A numbers game: Mosquito-based arbovirus surveillance in two distinct geographic regions of Latin America

Aedes mosquitoes, as vectors of medically important arthropod-borne viruses (arboviruses), constitute a major public health threat that requires entomological and epidemiological surveillance to guide vector control programs to prevent and reduce disease transmission. In this study, we present the collaborative effort of one year of mosquito-based arbovirus surveillance in two geographically distinct regions of Latin America (Nicaragua and Ecuador). Adult female mosquitoes were collected using backpack aspirators in over 2,800 randomly selected households (Nicaragua, Ecuador) and 100 key sites (Nicaragua) from eight distinct communities (Nicaragua: 2, Ecuador: 6). A total of 1,358 mosquito female pools were processed for RNA extraction and viral RNA detection using real-time RT-PCR. Ten positive dengue virus (DENV) pools were detected (3 in Nicaragua and 7 in Ecuador), all of which were found during the rainy season and matched the serotypes found in humans (Nicaragua: DENV-1 and DENV-4; Ecuador: DENV-2). Infection rates ranged from 1.13 to 23.13, with the Nicaraguan communities having the lowest infection rates. Our results demonstrate the feasibility of detecting DENV-infected Aedes mosquitoes in low-resource settings and underscore the need for targeted mosquito arbovirus sampling and testing, providing valuable insights for future surveillance programs in the Latin American region.

Whole Genome Sequencing of DENV-2 isolated from Aedes aegypti mosquitoes in Esmeraldas, Ecuador. Genomic epidemiology of genotype III Southern Asian-American in the country

Ecuador is a tropical country reporting Dengue virus (DENV) outbreaks with areas of hyperendemic viral transmission. Entomo-virological surveillance and monitoring effort conducted in the Northwestern border province of Esmeraldas in April 2022, five pools of female Aedes aegypti mosquitoes from a rural community tested positive for DENV serotype 2 by RT-qPCR. One pool was sequenced by Illumina MiSeq, and it corresponded to genotype III Southern Asian-American. Comparison with other genomes revealed genetic similarity to a human DENV genome sequenced in 2021, also from Esmeraldas. Potential introduction events to the country could have originated from Colombia, considering the vicinity of the collection sites to the neighboring country and high human movement. The inclusion of genomic information complements entomo-virological surveillance, providing valuable insights into genetic variants. This contribution enhances our understanding of Dengue virus (DENV) epidemiology in rural areas and guides evidence-based decisions for surveillance and interventions.

Increasing transmission of dengue virus across ecologically diverse regions of Ecuador and associated risk factors

The distribution and intensity of viral diseases transmitted by Aedes aegypti mosquitoes, including dengue, have rapidly increased over the last century. Here, we study dengue virus (DENV) transmission across the ecologically and demographically distinct regions or Ecuador. We analyzed province-level age-stratified dengue incidence data from 2000-2019 using catalytic models to estimate the force of infection of DENV over eight decades. We found that provinces established endemic DENV transmission at different time periods. Coastal provinces with the largest and most connected cities had the earliest and highest increase in DENV transmission, starting around 1980 and continuing to the present. In contrast, remote and rural areas with reduced access, like the northern coast and the Amazon regions, experienced a rise in DENV transmission and endemicity only in the last 10 to 20 years. The newly introduced chikungunya and Zika viruses have age-specific distributions of hospital-seeking cases consistent with recent emergence across all provinces. To evaluate factors associated with geographic differences in DENV transmission potential, we modeled DENV vector risk using 11,693 Aedes aegypti presence points to the resolution of 1 hectare. In total, 56% of the population of Ecuador, including in provinces identified as having increasing DENV transmission in our models, live in areas with high risk of Aedes aegypti, with population size, trash collection, elevation, and access to water as important determinants. Our investigation serves as a case study of the changes driving the expansion of DENV and other arboviruses globally and suggest that control efforts should be expanded to semi-urban and rural areas and to historically isolated regions to counteract increasing dengue outbreaks.

The biting rate of Aedes aegypti and its variability: A systematic review (1970-2022)

BACKGROUND

Transmission models have a long history in the study of mosquito-borne disease dynamics. The mosquito biting rate (MBR) is an important parameter in these models, however, estimating its value empirically is complex. Modeling studies obtain biting rate values from various types of studies, each of them having its strengths and limitations. Thus, understanding these study designs and the factors that contribute to MBR estimates and their variability is an important step towards standardizing these estimates. We do this for an important arbovirus vector Aedes aegypti.

METHODOLOGY/PRINCIPAL FINDINGS

We perform a systematic review using search terms such as 'biting rate' and 'biting frequency' combined with 'Aedes aegypti' ('Ae. aegypti' or 'A. aegypti'). We screened 3,201 articles from PubMed and ProQuest databases, of which 21 met our inclusion criteria. Two broader types of studies are identified: human landing catch (HLC) studies and multiple feeding studies. We analyze the biting rate data provided as well as the methodologies used in these studies to characterize the variability of these estimates across temporal, spatial, and environmental factors and to identify the strengths and limitations of existing methodologies. Based on these analyses, we present two approaches to estimate population mean per mosquito biting rate: one that combines studies estimating the number of bites taken per gonotrophic cycle and the gonotrophic cycle duration, and a second that uses data from histological studies. Based on one histological study dataset, we estimate biting rates of Ae. aegypti (0.41 and 0.35 bite/mosquito-day in Thailand and Puerto Rico, respectively).

CONCLUSIONS/SIGNIFICANCE

Our review reinforces the importance of engaging with vector biology when using mosquito biting rate data in transmission modeling studies. For Ae. aegypti, this includes understanding the variation of the gonotrophic cycle duration and the number of bites per gonotrophic cycle, as well as recognizing the potential for spatial and temporal variability. To address these variabilities, we advocate for site-specific data and the development of a standardized approach to estimate the biting rate.

Genetic Variability in the E6/E7 Region of Human Papillomavirus 16 in Women from Ecuador

Human Papillomavirus (HPV) infection is associated with intraepithelial neoplasia and cervical cancer (CC). Ecuador has a high prevalence of cervical cancer, with more than 1600 new cases diagnosed annually. This study aimed to analyze oncogenes E6 and E7 of HPV16 in samples collected from women with cancerous and precancerous cervical lesions from the Ecuadorian coast. Twenty-nine women, including six with ASCUS, three with LSIL, thirteen with HSIL, and seven with Cacu, were analyzed. The most common SNPs were E6 350G or L83V (82.6%) and E6 145T/286A/289G/335T/350G or Q14H/F78Y/L83V (17.4%). Both variants are reported to be associated with an increased risk of cervical cancer in worldwide studies. In contrast, all E7 genes have conserved amino-acid positions. Phylogenetic trees showed the circulation of the D (26.1%) and A (73.9) lineages. The frequency of D was higher than that reported in other comparable studies in Ecuador and Latin America, and may be related to the ethnic composition of the studied populations. This study contributes to the characterization of the potential risk factors for cervical carcinogenesis associated with Ecuadorian women infected with HPV16.

