We conducted a study in a dengue-endemic area of Colombia to evaluate the dynamics of transmission of dengue viruses during and after epidemics. Information was simultaneously gathered about occurrence of infection in humans and mosquitoes every three months in four cities with endemic transmission. Viral isolation was confirmed in 6.7% of the persons and most were asymptomatic. Adult mosquito and larvae house indexes were not found associated with increased burden of disease. The only entomologic indicator related to dengue infection in humans was the pooled infection rate of mosquitoes. Aedes aegypti infection rates showed significant differences between the epidemic (10.68, 95% confidence interval [CI] = 7.04-15.62) and after epidemic periods of the study (6.15, 95% CI = 3.46-10.19). In addition, Ae. albopictus were also infected with dengue viruses. Increases in mosquito infection rates were associated with increases in human infection rates in the following trimester.
Airborne transmission is predicted to be a prevalent route of human exposure with SARS-CoV-2. Aside from African green monkeys, nonhuman primate models that replicate airborne transmission of SARS-CoV-2 have not been investigated. A comparative evaluation of COVID-19 in African green monkeys, rhesus macaques, and cynomolgus macaques following airborne exposure to SARS-CoV-2 was performed to determine critical disease parameters associated with disease progression, and establish correlations between primate and human COVID-19. Respiratory abnormalities and viral shedding were noted for all animals, indicating successful infection. Cynomolgus macaques developed fever, and thrombocytopenia was measured for African green monkeys and rhesus macaques. Type II pneumocyte hyperplasia and alveolar fibrosis were more frequently observed in lung tissue from cynomolgus macaques and African green monkeys. The data indicate that, in addition to African green monkeys, macaques can be successfully infected by airborne SARS-CoV-2, providing viable macaque natural transmission models for medical countermeasure evaluation.
Airborne transmission is predicted to be a prevalent route of human exposure with SARS-CoV-2. Aside from African green monkeys, nonhuman primate models that replicate airborne transmission of SARS-CoV-2 have not been investigated. A comprehensive and comparative evaluation of COVID-19 in African green monkeys, rhesus macaques, and cynomolgus macaques following airborne exposure to SARS-CoV-2 was performed to define parameters critical to disease progression and the extent to which they correlate with human COVID-19. Respiratory abnormalities and viral shedding were noted for all animals, indicating successful infection. Cynomolgus macaques developed fever, and thrombocytopenia was measured for African green monkeys and rhesus macaques. Type II pneumocyte hyperplasia and alveolar fibrosis were more frequently observed in lung tissue from cynomolgus macaques and African green monkeys. The data indicate that, in addition to African green monkeys, macaques can be successfully infected by airborne SARS-CoV-2, providing viable macaque natural transmission models for medical countermeasure evaluation.One Sentence SummaryNonhuman primates develop COVID-19 following airborne virus exposure.
Objetivo Predecir el número de casos de COVID-19 en la ciudad de Cali-Colombia mediante el desarrollo de un modelo SEIR.Métodos Se utilizó un modelo determinista compartimental SEIR considerando los estados: susceptibles (S), expuestos (E), infectados (I) y recuperados (R). Los parámetros del modelo fueron seleccionados de acuerdo a la revisión de literatura. En el casode la tasa de letalidad, se usaron los datos de la Secretaría de Salud Municipal de Cali. Se plantearon varios escenarios teniendo en cuenta variaciones en el número básico de reproducción (R0) y en la tasa de letalidad; además, se comparó la predicción hasta el 9 de abril con los datos observados.Resultados A través del modelo SEIR se encontró que, con el número básico de reproducción más alto (2,6) y utilizando la letalidad calculada para la ciudad de 2,0%, el número máximo de casos se alcanzaría el primero de junio con 195 666 (prevalencia); sin embargo, al comparar los casos observados con los esperados, al inicio la ocurrencia observada estaba por encima de la proyectada; pero luego cambia la tendencia con una disminución marcada de la pendiente.Conclusiones Los modelos epidemiológicos SEIR son métodos muy utilizados para la proyección de casos en enfermedades infecciosas; sin embargo, se debe tener en cuenta que son modelos deterministas que pueden utilizar parámetros supuestos y podrían generar resultados imprecisos.
Se cuantificó la concentración de cadmio (Cd), mercurio (Hg) y plomo (Pb) en tejido muscular de los peces Prochilodus magdalenae (bocachico) y Chaetostoma spp. (corroncho). Se estimó el riesgo por consumo de estos pescados en la salud de madres lactantes residentes en tres localidades ubicadas en la ribera del río Cauca (una rural y una urbana en el municipio de Cali, y una rural en el municipio de Yumbo). Se cuantificó el riesgo cancerígeno y no cancerígeno usando modelación probabilística con Crystal Ball 11.0Ò, aplicando el modelo de simulación Monte Carlo para cien mil iteraciones. Se obtuvieron las siguientes concentraciones promedio de metales: Cd = 46 μg/kg-1, Hg = 235 μg/kg-1 y Pb = 35 μg/kg-1. Para el mercurio, se encontró que en las dos localidades ubicadas en Cali, los valores de riesgo no cancerígeno y la ingesta semanal tolerable están por encima de los límites máximos permitidos por la Agencia de Protección Ambiental de los Estados Unidos.
Our study is based on the Colombia SABE survey (Health, Well-Being, and Aging Study), which included 23,694 individuals aged 60+ in urban and rural areas of the country. The analysis addresses adult self-perception of health status as a dependent variable and its relationships to ethnic/racial self-recognition and to interviewer-ascribed skin color as a phenotypic trait using a validated technique with a color palette. Social inequalities were determined based on the characterization of socioeconomic status, urban or rural residence, literacy, and the average years of education attained. Our study brought together socioeconomic factors, ethnic-racial self-recognition and skin color as factors of discrimination. Descriptive statistical tests and four adjusted logistic models were developed, controlling by the sex and the age of the individuals. The findings show that adults in households with better socioeconomic conditions have a better self-perception of health. Regarding ethnic-racial self-recognition, Afro-descendant, black, and mulatto adults have less good health perception than white-mestizo adults and face the worst socioeconomic conditions. In summary, skin color and ethnic and racial self-recognition categories, together with classic socioeconomic variables, are relevant to understand the health status self-perception of older adults as part of the processes of exclusion and discrimination that have consequences for health inequalities.
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