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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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Control of this parasite should be directed against reducing the level of
environmental contamination. Treatment of heavily infected individuals is one
way to reduce the source of contamination (one study has estimated that 60% of
the total worm burden resides in less than 10% of the population). Other
obvious methods are to improve access to sanitation, e.g. toilets, but also
convincing people to maintaining them in a clean, functional state, thereby making
them conducive to use.
Education, improved sanitation, and controlled disposal of human feces are critical for prevention. Nonetheless, wearing shoes in endemic areas helps reduce the prevalence of infection.
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.
Prevention and control measures to prevent soil-transmitted helminthiasis are the following: availability of clean water for personal and domestic uses, improved access to sanitation which includes the use of properly functioning and clean toilets by all community members, education on personal hygiene such as hand washing and hygienic and safe food preparation; eliminating the use of untreated human faeces as fertilizer.
An infection of "N. americanus" parasites can be treated by using benzimidazoles: albendazole or mebendazole. A blood transfusion may be necessary in severe cases of anemia. Light infections are usually left untreated in areas where reinfection is common. Iron supplements and a diet high in protein will speed the recovery process. In a case study involving 56-60 men with "Trichuris trichiura" and/or "N. americanus" infections, both albendazole and mebendazole were 90% effective in curing "T. trichiura". However, albendazole had a 95% cure rate for "N. americanus", while mebendazole only had a 21% cure rate. This suggests albendazole is most effective for treating both "T. trichiura" and "N. americanus".
Cryotherapy by application of liquid nitrogen to the skin has been used to kill cutaneous larvae migrans, but the procedure has a low cure rate and a high incidence of pain and severe skin damage, so it now is passed over in favor of suitable pharmaceuticals. Topical application of some pharmaceuticals has merit, but requires repeated, persistent applications and is less effective than some systemic treatments.
The drug of choice for the treatment of hookworm disease is mebendazole which
is effective against both species, and in addition, will remove the intestinal
worm Ascaris also, if present. The drug is very efficient, requiring only a
single dose and is inexpensive. However, treatment requires
more than giving the anthelmintic, the patient should also receive dietary
supplements to improve their general level of health, in particular iron
supplementation is very important. Iron is an important constituent of a
multitude of enzyme systems involved in energy metabolism, DNA synthesis and
drug detoxification.
An infection of "N. americanus" parasites can be treated by using benzimidazoles, albendazole, and mebendazole. A blood transfusion may be necessary in severe cases of anemia. Light infections are usually left untreated in areas where reinfection is common. Iron supplements and a diet high in protein will speed the recovery process. In a case study involving 56–60 men with "Trichuris trichiura" and/or "N. americanus" infections, both albendazole and mebendazole were 90% effective in curing "T. trichiura". However, albendazole had a 95% cure rate for "N. americanus", while mebendazole only had a 21% cure rate. This suggests albendazole is most effective for treating both "T. trichiura" and "N. americanus".
Moderate hookworm infections have been demonstrated to have beneficial effects on hosts suffering from diseases linked to overactive immune systems. This is possibly explained by the hygiene hypothesis. Research at the University of Nottingham conducted in Ethiopia observed a small subset of people with hookworm infections were half as likely to experience asthma or hay fever. Potential benefits have also been hypothesized in cases of multiple sclerosis, Crohn's Disease and diabetes.
Some research conducted has shown favourable results using hookworms to treat coeliac disease. Though research points to anti-allergenic properties associated with hook worm infections, the FDA does not currently recognize hookworms as a treatment.
The World Health Organizations recommended albendazole or mebendazole for treatment.
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.
While annual or semi-annual mass antihelminthic administration is a critical aspect of any public health intervention, many have begun to realize how unsustainable it is due to aspects such as poverty, high rates of re-infection, and diminished efficacy of drugs with repeated use. Current research, therefore, has focused on the development of a vaccine that could be integrated into existing control programs. The goal of vaccine development is not necessarily to create a vaccine with sterilizing immunity or complete protection against immunity. A vaccine that reduces the likelihood of vaccinated individuals developing severe infections and thus reduced blood and nutrient levels could still have a significant impact on the high burden of disease throughout the world.
Current research focuses on targeting two stages in the development of the worm: the larval stage and the adult stage. Research on larval antigens has focused on proteins that are members of the pathogenesis-related protein superfamily, "Ancylostoma" Secreted Proteins. Although they were first described in "Anyclostoma", these proteins have also been successfully isolated from the secreted product of "N. americanus". "N. americanus" ASP-2 (Na-ASP-2) is currently the leading larval-stage hookworm vaccine candidate. A randomized, double-blind, placebo-controlled study has already been performed; 36 healthy adults without a history of hookworm infection were given three intramuscular injections of three different concentrations of Na-ASP-2 and observed for six months after the final vaccination. The vaccine induced significant anti-Na-ASP-2 IgG and cellular immune responses. In addition, it was safe and produced no debilitating side effects. The vaccine is now in a phase one trial; healthy adult volunteers with documented evidence of previous infection in Brazil are being given the same dose concentration on the same schedule used in the initial study. If this study is successful, the next step would be to conduct a phase two trial to assess the rate and intensity of hookworm infection among vaccinated persons. Because the Na-ASP-2 vaccine only targets the larval stage, it is critical that all subjects enrolled in the study be treated with antihelminthic drugs to eliminate adult worms prior to vaccination.
