Knowledge, attitudes, and practices towards COVID-19 among Venezuelans during the 2020 epidemic:An online cross-sectional survey

BACKGROUND: COVID-19 threatens health systems worldwide, but Venezuela's system is particularly vulnerable. To prevent the spread of COVID-19, individuals must adopt preventive behaviors. However, to encourage behavior change, we must first understand current knowledge, attitudes, and practices (KAPs) that inform response to this health threat. METHODS: We explored KAPs among Venezuelans using a cross-sectional, internet-based questionnaire. The questionnaire explored individuals' knowledge about COVID-19; their attitudes toward the world's and the Venezuelan authorities' abilities to control it; and their self-reported practices. We also collected demographic data. Binomial logistic regression analyses were used to predict the adoption of preventive behaviors based on demographic variables, individual knowledge level, and individual attitudes. RESULTS: 3122 individuals completed the questionnaire. Participants had a high level of knowledge about COVID-19. They expressed high levels of optimism that the world would eventually control COVID-19, but they were very pessimistic about the public authorities in Venezuela. Most participants adopted preventive practices. Binomial regression suggests younger people, less educated people, and manual laborers hold lower levels of knowledge, and these groups, as well as men, were less likely to adopt preventive practices. Knowledge, by itself, had no association with optimism and little association with self-reported practices. CONCLUSIONS: As other KAP studies in Latin America found, knowledge is not sufficient to prompt behavior change. Venezuelans' pessimism about their own country's ability should be explored in greater depth. Health promotion in Venezuela may wish to target the most at risk groups: men, younger people, less educated people, and manual laborers

COVID-19 Vaccine Hesitancy in Three Latin American Countries:Reasons Given for Not Becoming Vaccinated in Colombia, Ecuador, and Venezuela

Although vaccines have been developed to prevent COVID-19, vaccine hesitancy is a significant barrier for vaccination programs. Most research on COVID-19 vaccine hesitancy has blamed misinformation and misstated concerns about effectiveness, safety, and side effects of these vaccines. The preponderance of these studies has been performed in the Global North. Although Latin American has been substantially and negatively impacted by COVID-19, few studies have examined COVID-19 vaccine hesitancy there. We explored reasons volunteered for COVID-19 vaccine hesitancy from a sample of 1,173 Colombians, Ecuadorians, and Venezuelans. Overall, COVID-19 vaccine hesitancy in these three countries is higher than desirable, but most people who are COVID-19 vaccine hesitant offered one reason or fewer. The reasons offered are diverse, including myths and exaggerations, but also individual-level contraindications for vaccination and structural barriers. Because of the diversity of reasons, single-issue mass campaigns are unlikely to bring about large shifts in COVID-19 vaccine hesitancy in Colombia, Ecuador, and Venezuela. Our data suggest that interpersonal communication, particularly in Ecuador, and addressing structural concerns, particularly in Venezuela, are likely to have the greatest impact on vaccine uptake

2b-RAD genotyping for population genomic studies of Chagas disease vectors: Rhodnius ecuadoriensis in Ecuador