Increasing transmission of dengue virus across ecologically diverse regions of Ecuador and associated risk factors

The distribution and intensity of viral diseases transmitted by Aedes aegypti mosquitoes, including dengue, have rapidly increased over the last century. Ecuador is an interesting country to study drivers of dengue virus (DENV) transmission given it has multiple ecologically and demographically distinct regions. Here, we analyze province-level age-stratified dengue prevalence data from 2000-2019 using catalytic models to estimate the force of infection of DENV over eight decades and across provinces in Ecuador. We found that provinces established endemic DENV transmission at different time periods. Coastal provinces with the largest and most connected cities had the earliest and highest increase in DENV transmission, starting around 1980 and continuing to the present. In contrast, remote and rural areas with reduced access, like the northern coast and the Amazon regions, experienced a rise in DENV transmission and endemicity only in the last 10 to 20 years. The newly introduced chikungunya and Zika viruses have distinct age-specific prevalence distributions consistent with recent emergence across all provinces. We evaluated factors to the resolution of 1 hectare associated with geographic differences in vector suitability and arbovirus disease in the last 10 years by modeling 11,693 A aegypti presence points and 73,550 arbovirus cases. In total, 56% of the population of Ecuador lives in areas with high risk of Aedes aegypti. Most suitable provinces had hotspots for arbovirus disease risk, with population size, elevation, sewage connection, trash collection, and access to water as important determinants. Our investigation serves as a case study of the changes driving the expansion of DENV and other arboviruses globally and suggest that control efforts should be expanded to semi-urban and rural areas and to historically isolated regions to counteract increasing dengue outbreaks.

Validity of Self-Reported Mosquito Bites to Assess Household Mosquito Abundance in Six Communities of Esmeraldas Province, Ecuador

Mosquito-borne diseases are a global burden; however, current methods of evaluating human-mosquito contact rates are expensive and time consuming. Validated surveys of self-reported mosquito bites may be an inexpensive way to determine mosquito presence and bite exposure level in an area, but this remains untested. In this study, a survey of self-reported mosquito bites was validated against household mosquito abundance from six communities in Esmeraldas, Ecuador. From February 2021 to July 2022, households were interviewed monthly, and five questions were used to ask participants how often they were bitten by mosquitoes at different times during the day. At the same time, adult mosquitoes were collected using a Prokopack aspirator. Species were identified and counted. Survey responses were compared with the total number of mosquitoes found in the home using negative binomial regression. More frequent self-reported mosquito bites were significantly associated with higher numbers of collected adult mosquitoes. These associations were driven by the prevalence of the dominant genera, Culex. These results suggest that surveys of perceived mosquito bites relate to actual mosquito presence, making them a potentially useful tool for determining the impact of vector-control interventions on community perceptions of risk but less useful for assessing the risk of nondominant species such as Aedes aegypti. Further work is needed to examine the robustness of these results in other contexts.

P-040 DIFFUSE LARGE CELL B LYMPHOMA TYPE ACTIVATED B CELL (MANTLE LYMPHOMA) AS A DIFFERENTIAL DIAGNOSIS OF INGUINAL HERNIA. A RARE FINDING

Introduction

Mantle cell lymphoma is a rare type of B-cell non-Hodgkin lymphoma. It represents 7% of lymphomas in Europe, with an incidence of between 4 and 8 cases/year per million-hab. More frequent in men with a 4:1 ratio and middle-age.

We present a diagnosed clinical case of MCL with an infrequent presentation.

Material & Methods

A 70-year-old male affected by left inguinal tumor after physical exertion 6 months before the consultation.

Abdominal ultrasound and CT scan describe an extra testicular 3cm lesion with irregular edges without extension to other structures with possible signs of malignancy.

Surgery is performed with the lesion bloc excision including left test and elements of the spermatic cord.

Results

The analysis of Pathological Anatomy shows us as a result a diffuse large cell B Lymphoma type Polymorphic Mantle Cell Lymphoma.

The postoperative extension study (PET) shows no residual tumor or medullary involvement, suggestive of stage I.

Discussion

MCL is a rare type of lymphoma, characterized by translocation (11;14) (q13; q32) leading to overexpression of cyclin D1.

Most common presentation of MCL is B symptoms (up to 40%) fever, night sweats. Others include asthenia, nighttime pruritus, adenopathies, and hepatic or splenic enlargement.

Finally, CML can present with extranodal disease, digestive system, respiratory system, nervous system, endocrine or salivary glands.

It is a highly aggressive type of lymphoma that is usually diagnosed in advanced stages (90% cases), with poor prognosis with a life expectancy of 4 years despite optimal treatment.

Current treatment consists of a combination of chemotherapy and immunotherapy.

Multicenter international assessment of a SARS-CoV-2 RT-LAMP test for point of care clinical application

Continued waves, new variants, and limited vaccine deployment mean that SARS-CoV-2 tests remain vital to constrain the coronavirus disease 2019 (COVID-19) pandemic. Affordable, point-of-care (PoC) tests allow rapid screening in non-medical settings. Reverse-transcription loop-mediated isothermal amplification (RT-LAMP) is an appealing approach. A crucial step is to optimize testing in low/medium resource settings. Here, we optimized RT-LAMP for SARS-CoV-2 and human β-actin, and tested clinical samples in multiple countries. "TTTT" linker primers did not improve performance, and while guanidine hydrochloride, betaine and/or Igepal-CA-630 enhanced detection of synthetic RNA, only the latter two improved direct assays on nasopharygeal samples. With extracted clinical RNA, a 20 min RT-LAMP assay was essentially as sensitive as RT-PCR. With raw Canadian nasopharygeal samples, sensitivity was 100% (95% CI: 67.6% - 100%) for those with RT-qPCR Ct values ≤ 25, and 80% (95% CI: 58.4% - 91.9%) for those with 25 < Ct ≤ 27.2. Highly infectious, high titer cases were also detected in Colombian and Ecuadorian labs. We further demonstrate the utility of replacing thermocyclers with a portable PoC device (FluoroPLUM). These combined PoC molecular and hardware tools may help to limit community transmission of SARS-CoV-2.