Adult hookworm antigens have also been identified as potential candidates for vaccines. When adult worms attach to the intestinal mucosa of the human host, erythrocytes are ruptured in the worm’s digestive tract which causes the release of free hemoglobin which is subsequently degraded by a proteolytic cascade. Several of these proteins that are responsible for this proteolytic cascade are also essential for the worm’s nutrition and survival. Therefore, a vaccine that could induce antibodies for these antigens could interfere with the hookworm’s digestive pathway and impair the worm’s survival. Three proteins have been identified: the aspartic protease-hemoglobinase APR-1, the cysteine protease-hemoglobinase CP-2, and a glutathione S-transferase.
Parasitic infections can usually be treated with antiparasitic drugs.
Albendazole and mebendazole have been the treatments administered to entire populations to control hookworm infection. However, it is a costly option and both children and adults become reinfected within a few months after deparasitation occurs raising concerns because the treatment has to repeatedly be administered and drug resistance may occur.
Another medication administered to kill worm infections has been pyrantel pamoate. For some parasitic diseases, there is no treatment and, in the case of serious symptoms, medication intended to kill the parasite is administered, whereas, in other cases, symptom relief options are used. Recent papers have also proposed the use of viruses to treat infections caused by protozoa.
Mammals can get parasites from contaminated food or water, bug bites, or sexual contact. Ingestion of contaminated water can produce Giardia infections.
Parasites normally enter the body through the skin or mouth. Close contact with pets can lead to parasite infestation as dogs and cats are host to many parasites.
Other risks that can lead people to acquire parasites are walking barefeet, inadequate disposal of feces, lack of hygiene, close contact with someone carrying specific parasites, and eating undercooked foods, unwashed fruits and vegetables or foods from contaminated regions.
Parasites can also be transferred to their host by the bite of an insect vector, i.e. mosquito, bed bug, fleas.
Snakebite was added to the list in 2017, after years of criticism of the WHO by activists for not making it a priority. The greatest burden of snakebite morbidity is in India and Southeast Asia. Globally, there are an estimated 421,000 envenomings each year (about 1 in 4 snakebites) and 20,000 deaths, but snakebites often go unreported.
There are 21.4 million people infected with trachoma, of whom 2.2 million are partially blind and 1.2 million are blind. It is found in Africa, Asia, Central and South America, Middle East, and Australia. The disease disproportionately affects women and children. The mortality risk is very low, although multiple re-infections eventually lead to blindness. The symptoms are internally scarred eyelids, followed by eyelids turning inward. Trachoma is caused by a micro-organism that spreads through eye discharges (on hands, cloth, etc.) and by "eye-seeking flies".
It is treated with antibiotics. The only known prevention method is interpersonal hygiene.
CLM can be treated in a number of different ways:
- Systemic (oral) agents include albendazole (trade name "Albenza") and ivermectin (trade name "Stromectol")).
- Another agent which can be applied either topically "or" taken by mouth is thiabendazole (trade name "Mintezol")), an anti-helminthic.
- Topical freezing agents, such as ethylene chloride or liquid nitrogen, applied locally can freeze and kill the larvae, but this method has a high failure rate because the larvae are usually located away from the site of the visible skin trails. Additionally, this is a painful method which can cause blistering and/or ulceration of the skin and it is therefore not recommended.
- It is recommended to use Benadryl or some anti-itch cream (i.e. Cortizone or Calamine lotion). This will help relieve some of the itch.
- Wearing shoes in areas where these parasites are known to be endemic offers protection from infection. In general, avoiding exposure of skin to contaminated soil or sand offers the best protection. In some areas dogs have been banned from beaches in an attempt to control human infection.
The first step in treatment includes washing and then irrigating the bite wound.
Seek medical attention if: if the cat has not been vaccinated against rabies.
A tetanous booster is given to the person if It has been more than 5 years since their last tetanus shot. If a cat has bitten someone, and there is no evidence that the cat has been vaccinated against rabies, the person will be treated for rabies infection.
Cat bites can often be prevented by:
- instructing children not to tease cats or other pets.
- being cautious with unfamiliar cats.
- approaching cats with care, even if they appear to be friendly.
- avoiding rough play with cats and kittens.
Rough play causes is perceived as aggressive. This will lead to the cat being defensive when approached by people. Preventing cat bites includes not provoking the cat.
