To eliminate lymphatic filariasis (LF) by 2020, the World Health Organization (WHO) has launched a campaign against the disease. Since the launch in 2000, significant progress has been made to achieve this ambitious goal. In this article we review the progress and status of the LF programme in Afric...a through the WHO neglected
tropical diseases preventive chemotherapy databank, the Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN) portal and other publications. In the African Region there are 35 countries endemic for LF. The Gambia was reclassified as not requiring preventive chemotherapy in 2015, while Togo and Malawi eliminated LF as a public health problem in 2017 and 2020, respectively. Cameroon discontinued mass drug administration (MDA) and transitioned to post-MDA surveillance to validate elimination. The trajectory of coverage continues to accelerate; treatment coverage increased from 0.1% in 2000 to 62.1% in 2018. Geographical coverage has also significantly increased, from 62.7% in 2015 to 78.5% in 2018. In 2019, 23 of 31 countries requiring MDA achieved 100% geographic coverage. Although much remains to be done, morbidity management and disability prevention services have steadily increased in recent years. Vector control interventions conducted by other programmes, particularly malaria vector control, have had a profound effect in stopping transmission in some endemic countries in the region. In conclusion, significant progress has been made in the LF programme
in the region while we identify the key remaining challenges in achieving an Africa free of LF.
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Better drug regimens for mass drug administration (MDA) could accelerate the Global Programme to Eliminate Lymphatic Filariasis (LF). This community study was designed to compare the safety and efficacy of MDA with IDA (ivermectin, diethylcarbamazine and albendazole) or DA (diethylcarbamazine and ...albendazole) in India.
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Rabies is a fatal viral zoonosis and serious public health problem.1 All mammals are believed to be susceptible to the disease, and for the purposes of this document, use of the term animal refers to mammals. The disease is an acute, progressive encephalitis caused by viruses in the genus Lyssavirus....
2 Rabies virus is the most important lyssavirus globally. In the
United States, multiple rabies virus variants are maintained in wild mammalian reservoir populations such as raccoons, skunks, foxes, and bats. Although the United States has been declared free from transmission of canine rabies virus variants, there is always a risk of reintroduction of these variants.The rabies virus is usually transmitted from animal to animal through bites. The incubation period is
highly variable. In domestic animals, it is generally 3 to 12 weeks, but can range from several days to months, exceeding 6 months.8 Rabies is communicable during the period of salivary shedding of rabies virus. Experimental and historic evidence documents that dogs, cats, and ferrets shed the virus for a few days prior to the onset of clinical signs and during illness. Clinical signs of rabies are variable and include inappetance, dysphagia, cranial nerve deficits, abnormal behavior, ataxia, paralysis, altered vocalization, and seizures. Progression to death is rapid. There are currently no known effective rabies antiviral drugs.
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Soil-transmitted helminths (STH) affect 1.45 billion people worldwide, and high intensity infections are associated with anemia, undernutrition and impaired cognition, particularly among children. Mathematical models suggest it may be possible to interrupt the transmission of STH in a community by e...xpanding mass drug administration (MDA) from targeted high-risk groups (primarily school-aged children and women of child-bearing age) to all community members with high coverage. The DeWorm3 Project will test the feasibility of this approach to interrupting the transmission of STH using a series of cluster randomized trials in Benin, India and Malawi. Each study area (population 80,000) will be divided into 40 clusters and randomized to community-wide or standard-of-care targeted MDA for three years. Two years following the final round of MDA, prevalence of STH will be compared between arms and transmission interruption assessed in each cluster. The DeWorm3 trials will provide stakeholders with information regarding the potential to switch from STH control to a more ambitious and sustainable strategy.
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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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Over 6 million people worldwide are infected with Trypanosoma cruzi, the protozoan that causes Chagas disease
(CD). T. cruzi is transmitted by triatomine insects, congenitally, through uncontrolled blood donations and organ transplants,
and via consumption of food or drink contaminated by triatomi...nes.
