Background: The human helminth infections include ascariasis, trichuriasis, hookworm infections, schistosomiasis, lymphatic filariasis (LF) and onchocerciasis. It is estimated that almost 2 billion people worldwide are infected with helminths. Whilst the WHO treatment guidelines for helminth infecti...ons are mostly aimed at controlling morbidity, there has been a recent shift with some countries moving towards goals of disease elimination through mass drug administration, especially for LF and onchocerciasis. However, as prevalence is driven lower, treating entire populations may no longer be the most efficient or cost-effective strategy. Instead, it may be beneficial to identify individuals or demographic groups who are persistently infected, often termed as being “predisposed” to infection, and target treatment at them.
Methods: The authors searched Embase, MEDLINE, Global Health, and Web of Science for all English language, humanbased papers investigating predisposition to helminth infections published up to October 31st, 2017. The varying definitions used to describe predisposition, and the statistical tests used to determine its presence, are summarised. Evidence for predisposition is presented, stratified by helminth species, and risk factors for predisposition to infection are identified and discussed.
Results: In total, 43 papers were identified, summarising results from 34 different studies in 23 countries. Consistent evidence of predisposition to infection with certain species of human helminth was identified. Children were regularly found to experience greater predisposition to Ascaris lumbricoides, Schistosoma mansoni and S. haematobium than adults. Females were found to be more predisposed to A. lumbricoides infection than were males. Household clustering of infection was identified for A. lumbricoides, T. trichiura and S. japonicum. Ascaris lumbricoides and T. trichiura also showed evidence of familial predisposition. Whilst strong evidence for predisposition to hookworm infection was identified, findings with regards to which groups were affected were considerably more varied than for other helminth species.
Conclusion: This review has found consistent evidence of predisposition to heavy (and light) infection for certain human helminth species. However, further research is needed to identify reasons for the reported differences between demographic groups. Molecular epidemiological methods associated with whole genome sequencing to determine ‘who infects whom’ may shed more light on the factors generating predisposition.
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El documento proporciona información básica sobre la malaria (paludismo), una enfermedad grave causada por un parásito que se transmite a través de la picadura de ciertos mosquitos, describe sus síntomas principales, cómo se diagnostica y trata, y ofrece recomendaciones de prevención, especia...lmente para quienes viajan a zonas donde la enfermedad es común.
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La enfermedad de Chagas, también conocida como tripanosomiasis americana, es causada por el parásito Trypanosoma cruzi. La forma más común de contraer la infección es a través del contacto con las heces de un insecto triatominio (conocido con los nombres de chinche besucona, benchuca, vinchuca..., chipo o barbeiro), el cual se alimenta de la sangre de seres humanos y animales.
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Mass population movements have accounted for the emergence of Chagas disease (CD) outside endemic regions,
including the European Union/European Economic Area (EU/EEA). The parasite responsible for causing CD,
Trypanosoma cruzi (T. cruzi), can be transmitted through substances of human origin (SoH...O), such as blood
transfusions and organ transplantations [1], posing a risk to the recipients. This, together with congenital
transmission, is of increasing concern in non-endemic countries
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As of 14 December 2021, a total of 19 laboratory-confirmed human rabies cases has been reported in South Africa for 2021. The cases are from Eastern Cape, KwaZuluNatal and Limpopo provinces. In addition, four probable rabies cases were reported from KwaZulu-Natal and the Eastern Cape provinces. A pr...obable case of rabies is defined as a person who has had a history of contact with a suspected or confirmed rabid animal and has developed an acute encephalitis with hyperactivity and paralytic signs and symptoms that progressed and resulted in death, usually by cardiac or respiratory failure, typically within ten days.
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Antimicrobials are medicines, including antibiotics, antivirals, antifungals, and antiparasitics, that are used to prevent and treat infections in humans, animals, and plants. Antimicrobial Resistance (AMR) arises when bacteria, viruses, fungi, and parasites no longer respond to these medicines, ren...dering them ineffective and making infections more difficult to treat. This resistance increases the risk of disease spread, severe illness, disability, and death. Although AMR is a natural phenomenon driven by genetic
changes in pathogens, it is significantly accelerated by human activities such as the misuse and overuse of antimicrobials in healthcare, agriculture, and animal husbandry.
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A parasitic disease caused by the larval stage of tapeworms in the Echinococcus.
The disease often starts without symptoms and this may last for years. The symptoms depend on the cyst's location and size.
Alveolar disease usually begins in the liver, but can spread to other parts of the body, such... as the lungs or brain.