Visceral larva migrans (VLM) is a condition in humans caused by the migratory larvae of certain nematodes, humans being a dead-end host, and was first reported in 1952. Nematodes causing such zoonotic infections are "Baylisascaris procyonis", "Toxocara canis", "Toxocara cati", and "Ascaris suum". These nematodes can infect but not mature in humans and after migrating through the intestinal wall, travel with the blood stream to various organs where they cause inflammation and damage. Affected organs can include the liver, heart (causing myocarditis) and the CNS (causing dysfunction, seizures, and coma). A special variant is ocular larva migrans where usually "T. canis" larvae travel to the eye.
Only a few roundworm eggs are necessary to cause larva migrans in the human child or adult. However, visceral larva migrans seems to affect children aged 1–4 more often while ocular larva migrans more frequently affects children aged 7–8. Between 4.6% and 23% of U.S. children have been infected with the dog roundworm egg. This number is much higher in other parts of the world, such as Colombia, where up to 81% of children have been infected.
Cutaneous larva migrans is a condition where nematodes such as "Ancylostoma braziliense" migrate to the skin.
A list of causative agents of larva migrans syndromes is not agreed upon and varies with the author.
Cutaneous larva migrans (abbreviated CLM) is a skin disease in humans, caused by the larvae of various nematode parasites of the hookworm family (Ancylostomatidae). The most common species causing this disease in the Americas is "Ancylostoma braziliense". These parasites live in the intestines of dogs, cats, and wild animals and should not be confused with other members of the hookworm family for which humans are definitive hosts, namely "Ancylostoma duodenale" and "Necator americanus".
Colloquially called creeping eruption due to its presentation, the disease is also somewhat ambiguously known as "ground itch" or (in some parts of the Southern USA) "sandworms", as the larvae like to live in sandy soil. Another vernacular name is plumber's itch. The medical term CLM literally means "wandering larvae in the skin".
Nematode dermatitis is a cutaneous condition characterized by widespread folliculitis caused by "Ancylostoma caninum".
Löffler's syndrome or Loeffler's syndrome is a disease in which eosinophils accumulate in the lung in response to a parasitic infection.
It was first described in 1932 by Wilhelm Löffler in cases of eosinophilic pneumonia caused by the parasites "Ascaris lumbricoides", "Strongyloides stercoralis" and the hookworms "Ancylostoma duodenale" and "Necator americanus".
Although Löffler only described eosinophilic pneumonia in the context of infection, many authors give the term "Löffler's syndrome" to any form of acute onset pulmonary eosinophilia no matter what the underlying cause. If the cause is unknown, it is specified and called "simple pulmonary eosinophilia". Cardiac damage caused by the damaging effects of eosinophil granule proteins (ex. major basic protein) is known as Loeffler endocarditis and can be caused by idiopathic eosinophilia or eosinophilia in response to parasitic infection.
DUSN may be caused by a helminthic infection with Toxocara canis, Baylisascaris procyonis, or Ancylostoma caninum. The characteristic lesions are believed to result from a single nematode migrating within the subretinal space. Although previously thought to be endemic in some areas, that belief was likely due to under awareness. DUSN has been diagnosed in patients in many countries and climates including America, Brazil, China and India.
If the nematode can be seen by an ophthalmologist, which occurs in less than half of cases, it should be treated with photocoagulation for extramacular location and surgical removal in case the larva is lying in the macula. After the worm is killed, visual acuity loss usually does not progress. Alternatively, Antihelminthic treatment such as high dose oral Albendazole and prednisolone may be used.
When eosinophilic pneumonia is related to an illness such as cancer or parasitic infection, treatment of the underlying cause is effective in resolving the lung disease. When due to AEP or CEP, however, treatment with corticosteroids results in a rapid, dramatic resolution of symptoms over the course of one or two days. Either intravenous methylprednisolone or oral prednisone are most commonly used. In AEP, treatment is usually continued for a month after symptoms disappear and the x-ray returns to normal (usually four weeks total). In CEP, treatment is usually continued for three months after symptoms disappear and the x-ray returns to normal (usually four months total). Inhaled steroids such as fluticasone have been used effectively when discontinuation of oral prednisone has resulted in relapse.
Because EP affects the lungs, individuals with EP have difficulty breathing. If enough of the lung is involved, it may not be possible for a person to breathe without support. Non-invasive machines such as a bilevel positive airway pressure machine may be used. Otherwise, placement of a breathing tube into the mouth may be necessary and a ventilator may be used to help the person breathe.
Eosinophilic pneumonia due to cancer or parasitic infection carries a prognosis related to the underlying illness. AEP and CEP, however, have very little associated mortality as long as intensive care is available and treatment with corticosteroids is given. CEP often relapses when prednisone is discontinued; therefore, some people with CEP require lifelong therapy. Chronic prednisone is associated with many side effects, including increased infections, weakened bones, stomach ulcers, and changes in appearance.