Background: Rhodnius ecuadoriensis is the main triatomine vector of Chagas disease, American trypanosomiasis, in Southern Ecuador and Northern Peru. Genomic approaches and next generation sequencing technologies have become powerful tools for investigating population diversity and structure which is a key consideration for vector control. Here we assess the effectiveness of three different 2b restriction site-associated DNA (2b-RAD) genotyping strategies in R. ecuadoriensis to provide sufficient genomic resolution to tease apart microevolutionary processes and undertake some pilot population genomic analyses. Methodology/Principal findings: The 2b-RAD protocol was carried out in-house at a non-specialized laboratory using 20 R. ecuadoriensis adults collected from the central coast and southern Andean region of Ecuador, from June 2006 to July 2013. 2b-RAD sequencing data was performed on an Illumina MiSeq instrument and analyzed with the STACKS de novo pipeline for loci assembly and Single Nucleotide Polymorphism (SNP) discovery. Preliminary population genomic analyses (global AMOVA and Bayesian clustering) were implemented. Our results showed that the 2b-RAD genotyping protocol is effective for R. ecuadoriensis and likely for other triatomine species. However, only BcgI and CspCI restriction enzymes provided a number of markers suitable for population genomic analysis at the read depth we generated. Our preliminary genomic analyses detected a signal of genetic structuring across the study area. Conclusions/Significance: Our findings suggest that 2b-RAD genotyping is both a cost effective and methodologically simple approach for generating high resolution genomic data for Chagas disease vectors with the power to distinguish between different vector populations at epidemiologically relevant scales. As such, 2b-RAD represents a powerful tool in the hands of medical entomologists with limited access to specialized molecular biological equipment. Author summary: Understanding Chagas disease vector (triatomine) population dispersal is key for the design of control measures tailored for the epidemiological situation of a particular region. In Ecuador, Rhodnius ecuadoriensis is a cause of concern for Chagas disease transmission, since it is widely distributed from the central coast to southern Ecuador. Here, a genome-wide sequencing (2b-RAD) approach was performed in 20 specimens from four communities from Manabí (central coast) and Loja (southern) provinces of Ecuador, and the effectiveness of three type IIB restriction enzymes was assessed. The findings of this study show that this genotyping methodology is cost effective in R. ecuadoriensis and likely in other triatomine species. In addition, preliminary population genomic analysis results detected a signal of population structure among geographically distinct communities and genetic variability within communities. As such, 2b-RAD shows significant promise as a relatively low-tech solution for determination of vector population genomics, dynamics, and spread

Cardiometabolic Risk Factors, Metabolic Syndrome and Pre-Diabetes in Adolescents in the Sierra Region of Ecuador

Background: Excess weight (overweight and obesity) is the major modifiable risk factor for type 2 diabetes mellitus (T2DM) and other non-communicable diseases. However, excess weight may not be as predictive of diabetes risk as once thought. While excess weight and other obesity-related non-communicable diseases are of growing concern in low-middle income countries in Latin America, there is limited research on risk factors associated with T2DM in adolescents. This study investigated prevalence of overweight, obesity, prediabetes, diabetes and metabolic syndrome in adolescents in Ecuador. Methods: A cross-sectional study was conducted with 433 adolescents from two schools in a small urban center in southern Ecuador and two schools in a large urban center in Quito. Risk factors were measured, including: height, weight, BMI, waist-to-hip ratio, fasting glucose, lipid panel, and HbA1c. Multivariate analysis of variance (MANOVA) was separately applied to risk factors and demographic factors as a set of dependent variables with sex, location and their interaction included as predictors. An independent t test was run on the data at 95% confidence intervals for the mean difference. The values for the triglycerides, LDL and VLDL were positively skewed. A Mann–Whitney U test was run on these data. Results: Using IOTF standards, 9.8% were overweight and 1.9% were obese. Only 1.6% of the sample met the criteria for prediabetes by fasting glucose but 12.4% of the sample met the criteria for prediabetes by HbA1c. None of the participants met criteria for diabetes. There were 2.3% of the participants that met the IDF criteria for metabolic syndrome. Adolescents from the larger urban center had higher rates of prediabetes, higher mean HbA1c, blood pressure, lipid values, and lower HDL levels. Conclusions: Use of HbA1c identifed more adolescents with prediabetes than FBG. The HbA1c measure is an attractive screening tool for prediabetes in developing countries. Although rates of obesity in Ecuadorian adolescents are low there is significant evidence to suggest that prediabetes is permeating the smaller urban centers. Traditional screening tools may underestimate this risk

Seroprevalence of Trypanosoma cruzi in Rural Ecuador and Clustering of Seropositivity within Households

