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Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
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A goal of community base efforts is to eliminate microfilariae from the blood of infected individuals in order to prevent transmission to the mosquito. This is primarily accomplished through the use of drugs. The treatment for "B. malayi" infection is the same as for bancroftian filariasis. Diethylcarbamazine (DEC) has been used in mass treatment programs in the form of DEC-medicated salt, as an effective microfilaricidal drug in several locations, including India. While DEC tends to cause adverse reactions like immediate fever and weakness, it is not known to cause any long-term adverse drug effects. DEC has been shown to kill both adult worms and microfilariae. In Malaysia, DEC dosages (6 mg/kg weekly for 6 weeks; 6 mg/kg daily for 9 days) reduced microfilariae by 80% for 18–24 months after treatment in the absence of mosquito control. Microfilariae numbers slowly return many months after treatment, thus requiring multiple drug doses over time in order to achieve long-term control. However, it is not known how many years of mass drug administration is required to eliminate transmission. But currently, there have been no confirmed cases of DEC resistance.
Single doses of two drugs (albendazole-DEC and albendazole-ivermectin) have been shown to remove 99% of microfilariae for a year after treatment and help to improve elephantiasis during early stages of the disease. Ivermectin does not appear to kill adult worms but serves as a less toxic microfilaricide.
Since the discovery of the importance of "Wolbachia" bacteria in the life cycle of "B. malayi" and other nematodes, novel drug efforts have targeted the endobacterium. Tetracyclines, rifampicin, and chloramphenicol have been effective in vitro by interfering with larvae molting and microfilariae development. Tetracyclines have been shown to cause reproductive and embryogenesis abnormalities in the adult worms, resulting in worm sterility. Clinical trials have demonstrated the successful reduction of "Wolbachia" and microfilariae in onchocerciasis and "W. bancrofti" infected patients. These antibiotics, while acting through a slightly more indirect route, are promising antifilarial drugs.
In 2015 William C. Campbell and Satoshi Ōmura were Co-awarded half of that year's Nobel prize in Physiology or Medicine for the discovery of the drug avermectin, which, in the further developed form ivermectin, has decreased the occurrence of lymphatic filariasis.
Filarial diseases in humans offer prospects for elimination by means of vermicidal treatment. If the human link in the chain of infection can be broken, then notionally the disease could be wiped out in a season. In practice it is not quite so simple, and there are complications in that multiple species overlap in certain regions and double infections are common. This creates difficulties for routine mass treatment because people with onchocerciasis in particular react badly to treatment for lymphatic filariasis.
Secondary bacterial infection is often observed with lymphatic filariasis. Rigorous hygiene practices, including washing with soap and water daily and disinfecting wounds can help heal infected surfaces, and slow and potentially reverse existing tissue damage. Promoting hygiene is essential for lymphatic filariasis patients given the compromised immune and damaged lymphatic systems and can help prevent suffering and disability.
The WHO is coordinating an effort to eradicate filariasis. The mainstay of this programme is the mass use of antifilarial drugs on a regular basis for at least five years.
In April 2011, Sri Lanka was certified by the WHO as having eradicated this disease.
Anthelmintics such as diethylcarbamazine and albendazole have shown promise in the treatment of "Brugia timori" filariasis. Some researchers are confident that "Brugia timori" filariasis may be an eradicable disease. Related filarial nematodes have been found highly sensitive to elimination of their endosymbiotic Wolbachia bacteria, and this may be a powerful attack route against "Brugia timori" as well.
Prevention focuses on protecting against mosquito bites in endemic regions. Insect repellents and mosquito nets are useful to protect against mosquito bites. Public education efforts must also be made within the endemic areas of the world to successfully lower the prevalence of "W. bancrofti" infections.
The World Health Organization recommends mass deworming—treating entire groups of people who are at risk with a single annual dose of two medicines, namely albendazole in combination with either ivermectin or diethylcarbamazine citrate. With consistent treatment, since the disease needs a human host, the reduction of microfilariae means the disease will not be transmitted, the adult worms will die out, and the cycle will be broken. In sub-Saharan Africa, albendazole (donated by GlaxoSmithKline) is being used with ivermectin (donated by Merck & Co.) to treat the disease, whereas elsewhere in the world, albendazole is used with diethylcarbamazine. Transmission of the infection can be broken when a single dose of these combined oral medicines is consistently maintained annually for a duration of four to six years. Using a combination of treatments better reduces the number of microfilariae in blood. Avoiding mosquito bites, such as by using insecticide-treated mosquito bed nets, also reduces the transmission of lymphatic filariasis.
