Diphtheria is caused by Corynebacterium species, mostly by toxin-producing Corynebacterium diphtheriae and rarely by toxin-producing strains of C. ulcerans and C. pseudotuberculosis. The most common type of diphtheria is classic respiratory diphtheria, whereby the exotoxin produced characteristicall...y causes the formation of a pseudomembrane in the upper respiratory tract and damages other organs, usually the myocardium and peripheral nerves. Acute respiratory obstruction, acute systemic toxicity, myocarditis and neurologic complications are the usual causes of death. The infection can also affect the skin (cutaneous diphtheria). More rarely, it can affect mucous membranes at other non-respiratory sites, such as genitalia and conjunctiva.
C. diphtheriae is transmitted from person to person by intimate respiratory and direct contact; in contrast, C. ulcerans and C. pseudotuberculosis are zoonotic infections, not transmitted person-to-person. The incubation period of C. diphtheriae is two to five days (range 1– 10 days). A person is infectious as long as virulent bacteria are present in respiratory secretions, usually two weeks without antibiotics, and seldom more than six weeks. In rare cases, chronic carriers may shed organisms for six months or more. Skin lesions are often chronic and infectious for longer periods. Effective antibiotic therapy (penicillin or erythromycin) promptly terminates shedding in about one or two days.
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The aim of the people-centred framework is to help countries to develop fully prioritized and budgeted NSPs based on a culture of making full use of the available data, which are aligned with national planning cycles and which provide the basis for a robust national response that can accelerate prog...ress towards the goal of ending TB. In addition, applying the framework for other possible applications according to the country’s planning and policy cycle encourages the culture of data utilization and evidence translation into decision making and planning.
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Version 1: March 9, 2021. A living document
Scientific brief
8 April 2020
PLoS Medicine Vol. 6 no. 10 (2009) e1000165
Weekly Epidemiological Record. This report summarizes application of the SAFE strategy against trachoma during 2023. It includes estimates of the global population at risk of trachoma blindness based on district-by-district data submitted to WHO by national programmes. Summarizing the epidemiologica...l situation in this way is inherently complex because, for any district, up to 3 serial estimates of prevalence may be valid at different times during a calendar year.
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A new respiratory infectious disease, COVID-19, caused by a new coronavirus called SARS-CoV-2, emerged in early December 2019. Since then, the virus has spread to India and 106 other countries in Asia, Europe, North America, Africa, and Oceania. On March 11, the World Health Organization (WHO) decl...ared the outbreak a pandemic, which has since rapidly evolved. As an economic hub with substantial global connectivity and movement of people and goods, India is directly impacted by the COVID-19 pandemic. Although it is too early to gauge the full spectrum of the outbreak’s social and economic impacts, COVID-19 has already caused lockdowns in China, Korea, and in many countries in Europe, and in some states of India, suspension of schools and universities, disruption of food systems and other supply chains, as well as a slowdown in trade between India and rest of the world.
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A regional consultation report and draft transition framework