Establishment, Genetic Diversity, and Habitat Suitability of Aedes albopictus Populations from Ecuador

Simple Summary

The tiger mosquito, Aedes albopictus, is a vector of multiple viral diseases. Therefore, it is crucial to understand its distribution and the genetic diversity of Ecuadorian populations. This study used a genetic marker to understand aspects of the dynamics of the Ecuadorian populations of Aedes albopictus from five sites along the coastal, Amazon basin, and Andean lowland regions. Our results evidence two haplotypes within the Ecuadorian populations. Haplotype 1 was found in the coastal regions and Amazon basin, while haplotype 2 was found in the northeastern lowlands. Worldwide, haplotype 1 has been found in 21 countries in temperate and tropical habitats, and haplotype 2 has been found in five countries in tropical habitats. Hence, a difference in adaptation traits could be speculated between both haplotypes. Our study presents a prediction model that shows the suitable habitats for Aedes albopictus in Ecuador. Our results showed that the vector could spread through all country regions, including the Galapagos Islands. Thus, understanding the different aspects of the local populations can help establish better vector surveillance and control strategies.

Abstract

Aedes albopictus, also known as the tiger mosquito, is widespread worldwide across tropical, subtropical, and temperate regions. This insect is associated with the transmission of several vector-borne diseases, and, as such, monitoring its distribution is highly important for public health. In Ecuador, Ae. albopictus was first reported in 2017 in Guayaquil. Since then, the vector has been identified in the Northeastern lowlands and the Amazon basin. This study aims to determine the genetic diversity of Ecuadorian populations of Ae. albopictus through the analysis of the mitochondrial gene COI and to describe the potential distribution areas of this species within the country. The genetic diversity was determined by combining phylogenetic and population genetics analyses of five localities in Ecuador. Results showed two haplotypes in the Ecuadorian populations of Ae. albopictus. Haplotype 1 (H1) was found in the coastal and Amazon individuals, while haplotype 2 (H2) was only found in the three northeastern lowlands sites. In a worldwide context, H1 is the most widespread in 21 countries with temperate and tropical habitats. In contrast, H2 distribution is limited to five countries in tropical regions, suggesting fewer adaptation traits. Our prediction model showed a suitable habitat for Ae. albopictus in all regions (coastal, Amazon basin, and Andean lowland regions and the Galápagos Islands) of Ecuador. Hence, understanding different aspects of the vector can help us implement better control strategies for surveillance and vectorial control in Ecuador.

Field validation of the performance of paper-based tests for the detection of the Zika and chikungunya viruses in serum samples

In low-resource settings, resilience to infectious disease outbreaks can be hindered by limited access to diagnostic tests. Here we report the results of double-blinded studies of the performance of paper-based diagnostic tests for the Zika and chikungunya viruses in a field setting in Latin America. The tests involved a cell-free expression system relying on isothermal amplification and toehold-switch reactions, a purpose-built portable reader and onboard software for computer vision-enabled image analysis. In patients suspected of infection, the accuracies and sensitivities of the tests for the Zika and chikungunya viruses were, respectively, 98.5% (95% confidence interval, 96.2–99.6%, 268 serum samples) and 98.5% (95% confidence interval, 91.7–100%, 65 serum samples) and approximately 2 aM and 5 fM (both concentrations are within clinically relevant ranges). The analytical specificities and sensitivities of the tests for cultured samples of the viruses were equivalent to those of the real-time quantitative PCR. Cell-free synthetic biology tools and companion hardware can provide de-centralized, high-capacity and low-cost diagnostics for use in low-resource settings.

The Shortcomings of COVID-19 Testing in Ecuador: Time to Incentivize Research and Innovation

The COVID-19 pandemic hit Ecuador severely. The country caught the attention of international media due to its high death toll and overwhelmed healthcare system. The clinical diagnostics system was rapidly overloaded, and the import of PCR tests was delayed. The case of Ecuador illustrates how middle-income countries rely heavily on the importation of biotechnological products for their healthcare systems. The Ecuadorian experience during the COVID-19 pandemic serves as a call for the formation of policies for the development of the biotechnological industry.

Alternative RNA extraction-free techniques for the real-time RT-PCR detection of SARS-CoV-2 in nasopharyngeal swab and sputum samples

Standard diagnoses of SARS-CoV-2 infections are done by RNA extraction and real-time RT-PCR (rRT-PCR). However, the need for RNA extraction complicates testing due to increased processing time, high cost, and limited availability of commercial kits. Therefore, alternative methods for rRT-PCR detection of SARS-CoV-2 without RNA extraction were investigated. Nasopharyngeal and sputum samples were used to compare the sensitivity of three techniques: Trizol RNA extraction, thermal shock, and the direct use of samples with an RNase inhibitor. Direct, extraction-free use of primary samples plus the RNase inhibitor produced diagnostic values of 100 % sensitivity and specificity compared to standard protocols, and these findings were validated in a second, independent laboratory.

Determinants of Aedes mosquito density as an indicator of arbovirus transmission risk in three sites affected by co-circulation of globally spreading arboviruses in Colombia, Ecuador and Argentina

Background

The global impact of Zika virus in Latin America has drawn renewed attention to circulating mosquito-borne viruses in this region, such as dengue and chikungunya. Our objective was to assess socio-ecological factors associated with Aedes mosquito vector density as a measure of arbovirus transmission risk in three cities of potentially recent Zika virus introduction: Ibagué, Colombia; Manta, Ecuador; and Posadas, Argentina, in order to inform disease mitigation strategies.

Methods

We sampled Aedes mosquito populations in a total of 1086 households, using indoor and peridomestic mosquito collection methods, including light traps, resting traps, traps equipped with chemical attractant and aspirators. For each sampled household, we collected socio-economic data using structured questionnaires and data on microenvironmental conditions using iButton data loggers.

Results

A total of 3230 female Aedes mosquitoes were collected, of which 99.8% were Aedes aegypti and 0.2% were Aedes albopictus. Mean female Aedes mosquito density per household was 1.71 (standard deviation: 2.84). We used mixed-effects generalized linear Poisson regression analyses to identify predictors of Aedes density, using month, neighborhood and country as random-effects variables. Across study sites, the number of household occupants [incidence rate ratio (IRR): 1.08, 95% confidence interval (CI): 1.01–1.14], presence of entry points for mosquitoes into the household (IRR: 1.51, 95% CI: 1.30–1.76) and presence of decorative vegetation (IRR: 1.52, 95% CI: 1.22–1.88) were associated with higher Aedes density; while being in the highest wealth tertile of household wealth (IRR: 0.78, 95% CI: 0.66–0.92), knowledge of how arboviruses are transmitted (IRR: 0.94, 95% CI: 0.89–1.00) and regular emptying of water containers by occupants (IRR: 0.79, 95% CI: 0.67–0.92) were associated with lower Aedes density.