The Carter Center's International Task Force for Disease Eradication declared lymphatic filariasis one of six potentially eradicable diseases. According to medical experts, the worldwide effort to eliminate lymphatic filariasis is on track to potentially succeed by 2020.
For similar-looking but causally unrelated podoconiosis, international awareness of the disease will have to increase before elimination is possible. In 2011, podoconiosis was added to the World Health Organization's Neglected Tropical Diseases list, which was an important milestone in raising global awareness of the condition.
The efforts of the Global Programme to Eliminate LF are estimated to have prevented 6.6 million new filariasis cases from developing in children between 2000 and 2007, and to have stopped the progression of the disease in another 9.5 million people who had already contracted it. Dr. Mwele Malecela, who chairs the programme, said: "We are on track to accomplish our goal of elimination by 2020." In 2010, the WHO published a detailed progress report on the elimination campaign in which they assert that of the 81 countries with endemic LF, 53 have implemented mass drug administration, and 37 have completed five or more rounds in some areas, though urban areas remain problematic.
Treatments for lymphatic filariasis differ depending on the geographic location of the endemic area. In sub-Saharan Africa, albendazole is being used with ivermectin to treat the disease, whereas elsewhere in the world, albendazole is used with diethylcarbamazine. Geo-targeting treatments is part of a larger strategy to eventually eliminate lymphatic filariasis by 2020.
Additionally, surgical treatment may be helpful for issues related to scrotal elephantiasis and hydrocele. However, surgery is generally ineffective at correcting elephantiasis of the limbs. A vaccine is not yet available but in 2013 the University of Illinois was reporting 95% efficacity in testing against "B. malayi" in mice.
Treatment for podoconiosis consists of consistent shoe-wearing (to avoid contact with the irritant soil) and hygiene - daily soaking in water with an antiseptic (such as bleach) added, washing the feet and legs with soap and water, application of ointment, and in some cases, wearing elastic bandages. Antibiotics are used in cases of infection.
Prevention can be partially achieved through limiting contact with vectors through the use of DEET and other repellents, but due to the predominantly relatively mild symptoms and the infection being generally asymptomatic, little has formally been done to control the disease.
In regions where helminthiasis is common, mass deworming treatments may be performed, particularly among school-age children, who are a high-risk group. Most of these initiatives are undertaken by the World Health Organization (WHO) with positive outcomes in many regions. Deworming programs can improve school attendance by 25 percent. Although deworming improves the health of an individual, outcomes from mass deworming campaigns, such as reduced deaths or increases in cognitive ability, nutritional benefits, physical growth, and performance, are uncertain or not apparent.
There is no consensus on optimal therapeutic approach. The most commonly used drug is diethylcarbamazine (DEC), but it is, however, often ineffective. Although other drugs have been tried such as praziquantel, ivermectin, and albendozole, none has proven to be reliably and rapidly effective. Mebendazole appeared more active than DEC in eliminating the infection, and had comparable overall responses. Thiabendazole evidenced a small, but significant activity against the infection. A combination of treatments, DEC plus mebendazole, was much more effective than single drug doses.
Broad-spectrum benzimidazoles (such as albendazole and mebendazole) are the first line treatment of intestinal roundworm and tapeworm infections. Macrocyclic lactones (such as ivermectin) are effective against adult and migrating larval stages of nematodes. Praziquantel is the drug of choice for schistosomiasis, taeniasis, and most types of food-borne trematodiases. Oxamniquine is also widely used in mass deworming programmes. Pyrantel is commonly used for veterinary nematodiasis. Artemisinins and derivatives are proving to be candidates as drugs of choice for trematodiasis.
Aside from vectoring "Brugia" species, mosquitoes also maintain "Wolbachia" spp. which has been found to be an obligate intracellular bacterial endosymbiont of "Brugia" spp. "Wolbachia" supports essential biochemical pathways necessary for the survival of "Brugia", especially processes such as embryogenesis and molting.
