The WHO COVID-19 LENS (Living Evidence Synthesis) working group consolidated available evidence, based on rapid reviews of the literature and results of a living systematic review on pregnancy and COVID-19 (up to October 7, 2020), on potential mechanisms of vertical transmission of infectious pathog...ens, feasibility of vertical transmission of SARS-CoV-2, data related to interpretation of positive SARS-CoV-2 virologic and serologic neonatal tests, lessons from diagnosis of other congenital infections, and existing proposed definitions to classify timing of vertical transmission of SARS-CoV-2.
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This is a case-ascertained prospective investigation of all identified health care contacts working in a health care facility in which a laboratory confirmed 2019-nCoV infected patient (see 2.2 Study population) receives care. Note that this study can be done in health care facilities at all 3 level...s of a health system – not just in hospitals. It is intended to provide epidemiological and serologic information which will inform the identification of risk factors 2019-nCoV infection among health care workers.
There are three primary objectives of this investigation among health care workers in a health care setting where a 2019-nCoV infected patient is being cared for:
To better understand the extent of human-to-human transmission among health care workers, by estimating the secondary infection rate1 for health care worker contacts at an individual level.
To characterize the range of clinical presentation of infection and the risk factors for infection among health care workers.
To evaluate effectiveness of infection prevention and control measures among health care workers
To evaluate effectiveness of infection prevention and control programmes at health facility and national level
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The household transmission investigation is a case-ascertained prospective study of all identified household contacts of a laboratory confirmed 2019-nCoV infection (see 2.2 Study population). It is intended to provide rapid and early information on the clinical, epidemiological and virological chara...cteristics of 2019-nCoV.
There are three primary objectives of this household transmission study:
To better understand the extent of transmission within a household by estimating the secondary infection rate for household contacts at an individual level, and factors associated with any variation in the secondary infection risk.
To characterize secondary cases including the range of clinical presentation, risk factors for infection, and the extent and fraction of asymptomatic infections.
To characterize serologic response following confirmed 2019-nCoV infection (highly encouraged, but optional depending on laboratory capacity and resources)
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La serovigilancia es una herramienta que complementa los métodos tradicionales de salud pública para la vigilancia de las enfermedades transmisibles y proporciona información valiosa sobre la transmisión de enfermedades en los grupos de la población; por ejemplo, para detectar brechas en la inm...unidad frente a las enfermedades prevenibles mediante vacunación. Esta información es útil para hacer un seguimiento de la exposición de la población a enfermedades como la malaria, las enfermedades infecciosas desatendidas, las enfermedades transmitidas por alimentos, agua y vectores, así como las enfermedades infecciosas emergentes. Como muchas enfermedades infecciosas están o han estado presentes en grupos que viven en entornos donde se superponen diversos factores de riesgo, la serovigilancia integrada facilita las sinergias y optimiza la utilización de los recursos de salud pública. Este conjunto de herramientas se elaboró para facilitar el diseño, la puesta en marcha, el análisis, la interpretación y el uso de los resultados de las encuestas serológicas integradas para reforzar las capacidades de los países con vistas a la eliminación de las enfermedades transmisibles. En la primera parte se describen los conceptos básicos sobre encuestas y vigilancia serológicas, sus usos, ventajas y desafíos, formas de mejorar su eficiencia, así como su potencial para contribuir a la toma de decisiones de salud pública. Posteriormente, se presenta un proceso gradual para la puesta en marcha de la vigilancia serológica integrada basada en encuestas serológicas. Incluye recomendaciones sobre cómo determinar la necesidad y el propósito de recopilar información serológica; el diseño y la metodología de la encuesta; los métodos del laboratorio; las consideraciones prácticas para la realización de encuestas; el análisis e interpretación de los datos y el uso de los resultados para respaldar la toma de decisiones. Su objetivo principal es apoyar a los directores de programas y equipos que participan en el control y eliminación de las enfermedades transmisibles. Se elaboró para ser usado, entre otros, por los coordinadores de enfermedades transmisibles, enfermedades infecciosas desatendidas y programas de vacunación; directores de vigilancia epidemiológica; personal de laboratorios de salud pública; y otros profesionales de los ministerios de salud y autoridades nacionales y subnacionales de salud que puedan estar interesados en incorporar la vigilancia serológica integrada como parte de las herramientas de sus sistemas de vigilancia, para obtener información adicional sobre la transmisión de enfermedades infecciosas en la población.