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Schistosomiasis is a parasitic disease caused by infection with
Schistosoma trematodes. The disease affects poor rural communities
but has spread to urban areas and to tourists visiting endemic areas
Leishmaniasis is a parasitic disease caused by the Leishmania parasite. This parasite typically lives in infected sand flies. You can contract leishmaniasis from a bite of an infected sand fly.
The sand flies that carry the parasite typically reside in tropical and subtropical environments. Fatal... epidemics have occurred in areas of Asia, East Africa, and South America.
Affected regions are often remote and unstable, with limited resources for treating this disease. Doctors Without Borders calls leishmaniasis one of the most dangerous neglected tropical diseases. The organization also states this disease is second only to malaria in parasitic causes of death.
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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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Leishmaniasis is a vector-borne disease with a wide variety of parasite species, reservoirs, and vectors involved in transmission. It is caused by different species of the protozoa Leishmania and is transmitted to animals and humans through a bite of insects in the Psychodidae family. Its presence i...s directly linked to poverty, but social, environmental, and climatalogic factors directly influence the disease's epidemiology.
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Human strongyloidiasis is a chronic parasitic disease caused by infection with Strongyloides stercoralis, a soil-transmitted helminth that is estimated to infect 300–600 million people worldwide. This neglected tropical disease (NTD) is endemic globally, predominately in the South-East Asia, Afric...an and Western Pacific regions, and in South and Central America. Strongyloidiasis has a wide range of clinical presentations, including subclinical disease, symptomatic disease (often with diarrhoea, abdominal pain and urticaria) and a rare but deadly complication of hyperinfection with disseminated disease. The feared complication of disseminated strongyloidiasis can occur in the setting of immunocompromising conditions (e.g. human T-cell lymphotropic virus type 1 infection and malignancies) or immunosuppressive medications (e.g. steroids) and has an estimated case-fatality rate exceeding 60%. The standard treatment for chronic S. stercoralis infection is oral medication with ivermectin.
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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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Schistosomiasis is an acute and chronic parasitic disease caused by blood flukes (trematode
worms) of the genus Schistosoma. At least 249 million people required preventive treatment in
2012. Preventive treatment, which should be repeated over a number of years, will reduce and
prevent morbidity.
Cutaneous leishmaniasis (CL) is a parasitic disease caused by infection with a vector-borne protozoan parasite of the genus Leishmania spp. The parasite is transmitted by the bite of an infected phlebotomine sand fly. Infection results in skin lesions which take a long time to heal and may leave per...manent, disfiguring scars (de Vries et al. 2015). CL is classified as a neglected tropical disease (NTD), and in common with several other NTDs, is associated with psychosocial effects including stigma, social exclusion, and declining mental health (Bailey et al. 2019; Bennis et al. 2018; Wenning et al. 2022). Emerging evidence suggests that people with CL are at a higher risk of experiencing anxiety, depression, decreased body satisfaction, loss of social status, and lower quality of life (Bennis et al. 2018; Yanik et al. 2004). The global mean age-standardised disability-adjusted life years (DALYs) lost by CL was 0.58 per 100,000 people (Karimkhani et al. 2016). Notably, this statistic only considers the physical effects of the lesions and does not account for the potentially considerable psychological and social effects of CL (Bailey et al. 2017; Bailey et al. 2019; Wenning et al. 2022).
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Onchocerciasis – or “river blindness” – is a parasitic disease caused by the filarial worm
Onchocerca volvulus. It is transmitted through the bites of infected blackflies (Simulium spp.) that
breed in fast-flowing rivers and streams, mostly in remote villages located near fertile land wher...e
people rely on agriculture.
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Schistosomiasis is a tropical disease caused by a group of parasitic worms. It has an interesting life-cycle involving freshwater snails and can cause short term and long term disease. Schistosomiasis is classified as a neglected tropical disease and affects some of the poorest countries in the worl...d.
This video takes a look at the parasites, the disease that it causes and control methods.
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Dracunculiasis (Guinea worm disease), caused by the parasite Dracunculus medinensis, is traditionally acquired by drinking water containing copepods (water fleas) infected with D. medinensis larvae, but in recent years also appears increasingly to be transmitted by eating fish or other aquatic anima...ls. The worm typically emerges through the skin on a lower limb of the host 1 year after infection, causing pain and disability.
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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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Leishmaniasis is an infectious disease caused by protozoan parasites of the genus, Leishmania. Protozoa are microscopic, single-celled organisms. The parasites that cause the disease are transmitted to people through the bites of certain species of infected sand flies.