Research and Reports in Tropical Medicine 2022:13 25–40
Chagas disease (CD) or American trypanosomiasis is a neglected parasitic disease associated with significant mortality and morbidity that includes long-term disability, social stigma and a mental health toll. Perceived as a disease of the ve...ry poor, this infection, once limited to rural areas of Latin America (LA), has now spread via migration to non-endemic areas and countries, where transmission is maintained via non-vectorial routes.
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In 2005, the World Health Organization (WHO) recognized Chagas disease (CD; Trypanosoma cruzi infection) as a neglected tropical disease (NTD) [1] and included it into the global plan to combat NTDs [2]. The Target 3.3 of the United Nations Sustainable Development Goals (UN/SDG) aims at ending the e...pidemics of NTDs by 2030 [3]. Mother-to-child (congenital/connatal) transmission is currently the main mode of transmission of T. cruzi over blood transfusions and organ transplantations in vector-free areas within and outside Latin America (LA). Based on recent demonstrations that congenital transmission can be prevented [4–7], WHO has shifted its objective, in 2018, from control to elimination of congenital CD (cCD).
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Trypanosoma cruzi is the etiological agent of Chagas disease (CD), considered one of the most important parasitic infections in Latin America. Between 25 and 90 million humans are at infection risk via at least one of multiple infection mechanisms. Under natural conditions, the principal transmissio...n modes are transplacental or via one of more than 140 hematophagous triatomine bugs (Reduviidae: Triatominae). Triatomines acquire the parasite from mammal reservoirs due to their obligate blood-feeding (albeit triatomines can also feed on non-reservoir vertebrates such as birds and reptiles). The disease burden for CD in the Latin America and Caribbean region, based on disability-adjusted life-years (DALYs), is at least five times greater than that of malaria, and is approximately one-fifth that of HIV/AIDS. In recent decades, CD has extended to other continents outside natural reservoir or vector distributions due to human migration, with a minimum estimated 10 million individuals infected worldwide.
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Epidemiology
Chagas disease (American trypanosomiasis) is caused by the protozoan parasite Trypanosoma cruzi, and transmitted to humans by infected triatomine bugs, and less commonly by transfusion, organ transplant, from mother to infant, and in rare instances, by ingestion of contaminated food or... drink.1-4 The hematophagous triatomine vectors defecate during or immediately after feeding on a person. The parasite is present in large numbers in the feces of infected bugs, and enters the human body through the bite wound, or through the intact conjunctiva or other mucous membrane.
Vector-borne transmission occurs only in the Americas, where an estimated 8 to 10 million people have Chagas disease.5 Historically, transmission occurred largely in rural areas in Latin America, where houses built of mud brick are vulnerable to colonization by the triatomine vectors.4 In such areas, Chagas disease usually is acquired in childhood. In the last several decades, successful vector control programs have substantially decreased transmission rates in much of Latin America, and large-scale migration has brought infected individuals to cities both within and outside of Latin America.
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Chagas disease (CD) is endemic in the Americas, being present in 21 countries, where it affects about 6 million
people.(1) With such relevant numbers of people affected and disability adjusted life years lost, CD is a poverty-related
and poverty-promoting disease.
Although data describe a relevan...t ongoing public health problem for the American continent, significant results
in the interruption of transmission has been achieved by coordinated multi-country programs. In particular, the
Southern Cone Initiative (SCI), officially formalised in November 1991 by the Ministers of Health of Argentina, Brazil, Bolivia, Chile, Paraguay and Uruguay, has shown how a well-designed control program can significantly reduce
CD transmission.(2) Before this initiative, in these countries, there were 11 million infected persons and 50 million at
risk, 62% of the infected individuals of the whole continent.
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Human schistosomiasis otherwise called bilharzia, is a fresh- water snail transmitted intravascular debilitating disease resulting from infection by the parasitic dimorphic Schistosoma trematode worms, which lives in the bloodstream of humans. The World Health Organization (WHO) regards the disease ...as a neglected tropical disease, with an estimated 732 million persons being vulnerable to infection worldwide in renowned transmission areas. Steinmann and co-workers documented that over 200 million individuals from Africa, Asia, and South America are infected with this disease. The WHO further estimated that schistosome infections and geohelminths accounts for over 40% of the world tropical disease burden with the exclusion of malaria. Humans get infected with this disease when they make contact with water contaminated with the skin-penetrating cercariae. Prevalence of schistosomiasis, at present, is still high in sub-Saharan Africa. In 2008, 17.5 million people were treated globally for schistosomiasis, 11.7 million of those from sub-Saharan Africa only. Approximately 120 million individuals in sub-Saharan Africa have schistosomiasis-related symptoms while about 20 million undergo hardship as a result of chronic presentations of the disease.
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Schistosomiasis is an acute and chronic parasitic disease caused by blood flukes (trematode worms) of the genus Schistosoma. Estimates show that at least 251.4 million people required preventive treatment in 2021. Preventive treatment, which should be repeated over a number of years, will reduce and... prevent morbidity. Schistosomiasis transmission has been reported from 78 countries. However, preventive chemotherapy for schistosomiasis, where people and communities are targeted for large-scale treatment, is only required in 51 endemic countries with moderate-to-high transmission.