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HAT diagnosis relies on laboratory techniques because clinical signs and symptoms are unspecific. Serodiagnostic tests exist only for Tbg and are based on the detection of specific antibodies, thus they are not confirmatory of infection. With the current low disease prevalence, the positive predicti...ve value of serological tests is particularly low. Field-applicable tools include the card agglutination test for trypanosomiasis (CATT) used mainly in active screening by specialized mobile teams, and the rapid diagnostic tests that are more suitable for individual testing at point-of-care. Confirmation of Tbg infection requires microscopic examination of body fluids necessitating specific training. The best performing methods are laborious and reach 85–95% diagnostic sensitivity when performed by skilled personnel.
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HAT diagnosis relies on laboratory techniques because clinical signs and symptoms are unspecific. Serodiagnostic tests exist only for Tbg and are based on the detection of specific antibodies, thus they are not confirmatory of infection. With the current low disease prevalence, the positive predicti...ve value of serological tests is particularly low. Field-applicable tools include the card agglutination test for trypanosomiasis (CATT) used mainly in active screening by specialized mobile teams, and the rapid diagnostic tests that are more suitable for individual testing at point-of-care.
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Dengue is a significant public health problem. There are four dengue virus serotypes identified; however, its diagnosis is difficult due to the existence of many viruses, bacteria, and parasites producing the same clinical presentation, being present in the same geographical area and even producing ...coinfections. Therefore, determining whether a person has, had, or is infected with dengue virus is of great importance. In order to do so, direct and indirect laboratory tests have been developed to identify the virus or part of its structure that generally detects the antibody response. These techniques are used for diagnosis, epidemiological studies, monitoring, assessment and production of vaccines and antivirals, etc. They range from the use of cell cultures, animal models, inoculation by insects, and serology tests to the use of detection molecular tests and quantification of genetic material that are described in this chapter herein, a brief explanation of this methodology, its strengths and weaknesses, and its application in the dengue research.
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Microorganisms . 2022 Jul 14;10(7):1427.
Chagas disease (CD) is endemic in about 21 countries of the Americas. The disease has spread to recently Chagas-free regions, mainly due to migration, and can now also be diagnosed in countries such as the USA, Canada, many European and some African, eastern... Mediterranean and western Pacific countries. About 6 million people are infected and 70 million live with a daily risk of infection. Although many efforts have been made to control the disease, and some improvements were achieved, still, less than about 1% of the infected have access to diagnosis and treatment. This causes high morbidity and mortality rates with more than 12,000 deaths per year
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This algorithm is addressed to laboratories
with established capacity(molecular, antigenic and/orserological) to detect dengue (DENV), Zika (ZIKV), and chikungunya(CHIKV) as part of the differential diagnosis for arborviruses. A BSL2 containment level is required to handle suspected samples.
When is laboratory testing for Zika Virus infection reasonable? Testing algorithm for patients with and without symptoms.
Testing Guidance and Interpretation of Results for Healthcare providers
Testing Guidance and Interpretation of Results for Healthcare Providers Dengue and Zika Virus
Für wen ist eine Laboruntersuchung auf eine Zika Virus-Infektion sinnvoll? Diagnostisches Vorgehen bei Patienten mit und ohne Symptomen
Научная справка
24 апреля 2020 г.
При инфицировании в естественных условиях выработка иммунитета к патогенному микроорганизму проходит в несколько этапов и заним...ет от 1 до 2 недель. При вирусной инфекции врожденный иммунитет обеспечивает немедленную реакцию организма, которая заключается в активации неспецифического иммунного ответа, приводящего к замедлению инфекционного процесса макрофагами, нейтрофилами и дендритными клетками, и которая в ряде случаев обусловливает бессимптомное течение инфекции. Затем происходит активация адаптивного иммунного ответа, при котором в организме начинается выработка специфических антител, способных к связыванию с вирусными частицами. Данные антитела являются белками и носят название иммуноглобулинов. Кроме того, в организме образуются Т-клетки, способные распознавать и уничтожать другие клетки, пораженные вирусом. Это звено иммунитета носит название клеточного. Функционирование нескольких звеньев иммунитета при адаптивном ответе может способствовать элиминации вируса из организма, а при достаточной активности реакции – препятствовать переходу заболевания в тяжелую форму и повторному заражению той же инфекцией. Количественной мерой данного процесса является уровень антител в крови.
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Научная справка
8 апреля 2020 г.
В ответ на растущую пандемию COVID-19 и нехватку ресурсов и реагентов для молекулярного тестирования, многие производители диагностич...ских тестов разработали и начали продавать простые в использовании экспресс-системы, позволяющие выполнять тестирование вне лабораторий. Эти простые тестовые наборы основаны либо на обнаружении белков вируса COVID-19 в респираторных образцах (например, мокроте, мазке из зева), либо на обнаружении в крови или сыворотке человека антител, образующихся в ответ на инфекцию.
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The Lancet Regional Health - Americas 2024;36: 100821 https://doi.org/10.1016/j.lana.2024.100821