Phenology of five tick species in the central Great Plains.

The states of Kansas and Oklahoma, in the central Great Plains, lie at the western periphery of the geographic distributions of several tick species. As the focus of most research on ticks and tick-borne diseases has been on Lyme disease which commonly occurs in areas to the north and east, the ticks of this region have seen little research attention. Here, we report on the phenology and activity patterns shown by tick species observed at 10 sites across the two states and explore factors associated with abundance of all and life specific individuals of the dominant species. Ticks were collected in 2020-2022 using dragging, flagging and carbon-dioxide trapping techniques, designed to detect questing ticks. The dominant species was A. americanum (24098, 97%) followed by Dermacentor variabilis (370, 2%), D. albipictus (271, 1%), Ixodes scapularis (91, <1%) and A. maculatum (38, <1%). Amblyomma americanum, A. maculatum and D. variabilis were active in Spring and Summer, while D. albipictus and I. scapularis were active in Fall and Winter. Factors associated with numbers of individuals of A. americanum included day of year, habitat, and latitude. Similar associations were observed when abundance was examined by life-stage. Overall, the picture is one of broadly distributed tick species that shows seasonal limitations in the timing of their questing activity.

Doctors for the people? The problematic distribution of rural service doctors in Ecuador.

Primary health care is at the core of health systems that aim to ensure equitable health outcomes. With an estimated 36% of rural population, Ecuador has a service year programme (created in 1970) for recently graduated doctors to provide primary care services in rural and remote communities. However, little has been done to monitor or evaluate the programme since its inception. The aim of this study was to assess Ecuador's rural medical service implementation with a focus on equitable distribution of doctors across the country. For this purpose, we analysed the distribution of all doctors, including rural service doctors, in health-care facilities across rural and remote areas of Ecuador in the public sector at the canton level for 2015 and 2019, by level of care (primary, secondary and tertiary). We used publicly available data from the Ministry of Public Health, the Ecuadorian Institute of Social Security and the Peasant Social Security. Our analyses show that two of every three rural service doctors are concentrated at the secondary level, while almost one in five rural service doctors, at the tertiary level. Moreover, cantons concentrating most rural service doctors were in the country's major urban centres (Quito, Guayaquil, Cuenca). To our knowledge, this is the first quantitative assessment of the mandatory rural service year in Ecuador in its five-decade existence. We provide evidence of gaps and inequities impacting rural communities and present decision makers with a methodology for placement, monitoring and support of the rural service doctors programme, provided that legal and programmatic reforms come into place. Changing the programme's approach would be more likely to fulfill the intended goals of rural service and contribute to strengthening primary health care.

Transmission risk of Oropouche fever across the Americas.

BACKGROUND: Vector-borne diseases (VBDs) are important contributors to the global burden of infectious diseases due to their epidemic potential, which can result in significant population and economic impacts. Oropouche fever, caused by Oropouche virus (OROV), is an understudied zoonotic VBD febrile illness reported in Central and South America. The epidemic potential and areas of likely OROV spread remain unexplored, limiting capacities to improve epidemiological surveillance. METHODS: To better understand the capacity for spread of OROV, we developed spatial epidemiology models using human outbreaks as OROV transmission-locality data, coupled with high-resolution satellite-derived vegetation phenology. Data were integrated using hypervolume modeling to infer likely areas of OROV transmission and emergence across the Americas. RESULTS: Models based on one-support vector machine hypervolumes consistently predicted risk areas for OROV transmission across the tropics of Latin America despite the inclusion of different parameters such as different study areas and environmental predictors. Models estimate that up to 5 million people are at risk of exposure to OROV. Nevertheless, the limited epidemiological data available generates uncertainty in projections. For example, some outbreaks have occurred under climatic conditions outside those where most transmission events occur. The distribution models also revealed that landscape variation, expressed as vegetation loss, is linked to OROV outbreaks. CONCLUSIONS: Hotspots of OROV transmission risk were detected along the tropics of South America. Vegetation loss might be a driver of Oropouche fever emergence. Modeling based on hypervolumes in spatial epidemiology might be considered an exploratory tool for analyzing data-limited emerging infectious diseases for which little understanding exists on their sylvatic cycles. OROV transmission risk maps can be used to improve surveillance, investigate OROV ecology and epidemiology, and inform early detection.