Conclusions

Our study addresses the complexities of arbovirus vectors of global significance at the interface between human and mosquito populations. Our results point to several predictors of Aedes mosquito vector density in countries with co-circulation of multiple Aedes-borne viruses, and point to modifiable risk factors that may be useful for disease prevention and control.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04984-z.

Household-level risk factors for Aedes aegypti pupal density in Guayaquil, Ecuador

Background

Vector-borne diseases are a major cause of disease burden in Guayaquil, Ecuador, especially arboviruses spread by Aedes aegypti mosquitoes. Understanding which household characteristics and risk factors lead to higher Ae. aegypti densities and consequent disease risk can help inform and optimize vector control programs.

Methods

Cross-sectional entomological surveys were conducted in Guayaquil between 2013 and 2016, covering household demographics, municipal services, potential breeding containers, presence of Ae. aegypti larvae and pupae, and history of using mosquito control methods. A zero-truncated negative binomial regression model was fitted to data for estimating the household pupal index. An additional model assessed the factors of the most productive breeding sites across all of the households.

Results

Of surveyed households, 610 satisfied inclusion criteria. The final household-level model found that collection of large solid items (e.g., furniture and tires) and rainfall the week of and 2 weeks before collection were negatively correlated with average pupae per container, while bed canopy use, unemployment, container water volume, and the interaction between large solid collection and rainfall 2 weeks before the sampling event were positively correlated. Selection of these variables across other top candidate models with ∆AICc < 1 was robust, with the strongest effects from large solid collection and bed canopy use. The final container-level model explaining the characteristics of breeding sites found that contaminated water is positively correlated with Ae. aegypti pupae counts while breeding sites composed of car parts, furniture, sewerage parts, vases, were all negatively correlated.

Conclusions

Having access to municipal services like bulky item pickup was effective at reducing mosquito proliferation in households. Association of bed canopy use with higher mosquito densities is unexpected, and may be a consequence of large local mosquito populations or due to limited use or effectiveness of other vector control methods. The impact of rainfall on mosquito density is multifaceted, as it may both create new habitat and “wash out” existing habitat. Providing services and social/technical interventions focused on monitoring and eliminating productive breeding sites is important for reducing aquatic-stage mosquito densities in households at risk for Ae. aegypti-transmitted diseases.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04913-0.

A dengue outbreak in a rural community in Northern Coastal Ecuador: An analysis using unmanned aerial vehicle mapping

Dengue is recognized as a major health issue in large urban tropical cities but is also observed in rural areas. In these environments, physical characteristics of the landscape and sociodemographic factors may influence vector populations at small geographic scales, while prior immunity to the four dengue virus serotypes affects incidence. In 2019, a rural northwestern Ecuadorian community, only accessible by river, experienced a dengue outbreak. The village is 2-3 hours by boat away from the nearest population center and comprises both Afro-Ecuadorian and Indigenous Chachi households. We used multiple data streams to examine spatial risk factors associated with this outbreak, combining maps collected with an unmanned aerial vehicle (UAV), an entomological survey, a community census, and active surveillance of febrile cases. We mapped visible water containers seen in UAV images and calculated both the green-red vegetation index (GRVI) and household proximity to public spaces like schools and meeting areas. To identify risk factors for symptomatic dengue infection, we used mixed-effect logistic regression models to account for the clustering of symptomatic cases within households. We identified 55 dengue cases (9.5% of the population) from 37 households. Cases peaked in June and continued through October. Rural spatial organization helped to explain disease risk. Afro-Ecuadorian (versus Indigenous) households experience more symptomatic dengue (OR = 3.0, 95%CI: 1.3, 6.9). This association was explained by differences in vegetation (measured by GRVI) near the household (OR: 11.3 95% 0.38, 38.0) and proximity to the football field (OR: 13.9, 95% 4.0, 48.4). The integration of UAV mapping with other data streams adds to our understanding of these dynamics.

Two Haplotypes of Aedes aegypti Detected by ND4 Mitochondrial Marker in Three Regions of Ecuador

Simple Summary

The yellow fever mosquito, Aedes aegypti, is a widespread species associated with the transmission of vector-borne diseases across tropical and subtropical areas of the world. The genetic variability of its populations has been assessed with the use of several molecular markers to understand aspects of the population dynamics and their implication in disease transmission. However, the genetic diversity of Ecuadorian populations of the vector have not been investigated. In this study, we evaluated the genetic diversity of Ecuadorian populations of Ae. aegypti from 17 sites (Galapagos Islands, Amazon basin, and Coastal regions). These analyses revealed the presence of only two haplotypes among the Ecuadorian population of the vector. Haplotype 1, appears to be related to previously reported haplotypes from America, Asia, and West Africa. While haplotype 2 is only related to samples from America. The genetic diversity of Ecuadorian populations seems to be low, according to different statistical analyses, which show only one main population across sampled localities and no effect of the main geographical barriers. Understanding the genetic diversity of local populations is a key element in vector control strategies.

Abstract

Aedes aegypti, also known as the yellow fever mosquito, is the main vector of several arboviruses. In Ecuador, dengue and chikungunya are the most prevalent mosquito-borne diseases. Hence, there is a need to understand the population dynamics and genetic structure of the vector in tropical areas for a better approach towards effective vector control programs. This study aimed to assess the genetic diversity of Ae. aegypti, through the analyses of the mitochondrial gene ND4, using a combination of phylogenetic and population genetic structure from 17 sites in Ecuador. Results showed two haplotypes in the Ecuadorian populations of Ae. aegypti. Haplotype 1 was closely related to Ae. aegypti reported from America, Asia, and West Africa. Haplotype 2 was only related to samples from America. The sampled vectors from the diverse localities showed low nucleotide diversity (π = 0–0.01685) and genetic differentiation (FST = 0.152). AMOVA analyses indicated that most of the variation (85–91%) occurred within populations, suggesting that geographical barriers have little effect on the genetic structure of Ecuadorian populations of Ae. aegypti. These results agree with the one main population (K = 1) detected by Structure. Vector genetic identity may be a key factor in the planning of vector control strategies.