We performed a cross-sectional study of Trypanosoma cruzi seroprevalence in 14 communities in three provinces of Ecuador and estimated the magnitude of the association of seropositive individuals within households. A total of 3,286 subjects from 997 households were included. Seroprevalence was 5.7%, 1.0%, and 3.6% in subjects in the Manabí, Guayas, and Loja provinces, respectively. Seroprevalence increased with increasing age in Manabí and Guayas, whereas in Loja, the highest prevalence occurred in children ≤ 10 years of age. In the coastal provinces, clustering of seropositives within households was not observed after adjustment for other household factors. However, in the Andean province of Loja, the odds of seropositivity were more than two times greater for an individual living in a household with another seropositive person. Our results indicate that transmission of T. cruzi is ongoing in Ecuador, although intensity of transmission and mechanisms of interaction between humans and the insect vectors of disease vary between geographic regions

Limitations of selective deltamethrin application for triatomine control in central coastal Ecuador

<p>Abstract</p> <p>Background</p> <p>This year-long study evaluated the effectiveness of a strategy involving selective deltamethrin spraying and community education for control of Chagas disease vectors in domestic units located in rural communities of coastal Ecuador.</p> <p>Results</p> <p>Surveys for triatomines revealed peridomestic infestation with <it>Rhodnius ecuadoriensis </it>and <it>Panstrongylus howardi</it>, with infestation indices remaining high during the study (13%, 17%, and 10%, at initial, 6-month, and 12-month visits, respectively), which indicates a limitation of this strategy for triatomine population control. Infestation was found 6 and 12 months after spraying with deltamethrin. In addition, a large number of previously vector-free domestic units also were found infested at the 6- and 12-month surveys, which indicates new infestations by sylvatic triatomines. The predominance of young nymphs and adults suggests new infestation events, likely from sylvatic foci. In addition, infection with <it>Trypanosoma cruzi </it>was found in 65%, 21% and 29% at initial, 6-month and 12-month visits, respectively. All parasites isolated (n = 20) were identified as TcI.</p> <p>Conclusion</p> <p>New vector control strategies need to be devised and evaluated for reduction of <it>T. cruzi </it>transmission in this region.</p

Ecological factors related to the widespread distribution of sylvatic Rhodnius ecuadoriensis populations in southern Ecuador

<p>Abstract</p> <p>Background</p> <p>Chagas disease transmission risk is a function of the presence of triatomines in domestic habitats. <it>Rhodnius ecuadoriensis </it>is one of the main vectors implicated in transmission of <it>Trypanosoma cruzi </it>in Ecuador. This triatomine species is present in domestic, peridomestic and sylvatic habitats in the country. To determine the distribution of sylvatic populations of <it>R. ecuadoriensis </it>and the factors related to this distribution, triatomine searches were conducted between 2005 and 2009 in southern Ecuador.</p> <p>Methods</p> <p>Manual triatomine searches were conducted by skilled bug collectors in 23 communities. Sylvatic searched sites were selected by a) directed sampling, where microhabitats were selected by the searchers and b) random sampling, where sampling points where randomly generated. Domiciliary triatomine searches were conducted using the one man-hour method. Natural trypanosome infection was determined by microscopic examination and PCR. Generalized linear models were used to test the effect of environmental factors on the presence of sylvatic triatomines.</p> <p>Results</p> <p>In total, 1,923 sylvatic individuals were collected representing a sampling effort of 751 man-hours. Collected sylvatic triatomines were associated with mammal and bird nests. The 1,219 sampled nests presented an infestation index of 11.9%, a crowding of 13 bugs per infested nest, and a colonization of 80% of the nests. Triatomine abundance was significantly higher in squirrel (<it>Sciurus stramineus</it>) nests located above five meters from ground level and close to the houses. In addition, 8.5% of the 820 examined houses in the same localities were infested with triatomines. There was a significant correlation between <it>R. ecuadoriensis </it>infestation rates found in sylvatic and synanthropic environments within communities (<it>p </it>= 0.012). Parasitological analysis revealed that 64.7% and 15.7% of the sylvatic bugs examined (n = 300) were infected with <it>Trypanosoma cruzi </it>and <it>T. rangeli </it>respectively, and 8% of the bugs presented mixed infections.</p> <p>Conclusions</p> <p>The wide distribution of sylvatic <it>R. ecuadoriensis </it>populations may jeopardize the effectiveness of control campaigns conducted to eliminate domestic populations of this species. Also, the high <it>T. cruzi </it>infection rates found in sylvatic <it>R. ecuadoriensis </it>populations in southern Ecuador could constitute a risk for house re-infestation and persistent long-term Chagas disease transmission in the region.</p

Development of peptide-based lineage-specific serology for chronic Chagas disease: geographical and clinical distribution of epitope recognition.

