Hymenolepiasis
Hymenolepiasis Causes
Humans and other animals become infected when they intentionally or unintentionally eat material contaminated by parasites. In an infected person, it is possible for the worm's entire life-cycle to be completed inside the bowel, so infection can persist for years. Hymenolepis nana infections are much more commonly-found than Hymenolepis diminuta infections in humans because, in addition to being spread by insects, the disease can be spread directly from person to person by eggs in feces. When this happens, H nana oncosphere larvae encyst in the intestinal wall and grow into cysticercoids and then adults.
Hymenolepiasis Definition
Hymenolepiasis is infestation by one of two species of tapeworm: Hymenolepis nana and Hymenolepis diminuta.
Hymenolepiasis Diagnosis
Examination of the stool for eggs and parasites confirms the diagnosis for the disease. The eggs and proglottids of H nana are more small than H diminuta. Proglottids of both species are relatively wide and have three testes. Identifying the parasites to the species level is often not needed from a medical perspective, as the treatment is the same for both.
Hymenolepiasis Symptoms and Signs
It is not clear whether hymenolepiasis necessarily has any symptoms. The symptoms of hymenolepiasis are traditionally described as abdominal pain, irritability, loss of appetite (anorexia), itching around the anus, and diarrhea. However, in one study of 25 patients conducted in Peru, effective treatment of the infection made no significant difference to symptoms. Some authorities report that heavily infected cases are more probable to be symptomatic
Hymenolepiasis Treatment
Praziquantel as a single dose (25 mg/kg) is the current treatment of choice for hymenolepiasis and has a success rate of 96%. Single dose albendazole (400 mg) is also very effective (>95%). Niclosamide has also been administered. A three-day course of nitazoxanide is 75?93% effective. The dose is 1g daily for adults and children over 12; 400mg daily for children aged 4 to 11 years; and 200mg daily for children aged 3 years and below.