Combined effects of acute exercise and hypoxia on memory

No previous studies have evaluated the potential combined effects of acute exercise and acute hypoxia exposure on memory function, which was the purpose of this study. Twenty-five participants (Mage = 21.2 years) completed two laboratory visits in a counterbalanced order, involving 1) acute exercise (a 20-min bout of moderate-intensity exercise) and then 30 min of exposure to hypoxia (FIO2 = 0.12), and 2) exposure to hypoxia alone (FIO2 = 0.12) for 30 min. Following this, participants completed a cued-recall and memory interference task (AB/AC paradigm), assessing cued-recall memory (recall 1 and recall 2) and memory interference (proactive and retroactive interference). For cued-recall memory, we observed a significant main effect for condition, with Exercise + Hypoxia condition having significantly greater cued-recall performance than Hypoxia alone. Memory interference did not differ as a function of the experimental condition. This experiment demonstrates that engaging in an acute bout of exercise prior to acute hypoxia exposure had an additive effect in enhancing cued-recall memory performance.

Cardiac surgery in infective endocarditis and predictors of in-hospital mortality

INTRODUCTION

Infective endocarditis (IE) is a serious disease with significant in-hospital mortality (15-30%) despite advances in medical and surgical therapy.

AIMS

To perform a clinical characterization of patients undergoing cardiac surgery for IE and to identify factors that predict in-hospital mortality.

METHODS

We retrospectively analyzed 145 patients with IE admitted between January 2006 and October 2017.

RESULTS

The median age was 72 years. IE was acquired mainly in the community (69%), and involved the native aortic valve in 54% of patients, biological prosthetic valves in 22.1% and mechanical valves in 10.3%. Staphylococcus spp. (31.0%) were the most frequent etiological agents. Cardiac surgery was emergent in 29 patients, urgent in 108, and elective in eight. The main indications were heart failure (57.9%), large vegetations (20%), systemic embolism (17.2%) and valve dysfunction (15.2%). Overall, biological valves were implanted in 62.1% of patients and mechanical valves in 37.2%. A total of 19 patients (13.1%) died. Predictors of mortality were preoperative atrial fibrillation and lower left ventricular ejection fraction, postoperative severe valve regurgitation associated with cardiogenic shock, sepsis, septic shock associated with cardiogenic shock, cardiac tamponade, need for renal replacement therapy and, although without statistical significance, emergent surgery.

CONCLUSIONS

There is a need for better indicators to enable early identification of surgical candidates for IE, implementation of a heart team, and better surgical strategies, including more rapid intervention, more specific postoperative care, and optimal antibiotic therapy.

Data scarcity and ecological complexity: the cutaneous leishmaniasis dynamics in Ecuador

Cutaneous leishmaniasis (CL) is a neglected tropical disease transmitted by species of Phlebotominae sand flies. CL is responsible for more than 1000 reported cases per year in Ecuador. Vector collection studies in Ecuador suggest that there is a strong association between the ecological diversity of an ecosystem, the presence of potential alternative or reservoir hosts and the abundance of sand fly species. Data collected from a coastal community in Ecuador showed that Leishmania parasites may be circulating in diverse hosts, including mammalian and potentially avian species, and these hosts may serve as potential hosts for the parasite. There has been limited reporting of CL cases in Ecuador because the disease is non-fatal and its surveillance system is passive. Hence, the actual incidence of CL is unknown. In this study, an epidemic model was developed and analysed to understand the complexity of CL transmission dynamics with potential non-human hosts in the coastal ecosystem and to estimate critical epidemiological quantities for Ecuador. The model is fitted to the 2010 CL outbreak in the town of Valle Hermoso in the Santo Domingo de los Tsachilas province of Ecuador and parameters such as CL transmission rates in different types of hosts (primary and alternative), and levels of case reporting in the town are estimated. The results suggest that the current surveillance in this region fails to capture 38% (with 95% CI (29%, 47%)) of the actual number of cases under the assumption that alternative hosts are dead-end hosts and that the mean CL reproduction number in the town is 3.9. This means that on the average 3.9 new human CL cases were generated by a single infectious human in the town during the initial period of the 2010 outbreak. Moreover, major outbreaks of CL in Ecuador in coastal settings are unavoidable until reporting through the surveillance system is improved and alternative hosts are managed properly. The estimated infection transmission probabilities from alternative hosts to sand flies, and sand flies to alternative hosts are 27% and 32%, respectively. The analysis highlights that vector control and alternative host management are two effective programmes for Ecuador but need to be implemented concurrently to avoid future major outbreaks.

Resistance Status of Aedes aegypti to Deltamethrin, Malathion, and Temephos in Ecuador

In Ecuador, the status of insecticide resistance for Aedes aegypti, the principal arboviral vector in the country, has not been previously evaluated. The aim of this research was to describe the resistance status of Ae. aegypti to the principal insecticides used for vector control in provinces with high reports of arboviral clinical cases. This was a descriptive study performed on Ae. aegypti collected from 2016 to 2017 in 14 localities of Ecuador. The larvae were reared and tested using bioassays applying the adulticides malathion and deltamethrin, and the larvicide temephos. The lethal concentrations were obtained for field-collected specimens and compared to the susceptible reference strain ROCK, MRA-734. Mosquitoes from all the localities showed resistance to deltamethrin and susceptibility to malathion. On the other hand, mosquitoes demonstrated resistance to the larvicide temephos in 5 of the 14 localities analyzed. The results obtained in this research may be used by healthcare decision-makers to improve vector control in Ecuador. Rotation of insecticides and alternative biological vector control strategies should be considered to manage the resistance observed in Ae. aegypti to deltamethrin and temephos. New strategies to use insecticides should also be aimed to prevent selective pressure with malathion.

Hypothesized mechanisms through which acute exercise influences episodic memory

Emerging research demonstrates that exercise is favorably associated with several cognitive outcomes, including episodic memory function. The majority of the mechanistic work describing the underlying mechanisms of this effect has focused on chronic exercise engagement. Such mechanisms include, e.g., chronic exercise-induced neurogenesis, gliogenesis, angiogenesis, cerebral circulation, and growth factor production. Less research has examined the mechanisms through which acute (vs. chronic) exercise subserves episodic memory function. The purpose of this review is to discuss these potential underlying mechanisms, which include, e.g., acute exercise-induced (via several pathways, such as vagus nerve and muscle spindle stimulation) alterations in neurotransmitters, synaptic tagging/capturing, associativity, and psychological attention.

Increased use of Catheters as Vascular Access: Is it Justified by Patients' Clinical Conditions?

Background

Over the last years many technical improvements have been made in hemodialysis treatment. Vascular access (VA) still remains an important problem. Although the use of indwelling vascular catheters is discouraged, in Europe there is an increasing use of them. The K/DOQI Guidelines recommend a native arteriovenous fistula (AVF) as VA of choice. As reported by DOPPS, there is considerable geographic variation in the distribution of type of VA used amongst hemodialysis patients. The aim of this study was to evaluate the time patients in four European countries have to wait before undergoing their first surgery for VA (AVF or graft).