Epidemiology and clinical features of venomous snake bites in the Northern Amazon of Ecuador (2017-2021) / Epidemiología y características clínicas de las mordeduras de serpientes venenosas en el norte de la Amazonía del Ecuador (2017-2021)

Introduction: In Ecuador, poisonous snakebites are a public health problem. However, there is no recent hospital information from the Amazon. Objective: To retrospectively analyse the clinical-epidemiological characteristics of snakebites in patients admitted to a hospital in the Ecuadorian Amazon. Materials and methods: This is a cross-sectional study conducted at the Nueva Loja-Sucumbíos Provincial Hospital, bordering Colombia (2017-2021). Demographic, epidemiological and clinical variables, and condition at hospital discharge, were obtained from the epidemiological file of the Ministerio de Salud Pública. Results: In 5 years, 147 patients (29.4 per year) were hospitalized with no mortality. They corresponded to 26, 34, 32, 29 and 26 cases, in 2017, 2018, 2019, 2020 and 2021, respectively. Men with 99 (67.3%), aged 21-30 years with 28, mixed race with 94 cases, students, and farmers, were the most affected. The most affected (99; 67.3%) were men, people 21 to 30 years-old (28; 19.0%), mestizos (94; 63.9%), students, and farmers. The median age was 28 (range: 4-81) years. Prevalence was higher in April, June, and September. All accidents were caused by Viperidae snakes. Twenty (13.6%) cases were mild, (61.2%) were moderate and 37 (25.2%) were severe. The feet with 45 were the most bitten. Pre-hospitalization anti-venom serum was received by 53.1% and tourniquet by 19.8% patients. Median hospital arrival time was 5 (range 1-192) hours, mostly between 2-3 hours with 41 cases. No statistically significant differences were found considering the severity. Conclusions: A high prevalence of snakebites was evidenced in the north of the Amazon in Ecuador, with a higher incidence in the rainy season and all by Viperidae species. It is important to highlight the null mortality. Information campaigns on prevention and first aid, such as discouraging the use of tourniquets, especially among vulnerable groups.

Introducción. En Ecuador, las mordeduras de serpientes venenosas son un problema de salud pública. Sin embargo, no existe información hospitalaria reciente desde la Amazonía. Objetivo. Analizar retrospectivamente las características clínico-epidemiológicas de las mordeduras de serpientes en pacientes ingresados en un hospital de la Amazonía del Ecuador. Materiales y métodos. Se llevó a cabo un estudio transversal en el hospital provincial de Nueva Loja (Sucumbíos), que colinda con Colombia, 2017-2021. La información sobre las variables demográficas, epidemiológicas y clínicas, y la condición al egreso hospitalario, se obtuvieron de la ficha epidemiológica del Ministerio de Salud Pública. Resultados. En cinco años se hospitalizaron 147 pacientes (29,4 por año), sin que se presentaran muertes. Corresponden a 26, 34, 32, 29 y 26 casos, en el 2017, 2018, 2019, 2020 y 2021, respectivamente. Según el sexo, los más afectados fueron los hombres (n=99; 67,3 %), según el grupo etario, los de 21 a 30 años (n=28; 19,0 %) y, según la raza, los de etnia mestiza (n=94; 63,9 %), estudiantes y agricultores. La mediana de edad fue de 28 años (rango: 4 a 81). Hubo mayor prevalencia en abril, junio y septiembre. Todos los accidentes fueron causados por serpientes Viperidae. Veinte (13,6 %) casos fueron leves, 90 (61,2 %), moderados, y 37 (25,2 %), graves. La mordedura fue más frecuente en los pies (45 casos). El 53,1 % recibió suero antiofídico antes de la hospitalización y en el 19,8 % de los pacientes se colocó un torniquete. La mediana de tiempo de llegada al hospital fue de 5 horas (rango: 1-192), y lo más frecuente fue entre 2 y 3 horas (41 casos). No se encontraron diferencias estadísticamente significativas según la gravedad del caso. Conclusiones. Se evidenció una gran prevalencia de mordeduras de serpientes en el norte de la región amazónica-Ecuador, con mayor incidencia en la estación lluviosa y todas causadas por Viperidae. Es importante resaltar la mortalidad nula. Las campañas informativas sobre prevención y primeros auxilios, como la desmotivación del uso de torniquetes, serían fundamentales para reducir los casos, especialmente, en los grupos vulnerables.

