This review focusses on the interactions between the etiologic agent of Chagas disease, Trypanosoma cruzi, and its triatomine vector. The flagellate mainly colonizes the intestinal tract of the insect. The effect of triatomines on trypanosomes is indicated by susceptibility and refractoriness phenom...ena that vary according to the combination of the strains. Other effects are apparent in the different regions of the gut. In the stomach, the majority of ingested blood trypomastigotes are killed while the remaining transform to round stages. In the small intestine, these develop into epimastigotes, the main replicative stage. In the rectum, the population density is the highest and is where the infectious stage develops, the metacyclic trypomastigote. In all regions of the gut, starvation and feeding of the triatomine affect T. cruzi. In the small intestine and rectum, starvation reduces the population density and more spheromastigotes develop. In the rectum, feeding after short-term starvation induces metacyclogenesis and after long-term starvation the development of specific cells, containing several nuclei, kinetoplasts and flagella. When considering the effects of T. cruzi on triatomines, the flagellate seems to be of low pathogenicity. However, during stressful periods, which are normal in natural populations, effects occur often on the behaviour, eg, in readiness to approach the host, the period of time before defecation, dispersal and aggregation. In nymphs, the duration of the different instars and the mortality rates increase, but this seems to be induced by repeated infections or blood quality by the feeding on infected hosts. Starvation resistance is often reduced by infection. Longevity and reproduction of adults is reduced, but only after infection with some strains of T. cruzi. Only components of the surface coat of blood trypomastigotes induce an immune reaction. However, this seems to act against gut bacteria and favours the development of T. cruzi.
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26 March 2021
If you have already had COVID-19 do you still need both doses of the vaccine? Do these vaccines protect you against infection? Do they protect us against variants? WHO’s Dr Katherine O’Brien answers these questions in Science in 5 this week.
About six to seven million people worldwide, mostly in Latin America, are estimated to be infected with
Trypanosoma cruzi, the parasite that causes Chagas disease (WHO data from 2021). Chagas disease is
found mainly in endemic areas of 21 Latin American countries. Chagas disease was once entirely
...
confined to rural areas but in the last decades, due to population movements, most infected people live
in urban settings and the disease has spread to other continents. The burden of disease is due to its
chronic progression with people still suffering years later after initial infection.
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WHO Factsheet (French version). March 2016
The article discusses the significant impact of chronic obstructive pulmonary disease (COPD) as a global health issue, with cigarette smoking as the main risk factor. However, in developing countries, the causes of COPD are often multifactorial, involving environmental tobacco smoke, biomass fuel sm...oke, dust, fumes, childhood illnesses, and tuberculosis (TB). Up to half of COPD patients in these regions are non-smokers. The article emphasizes that while smoking is crucial, other risk factors contribute significantly to COPD, particularly in low- and middle-income countries. It highlights the need for targeted research and public health strategies to address these diverse contributors to COPD, especially in Africa.
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Every country has been affected by COVID-19, with nearly a quarter
of a billion cases and almost 5 million deaths reported globally as of
end of September 2021. Despite the stunning speed with which highly
effective and safe vaccines have been developed, new waves of disease
are still pushin...g health systems to the breaking point, increasingly
transmissible variants are emerging, some survivors are suffering
serious long-term sequelae, and the International Monetary Fund
estimates that global economic losses could exceed US$5.3 trillion
by 2026, if COVID-19 becomes endemic.
Although over 6 billion doses of COVID-19 vaccine have already been
administered, and global production is now reaching 1.5 billion doses
per month, the world is not positioned to end the pandemic. In areas of
high vaccine coverage, there have been massive reductions in serious
disease, hospitalization and death but, globally, vaccine access is highly
inequitable with coverage ranging from 1% to over 70%, depending
largely on a country’s wealth. Consequently, SARS CoV-2 variants
continue to emerge, causing surges of disease and slowing or even
reversing the reopening of societies and economies.
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Coronavirus disease (COVID-19) science conversation
In this video and audio series WHO experts explain the science related to COVID-19. This series is available every week on WHO's YouTube, Instagram, Facebook, Twitter, and LinkedIn channels and on all major podcasts platforms.
Download all epis...ode transcripts in Arabic, Chinese, English, French, Portuguese, Russian, Spanish, Hindi, Maithili, Nepali
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This document aims to describe a minimum set of surveillance activities recommended at the national level to detect and monitor the relative prevalence of SARS-CoV-2 variants and outline a set of activities for the characterization and assessment of risk posed by these variants. A set of indicators ...is also provided to standardize monitoring and public reporting of variant circulation.
The document is primarily intended for national and sub-national public health authorities and partners who support implementation of surveillance for SARS-CoV-2 variants
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Die Johanniter haben im Rahmen ihrer Aktivitäten im Bereich Flüchtlingshilfe und Integration allgemeine, niedrigschwellige Informationen zum Thema Corona-Impfung in verschiedenen Sprachen bereitgestellt. Diese dienen als Ergänzung zu den offiziellen Informationsmaterialien der Bundeszentrale für... gesundheitliche Aufklärung u.a. Die Informationsblätter wurden in Zusammenarbeit mit dem Ethno-medizinischen Zentrum e.V. Hannover übersetzt und werden bei Bedarf aktualisiert.
Die Informationsblätter sind in zahlreichen Sprachen verfügbar
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The guide explains how vaccines work and answers your common questions as well as providing up-to-date information on the current approved COVID-19 vaccinations in the UK.
This guide was written in January 2021 and updated in March 2021 and is accurate at the time of publishing. Information will b...e updated as it becomes available.
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Summary of the Ethopian country office of WHO on COVID-19 activities.
Since the World Health Organization (WHO) launched the Global Antimicrobial Resistance Surveillance System (GLASS) in 2015, there has been rapidly growing awareness among many African countries that they need to be doing more to combat antimicrobial resistance (AMR). The Africa Centres fo...r Disease Control and Prevention (CDC) was officially inaugurated in January 2017 and will support countries commencing surveillance for serious infectious disease threats in Africa, including resistance. Review of the recent WHO GLASS report suggests that, while certain nations do have some surveillance systems in place, very few countries in Africa currently conduct effective routine surveillance.
African Journal of Laboratory MedicineISSN: (Online) 2225-2010, (Print) 2225-2002
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Immunization is among the most successful and cost effective public health interventions in preventing a child from dying before celebrating his or her first birthday. It is a priority intervention within Uganda’s minimum health care package which directly contributes to the Ministry of Health vis...ion and goal. Accessed Febr. 23,2017
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Sepsis remains a leading cause of mortality and morbidity, especially during the first five days of life and in low and middle-income countries (LMIC) [1]. Hospital infection also remains a major cause of mortality in children despite progress encountered in the last decades.
Immunisation - the safest way to protect your child