Genome analysis suggests HTLV-1aA introduction in Chile related to migrations of ancestral indigenous populations.

The human T cell lymphotropic virus type 1 (HTLV-1), unlike other RNA viruses such as HIV, has a stable genome and has infected humans since remote times. Although the HTLV-1 infection is endemic in South America, there is scarce information about HTLV-1 in Chile and its history of introduction. This study assessed the genomic content of HTLV-1 from Chile and its relationship with HTLV-1 lineages circulating worldwide by phylogenetic reconstruction and dating analyses. A total of 30 HTLV-1 genomes collected from the four continents were used to conduct dating analyses, including the first HTLV-1 genome from Amerindian/Mapuche ethnicity. Estimation was performed using a Bayesian Markov Chain Monte Carlo coalescent-based approach as implemented in the BEAST program. The time of the most recent ancestor of HTLV-1 from Chile was ∼1409 years ago, which coincides with the period of Amerindian population expansion across South America. Our results suggest HTLV-1aA was possibly introduced in Chile during the migrations of the ancestral indigenous populations.

Phylogenetic dating analysis of HTLV-1 from Chile suggests transmissions events related to ancient migrations and contemporary expansion.

Human T-cell lymphotropic virus type 1 (HTLV-1) is a globally-spread virus. It is estimated that there are about 5­10 million infected people in the world. HTLV is endemic in Chile, with higher seroprevalence among indigenous people. However, little is known about HTLV-1 genetic diversity, its introduction and dispersion in this country. To gain insights into these issues, a phylogenetic dating analysis was conducted based on Chilean and closed related long terminal repeat sequences. The time tree reconstruction showed that the introduction of HTLV-1aA occurred several times in Chile. It was hypothesized that these introductions took place at least in two different historical moments: (i) during the ancient human migrations and (ii) during/after the European colonization of South America. The present study contributes toward understanding the evolutionary history of HTLV-1 in Chile and South America.

[Onychomycosis: multicentre epidemiological, clinical and mycological study]. / Onicomicosis: estudio multicéntrico clínico, epidemiológico y micológico.

BACKGROUND: Onychomycosis accounts for up to 50% of all nail disorders. They can be caused by: yeasts, dermatophytes and non-dermatophyte moulds. OBJECTIVES AND METHODS: A multicentre study designed to determine the prevalence, mycological test results, aetiological agents, and clinical presentation of onychomycosis was carried out. All fingernail and toenail samples taken during a one year period at 9 diagnostic centres were included. RESULTS: A total of 5,961 samples were analysed, of which 82.3% were from toenails and 17.7% from fingernails. The mean age of the patients was 49.7 years, and 66% were females. Direct microscopic examination was positive in 61% of the samples. In adults, 61.2% of toenails were positive using potassium hydroxide (KOH), and 43.7% were positive in cultures. The prevailing aetiological agents belong to the dermatophyte group (82.8%), and distal subungual was the most common clinical form. In fingernails, direct examination showed 59.8% positive samples, and cultures were positive in 52.9%. The prevailing agents were yeasts belonging to Candida species, and onycholysis was the most common lesion. CONCLUSIONS: Direct mycological examinations were positive in 61%, a higher value than that found in other series. Dermatophytes were prevalent in toenails of both sexes, and in finger nails yeast were prevalent in females, and dermatophytes in males. Non-dermatophyte moulds corresponded to 4.8% of toenail and 2.05% of fingernails isolates.

Trends in obesity and diabetes prevalence in a Chilean urban population: 1993-2001.

BACKGROUND: In recent years, the Chilean population has suffered significant lifestyle changes associated with the rapid socioeconomic development of the country. These changes can induce a significant increase in the prevalence of some chronic diseases, such as obesity, dyslipidemia, and diabetes mellitus. We aimed to assess diabetes mellitus, obesity, and hypercholesterolemia trends in a Chilean urban population followed between 1993 and 2001. METHODS: A total of 1584 adults, living in Santiago, the capital of Chile, were randomly enrolled in a cross-sectional epidemiologic study in 1993. The same population was re-evaluated in 2001, recruiting 964 individuals from the original sample. Prevalences of diabetes mellitus, obesity, and hypercholesterolemia were determined according to standard criteria. We tested the significance of the differences between the observed prevalence of diabetes mellitus, obesity, and hypercholesterolemia in the 964 subjects evaluated in 2001 compared with the expected prevalence according to population aging based in data from 1993. FINDINGS: In 1993, 3.8% of the sample population had diabetes mellitus, 21.8% had obesity, and 37.3 % exhibited hypercholesterolemia. In 2001, the observed prevalence of diabetes mellitus, obesity, and hypercholesterolemia was 10.1%, 32%, and 58%, respectively. The latter percentages were significantly higher than the expected prevalence according to the aging of the population (6.5% for diabetes mellitus, 27.7% for obesity, and 47.7 for hypercholesteromia). INTERPRETATION: Our findings indicate that Chilean population has suffered an accelerated increase in the prevalence of diabetes mellitus, obesity, and hypercholesterolemia, due to the ongoing epidemiological transition that will lead to an enormous public health burden in the near future.