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Background: Mansonellosis is an undermapped insect-transmitted disease caused by filarial nematodes that are estimated to infect hundreds of millions of people. Despite their prevalence, there are many outstanding questions regarding the general biology and health impacts of the responsible parasites. Historical reports suggest that the Colombian Amazon is endemic for mansonellosis and may serve as an ideal location to pursue these questions., Methods: We deployed molecular and classical approaches to survey Mansonella prevalence among adults belonging to indigenous communities along the Amazon River and its tributaries near Leticia, Colombia., Results: Loop-mediated isothermal amplification (LAMP) assays on whole-blood samples detected a much higher prevalence of Mansonella ozzardi infection (approximately 40%) compared to blood smear microscopy or LAMP performed using plasma, likely reflecting greater sensitivity and the ability to detect low microfilaremias and occult infections. Mansonella infection rates increased with age and were higher among men. Genomic analysis confirmed the presence of M. ozzardi that clusters closely with strains sequenced in neighboring countries. We successfully cryopreserved M. ozzardi microfilariae, advancing the prospects of rearing infective larvae in controlled settings., Conclusion: These data suggest an underestimation of true mansonellosis prevalence, and we expect that these methods will help facilitate the study of mansonellosis in endemic and laboratory settings., Competing Interests: Potential conflicts of interest. C. K. S. C., Z. L., A. S., and S. R. are employed by New England Biolabs, a manufacturer and vendor of molecular biology reagents. All other authors report no potential conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Healthcare workers are at increased risk of infection due to occupational exposure to SARS-CoV-2-infected patients. The objective of this study was to determine the seroprevalence of SARS-CoV-2 in healthcare workers in Colombia., Methods: This study is a cross-sectional study focused on estimating the seroprevalence of SARS-CoV-2 antibodies in healthcare workers from 65 hospitals in 10 cities in Colombia during the second semester of 2020. The seroprevalence was determined using an automated immunoassay (Abbott SARS-CoV-2 CLIA IgG). The study included a survey to establish the sociodemographic variables and the risk of infection. A multivariate model was used to evaluate the association between the results of seroprevalence and risk factors., Results: The global seroprevalence of antibodies against SARS-CoV-2 was 35% (95% Bayesian CI 33% to 37%). All the personnel reported the use of protective equipment. General services personnel and nurses presented the highest ratios of seroprevalence among the healthcare workers. Low socioeconomic strata have shown a strong association with seropositivity., Conclusion: This study estimates the prevalence of SARS-CoV-2 infection among healthcare workers. Even though all the personnel reported the use of protective equipment, the seroprevalence in the general services personnel and nurses was high. Also, a significant difference by cities was observed., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Culturally significant interventions to prevent lead exposure of battery recyclers are required. Sulfuric acid used in batteries causes skin lesions and could facilitate the recognition of hazards. This study explored whether joint exposure to lead and sulfuric acid can be used in interventions to manage hazardous work conditions. Data were collected from 120 informal workers, and the blood lead level was measured. Predictors of blood lead levels were explored using a tobit model. The median blood lead level was 9.45 µg/dL (Q 75 -Q 25 : 48.9 µg/dL); when lead and sulfuric acid exposure occurred, the level increased to 11.44 µg/dL, and when exposure to lead and other substances occurred, the level was 11.50 µg/dL. Workers are unaware of the risks of obvious and acute silent chronic exposure. Future preventive interventions could confront the economic benefits of battery recycling with the recognition of susceptibility and severity related to lead and sulfuric acid exposure.

Background: The SARS-CoV-2 pandemic has forced health authorities across the world to take important decisions to curtail its spread. Genomic epidemiology has emerged as a valuable tool to understand introductions and spread of the virus in a specific geographic location., Methodology/principal Findings: Here, we report the sequences of 59 SARS-CoV-2 samples from inhabitants of the Colombian Amazonas department. The viral genomes were distributed in two robust clusters within the distinct GISAID clades GH and G. Spatial-temporal analyses revealed two independent introductions of SARS-CoV-2 in the region, one around April 1, 2020 associated with a local transmission, and one around April 2, 2020 associated with other South American genomes (Uruguay and Brazil). We also identified ten lineages circulating in the Amazonas department including the P.1 variant of concern (VOC)., Conclusions/significance: This study represents the first genomic epidemiology investigation of SARS-CoV-2 in one of the territories with the highest report of indigenous communities of the country. Such findings are essential to decipher viral transmission, inform on global spread and to direct implementation of infection prevention and control measures for these vulnerable populations, especially, due to the recent circulation of one of the variants of concern (P.1) associated with major transmissibility and possible reinfections., Competing Interests: The authors have declared that no competing interests exist.

This study explored the potential association between chronic exposure to pesticide mixtures including paraquat and respiratory outcomes among Colombian farmers. Sociodemographic and occupational data, respiratory symptoms and spirometric data were collected. Paraquat in spot urine samples were quantified with solid-phase extraction high-performance liquid chromatography. Multiple Poisson regressions with robust variance were used to determine factors associated with respiratory outcomes. Profiles of pesticide mixtures used were identified among 217 farmworkers, but profenofos and methamidophos-based mixtures were more frequent. Chronic paraquat exposure was slightly associated with self-reported asthma (PR: 1.06; 95% CI 1.00 to 1.13). Different pesticide mixtures were associated with flu, thoracic pain, allergic rhinitis, and obstructive pattern in spirometry. Although acute exposure to paraquat is low among Colombian farmers participating in the study, associations between respiratory outcomes and chronic pesticide mixtures exposure including profenofos, methamidophos or glyphosate require further specific studies.