Methods

All incident patients admitted to HD clinics located in Turkey, Italy, the UK and Portugal of the European FME clinics network between October 1, 2002 and September 30, 2004 were considered. Data were gained from the Clinical Database EuCliD®.

Results

2,152 patients (males 55.9%, mean age 62.5±15.7 years, diabetics 27%) were selected. Italy and Portugal had a higher proportion of elderly patients. At time of admission, the proportion of patients starting dialysis with AVF ranged between 23% and 60% from Turkey to Italy respectively. Patients with an indwelling catheter at admission are expected to undergo VA surgery as soon as possible. After 3 months of follow-up, about 75% of all patients had undergone surgery, however in the UK less than 50% of the patients had had a VA procedure. Overall, males have significantly higher probability of undergoing surgery, whilst elderly patients have a lower probability (27% and 14% respectively).

Conclusion

Significant differences exist between countries in the time interval from referral to creation of VA. Health care system related problems seem to be the major reason to explain such differences. Patients in the UK have longer waiting times than the other countries studied.

First Report of Aedes (Stegomyia) albopictus (Skuse) (Diptera: Culicidae), the Asian Tiger Mosquito, in Ecuador

Aedes (Stegomyia) albopictus (Skuse), (Diptera: Culicidae), the Asian tiger mosquito, is one of the most widespread invasive vector-borne disease insect in tropical and temperate zones. This species has invaded the Americas over the past 3 decades and has spread to six countries. We report Ae. albopictus in Guayaquil city, the first time it has been identified in Ecuador. Outdoor BG-Sentinel traps without lures collected a total of 21 Ae. albopictus.

Zika and Chikungunya virus detection in naturally infected Aedes aegypti in Ecuador

The wide and rapid spread of Chikungunya (CHIKV) and Zika (ZIKV) viruses represent a global public health problem, especially for tropical and subtropical environments. The early detection of CHIKV and ZIKV in mosquitoes may help to understand the dynamics of the diseases in high-risk areas, and to design data based epidemiological surveillance to activate the preparedness and response of the public health system and vector control programs. This study was done to detect ZIKV and CHIKV viruses in naturally infected fed female Aedes aegypti (L.) mosquitoes from active epidemic urban areas in Ecuador. Pools (n=193; 22 pools) and individuals (n=22) of field collected Ae. aegypti mosquitoes from high-risk arboviruses infection sites in Ecuador were analyzed for the presence of CHIKV and ZIKV using RT-PCR. Phylogenetic analysis demonstrated that both ZIKV and CHIKV viruses circulating in Ecuador correspond to the Asian lineages. Minimum infection rate (MIR) of CHIKV for Esmeraldas city was 2.3% and the maximum likelihood estimation (MLE) was 3.3%. The minimum infection rate (MIR) of ZIKV for Portoviejo city was 5.3% and for Manta city was 2.1%. Maximum likelihood estimation (MLE) for Portoviejo city was 6.9% and 2.6% for Manta city. Detection of arboviruses and infection rates in the arthropod vectors may help to predict an outbreak and serve as a warning tool in surveillance programs.

Molecular Identification of Leishmania spp. in Sand Flies (Diptera: Psychodidae, Phlebotominae) From Ecuador

The detection and identification of natural infections in sand flies by Leishmania protozoan species in endemic areas is a key factor in assessing the risk of leishmaniasis and in designing prevention and control measures for this infectious disease. In this study, we analyzed the Leishmania DNA using nuclear ribosomal internal transcript spacer (ITS) sequences. Parasite DNA was extracted from naturally infected, blood-fed sand flies collected in nine localities considered leishmaniasis-endemic foci in Ecuador.

The species of parasites identified in sand flies were Leishmania major-like, Leishmania naiffi, Leishmania mexicana, Leishmania lainsoni, and “Leishmania sp. siamensis”. Sand fly specimens of Brumptomyia leopoldoi, Mycropigomyia cayennensis, Nyssomyia yuilli yuilli, Nyssomyia trapidoi, Pressatia triacantha, Pressatia dysponeta, Psychodopygus carrerai carrerai, Psychodopygus panamensis, and Trichophoromyia ubiquitalis were found positive for Leishmania parasite. These findings contribute to a better understanding of the epidemiology and transmission dynamics of the disease in high-risk areas of Ecuador.

Blood-meal identification in phlebotomine sand flies (Diptera: Psychodidae) from Valle Hermoso, a high prevalence zone for cutaneous leishmaniasis in Ecuador

Cutaneous leishmaniasis is a neglected tropical disease transmitted by phlebotomine sand flies of the genus Lutzomyia. In South America, cutaneous leishmaniasis is endemic in the majority of countries. There are no previous reports of phlebotomine sand fly host feeding sources in Ecuador. We identified blood meal sources for phlebotomine sand fly species in Valle Hermoso, a hyper endemic area for leishmaniasis in Ecuador. Phlebotomine sand fly collections were carried out during the dry and rainy seasons. PCR and multiplex PCR were performed from DNA extracted from the abdomens of blood-fed females to specifically identify the avian and mammalian blood meal sources. Avian-blood (77%), mammalian-blood (16%) and mixed avian-mammalian blood (7%) were found in the samples. At the species level, blood from chickens (35.5%), humans (2.8%), cows (2.8%) and dogs (1.9%) was specifically detected. Nyssomyia trapidoi was the most common species of Lutzomyia found that fed on birds. The present results may aid the development of effective strategies to control leishmaniasis in Ecuador.

Nuclear ribosomal internal transcribed spacer 1 (ITS1) variation in the Anastrepha fraterculus cryptic species complex (Diptera, Tephritidae) of the Andean region

The nuclear ribosomal internal transcribed spacer 1 (ITS1) was sequenced for Anastrepha fraterculus (Wiedemann, 1830) originating from 85 collections from the northern and central Andean countries of South America including Argentina (Tucumán), Bolivia, Perú, Ecuador, Colombia, and Venezuela. The ITS1 regions of additional specimens (17 collections) from Central America (México, Guatemala, Costa Rica, and Panamá), Brazil, Caribbean Colombia, and coastal Venezuela were sequenced and together with published sequences (Paraguay) provided context for interpretation. A total of six ITS1 sequence variants were recognized in the Andean region comprising four groups. Type I predominates in the southernmost range of Anastrepha fraterculus. Type II predominates in its northernmost range. In the central and northern Andes, the geographic distributions overlap and interdigitate with a strong elevational effect. A discussion of relationships between observed ITS1 types and morphometric types is included.