Leptospirosis in Ecuador: Current Status and Future Prospects.

The location of Ecuador-an equatorial nation-favors the multiplication and dispersal of the Leptospira genus both on the Pacific Coast and in the Amazon tropical ecoregions. Nevertheless, leptospirosis epidemiology has not been fully addressed, even though the disease has been recognized as a significant public health problem in the country. The purpose of this literature review is to update knowledge on the epidemiology and geographical distribution of Leptospira spp. and leptospirosis in Ecuador to target future research and develop a national control strategy. A retrospective literature search using five international, regional, and national databases on Leptospira and leptospirosis including humans, animals, and environmental isolations of the bacteria and the disease incidence in Ecuador published between 1919 and 2022 (103 years) with no restriction on language or publication date was performed. We found and analyzed 47 publications including 22 of humans, 19 of animals, and two of the environments; three of these covered more than one of these topics, and one covered all three (i.e., One Health). Most (60%) of the studies were conducted in the Coastal ecoregion. Twenty-four (51%) were published in international journals, and 27 (57%) were in Spanish. A total of 7342 human and 6314 other animal cases were studied. Leptospirosis was a frequent cause of acute undifferentiated febrile illness in the Coast and Amazon and was associated with rainfall. All three major clusters of Leptospira-pathogenic, intermediate, and saprophytic-were identified from both healthy and febrile humans, the environment, and animals; moreover, nine species and 29 serovars were recorded over the three Ecuadorian ecoregions. Leptospira infections were diagnosed in livestock, companion, and wild animals from the Amazon and the Coast regions along with sea lions from the Galápagos Islands. Microscopic-agglutination test was the diagnostic tool most widely used. Three reviews covering national data on outpatients and inpatients determined the varied annual incidence and mortality rate, with males being more commonly affected. No human cases have been reported in the Galápagos Islands. Genomic sequences of three pathogenic Leptospira were reported. No studies on clinical ground, antibiotic resistance, or treatment were reported, nor were control programs or clinical-practice guidelines found. The published literature demonstrated that leptospirosis was and still is an endemic disease with active transmission in the four geoclimatic regions of Ecuador including the Galápagos Islands. Animal infections, distributed in mainland and insular Ecuador, pose a significant health risk for humans. Nationwide epidemiological surveys-encouraging more research on the fauna and environment with appropriate sampling design on risk factors for human and animal leptospirosis, Leptospira genotyping, increased laboratory capability, and readily available official data-are required to improve our understanding of transmission patterns and to develop effective national intervention strategies with the intention of applying One Health approaches.

Epidemiología y características clínicas de las mordeduras de serpientes venenosas en el norte de la Amazonía del Ecuador (2017-2021) / Epidemiology and clinical features of venomous snake bites in the Northern Amazon of Ecuador (2017-2021)

Introducción. En Ecuador, las mordeduras de serpientes venenosas son un problema de salud pública. Sin embargo, no existe información hospitalaria reciente desde la Amazonía. Objetivo. Analizar retrospectivamente las características clínico-epidemiológicas de las mordeduras de serpientes en pacientes ingresados en un hospital de la Amazonía del Ecuador. Materiales y métodos. Se llevó a cabo un estudio transversal en el hospital provincial de Nueva Loja (Sucumbíos), que colinda con Colombia, 2017-2021. La información sobre las variables demográficas, epidemiológicas y clínicas, y la condición al egreso hospitalario, se obtuvieron de la ficha epidemiológica del Ministerio de Salud Pública. Resultados. En cinco años se hospitalizaron 147 pacientes (29,4 por año), sin que se presentaran muertes. Corresponden a 26, 34, 32, 29 y 26 casos, en el 2017, 2018, 2019, 2020 y 2021, respectivamente. Según el sexo, los más afectados fueron los hombres (n=99; 67,3 %), según el grupo etario, los de 21 a 30 años (n=28; 19,0 %) y, según la raza, los de etnia mestiza (n=94; 63,9 %), estudiantes y agricultores. La mediana de edad fue de 28 años (rango: 4 a 81). Hubo mayor prevalencia en abril, junio y septiembre. Todos los accidentes fueron causados por serpientes Viperidae. Veinte (13,6 %) casos fueron leves, 90 (61,2 %), moderados, y 37 (25,2 %), graves. La mordedura fue más frecuente en los pies (45 casos). El 53,1 % recibió suero antiofídico antes de la hospitalización y en el 19,8 % de los pacientes se colocó un torniquete. La mediana de tiempo de llegada al hospital fue de 5 horas (rango: 1-192), y lo más frecuente fue entre 2 y 3 horas (41 casos). No se encontraron diferencias estadísticamente significativas según la gravedad del caso. Conclusiones. Se evidenció una gran prevalencia de mordeduras de serpientes en el norte de la región amazónica-Ecuador, con mayor incidencia en la estación lluviosa y todas causadas por Viperidae. Es importante resaltar la mortalidad nula. Las campañas informativas sobre prevención y primeros auxilios, como la desmotivación del uso de torniquetes, serían fundamentales para reducir los casos, especialmente, en los grupos vulnerables.

