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.

Adapting for the COVID-19 pandemic in Ecuador, a characterization of hospital strategies and patients.

The World Health Organization (WHO) declared coronavirus disease-2019 (COVID-19) a global pandemic on 11 March 2020. In Ecuador, the first case of COVID-19 was recorded on 29 February 2020. Despite efforts to control its spread, SARS-CoV-2 overran the Ecuadorian public health system, which became one of the most affected in Latin America on 24 April 2020. The Hospital General del Sur de Quito (HGSQ) had to transition from a general to a specific COVID-19 health center in a short period of time to fulfill the health demand from patients with respiratory afflictions. Here, we summarized the implementations applied in the HGSQ to become a COVID-19 exclusive hospital, including the rearrangement of hospital rooms and a triage strategy based on a severity score calculated through an artificial intelligence (AI)-assisted chest computed tomography (CT). Moreover, we present clinical, epidemiological, and laboratory data from 75 laboratory tested COVID-19 patients, which represent the first outbreak of Quito city. The majority of patients were male with a median age of 50 years. We found differences in laboratory parameters between intensive care unit (ICU) and non-ICU cases considering C-reactive protein, lactate dehydrogenase, and lymphocytes. Sensitivity and specificity of the AI-assisted chest CT were 21.4% and 66.7%, respectively, when considering a score >70%; regardless, this system became a cornerstone of hospital triage due to the lack of RT-PCR testing and timely results. If health workers act as vectors of SARS-CoV-2 at their domiciles, they can seed outbreaks that might put 1,879,047 people at risk of infection within 15 km around the hospital. Despite our limited sample size, the information presented can be used as a local example that might aid future responses in low and middle-income countries facing respiratory transmitted epidemics.

Analytical and clinical performance of a Chikungunya qRT-PCR for Central and South America.

Chikungunya was introduced into the Americas in 2015 causing a pandemic across the continent. Testing during the acute phase of infection relies on qRT-PCR, but available assays have a number of limitations. A qRT-PCR assay specific to the chikungunya E1 gene was designed using sequence data from contemporary strains. A probit analysis established the 95% limit of detection as 19.6 copies per reaction. We compared the assay with a US Centers for Disease Control (CDC) chikungunya qRT-PCR as the reference standard. The assay had a sensitivity and specificity of 98.4% and 100% in 90 samples retrospectively collected in Guatemala. In a further 74 febrile samples prospectively collected in Ecuador and Guatemala the test had a sensitivity and specificity of 100% and 98.4%, respectively. Sequencing the nsp4 gene of the discordant positive sample indicated the presence of chikungunya RNA, and mismatches to the primer binding sites of the CDC assay.

Reemergence of Measles in the Americas: The Genotype B3 2011-2012 Outbreak in Ecuador.

This study characterizes a measles outbreak which occurred in Ecuador in 2011-2012, analyzing data from 3700 suspected cases of measles reported to Ecuador's Ministry of Public Health. The study population had a large age range and included 333 confirmed cases of measles. The greatest number of cases were found in the <1 year (32.43%, n = 108) and 1-4 year (30.03%, n = 100) age-groups. Compared to Mestizos, indigenous people had the highest number of cases (68.2%, n = 227), as well as a higher risk of infection (OR 7.278 (CI 5.251-10.087)). The greatest protection from measles was observed in individuals who received two doses of the measles vaccine. Residents of Pastaza (OR 6.645 CI (3.183-13.873)) and Tungurahua (OR 8.346 CI (5.570-12.507)) had a higher risk of infection than the other provinces. Of the 17 laboratory confirmed cases, all were identified as genotype B3. Age-group, ethnicity, measles vaccinations, and residence in Tungurahua and Pastaza were correlated with rates of measles infection in the outbreak. Tungurahua and Pastaza, where the outbreak originated, have large indigenous populations. Indigenous children <1 year of age showed the highest incidence. It is likely that indigenous women do not have immunity to the virus, and so are unable to confer measles resistance to their newborns.

Staphylococcus aureus outbreak in the intensive care unit of the largest public hospital in Quito, Ecuador

Staphylococcus aureus is a frequent cause of nosocomial pneumonia and bacteremia worldwide. Classical and molecular epidemiology approaches were used to study a S. aureus outbreak in the intensive care unit (ICU) of one of the largest public hospitals in Quito. Staphylococcus aureus isolates from 17 patients and 19 potential carriers from the staff were collected from March 2007 to February 2008 and analyzed by pulsed-field gel electrophoresis (PFGE) to determine their clonal relationships. During this period the hospital reported 16 cases of hospital-acquired staphylococcal pneumonia and an apparent outbreak occurred from June to September 2007. DNA from these isolates formed six different PFGE patterns: four clonal groups, and two groups of clonally related isolates. Molecular typing failed to identify any staphylococcal reservoir among staff members. The current study suggested that a staphylococcal outbreak that occurred in the summer of 2007 was caused by different bacterial clones, although some clones were shared by two patients. Historical analysis of the staphylococcal infections in the ICU showed a higher incidence during the summer months, which coincided with the programmed personnel shift. This observation suggests that outbreaks might be produced by the introduction of improperly trained personnel (AU)

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Staphylococcus aureus outbreak in the intensive care unit of the largest public hospital in Quito, Ecuador.

