Leishmaniasis is a vector-borne disease with a broad global distribution and an increasing number of recorded cases worldwide. However, it is still one of the world's most neglected diseases. Over the last decades, the disease has been found to expand geographically with a global increase of cases o...f visceral and cutaneous leishmaniasis increasing the public health problems associated with the disease epidemics. The reported range expansion of the diseases has been associated with range expansions of vector populations in response to climate change. Leishmaniasis is caused by protozoan parasites of the genus Leishmania. The transmission can either be zoonotic and/or anthroponotic through the bite of an infected female phlebotomine sandfly. In Eurasia and Africa, all vector-competent sandfly species belong to the genus Phlebotomus. Cutaneous leishmaniasis (CL) is the most common form of leishmaniasis. In the ‘old world’, it is caused by five currently recognized Leishmania species: L. major, L. tropica and L. aethiopica (being main causative parasites) as well as L. infantum and L. donovani. Visceral leishmaniasis (VL), another common and more severe form of leishmaniasis, is only associated with the Leishmania species L. infantum and L. donovani. The specific Leishmania species cause different clinical symptoms in humans.
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Each year 1–2 million people are diagnosed with a tropical disease called leishmaniasis, which is caused by single-celled parasites. People are infected when they are bitten by sandflies carrying the parasite, and often develop skin lesions around the bite site. Though mild cases may recover on th...eir own or with treatment, sometimes the parasites multiply and spread elsewhere causing further skin lesions and facial disfigurement. Furthermore, the parasites can also infect internal organs such as the spleen and the liver, which without treatment can be fatal.
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Buruli ulcer is a disease of skin and soft tissue with the potential to leave sufferers scarred and disabled. It is caused by an environmental pathogen, Mycobacterium
ulcerans, that produces a destructive toxin. The exact mode of transmission is unclear. The main burden of disease falls on childre...n living in sub-Saharan Africa, but healthy people of all ages, races, and socioeconomic classes are susceptible.
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Human rabies remains a significant public health problem in Africa with outbreaks reported in most countries. In Nigeria–the most populous country in Africa–rabies causes a significant public health burden partly due to perennial obstacles to implementing a national prevention and control progra...m.
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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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Leishmaniasis is a parasitic disease caused by intracellular protozoan parasites of the genus Leishmania (Trypanosomatidae family); it is endemic in more than 98 countries worldwide [1]. Visceral (VL) and cutaneous (CL) leishmaniasis are the most common forms of the disease. VL causes a systemic dis...ease characterised by fever, hepatosplenomegaly, anaemia and lymph node enlargement and may be fatal without appropriate treatment, while CL mainly causes skin ulcers and is considered a less severe form of the disease [2]. The incubation period for VL varies from 10 days up to nearly 3 years and for CL from 2 weeks to 3 years [3]. The natural route of transmission is a bite of blood-feeding phlebotomine sandflies; it may be zoonotic or anthroponotic, depending on the parasite species and the geographical location
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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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Chagas is a complex, multidimensional phenomenon in which political, economic, environmental, biomedical, epidemiological, psychological, and sociocultural factors intersect. Nonetheless, the hegemonic conceptualisation has long envisioned Chagas as primarily a biomedical question, while ignoring or... downplaying the other dimensions, and this limited view has reinforced the disease’s long neglect. Integrating the multiple dimensions of the problem into a coherent approach adapted to field realities and needs represents an immense challenge, but the payoff is more effective and sustainable experiences, with higher social awareness, increased case detection and follow-up, improved adherence to care, and integrated participation of various actors from multiple action levels. Information, Education, and Communication (IEC) initiatives have great potential for impact in the implementation of multidimensional programs of prevention and control successfully customised to the diverse and complex contexts where Chagas disease persists.
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