Introduction: Coal workers’ pneumoconiosis is a chronic and irreversible disease representing a public health problem. Objective: To estimate the prevalence of pneumoconiosis and its associated factors among underground coal miners in the Colombian departments of Boyacá, Cundinamarca and Norte de Santander. Materials and methods: We conducted a cross-sectional study of 476 miners to measure the prevalence of pneumoconiosis and its associated factors such as coal dust and silica levels, as well as the occupational conditions. The medical assessment and a chest x-ray were performed according to the International Labor Organization criteria, along with spirometry and the identification of glutathione S-transferase and repair enzyme polymorphisms.The associations were explored using Cox regression models. Results: We performed a total of 479 environmental monitoring sessions in 31 companies and we evaluated 476 workers with 10 to 57 years of mining work experience. The prevalence of pneumoconiosis was 33.8% (95% CI: 27.0 - 41.3%). In the Cox multivariate regression model with a constant risk time, pneumoconiosis was significantly associated with working in medium-sized companies (PR=2.00, 95% CI: 0.995 - 2.690; p=0.052), the level of severe exposure to coal dust (PR=2.055, 95% CI: 1.043 - 4.048; p=0.038), and working in underground mining for 25 years or more (for those with 25.0-29.9 years: PR=2.199, 95% CI: 1.449 - 3.338; p=0.001). Conclusions: The prevalence of pneumoconiosis was very high and was found to be associated with severe exposure to coal dust, work exposure for 25 years or more and working in medium-sized enterprises

In Colombia, the inhabitants of the Mojana region have historically been subjected to high levels of environmental and occupational exposure to mercury; however, there are few robust data on the magnitude of this exposure and associated factors. This study aimed to describe the levels of mercury in the workers and inhabitants in this region, and to identify the main sociodemographic and occupational factors that are associated with this exposure. A cross-sectional study was conducted, in which mercury levels were determined in biological samples (blood, urine, hair) from 1119 people in the Mojana region. A questionnaire was also administered, which was adapted from the Global Mercury Assessment. Linear regression models were adjusted for the natural logarithm of mercury levels in blood, urine, and hair, using the factors that were explored as independent variables. The study reports high mercury levels in 35.0% of blood samples (95% CI 31.9⁻38.1%), 28.8% (95% CI 24.9⁻32.8%) of urine samples, and 56.3% (95% CI 53.1⁻59.5%) of hair samples. The reported source of water for consumption was associated with high levels of mercury ( p -value < 0.05). We provide evidence of high levels of mercury exposure for the population in the Mojana region.

Introduction: Painters of automobiles are exposed to pure and mixed solvents that have been associated with neurological effects and carcinogenic mutations., Objective: To characterize the health and work conditions of individuals who are occupationally exposed to organic solvents used in sheet metal and auto body shops in Bogota., Materials and Methods: Descriptive, cross-sectional study that characterizes the health and work conditions of individuals exposed to organic solvents in sheet metal and auto body shops in Bogota. A group exposed to the solvents was compared to an unexposed group. Air concentrations of benzene, toluene and xylene (BTX) were determined, individual questionnaires were administered and phenylmercapturic, hippuric and ortho- and para-methylhippuric acids were measured in urine. The results of the measurements and the questionnaires were correlated to determine the exposure panorama., Results: For the three BTX metabolites, statistically significant differences (p<0.001) were found between the population exposed to the solvents and the unexposed population. For the exposed population, positive correlations were found between toluene in air and hippuric acid in urine (rho=0.82) and between xylene in air and o-methylhippuric acid in urine (rho=0.76). Hippuric acid values exceeded permissible levels in 11 workers and p-methylhippuric acid exceeded permissible levels in 8 workers. None of the phenylmercapturic values exceeded the limit., Conclusion: Auto painters are exposed to high levels of organic solvents at the workplace and do not have adequate industrial health and safety conditions to perform their jobs.

Aim: To examine the presence of human papillomavirus (HPV) in esophageal squamous cell carcinoma (ESCC) specimens collected from Colombia and Chile located in the northern and southern ends of the continent, respectively., Methods: We examined 47 and 26 formalin-fixed and paraffin-embedded ESCC specimens from Colombia and Chile, respectively. HPV was detected using GP5+/GP6+ primer pair for PCR, and confirmed by Southern blot analysis. Sequencing analysis of L1 region fragment was used to identify HPV genotype. In addition, P16(INK4A) protein immunostaining of all the specimens was conducted., Results: HPV was detected in 21 ESCC specimens (29%). Sequencing analysis of L1 region fragment identified HPV-16 genome in 6 Colombian cases (13%) and in 5 Chilean cases (19%). HPV-18 was detected in 10 cases (21%) in Colombia but not in any Chilean case. Since Chilean ESCC cases had a higher prevalence of HPV-16 (without statistical significance), but a significantly lower prevalence of HPV-18 than in Colombian cases (P = 0.011) even though the two countries have similar ESCC incidence rates, the frequency of HPV-related ESCC may not be strongly affected by risk factors affecting the incidence of ESCC. HPV-16 genome was more frequently detected in p16 positive carcinomas, although the difference was not statistically significant. HPV-18 detection rate did not show any association with p16 expression. Well-differentiated tumors tended to have either HPV-16 or HPV-18 but the association was not statistically significant. HPV genotypes other than HPV-16 or 18 were not detected in either country., Conclusion: HPV-16 and HPV-18 genotypes can be found in ESCC specimens collected from two South American countries. Further studies on the relationship between HPV-16 presence and p16 expression in ESCC would aid understanding of the mechanism underlying the presence of HPV in ESCC.