Staphylococcus aureus is a frequent cause of nosocomial pneumonia and bacteremia worldwide. Classical and molecular epidemiology approaches were used to study a S. aureus outbreak in the intensive care unit (ICU) of one of the largest public hospitals in Quito. Staphylococcus aureus isolates from 17 patients and 19 potential carriers from the staff were collected from March 2007 to February 2008 and analyzed by pulsed-field gel electrophoresis (PFGE) to determine their clonal relationships. During this period the hospital reported 16 cases of hospital-acquired staphylococcal pneumonia and an apparent outbreak occurred from June to September 2007. DNA from these isolates formed six different PFGE patterns: four clonal groups, and two groups of clonally related isolates. Molecular typing failed to identify any staphylococcal reservoir among staff members. The current study suggested that a staphylococcal outbreak that occurred in the summer of 2007 was caused by different bacterial clones, although some clones were shared by two patients. Historical analysis of the staphylococcal infections in the ICU showed a higher incidence during the summer months, which coincided with the programmed personnel shift. This observation suggests that outbreaks might be produced by the introduction of improperly trained personnel.

[Scientific output in the health sciences in Ecuador]. / La producción científica en ciencias de la salud en Ecuador.

This cross-sectional study describes the characteristics and trends of health sciences-related studies published in Ecuador from 1999-2009. Its objective is to contribute to the design and implementation of a research and development policy whose work is centered on the country's health priorities. Bibliometric indicators of production applied to publications in health sciences in Ecuador were used for the analysis. The publications were from the LILACS and MEDLINE databases. It was found that 625 articles were published from 1999-2009, primarily in the clinical-surgical areas (60%), followed by epidemiology (17.4%), basic sciences (14.1%), and health systems (8.5%). Only 4.3% and 7.2% of the production in this period was related to the primary causes of morbidity and mortality, respectively. It was found that private institutions generated more health research than public institutions, and hospitals (public, private, and mixed) produced a higher percentage than universities. The analysis showed that there was limited scientific production in health sciences in Ecuador during the study period, with a slight increase in the last two years that may be due in part to greater investment in research and development by the National Secretariat of Science and Technology (SENACYT). Investment increased from 0.20% to 0.44% of gross domestic product between 2006 and 2009.

La producción científica en ciencias de la salud en Ecuador / Scientific output in the health sciences in Ecuador

El presente trabajo, de corte transversal, describe características y tendencias de los trabajos relacionados con las ciencias de la salud (CS) publicados en Ecuador durante el período 1999-2009. Su objetivo es contribuir al diseño e implementación de una política de investigación y desarrollo que centre sus esfuerzos en las prioridades de salud del país. Para el análisis se utilizaron indicadores bibliométricos de producción aplicados a las publicaciones científicas en CS de Ecuador, contenidas en las bases de datos LILACS y MEDLINE. Se halló que durante 1999-2009 se publicaron 625 artículos, observándose un predominio de las áreas clínico-quirúrgicas (60 por ciento) seguidas de la epidemiología (17,4 por ciento), las ciencias básicas (14,1 por ciento) y los sistemas de salud (8,5 por ciento). De todo lo producido durante ese período, solo 4,3 por ciento y 7,2 por ciento estaban relacionados con las principales causas de morbilidad y mortalidad, respectivamente. Se encontró que las instituciones privadas generaron más investigación en salud que las públicas, y los hospitales (públicos, privados y mixtos) en mayor proporción que las universidades. Del análisis realizado se puede decir que la producción científica en CS en Ecuador durante 1999-2009 ha sido escasa, con un leve repunte en los dos últimos años, que en parte podría explicarse por el aumento en la inversión en investigación y desarrollo a través de la Secretaría Nacional de Ciencia y Tecnología (SENACYT), la cual entre 2006 y 2009 pasó de 0,20 por ciento a 0,44 por ciento del producto interno bruto.