The dramatic response to a commonly used drug for filaria (diethylcarbamazine) almost confirms the diagnosis. No universal treatment guidelines have been established for tropical pulmonary eosinophilia. The antifilarial diethylcarbamazine (6 mg/kg/day in three divided doses for 21 days remains the main therapeutic agent, and is generally well tolerated. Reported side effects include headache, fever, pruritus and gastrointestinal upset. The eosinophil count often falls dramatically within 7–10 days of starting treatment.
Elephantiasis is a symptom of a variety of diseases, where parts of a person's body swell to massive proportions.
Some conditions that have this symptom include:
- Elephantiasis nostras, due to longstanding chronic lymphangitis
- Elephantiasis tropica or lymphatic filariasis, caused by a number of parasitic worms, particularly "Wuchereria bancrofti". More than 120 million people, mostly in Africa and Southeast Asia, are affected.
- Nonfilarial elephantiasis or podoconiosis, an immune disease affecting the lymph vessels
- Elephantiasis, Grade 3 lymphedema which may occur in people with breast cancer.
- Genital elephantiasis, end result of lymphogranuloma venereum
- Proteus syndrome, the genetic disorder of the so-called Elephant Man.
Tropical (pulmonary) eosinophilia, or TPE, is characterized by coughing, asthmatic attacks, and an enlarged spleen, and is caused by "Wuchereria bancrofti", a filarial infection. It occurs most frequently in India and Southeast Asia. Tropical eosinophilia is considered a manifestation of a species of microfilaria. This disease can be confused with tuberculosis, asthma, or coughs related to roundworms.
Tropical pulmonary eosinophilia is a rare, but well recognised, syndrome characterised by pulmonary interstitial infiltrates and marked peripheral eosinophilia. This condition is more widely recognised and promptly diagnosed in filariasis-endemic regions, such as the Indian subcontinent, Africa, Asia and South America. In nonendemic countries, patients are commonly thought to have bronchial asthma. Chronic symptoms may delay the diagnosis by up to five years. Early recognition and treatment with the antifilarial drug, diethylcarbamazine, is important, as delay before treatment may lead to progressive interstitial fibrosis and irreversible impairment.
The condition of marked eosinophilia with pulmonary involvement was first termed tropical pulmonary eosinophilia in 1950. The syndrome is caused by a distinct hypersensitive immunological reaction to microfilariae of" W. bancrofti" and "Brugia malayi". However, only a small percentage (< 0.5%) of the 130 million people globally who are infected with filariasis apparently develop this reaction. The clearance of rapidly opsonised microfilariae from the bloodstream results in a hypersensitive immunological process and abnormal recruitment of eosinophils, as reflected by extremely high IgE levels of over 1000 kU/L. The typical patient is a young adult man from the Indian subcontinent.
Chyloderma is swelling of the scrotum resulting from chronic lymphatic obstruction. Obstruction may be caused by a nematode such as "Wuchereria bancrofti". This condition is also known as lymphscrotum or elephantiasis scroti.
Complications are often diagnosed post-operatively, which can be differentiated through duplex ultrasound scanning and are bit observed until 24 to 48 hours for early complications such as drainage, infection, formation of haematocele, rupture, etc., but also for 1 to 6 weeks during follow-up on out-patient basis.
A hydrocele is an accumulation of serous fluid in a body cavity. A hydrocele testis is the accumulation of fluids around a testicle. It is often caused by fluid secreted from a remnant piece of peritoneum wrapped around the testicle, called the tunica vaginalis. Provided there is no hernia present, hydrocoeles below the age of 1 year usually resolve spontaneously. Primary hydrocoeles may develop in adulthood, particularly in the elderly and in hot countries, by slow accumulation of serous fluid, presumably caused by impaired reabsorption, which appears to be the explanation for most primary hydroceles, although the reason remains obscure. A hydrocele can also be the result of a plugged inguinal lymphatic system caused by repeated, chronic infection of "Wuchereria bancrofti" or "Brugia malayi", two mosquito-borne parasites of Africa and Southeast Asia, respectively. As such, the condition would be a part of more diffuse sequelae commonly referred to as elephantiasis, which also affects the lymphatic system in other parts of the body.