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Several Public Health Services and general practitioners in the Netherlands observed an increase in scabies in the Netherlands. Since individual cases of scabies are not notifiable in the Netherlands, the epidemiological situation is mostly unknown. To investigate the scabies incidence in the Nether...lands, we described the epidemiology of scabies between 2011 and 2021.
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Yaws is a non-venereal endemic treponemal infection caused by Treponema pallidum sub-species pertenue, a bacterium closely related to Treponema pallidum ssp. pallidum, the agent of venereal syphilis. Yaws predominantly affects children living in tropical regions of the world. It causes lesions of th...e skin, mucous membranes and bones which, without treatment, can become chronic and destructive. There is no widely available test to distinguish yaws from syphilis. Thus, migration of people from yaws-endemic areas to developed countries may present clinicians with diagnostic dilemmas. The other endemic treponemal infections are bejel (endemic syphilis) caused by Treponema pallidum ssp. endemicum and pinta caused by Treponema carateum.
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Female Genital Schistosomiasis (FGS) is a gynaecological disease caused by Schistosoma haematobium, a parasitic worm that is acquired by skin contact with freshwater contaminated by schistosome cerceriae. Communities in which the infection is most endemic have limited access to clean water and healt...hcare services. Up to 150 million adolescent girls and women are estimated to be at risk of FGS and about 16–56 milion womens are living with FGS, with the majority of these in sub-Saharan Africa. The variability of these estimates points to the fact that this neglected tropical disease is not well studied and frequently not prioritized by local, regional, and global health policy makers.
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Schistosomiasis is a helminthic infection and one of the neglected tropical diseases (NTDs). It is caused by blood flukes of the genus Schistosoma. It is an important public health problem, particularly in poverty-stricken areas, especially those within the tropics and subtropics. It is estimated th...at at least 236 million people worldwide are infected, 90% of them in sub-Saharan Africa, and that this disease causes approximately 300,000 deaths annually. The clinical manifestations are varied and affect practically all organs. There are substantial differences in the clinical presentation, depending on the phase and clinical form of schistosomiasis in which it occurs. Schistosomiasis can remain undiagnosed for a long period of time, with secondary clinical lesion. Here, we review the clinical profile of schistosomiasis. This information may aid in the development of more efficacious treatments and improved disease prognosis.
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Schistosomiasis is an infectious disease caused by helminth parasites of the genus Schistosoma. Worldwide, an estimated 250 million people are infected with these parasites with the majority of cases occurring in sub-Saharan Africa. Within Asia, three species of Schistosoma cause disease. Schistosom...a japonicum is the most prevalent, followed by S. mekongi and S. malayensis. All three species are zoonotic, which causes concern for their control, as successful elimination not only requires management of the human definitive host, but also the animal reservoir hosts. With regard to Asian schistosomiasis, most of the published research has focused on S. japonicum with comparatively little attention paid to S. mekongi and even less focus on S. malayensis. In this review, we examine the three Asian schistosomes and their current status in their endemic countries: Cambodia, Lao People’s Democratic Republic, Myanmar, and Thailand (S. mekongi); Malaysia (S. malayensis); and Indonesia, People’s Republic of China, and the Philippines (S. japonicum). Prospects for control that could potentially lead to elimination are highlighted as these can inform researchers and disease control managers in other schistosomiasis-endemic areas, particularly in Africa and the Americas.
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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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For the molecular diagnosis of Chagas disease by real-time PCR (polymerase chain reaction), optimization of diagnostic accuracy is desirable. The detection limit of real-time PCR assays for the diagnosis of Trypanosoma cruzi in human serum is affected by various influences including the choice of th...e nucleic acid extraction assay. In this study, three nucleic acid extraction assays were compared regarding their influence on the sensitivity of a T. cruzi-specific real-time PCR with 62 reference sera containing T. cruzi target DNA (deoxyribonucleotide acid). More than 95% of the positive sera were correctly identified after all three nucleic acid extraction strategies with a detection rate ranging from 96.8% (60/62) for the worst assay to 100% (62/62) for the best one. A matched pairs analysis for the comparison of the cycle threshold (Ct) values obtained with the 59 reference samples with positive real-time PCR results after all three nucleic acid extraction schemes indicated differences in a range of about 3 Ct steps. Summarized, all three compared nucleic acid extraction schemes were basically suitable for T. cruzi-specific PCR from serum with some minor differences. However, in the case of low quantities of circulating parasite DNA in the serum of a patient with Chagas disease, even minor effects can make a difference in the individual diagnosis.
