Hookworm infection

Pyrantel Pamoate. This dmg (10), C24H2qN20 S, cures pinworm infections and is close to 100% effective against A.scaris when given in a single dose (28,29). Pyrantel pamoate is also a principal dmg for the treatment of hookworm infections thus it is useful in patients with mixed worm infections. 

Hookworm infection is caused by Ancylostoma duodenale or Necator americanus. N. americanus is found in the southeastern United States. Infective larvae enter the host in contaminated food or water or penetrate the skin and migrate to the small intestine. The adult worm attaches to gastrointestinal mucosa and causes injury by lytic destruction of the tissue. Over a period of time, the adult worm can cause anemia and hypopro-teinemia in the host. 

Prociv, P. (1997) Pathogenesis of human hookworm infection insights from a new zoonosis. Chemical Immunology 66, 62—98. 

Mebendazole is a benzimidazole carbamate derivative that is used for the treatment of threadworm, roundworm, whipworm and hookworm infections. It is not recommended for women who are pregnant and in children under 2 years because the manufacturer reports that toxicity in animal studies has been reported. 

Albendazole has an even broader spectrum of activity than mebendazole. Its indications include pin-worm infection, ascariasis, trichuriasis, strongyloidiasis and hookworm infections. It is the preferred agent for inoperable cases of hydatid disease. 

Mebendazole is used primarily for the treatment of A. lumbricoides, T. trichiura, E. vermicularis, and hookworm infections, in which it produces high cure rates. It is an alternative agent for the treatment of trichinosis and visceral larva migrans. Owing to its broad-spectrum anthelmintic effect, mixed infections (ascariasis, hookworm infestation, or enterobiasis in association with trichuriasis) frequently respond to therapy. High doses have been used to treat hydatid disease, but albendazole is now thought to be superior. 

Albendazole, a broad-spectrum oral antihelminthic, is the drug of choice and is approved in the USA for treatment of hydatid disease and cysticercosis. It is also used in the treatment of pinworm and hookworm infections, ascariasis, trichuriasis, and strongyloidiasis. 

Benzimidazoles are thought to act against nematodes by inhibiting microtubule synthesis. Albendazole also has larvicidal effects in hydatid disease, cysticercosis, ascariasis, and hookworm infection and ovicidal effects in ascariasis, ancylostomiasis, and trichuriasis. 

For ascariasis, a single dose yields cure rates of 85-100%. Treatment should be repeated if eggs are found 2 weeks after treatment. For hookworm infections, a single dose is effective against light infections but for heavy infections, especially with N americanus, a 3-day course is necessary to reach 90% cure rates. A course of treatment can be repeated in 2 weeks. 

In the USA, mebendazole has been approved for use in ascariasis, trichuriasis, and hookworm and pinworm infection. It can be taken before or after meals the tablets should be chewed before swallowing. For pinworm infection, the dose is 100 mg once, repeated at 2 weeks. For ascariasis, trichuriasis, hookworm, and trichostrongylus infections, a dosage of 100 mg twice daily for 3 days is used for adults and for children over 2 years of age. Cure rates are 90-100% for pinworm infections, ascariasis, and trichuriasis. Cure rates are lower for hookworm infections, but a marked reduction in the worm burden occurs in those not cured. For intestinal capillariasis, mebendazole is used at a dosage of 400 mg/d in divided doses for 21 or more days. In trichinosis, limited reports suggest efficacy against adult worms in the intestinal tract and tissue larvae. Treatment is three times daily, with fatty foods, at 200-400 mg per dose for 3 days and then 400-500 mg per dose for 10 days. Corticosteroids should be coadministered for severe infections. 

Levamisole hydrochloride is used in the treatment of helminth infections and as an adjuvant in malignant disease. It is active against intestinal nematode worms and appears to act by paralyzing and eliminating susceptible worms. It has proven valuable in the treatment of ascariasis and hookworm infections. The use of levamisole should be avoided in patients with preexisting blood disorders. 

Esrey, S. A., Potash, J. B., Roberts, L., Shift, C. (1991). Effects of improved water supply and sanitation on ascariasis, diarrhoea, dracunculiasis, hookworm infection, schistosomiasis, and trachoma. Bulletin of the World Health Organization, 69, 609-621. 

Attempts to establish a connection between iron deficiency, impairment of neutrophil and lymphocyte function, and increased rale of infections have not been conclusive to date, One complicating issue in making the connection between iron deficiency and resultant infections is that sonxe infections can induce iron deficiency One example Is the hookworm infection, described later in this seclion-Among the most severely iron-deficient people in the wcirld arc children in Africa in areas where malaria is prm alcnt. The children die of malaria rather than of physiological defects resulting from the iron deficiency. 