Collagen type IV-related nephropathies in Portugal: pathogenic COL4A3 and COL4A4 mutations and clinical characterization of 25 families

Pathogenic mutations in genes COL4A3/COL4A4 are responsible for autosomal Alport syndrome (AS) and thin basement membrane nephropathy (TBMN). We used Sanger sequencing to analyze all exons and splice site regions of COL4A3/COL4A4, in 40 unrelated Portuguese probands with clinical suspicion of AS/TBMN. To assess genotype-phenotype correlations, we compared clinically relevant phenotypes/outcomes between homozygous/compound heterozygous and apparently heterozygous patients. Seventeen novel and four reportedly pathogenic COL4A3/COL4A4 mutations were identified in 62.5% (25/40) of the probands. Regardless of the mutated gene, all patients with ARAS manifested chronic renal failure (CRF) and hearing loss, whereas a minority of the apparently heterozygous patients had CRF or extrarenal symptoms. CRF was diagnosed at a significantly younger age in patients with ARAS. In our families, the occurrence of COL4A3/COL4A4 mutations was higher, while the prevalence of XLAS was lower than expected. Overall, a pathogenic COL4A3/COL4A4/COL4A5 mutation was identified in >50% of patients with fewer than three of the standard diagnostic criteria of AS. With such a population background, simultaneous next-generation sequencing of all three genes may be recommended as the most expedite approach to diagnose collagen IV-related glomerular basement membrane nephropathies.

Collagen type IV-related nephropathies in Portugal: pathogenic COL4A5 mutations and clinical characterization of 22 families

Alport syndrome (AS) is caused by pathogenic mutations in the genes encoding α3, α4 or α5 chains of collagen IV (COL4A3/COL4A4/COL4A5), resulting in hematuria, chronic renal failure (CRF), sensorineural hearing loss (SNHL) and ocular abnormalities. Mutations in the X-linked COL4A5 gene have been identified in 85% of the families (XLAS). In this study, 22 of 60 probands (37%) of unrelated Portuguese families, with clinical diagnosis of AS and no evidence of autosomal inheritance, had pathogenic COL4A5 mutations detected by Sanger sequencing and/or multiplex-ligation probe amplification, of which 12 (57%) are novel. Males had more severe and earlier renal and extrarenal complications, but microscopic hematuria was a constant finding irrespective of gender. Nonsense and splice site mutations, as well as small and large deletions, were associated with younger age of onset of SNHL in males, and with higher risk of CRF and SNHL in females. Pathogenic COL4A3 or COL4A4 mutations were subsequently identified in more than half of the families without a pathogenic mutation in COL4A5. The lower than expected prevalence of XLAS in Portuguese families warrants the use of next-generation sequencing for simultaneous COL4A3/COL4A4/COL4A5 analysis, as first-tier approach to the genetic diagnosis of collagen type IV-related nephropathies.

Angiotensin-converting enzyme inhibitors after renal transplantation

The blockade of the renin-angiotensin-aldosterone system may limit the progression of graft dysfunction in patients receiving kidney transplantations. We retrospectively evaluated the safety and efficacy of angiotensin-converting enzyme inhibitors (ACEI) in renal allograft recipients. Fifty-seven cadaveric kidney recipients (58% of recipients), were prescribed an ACEI (lisinopril). The indications for ACEI were isolated proteinuria (1 patient), erythrocytosis (6 patients), and arterial hypertension (50 patients). The choice of an ACEI for blood pressure control was due to presence of left ventricular hypertrophy (2 patients), mild proteinuria (4 patients), and high hemoglobin (4 patients). There was a significant reduction in the mean arterial pressure after 1 month (P = .0004) and 1 year (P = .0002) of therapy. Overall, the estimated glomerular filtrate rate (eGFR), calculated using the Cockcroft-Gault equation, remained unchanged. Among patients who had serum creatinine values above 2.0 mg/dL at the beginning of ACEI therapy, there was a significant rise in eGFR from 39.3 +/- 13.2 to 44.1 +/- 16.8 mL/min after 6 months (P = .01), and 43.3 +/- 17.3 mL/min after 1 year (P = .04). In patients with erythrocytosis, the hemoglobin showed a significant and sustained reduction after 1 month (P = .004) and 1 year (P = .001). Six patients suspended ACEI owing to adverse events: cough (n = 4), worsening of graft function (n = 1), and hypotension (n = 1). Six patients required erythropoiesis-stimulating agents. No patient suspended treatment owing to hyperkalemia. In conclusion, ACEI were well tolerated, safe, and effective antihypertensive agents in kidney graft recipients. They seemed to have some beneficial effect in preserving GFR in patients with worse graft function.

Evaluation of segmentation algorithms for coronary angiography

This paper presents an evaluation technique based on ROC analysis to compare four segmentation algorithms in coronary angiography images. We have implemented four algorithms and we have optimized their parameters; then, we have compared their performances. Both steps are done by means of a ROC analysis. Experimental results are presented on simulated data and real images.

Increased use of catheters as vascular access: is it justified by patients' clinical conditions?

BACKGROUND

Over the last years many technical improvements have been made in hemodialysis treatment. Vascular access (VA) still remains an important problem. Although the use of indwelling vascular catheters is discouraged, in Europe there is an increasing use of them. The K/DOQI Guidelines recommend a native arteriovenous fistula (AVF) as VA of choice. As reported by DOPPS, there is considerable geographic variation in the distribution of type of VA used amongst hemodialysis patients. The aim of this study was to evaluate the time patients in four European countries have to wait before undergoing their first surgery for VA (AVF or graft).

METHODS

All incident patients admitted to HD clinics located in Turkey, Italy, the UK and Portugal of the European FME clinics network between October 1, 2002 and September 30, 2004 were considered. Data were gained from the Clinical Database EuCliD.

RESULTS

2,152 patients (males 55.9%, mean age 62.5+/-15.7 years, diabetics 27%) were selected. Italy and Portugal had a higher proportion of elderly patients. At time of admission, the proportion of patients starting dialysis with AVF ranged between 23% and 60% from Turkey to Italy respectively. Patients with an indwelling catheter at admission are expected to undergo VA surgery as soon as possible. After 3 months of follow-up, about 75% of all patients had undergone surgery, however in the UK less than 50% of the patients had had a VA procedure. Overall, males have significantly higher probability of undergoing surgery, whilst elderly patients have a lower probability (27% and 14% respectively).

CONCLUSION

Significant differences exist between countries in the time interval from referral to creation of VA. Health care system related problems seem to be the major reason to explain such differences. Patients in the UK have longer waiting times than the other countries studied.