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The protozoan parasite Trypanosoma cruzi causes Chagas disease, an important public health problem throughout Latin America. Current therapeutic options are characterised by limited efficacy, long treatment regimens and frequent toxic side-effects. Advances in this area have been compromised by gaps... in our knowledge of disease pathogenesis, parasite biology and drug activity. Nevertheless, several factors have come together to create a more optimistic scenario. Drug-based research has become more systematic, with increased collaborations between the academic and commercial sectors, often within the framework of not-for-profit consortia. High-throughput screening of compound libraries is being widely applied, and new technical advances are helping to streamline the drug development pipeline. In addition, drug repurposing and optimisation of current treatment regimens, informed by laboratory research, are providing a basis for new clinical trials. Here, we will provide an overview of the current status of Chagas disease drug development, highlight those areas where progress can be expected, and describe how fundamental research is helping to underpin the process.
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This was a Phase 3, multi-center, randomized, open-label, parallel-group, active control study where 273 male and female patients with first stage Trypanosoma brucei gambiense HAT were treated at six sites: one trypanosomiasis reference center in Angola, one hospital in South Sudan, and four hospita...ls in the Democratic Republic of the Congo between August 2005 and September 2009 to support the registration of pafuramidine for treatment of first stage HAT in collaboration with the United States Food and Drug Administration. Patients were treated with either 100 mg of pafuramidine orally twice a day for 10 days or 4 mg/kg pentamidine intramuscularly once daily for 7 days to assess the efficacy and safety of pafuramidine versus pentamidine. Pregnant and lactating women as well as adolescents were included.
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The sub-Saharan African region, carries 90% of the over 250 million cases of schistosomiasis occurring worldwide. In this region, after Nigeria, Tanzania is second country having the highest cases of schistosomiasis and approximately 51.5%0 of the Tanzanian population is either exposed or live in ar...eas with high risk of exposure. The country is endemic to both Schistosoma mansoni and Schistosoma haematobium, these infections are common in communities characterised with limited access to water, sanitation, hygienic practices and health services. Schistosoma mansoni infection is associated with hepatosplenic disease characterised with hepatomegaly, splenomegaly, progressive periportal fibrosis (PPF) which can lead to portal hypertension and its related sequelae, mainly ascites, liver surface irregularities, oesophageal varices and haematemesis. The main consequences of S. haematobium infection are haematuria, dysuria, nutritional deficiencies, urinary bladder lesions, hydronephrosis, urinary bladder squamous cell carcinoma and in children, growth retardation. Preventive chemotherapy using mass drug administration (MDA) of praziquantel targeting primary school aged children is the main strategy for controlling schistosomiasis in Tanzania.
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Urogenital schistosomiasis is a common neglected tropical disease in many rural communities in African countries, with patches of infection in the Eastern Mediterranean Region. Globally, an estimated 239 million people are currently infected, with burden estimated at more than 3.5 million disability...-adjusted life years (DALYs). In many endemic areas, severely infected individuals may suffer fibrosis of the bladder, kidney damage, bladder cancer, and death if untreated. This, however, depends on several factors such as host-parasite genetics, degree and length of exposure, intensity of infection, host immune response to the parasites, and coinfections with other tropical diseases such as malaria and HIV-1.
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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, commonly known as bilharzia, is an acute and chronic tropical disease caused by trematodes of the genus Schistosoma. The schistosome parasite is transmitted through a snail intermediate host with the human being the definitive host. Worldwide, schistosomiasis continues to cause a pu...blic health problem with 779 million people exposed to the infection. The disease is present in 78 countries and endemic in 52 of those countries where an estimated 90% of people need treatment. Schistosomiasis has been successfully controlled in many countries but its burden remains high in Africa, particularly in sub-Saharan countries.
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