Introduction: In Ecuador, poisonous snakebites are a public health problem. However, there is no recent hospital information from the Amazon. Objective: To retrospectively analyse the clinical-epidemiological characteristics of snakebites in patients admitted to a hospital in the Ecuadorian Amazon. Materials and methods: This is a cross-sectional study conducted at the Nueva Loja-Sucumbíos Provincial Hospital, bordering Colombia (2017-2021). Demographic, epidemiological and clinical variables, and condition at hospital discharge, were obtained from the epidemiological file of the Ministerio de Salud Pública. Results: In 5 years, 147 patients (29.4 per year) were hospitalized with no mortality. They corresponded to 26, 34, 32, 29 and 26 cases, in 2017, 2018, 2019, 2020 and 2021, respectively. Men with 99 (67.3%), aged 21-30 years with 28, mixed race with 94 cases, students, and farmers, were the most affected. The most affected (99; 67.3%) were men, people 21 to 30 years-old (28; 19.0%), mestizos (94; 63.9%), students, and farmers. The median age was 28 (range: 4-81) years. Prevalence was higher in April, June, and September. All accidents were caused by Viperidae snakes. Twenty (13.6%) cases were mild, (61.2%) were moderate and 37 (25.2%) were severe. The feet with 45 were the most bitten. Pre-hospitalization anti-venom serum was received by 53.1% and tourniquet by 19.8% patients. Median hospital arrival time was 5 (range 1-192) hours, mostly between 2-3 hours with 41 cases. No statistically significant differences were found considering the severity. Conclusions: A high prevalence of snakebites was evidenced in the north of the Amazon in Ecuador, with a higher incidence in the rainy season and all by Viperidae species. It is important to highlight the null mortality. Information campaigns on prevention and first aid, such as discouraging the use of tourniquets, especially among vulnerable groups.

Ethnodemographic characterization of stroke incidence and burden of disease in hospital discharge records in Ecuador.

Introduction: Stroke is the second most common cause of death and disability-adjusted life years (DALYs) globally. However, the incidence and impact of stroke by ethnicity and gender is frequently distinct. This is particularly the case in Ecuador where geographic and economic marginalization are often correlated with ethnic marginalization and the extent to which females lack the same opportunities as their male counterparts. The aim of this paper is to investigate the differential impacts in terms of stroke diagnosis and burden of disease by ethnicity and gender, using hospital discharge records over the years 2015-2020. Methods: This paper calculates stroke incidence, and fatality rates using hospital discharge and death records over the years 2015-2020. The DALY package in R was employed to calculate the Disability Adjusted Life Years lost due to stroke in Ecuador. Results: The results show that while the incidence rate of stroke in males (64.96 per 100,000 persons-year) is higher than that for females on average (57.84 per 100,000 persons-year), males accounted for 52.41% of all stroke cases and 53% of all surviving cases. Thus, hospital data suggests that females had a higher death rate when compared to males. Case fatality rates also differed significantly by ethnicity. The highest fatality rate corresponded to the Montubio ethnic group (87.65%), followed by Afrodescendants (67.21%). The estimated burden of disease of stroke calculated using Ecuadorian hospital records (2015-2020) varied from 1,468 to 2,991 DALY per 1,000 population on average. Discussion: Differences in the burden of disease by ethnic group are likely to reflect differential access to care by region and socio-economic group, both of which are frequently correlated with ethnic composition in Ecuador. Equitable access to health services remains an important challenge in the country. The gender discrepancy in fatality rates suggests that there is a need for targeted educational campaigns to identify stroke signs early, especially in the female population.