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Leishmaniasis is a climate-sensitive disease. Changes in temperature, rainfall, and humidity can have strong impacts on
the sandfly vector, altering their distribution and influencing their survival and population sizes. Increased temperatures shorten vector development time, reduce Leishmania para...site incubation time, and increase vector biting rates, allowing transmission
in areas not previously endemic for the disease. Poor and
marginalized communities will be hit disproportionately harder by
the effects of climate change, and droughts, famines, and floods
can also lead to displacement and migration of immunologically
naive people to areas where leishmaniasis is endemic, posing a
threat of leishmaniasis outbreaks.
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During the year 2022, COVID-19 continued to be a significant challenge in Eritrea as in many other countries across the world. As COVID-19 devastated communities around the world, WHO worked with the MoH to strengthen the National and Sub-National health systems in order to meet community needs and ...mitigate the devastation during the pandemic and beyond.
One of the major achievements in the year 2022 was the beginning of the journey towards validation of
the elimination of mother to child transmission of HIV, syphilis, and hepatitis B. This is the culmination of years
of commitment and determination by the political leadership, national and international partnerships to
reduce the associated indices to levels that qualify for elimination.
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Over the past twenty years, huge efforts made by a broad coalition of stakeholders curbed the last epidemic and brought the disease to the brink of elimination. In this paper, the latest figures on disease occurrence, geographical distribution and control activities are presented. Strong evidence in...dicates that the elimination of sleeping sickness ‘as a public health problem’ by 2020 is well within reach. In particular, fewer than one thousand new cases were reported in 2018, and the area where the risk of infection is estimated as moderate, high or very high has shrunk to less than 200,000 km2. More than half of this area is in the Democratic Republic of the Congo. The interruption of transmission of the gambiense form, targeted by the World Health Organization (WHO) for 2030, will require renewed efforts to tackle a range of expected and unexpected challenges. The rhodesiense form of the disease represents a small part of the overall HAT burden. For this form, the problem of under detection is on the rise and, because of an important animal reservoir, the elimination of disease transmission is not envisioned at this stage.
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Human African trypanosomiasis (HAT) has been an alarming global public health issue. The disease affects mainly poor and marginalized people in low-resource settings and is caused by two subspecies of haemoflagellate parasite, Trypanosoma brucei and transmitted by tsetse flies. Progress made in HAT ...control during the past decade has prompted increasing global dialogue on its elimination and eradication. The disease is targeted by the World Health Organization (WHO) for elimination as a public health problem by 2020 and to terminate its transmission globally by 2030, along-side other Neglected Tropical Diseases (NTD). Several methods have been used to control tsetse flies and the disease transmitted by them. Old and new tools to control the disease are available with constraints.
Currently, there are no vaccines available. Efforts towards intervention to control the disease over the past decade have seen considerable progress and remarkable success with incidence dropping progressively, reversing the upward trend of reported cases. This gives credence in a real progress in its elimination. This study reviews various control measures, progress and a highlight of control issues, vector and parasite barriers that may have been hindering progress towards its elimination.
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Gambiense human African trypanosomiasis is a deadly infectious disease affecting West and Central Africa, South Sudan and Uganda, and transmitted between humans by tsetse flies. The disease has caused several major epidemics, the latest one in the 1990s. Thanks to recent innovations such as rapid di...agnostic tests for population screening, a single-dose oral treatment and a highly efficient vector control strategy, interruption of transmission of the causative parasite is now within reach. If indeed gHAT has an exclusively human reservoir, this could even result in eradication of the disease. Even if there were an animal reservoir, on the basis of epidemiological data, it plays a limited role. Maintaining adequate postelimination surveillance in known historic foci, using the newly developed tools, should be sufficient to prevent any future resurgence.
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La schistosomiase est une parasitose aiguë et chronique provoquée par des vers (trématodes) du genre Schistosoma. Selon les estimations, au moins 251,4 millions de personnes avaient besoin d’un traitement préventif en 2021. Le traitement préventif, qui devrait être renouvelé pendant un cert...ain nombre d’années, permettra de réduire et de prévenir la morbidité. La transmission de la schistosomiase est avérée dans 78 pays. Cependant, la chimioprophylaxie de la maladie, dont le but est de traiter à grande échelle les populations et les communautés, n’est nécessaire que dans 51 pays d’endémie où la transmission est de modérée à forte.
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Humans can become infected with T. saginata or T. asiatica when they consume infected beef meat or pig liver tissue, respectively, which has not been adequately cooked, but taeniasis due to T. saginata or T. asiatica has no major impact on human health. Therefore, this fact sheet refers to the trans...mission and health impacts of T. solium only.