Electrical spinal cord stimulation during radiotherapy and temozolomide in high grade gliomas. A phase II report

11510

Background: Ischemia-hypoxia in high grade gliomas (HGG) turns tumor cells more aggressive and more resistant to radiotherapy (RT) and temozolomide (TMZ). Higher glucose metabolism pre-treatment has been correlated with better response to TMZ using 18-FDG-PET. In preliminary works, we have reported that electrical spinal cord stimulation (SCS) can modify loco-regional oxygenation, blood flow and metabolism in HGG. The aim of this study was to evaluate tumor response and toxicity in HGG using SCS during RT plus TMZ. Methods: 10 patients (males/females: 8/2; median age: 51 years (30–68)) were enrolled in this trial. Tumors were 6 glioblastomas and 4 relapsed anaplastic gliomas. Diagnosis was after complete resection (1), subtotal resection (6), biopsy (1) or MRI + PET (2 relapsed HGG). Tetrapolar electrode for SCS was percutaneously inserted on the posterior surface of the cervical spinal cord at C2-C4 level. RT was at 2 Gy/fraction, 5 fractions/week, total dose 60 Gy (40 Gy in previously irradiated tumors). TMZ was administered at 75 mg/m2 daily during RT, followed by at least 6 cycles of adjuvant TMZ at 200 mg/m2. Tumor response was evaluated by CT and PET. Results: After concurrent RT+TMZ, CT showed: 5 partial response (PR), 3 complete response (CR), 2 stable disease (SD). After 6 adjuvant cycles of TMZ, CT (median 10 months after surgery) showed: 4 PR, 3 CR, 3 progression disease (PD). PET showed post-surgical residual tumor in the 9 evaluated patients. After 6 cycles of TMZ, PET showed: 4 CR, 2 PR (they obtained delayed CR after 12 and 18 cycles of TMZ), PD n = 2, and two patients without PET assessment (1 with PR in CT, and 1 without tumor in CT). For the study group median overall survival (OS) was 22 months (95% CI = 14–30) and for glioblastomas 16 months (95% CI = 6–26). For relapsed anaplastic gliomas mean OS was 37 months (95% CI = 22–52). One patient did not finish scheduled adjuvant TMZ and only one patient experienced hematological toxicity with neutropenia G-I and thrombopenia G-III. Conclusions: Electrical SCS during RT+TMZ did not increase toxicity. Preliminary data about tumor response and OS seem to be encouraging and they support further research. Supported by Grants: FUNCIS 03/09 and ISCiii, RTICCC C03/10.

No significant financial relationships to disclose.

REMEDIACIÓN DE LOS IMPACTOS CAUSADOS POR EL DERRAME DE PETRÓLEO EN LA LAGUNA DE PAPALLACTA EN ECUADOR-SUR AMERICA1 TIEMPO DE EJECUCIÓN: NOVIEMBRE 2003-MAYO 2004

Se limpió y remedió un área afectada aproximada de 7,2 ha (hectáreas) por un derrame con 22000 barriles de petroleó en la Laguna de Papallacta, producto de la rotura del oleoducto transecuatoriano. Se descontaminaron riberas, sedimento, agua de ríos y de la Laguna de Papallacta. Los hidrocarburos presentes en el agua fueron extraídos por skimming, adsorción, absorción y filtrado. Los sedimentos contaminados del fondo de la laguna, fueron extraidos por succión, deshidratados y transportados a estaciones de landfarming para su biorremediación utilizando microorganismos endémicos. Los análisis iniciales de concentración de hidrocarburos totales en las riberas de los ríos y de la laguna oscilaban entre 40245 y 85879 miligramosILitro (mg/L)MM1, 4500 mg/Kg en los sedimentos del fondo de la laguna y 89 mg/L en el agua de la laguna.

Los trabajos de remediación se subdividieronpor conveniencia logística en 5 tramos. La limpieza y remediación incluyó el lecho de los ríos, rocas, riberas de la Laguna de Papallacta, material vegetal y agua contaminada.

La remediación redujo los niveles de hidrocarburos de petróleoen los suelos a menos de 1000 mg/L, en sedimentos de la laguna por debajo de 500 mg/L y en el agua de la laguna por debajo de 0,5 mg/L. Los valor es de los hidrocarburos policíclicos aromáticos en agua y sedimento de la laguna alcanzaron valores menores a I mg/Kg-LMM2. Todos estos valores son los establecidos como limites permisibles para ecosistemas sensibles y agua para consumo humano. La recuperación del ecosistema, además, se estableció por la presencia de invertebrados bénticos en la laguna, que al inicio de la limpieza estaban ausentes. Entre los grupos registrados se incluyen bivalvos, caracoles, nemátodos y larvas de insectos.

La remediación se realizó sin utilizar productos químicos o biológicos en los procesos de limpieza en el área del derrame en la laguna.

[Two-years experience with the use of radial artery in coronary revascularization surgery]

INTRODUCTION

Among several other factors, in coronary surgery the results depend on the quality and durability of the grafts. Revascularization employing arterial conduits, namely the radial artery, has been playing a growing role, with the aim of replacing the autologous saphenous vein. The benefits and risks of this strategy is still a matter of controversy. The goal of the present study was the evaluation of the incidence of early complications related to the use of radial artery in the revascularization surgery of the myocardium.

METHODS

A series of consecutive patients who underwent coronary revascularization surgery in the CHVNGaia using radial artery, from January 2000 to December 2001, was retrospectively analyzed. Data were obtained through the revision of the clinical charts and hospital database. The major end-point assessed was the 30-day or intra hospital postoperative death; furthermore, acute myocardial infarction, stroke, renal failure, prolonged ventilation and reoperations for acute graft occlusion, bleeding and mediastistinitis were also evaluated.

RESULTS

During that period of time, 656 patients underwent coronary revascularization surgery, but the radial artery was used in only 230 (35%). Mean age was 60.2+/- 9.1 years and 42 (18.3%) were female. Two hundred and four patients (88.6%) were operated on under extracorporeal circulation. The average number of grafts was 2.6+/- 0.6 per patient. Mean duration of orotraqueal intubation was 2.4 +/- 6 hours. Thirty patients (14,3 %) developed atrial fibrillation and ten (4.3%) had postoperative bleeding. Perioperative myocardial infarction occurred in five cases (2.2%). Two patients (0.8%) underwent reoperation for mediastinitis and one patient (0.4%) was reoperated on for acute occlusion of the graft. The overall postoperative mortality was 1.3% (3 patients).

CONCLUSION

The use of radial artery in coronary revascularization did not caused morbidity and mortality, out of the usual context of coronary surgery. The results of our experience suggest that radial artery can be successfully used in myocardial revascularization surgery, enlarging the possibilities of utilization of arterial autografts.