Mycobacterium leprae in Armadillo Tissues from Museum Collections, United States.

We examined armadillos from museum collections in the United States using molecular assays to detect leprosy-causing bacilli. We found Mycobacterium leprae bacilli in samples from the United States, Bolivia, and Paraguay; prevalence was 14.8% in nine-banded armadillos. US isolates belonged to subtype 3I-2, suggesting long-term circulation of this genotype.

Extended-Spectrum Beta-Lactamases Producing Escherichia coli in South America: A Systematic Review with a One Health Perspective.

Purpose: Extended-spectrum beta-lactamase-producing (ESBL) Enterobacteriaceae, which includes Escherichia coli, has emerged as a global health threat. ESBL enzymes including CTX-M, TEM, and SHV are the most detected. Here, a systematic review was developed to assess the status of ESBLs in E. coli considering studies performed in the human, animal, food, and environmental realms in South America. Methods: Following PRISMA guidelines, a systematic review was performed using the PubMed database as a primary source to identify studies containing data on ESBL-producing E. coli in South America. To obtain a comprehensive sample, studies in English, Spanish, and Portuguese were included from 1990 to April 2021. Inclusion such as the reporting of sample origin and diagnostic method and exclusion criteria such as review/letter articles were established to complete data extraction steps. Results: Amongst 506 articles retrieved, 130 met the inclusion criteria. Brazil reported 65 (50%) of publications, followed by Argentina, and Ecuador with 11.5% each. According to the category of studies, human studies represented the 56%, animals the 20%, environmental the 11%, and food studies the 6%. Interestingly, studies assessing more than one category (ie, interdisciplinary) represented the 7%. Prevalence of ESBL producing E. coli in animal, food, and environmental studies was widely superior compared to human sources. In clinical studies, Brazil presented the greatest diversity in terms of ESBLs, featuring CTX-M, TEM, SHV, TOHO, OXA, and AmpC. CTX-M enzymes were the most frequent variants with 89.4% detections. Conclusion: The present One Health review of 130 studies conducted over the past 21 years found ESBLs producing E. coli distributed across human, animal, food, and environmental samples across South America. There is a need to increment studies in underrepresented countries and to strengthen multi-sectoral antimicrobial resistance research and surveillance. This information can be used as basis for subsequent implementation of monitoring programs, targeting potential critical points of transmission sources.

Low risk of acquiring melioidosis from the environment in the continental United States.

Melioidosis is an underreported human disease of tropical and sub-tropical regions caused by the saprophyte Burkholderia pseudomallei. Although most global melioidosis cases are reported from tropical regions in Southeast Asia and northern Australia, there are multiple occurrences from sub-tropical regions, including the United States (U.S.). Most melioidosis cases reported from the continental U.S. are the result of acquiring the disease during travel to endemic regions or from contaminated imported materials. Only two human melioidosis cases from the continental U.S. have likely acquired B. pseudomallei directly from local environments and these cases lived only ~7 km from each other in rural Texas. In this study, we assessed the risk of acquiring melioidosis from the environment within the continental U.S. by surveying for B. pseudomallei in the environment in Texas where these two human melioidosis cases likely acquired their infections. We sampled the environment near the homes of the two cases and at additional sampling locations in surrounding counties in Texas that were selected based on ecological niche modeling. B. pseudomallei was not detected at the residences of these two cases or in the surrounding region. These negative data are important to demonstrate that B. pseudomallei is rare in the environment in the U.S. even at locations where locally acquired human cases likely have occurred, documenting the low risk of acquiring B. pseudomallei infection from the environment in the continental U.S.

Using Google Health Trends to investigate COVID-19 incidence in Africa.