This cross-sectional study describes the characteristics and trends of health sciences-related studies published in Ecuador from 1999-2009. Its objective is to contribute to the design and implementation of a research and development policy whose work is centered on the country's health priorities. Bibliometric indicators of production applied to publications in health sciences in Ecuador were used for the analysis. The publications were from the LILACS and MEDLINE databases. It was found that 625 articles were published from 1999-2009, primarily in the clinical-surgical areas (60 percent), followed by epidemiology (17.4 percent), basic sciences (14.1 percent), and health systems (8.5 percent). Only 4.3 percent and 7.2 percent of the production in this period was related to the primary causes of morbidity and mortality, respectively. It was found that private institutions generated more health research than public institutions, and hospitals (public, private, and mixed) produced a higher percentage than universities. The analysis showed that there was limited scientific production in health sciences in Ecuador during the study period, with a slight increase in the last two years that may be due in part to greater investment in research and development by the National Secretariat of Science and Technology (SENACYT). Investment increased from 0.20 percent to 0.44 percent of gross domestic product between 2006 and 2009.

Environmental change and infectious disease: how new roads affect the transmission of diarrheal pathogens in rural Ecuador.

Environmental change plays a large role in the emergence of infectious disease. The construction of a new road in a previously roadless area of northern coastal Ecuador provides a valuable natural experiment to examine how changes in the social and natural environment, mediated by road construction, affect the epidemiology of diarrheal diseases. Twenty-one villages were randomly selected to capture the full distribution of village population size and distance from a main road (remoteness), and these were compared with the major population center of the region, Borbón, that lies on the road. Estimates of enteric pathogen infection rates were obtained from case-control studies at the village level. Higher rates of infection were found in nonremote vs. remote villages [pathogenic Escherichia coli: odds ratio (OR) = 8.4, confidence interval (CI) 1.6, 43.5; rotavirus: OR = 4.0, CI 1.3, 12.1; and Giardia: OR = 1.9, CI 1.3, 2.7]. Higher rates of all-cause diarrhea were found in Borbón compared with the 21 villages (RR = 2.0, CI 1.5, 2.8), as well as when comparing nonremote and remote villages (OR = 2.7, CI 1.5, 4.8). Social network data collected in parallel offered a causal link between remoteness and disease. The significant and consistent trends across viral, bacterial, and protozoan pathogens suggest the importance of considering a broad range of pathogens with differing epidemiological patterns when assessing the environmental impact of new roads. This study provides insight into the initial health impacts that roads have on communities and into the social and environmental processes that create these impacts.

Estudios comparativos clínicos y epidemiológicos de la oncocercosis entre dos grupos raciales del área hiperendémica de Ecuador / Comparative clinical and epidemiological studies between 2 racial groups in the hyperendemic area of onchocercosis in Ecuador

Se evaluó la importancia de los factores raciales en la epidemiología y las manifestaciones clínicas de la oncocercosis en la raza negra y la raza indígena Chachi, dos grupos étnicos diferentes del área hiperendémica del foco oncocercótico ecuatoriano. Los Chachi presentaron una significativa mayor densidad de microfilarias en la piel. De los negros, 72,2 por ciento presentaron lesiones oncocercóticas en la piel comparado con 56,4 por ciento en los Chachi. Se encontró mayor prevalencia de nódulos palpables en los Chachi (51,4 por ciento vs. 43,0 por ciento). La presencia de microfilarias en la cámara anterior del ojo fue más frecuente en los Chachi (51,9 por ciento vs. 34,2 por ciento), pero se evidenció una mayor prevalencia de corioretinitis y atrofia del nervio óptico en los negros (17,6 por ciento vs 11,2 por ciento y 8,5 por ciento vs. 0,5 por ciento, respectivamente)

Onchocerciasis in Ecuador: prevalence of infection on the Ecuador-Colombia border in the Province of Esmeraldas

The prevalence of onchocerciasis infection was determined in communities on 7 rivers located in the northern area of the canton San Lorenzo, province of Esmeraldas. Diagnosis of the infection was obtained by skin biopsies and recombinant-antigen based-serology. No evidence of infection was detected in 9 communities studied along the Rio Mataje, which forms the frontier between Ecuador and Colombia, nor in 10 adjacent communities located on 5 interior rivers. Evidence for Onchocerca volvulus infection was found in 4 communities on the Rio Tululvi with the following prevalence: La Boca (3,5 per cent by biopsy and 3,9 per cent by serology), Guayabal (9,1 per cent by both biopsy and serology), La Ceiva (51,5 per cent by biopsy and 53 per cent by serology), and Salidero (4 per cent by biopsy and 7,7 per cent by serology). A few individuals in these communities were seropositive for O. volvulus in the absence of detectable dermal microfilariae: these might harbor very light or prepatent infections. No clinical disease attributable to onchocerciasis was found. The infected communities will be included in the ivermectin-based National Control Program for the disease, with no evidence of the infection having extended north of the Ecuadorian-Colombian border.