including Peru. The purpose of this paper is to present the findings from a re-study of growth in the Nuñoan population, and to assess whether changing conditions in Nuñoa have resulted in secular increases in growth. A cross-sectional sample of 1,466 children and adults and mixed-longitudinal sample of 404 children (age 3-22), measured between 1983 and 1984, are compared to similar samples collected from the same location between 1964 and 1966. Adolescents are taller, heavier, and somewhat fatter in the present population, although these differences diminish or disappear in adulthood. Age of maturation, peak growth velocities, and cessation of growth may come 1 to 2 years earlier than in the 1960s. As was found in earlier studies, growth velocities are low, the adolescent growth spurt is small, and sexual dimorphism is delayed. No secular trends in adult stature were found. Thus, the effects of social and economic change on nutrition, health, and growth in the population are uneven and generally unclear. This points to inequalities in access to the benefits of change throughout the region.

Adolescent↗