The COVID-19 pandemic has caused over 500 million cases and over six million deaths globally. From these numbers, over 12 million cases and over 250 thousand deaths have occurred on the African continent as of May 2022. Prevention and surveillance remains the cornerstone of interventions to halt the further spread of COVID-19. Google Health Trends (GHT), a free Internet tool, may be valuable to help anticipate outbreaks, identify disease hotspots, or understand the patterns of disease surveillance. We collected COVID-19 case and death incidence for 54 African countries and obtained averages for four, five-month study periods in 2020-2021. Average case and death incidences were calculated during these four time periods to measure disease severity. We used GHT to characterize COVID-19 incidence across Africa, collecting numbers of searches from GHT related to COVID-19 using four terms: 'coronavirus', 'coronavirus symptoms', 'COVID19', and 'pandemic'. The terms were related to weekly COVID-19 case incidences for the entire study period via multiple linear and weighted linear regression analyses. We also assembled 72 variables assessing Internet accessibility, demographics, economics, health, and others, for each country, to summarize potential mechanisms linking GHT searches and COVID-19 incidence. COVID-19 burden in Africa increased steadily during the study period. Important increases for COVID-19 death incidence were observed for Seychelles and Tunisia. Our study demonstrated a weak correlation between GHT and COVID-19 incidence for most African countries. Several variables seemed useful in explaining the pattern of GHT statistics and their relationship to COVID-19 including: log of average weekly cases, log of cumulative total deaths, and log of fixed total number of broadband subscriptions in a country. Apparently, GHT may best be used for surveillance of diseases that are diagnosed more consistently. Overall, GHT-based surveillance showed little applicability in the studied countries. GHT for an ongoing epidemic might be useful in specific situations, such as when countries have significant levels of infection with low variability. Future studies might assess the algorithm in different epidemic contexts.

Leptospirosis: Morbidity, mortality, and spatial distribution of hospitalized cases in Ecuador. A nationwide study 2000-2020.

BACKGROUND: In Ecuador, leptospirosis surveillance involves a mandatory notification of all cases and a hospitalization for severe illness. Morbidity and mortality are, nevertheless, underestimated and contribute directly to the status of leptospirosis as a neglected disease. Leptospira spp. is zoonotic in Ecuador with established endemic transmission in the Tropics. Here, we review retrospective national data within the country to aid in control strategies. METHODOLOGY/PRINCIPAL FINDINGS: In a population-based nationwide study, we analysed morbidity, mortality, and spatial distribution on confirmed hospital-discharged leptospirosis cases from 2000-2020 from a publicly accesible National Database, including males and females of all ages. We computed data for the 24 provinces across the four-geoclimatic regions of Ecuador based on seasonal and monthly variations and calculated rates according to age and sex. The spatial distribution was estimated at the level of ecoregions, provinces, and cantons. A total of 2,584 hospitalizations were recorded over all three continental regions in 22 provinces, except Carchi province and the Galapagos Islands. The annual incidence varied from 0.27 to 2.45 cases per 100,000 inhabitants with ages ranging from 1 to 98 years-old and an overall male/female ratio of 1.92:1. Most hospitalizations and deaths occurred in males ages 25-34 years. We registered 79 fatalities (3.06%); the highest mortality rate was 0.05 per 100,000 inhabitants. More cases clustered in the tropical cantons of central and north of the Coast and in the southern Amazon when compared to the Andes. CONCLUSIONS AND SIGNIFICANCE: Our findings evidence leptospirosis endemicity and pinpoint the highest incidence within resource-poor tropical settings. The highest incidence occurred in males of adult age, with those also exhibiting the highest mortality. The national incidence rate was stable, but peaks occurred intermittently during the rainy seasons. Thus, strategies aimed at leptospirosis monitoring and control involving the application of preventive measures should consider this season and the aforementioned high-risk groups.

To isolate or not to isolate: the impact of changing behavior on COVID-19 transmission.

BACKGROUND: The COVID-19 pandemic has caused more than 25 million cases and 800 thousand deaths worldwide to date. In early days of the pandemic, neither vaccines nor therapeutic drugs were available for this novel coronavirus. All measures to prevent the spread of COVID-19 are thus based on reducing contact between infected and susceptible individuals. Most of these measures such as quarantine and self-isolation require voluntary compliance by the population. However, humans may act in their (perceived) self-interest only. METHODS: We construct a mathematical model of COVID-19 transmission with quarantine and hospitalization coupled with a dynamic game model of adaptive human behavior. Susceptible and infected individuals adopt various behavioral strategies based on perceived prevalence and burden of the disease and sensitivity to isolation measures, and they evolve their strategies using a social learning algorithm (imitation dynamics). RESULTS: This results in complex interplay between the epidemiological model, which affects success of different strategies, and the game-theoretic behavioral model, which in turn affects the spread of the disease. We found that the second wave of the pandemic, which has been observed in the US, can be attributed to rational behavior of susceptible individuals, and that multiple waves of the pandemic are possible if the rate of social learning of infected individuals is sufficiently high. CONCLUSIONS: To reduce the burden of the disease on the society, it is necessary to incentivize such altruistic behavior by infected individuals as voluntary self-isolation.