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The WHO continuously reviews available data on SARS-CoV-2 variants of concern. For this version, the global epidemiological
situation of the COVID-19 pandemic as of 21 January 2022 – at a time when the Omicron VOC had been identified in 171
countries across all six WHO Regions and was rapidly re...placing Delta worldwide – was considered Omicron has a substantial growth advantage, higher secondary attack rates and a higher observed reproduction number than Delta.
There is now significant evidence that immune evasion contributes to the rapid spread of Omicron. Other factors may be a shorter
serial interval (by about 0.8 to 1.2 days compared to Delta) and potential increased intrinsic transmission fitness . There is
growing evidence that with Omicron, there is lower vaccine effectiveness (VE) against infection and symptomatic disease soon after vaccination compared to Delta. There is also evidence of accelerated waning of VE over time of the primary series against infection and symptomatic disease for the studied vaccines. Further studies are required to better understand the drivers of transmission and declining incidence in various settings. These factors include the intrinsic transmission fitness properties of the virus, degree of immune evasion, vaccination coverage and level of vaccine-derived and post-infection immunity, levels of social mixing and degree of application of public health and social measures (PHSM).
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Infections by the soil-transmitted helminths (STH), including Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale/Necator americanus (hookworms), and Strongyloides stercoralis, disproportionately affect children around the world. Because of their transmission associated with poor sanita...ry conditions and inadequate hygiene practices, higher burden of disease is seen in children from developing countries from sub-Saharan Africa, Southeast Asia, and Latin America. Approximately 267 million preschool-age children (PSAC) and 568 million school-age children (SAC) worldwide are at risk of STH infection as well as impaired child growth and cognitive development from A. lumbricoides, T. trichiura, and hookworm infections, and death due to severe S. stercoralis infection. Thus, their control is a global health priority.
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Human African trypanosomiasis (HAT) is a lethal neglected tropical disease (NTD) transmitted by the bite of infected tsetse flies. The disease is also known as “sleeping sickness”. During the 20th century it caused enormous suffering in the endemic areas in sub-Saharan Africa. HAT transmission l...ast soared in the late 1990s, triggering a renewed, coordinated and very successful control effort. In this paper, we present achievements towards HAT elimination, with a focus on the WHO road map targets for 2020. In particular, reported cases continue to decline, from over 30,000 cases per year at the turn of the century to 663 cases in 2020. Despite the impact of the COVID-19 pandemic, HAT surveillance was largely sustained, and the network of health facilities able to diagnose and treat the disease further expanded. Looking to the future, the World Health Organization (WHO) set bold new targets for HAT in its 2021–2030 road map for NTDs, namely: the elimination of transmission of gambiense HAT, which occurs in western and central Africa, and the elimination as a public health problem of rhodesiense HAT, which is found in eastern and southern Africa. The strong commitment of national health authorities and the international community will be essential if these goals are to be achieved.
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The new WHO recommendations for rabies immunization supersede the 2010 WHO position
on pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) for rabies. These updated
recommendations are based on new evidence and directed by public health needs that are cost-,
dose- and time-sparing..., while assuring safety and clinical effectiveness. In addition, new guidance on
prudent use of rabies immunoglobulins (RIG) is provided.
The following sections summarize the main points of the updated WHO position as endorsed by the
Strategic Advisory Group of Experts on immunization (SAGE) at its meeting in October 20171. The full
version of the WHO position on rabies vaccines and immunoglobulins will be published in the Weekly
Epidemiological Record2 in April 2018.
Rabies prevention involves two main strategies: (i) dog vaccination to interrupt virus transmission to
humans; and (ii) human vaccination as a series of vaccine administrations before or after an exposure.
Currently, rabies vaccines made from inactivated cell cultures are extremely well tolerated and have no
contraindications.
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Those who clean are the first line of defense against health care-associated infections (HAIs), and support efforts to reduce antimicrobial resistance (AMR).
Strengthening the training of this important group can contribute to resolving many of today’s public health challenges. This is importan...t given that cleaning both surfaces and hands is vital to control the transmission of a number of HAIs.
This two-part training package targets those who clean heath care facilities.
The Trainer’s Guide takes the user through how to prepare, deliver and sustain an effective training for those who clean. The Modules and Resources provides instructions, definitions, photographs, posters and specific illustrations of recommended practices
The package can be used by those who deliver environmental cleaning training programmes and/or those with a background in IPC including ministries of health, nongovernmental organizations, academic institutions, experts working in Quality of care, IPC and environmental cleaning/ Water, sanitation and Hygiene (WASH) and Health facility IPC focal points and onsite cleaning supervisors
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Rabies is a vaccine-preventable, zoonotic, viral disease affecting the central nervous system. Once clinical symptoms appear, rabies is virtually 100% fatal. In up to 99% of cases, domestic dogs are responsible for rabies virus transmission to humans. Yet, rabies can affect both domestic and wild an...imals. It spreads to people and animals via saliva, usually through bites, scratches or direct contact with mucosa (e.g. eyes, mouth or open wounds). Children between the age of 5 and 14 years are frequent victims.
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