BACKGROUND: Chagas disease, caused by infection with the protozoan Trypanosoma cruzi, remains a serious public health issue in Latin America. Genetically diverse, the species is sub-divided into six lineages, known as TcI-TcVI, which have disparate geographical and ecological distributions. TcII, TcV, and TcVI are associated with severe human disease in the Southern Cone countries, whereas TcI is associated with cardiomyopathy north of the Amazon. T. cruzi persists as a chronic infection, with cardiac and/or gastrointestinal symptoms developing years or decades after initial infection. Identifying an individual's history of T. cruzi lineage infection directly by genotyping of the parasite is complicated by the low parasitaemia and sequestration in the host tissues. METHODOLOGY/PRINCIPAL FINDINGS: We have applied here serology against lineage-specific epitopes of the T. cruzi surface antigen TSSA, as an indirect approach to allow identification of infecting lineage. Chagasic sera from chronic patients from a range of endemic countries were tested by ELISA against synthetic peptides representing lineage-specific TSSA epitopes bound to avidin-coated ELISA plates via a biotin labelled polyethylene glycol-glycine spacer to increase rotation and ensure each amino acid side chain could freely interact with their antibodies. 79/113 (70%) of samples from Brazil, Bolivia, and Argentina recognised the TSSA epitope common to lineages TcII/TcV/TcVI. Comparison with clinical information showed that a higher proportion of Brazilian TSSApep-II/V/VI responders had ECG abnormalities than non-responders (38% vs 17%; p<0.0001). Among northern chagasic sera 4/20 (20%) from Ecuador reacted with this peptide; 1/12 Venezuelan and 1/34 Colombian samples reacted with TSSApep-IV. In addition, a proposed TcI-specific epitope, described elsewhere, was demonstrated here to be highly conserved across lineages and therefore not applicable to lineage-specific serology. CONCLUSIONS/SIGNIFICANCE: These results demonstrate the considerable potential for synthetic peptide serology to investigate the infection history of individuals, geographical and clinical associations of T. cruzi lineages

Bats, Trypanosomes, and Triatomines in Ecuador: New Insights into the Diversity, Transmission, and Origins of Trypanosoma cruzi and Chagas Disease

The generalist parasite Trypanosoma cruzi has two phylogenetic lineages associated almost exclusively with bats—Trypanosoma cruzi Tcbat and the subspecies T. c. marinkellei. We present new information on the genetic variation, geographic distribution, host associations, and potential vectors of these lineages. We conducted field surveys of bats and triatomines in southern Ecuador, a country endemic for Chagas disease, and screened for trypanosomes by microscopy and PCR. We identified parasites at species and genotype levels through phylogenetic approaches based on 18S ribosomal RNA (18S rRNA) and cytochrome b (cytb) genes and conducted a comparison of nucleotide diversity of the cytb gene. We document for the first time T. cruzi Tcbat and T. c. marinkellei in Ecuador, expanding their distribution in South America to the western side of the Andes. In addition, we found the triatomines Cavernicola pilosa and Triatoma dispar sharing shelters with bats. The comparisons of nucleotide diversity revealed a higher diversity for T. c. marinkellei than any of the T. c. cruzi genotypes associated with Chagas disease. Findings from this study increased both the number of host species and known geographical ranges of both parasites and suggest potential vectors for these two trypanosomes associated with bats in rural areas of southern Ecuador. The higher nucleotide diversity of T. c. marinkellei supports a long evolutionary relationship between T. cruzi and bats, implying that bats are the original hosts of this important parasite