Updated distribution maps of predominant Culex mosquitoes across the Americas.

BACKGROUND: Estimates of the geographical distribution of Culex mosquitoes in the Americas have been limited to state and provincial levels in the United States and Canada and based on data from the 1980s. Since these estimates were made, there have been many more documented observations of mosquitoes and new methods have been developed for species distribution modeling. Moreover, mosquito distributions are affected by environmental conditions, which have changed since the 1980s. This calls for updated estimates of these distributions to understand the risk of emerging and re-emerging mosquito-borne diseases. METHODS: We used contemporary mosquito data, environmental drivers, and a machine learning ecological niche model to create updated estimates of the geographical range of seven predominant Culex species across North America and South America: Culex erraticus, Culex nigripalpus, Culex pipiens, Culex quinquefasciatus, Culex restuans, Culex salinarius, and Culex tarsalis. RESULTS: We found that Culex mosquito species differ in their geographical range. Each Culex species is sensitive to both natural and human-influenced environmental factors, especially climate and land cover type. Some prefer urban environments instead of rural ones, and some are limited to tropical or humid areas. Many are found throughout the Central Plains of the USA. CONCLUSIONS: Our updated contemporary Culex distribution maps may be used to assess mosquito-borne disease risk. It is critical to understand the current geographical distributions of these important disease vectors and the key environmental predictors structuring their distributions not only to assess current risk, but also to understand how they will respond to climate change. Since the environmental predictors structuring the geographical distribution of mosquito species varied, we hypothesize that each species may have a different response to climate change.

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.

Cycle Threshold Values in the Context of Multiple RT-PCR Testing for SARS-CoV-2.

PURPOSE: Discharge or follow up of confirmed coronavirus disease 2019 (COVID-19) cases depend on accurate interpretation of RT-PCR. Currently, positive/negative interpretations are based on amplification instead of quantification of cycle threshold (Ct) values, which could be used as proxies of patient infectiousness. Here, we measured Ct values in hospitalized confirmed COVID-19 patients at different times and its implications in diagnosis and follow up. PATIENTS AND METHODS: Observational study between March 17th-May 12th, 2020 using multiple RT-PCR testing. A cohort of 118 Hispanic hospitalized patients with confirmed COVID-19 diagnosis in a reference hospital in Quito, Ecuador. Multiple RT-PCR tests were performed using deep nasal swab samples and the assessment of SARS-CoV-2 genes N, RdRP, and E. RESULTS: Patients' median age was of 49 years (range: 24-91) with a male majority (62.7%). We found increasing levels of Ct values in time, with a mean Ct value of 29.13 (n = 61, standard deviation (sd) = 5.55) for the first test and 34.38 (n = 60, sd = 4), 35.52 (n = 20, sd = 2.85), and 36.12 (n = 6, sd = 3.28), for the second, third, and fourth tests, respectively. Time to RT-PCR lack of amplification for all tests was of 34 days while time to RT-PCR Ct values >33 was of 30 days. CONCLUSION: Cycle thresholds can potentially be used to improve diagnosis, management and control. We found that turnover time for negativity can be large for hospitalized patients and that 11% cases persisted with infectious Ct values for more time than the current isolation recommendations.

An ecological niche shift for Neanderthal populations in Western Europe 70,000 years ago.

Middle Paleolithic Neanderthal populations occupied Eurasia for at least 250,000 years prior to the arrival of anatomically modern humans. While a considerable body of archaeological research has focused on Neanderthal material culture and subsistence strategies, little attention has been paid to the relationship between regionally specific cultural trajectories and their associated existing fundamental ecological niches, nor to how the latter varied across periods of climatic variability. We examine the Middle Paleolithic archaeological record of a naturally constrained region of Western Europe between 82,000 and 60,000 years ago using ecological niche modeling methods. Evaluations of ecological niche estimations, in both geographic and environmental dimensions, indicate that 70,000 years ago the range of suitable habitats exploited by these Neanderthal populations contracted and shifted. These ecological niche dynamics are the result of groups continuing to occupy habitual territories that were characterized by new environmental conditions during Marine Isotope Stage 4. The development of original cultural adaptations permitted this territorial stability.