The hciokworm is a parasitic worm. It is a common source of anemia in warm climates, including the southern United States. The parasitic worms are classed as flukes (trematodes), tapeworms (cestodes), and roundworms (nematodes). Tapeworms, for example, are mentioned under Vitamin B 2 in Chapter 9. The hookworm is a roundworm. It enters the body via the skin, that is, bare feet. The hookworm resides in the lumen of the small intestines w here it attaches itself to the villi. This results in damage to the villi, blood losses, secondary infections by other microoi anisms, and inflammation. The roundworm secretes anticoagulants that promote continued bleeding. Each worm may be responsible for the loss of up to 0.25 ml of blood per day. Hb levels as low as 20 mg/ml have been associated with hookworm infections. The disease can be prevented by the sanitary disposal of feces and by wearing shoes. 

Bitoscanate (phenylene 1,4-diisothiocyanate) enjoyed some clinical interest in the treatment of hookworm infection in around 1975 (1), but it proved highly dangerous, and deaths have occurred with as little as 300 mg. Most of the publicity that it has had in recent years relates to its listing as an extremely hazardous substance, and the US Office of Homeland Security has actually regarded it as a possible tool for bioterrorism. 

Tetrachloroethylene is a chlorinated derivative of a simple hydrocarbon, H2C=CH2, in which each of the four hydrogen atoms is replaced by chlorine, Cl2C=CCl2. It is a heavy liquid that has been used to treat hookworm infection. It is given orally in a dose of 0.1 ml/kg up to a maximum of 5 ml as a single dose on an empty stomach. Usually formulated as capsules or emulsion, it is unstable, especially if exposed to hght. Concurrent Ascaris infection should be treated first to avoid migration of worms and the risk of peritonitis. 

The inhalation of thymol, in combination with other volatile substances, is used to alleviate the symptoms of colds, coughs, and associated respiratory disorders. Externally, thymol has been used in dusting powders for the treatment of fungal skin infections. Thymol was formerly used in the treatment of hookworm infections but has now been superseded by less toxic substances. 

Thiabendazole has broad-.spectmm anthelmintic activity. It is used to (real enterobiasis, strongyloidiasis (threadworm infection), a.scariasis, uncinariasis (hookworm infection), and trichuriasis (whipworm infection). It has also been u.sed to relieve symptoms associated with cutaneous larva migrans (creeping eruption) and the inva.sive phase of trichinosis. In addition to its use in human medicine, thiabendazole is widely used in veterinary practice to control intestinal helminths in iive.stock. 

The hookworms are other important human parasites which cause high degree of economic losses among the victims. An early estimate [10] showed that Japan suffered an economic loss of US 60 million per year due to hookworm infections that could have been prevented by treating the patients with anthelmintics costing... 

Hookworm infections are usually found amongst the field workers and poor masses of the tropics. The most common clinical symptom of the disease is hypochromic anaemia resulting from heavy blood loss. This leads to general weakness, fatigue, anorexia and poor health. Hookworm infection is also known to cause various gastrointestinal disturbances and epigastric pain. Children, with heay worm burden, show poor mental and physical growth. 

Hookworm infection Ancylostoma duodenale, A. ceylanicum, Necalor americanus Tetrachloroethylene, bephenium, thiabendazole, pyrantel, albendazole, mebendazole... 

Oxantel may also be used to treat ascariasis, enterobiasis, hookworm infections and trichuriasis if given in combination with pyrantel pamoate or levamisole [18,23]. Thus, a combination of pyrantel pamoate (5 mg/kg) and oxantel pamoate (5 mg/kg) given on two consecutive days produced 94% reduction in egg output in a large number of Chinese patients infected with Ascaris, whipworms and hookworms [34]. Like pyrantel pamoate, oxantel is also well tolerated producing only mild and transient side effects [18]. 

Tetramisole has been found to be highly effective against Ascaris lumbricoides in humans. At a single oral dose of 3-8 mg/kg, the drug has been shown to produce 79-100% cure rates with high reduction in faecal egg counts. The recommended dose of tetramisole for ascariasis is 50-80 mg/child and 100-150 mg/adult [1,50,51]. Tetramisole also yields cures upto 75% against hookworm infections in man at a dose of 2.5-5 mg/kg given daily for 3 days [50-52]. 

Carbendazim (10) Clinical trials have shown this drug to be effective against ascari-asis, trichuriasis, hookworm infections, strongyloidiasis and mixed infections in humans at a dose of 200 mg given thrice daily for 1-3 days when 55-100% cure rates were obtained [203,204]. 

Ciclobendazole (16) This drug shows high activity against ascariasis and hookworm infections. Consequently, it has been used to treat patients with mild helminthiasis at a dose of 200 or 400 mg/day for 3 days. Ciclobendazole was found to be highly effective and well tolerated except for vomiting and diarrhea occurring in only a few cases [210]. 

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