Hymenolepiasis

Infectious diseases

Clinicals - History

Fact Explanation
Abdominal pain Hymenolepiasis is caused by cestods called Hymenolepis nana (dwarf tapeworm) and Hymenolepis diminuta (rat tapeworm). H deminuta rarely cause human infestation while H. nana causes most of Hymenolepiasis cases. It is commonly found in warm countries in Africa, South America, Asia and Europe. Humans become infected with H. nana by ingesting the infective eggs, most commonly by through fecal-oral exposure. Auto infection is also not uncommon. Infective eggs passed out in stools.
Humans get H.diminuta through swallowing of infected fleas or grain beetles in dried grains or fruits. They are accidentally swallowed by men. Adult worms get attached to mucosa of small intestine. The symptoms depends on the parasite load. Most of them are asymptomatic. An insidious onset epigastric pain occurs due to the trauma by adult worms in the in upper two thirds of ileum. This results in an allergic/ inflammatory reaction. The pain is accompanied by anorexia, increased appetite, nausea and vomiting.
Abdominal pain
Hymenolepiasis is caused by cestods called Hymenolepis nana (dwarf tapeworm) and Hymenolepis diminuta (rat tapeworm). H deminuta rarely cause human infestation while H. nana causes most of Hymenolepiasis cases. It is commonly found in warm countries in Africa, South America, Asia and Europe. Humans become infected with H. nana by ingesting the infective eggs, most commonly by through fecal-oral exposure. Auto infection is also not uncommon. Infective eggs passed out in stools.
Humans get H.diminuta through swallowing of infected fleas or grain beetles in dried grains or fruits. They are accidentally swallowed by men. Adult worms get attached to mucosa of small intestine. The symptoms depends on the parasite load. Most of them are asymptomatic. An insidious onset epigastric pain occurs due to the trauma by adult worms in the in upper two thirds of ileum. This results in an allergic/ inflammatory reaction. The pain is accompanied by anorexia, increased appetite, nausea and vomiting.
Diarrhea The diarrhea is watery type and often mild. Diarrhea
The diarrhea is watery type and often mild.
Hives Generalized toxic and allergic reactions causes red, itchy, raised areas of skin that appear in varying shapes and sizes. Hives
Generalized toxic and allergic reactions causes red, itchy, raised areas of skin that appear in varying shapes and sizes.
Non specific symptoms Itching around the anus, extremity pain, headache, dizziness, behavioral disturbances, and seizures are rare and non specific symptoms of the disease. Non specific symptoms
Itching around the anus, extremity pain, headache, dizziness, behavioral disturbances, and seizures are rare and non specific symptoms of the disease.

Clinicals - Examination

Fact Explanation
Urticaria Red, itchy raised areas (hives) occur all over the body due to allergy. Urticaria
Red, itchy raised areas (hives) occur all over the body due to allergy.
Abdominal tenderness Abdominal tenderness is rare and more common in the epigastric and peri-umbilical region. Abdominal tenderness
Abdominal tenderness is rare and more common in the epigastric and peri-umbilical region.

Investigations - Diagnosis

Fact Explanation
Full blood count Parasitic infestation is characterized by high degree of eosinophilia. Leukocytosis and anemia (rarely) may also occur. Full blood count
Parasitic infestation is characterized by high degree of eosinophilia. Leukocytosis and anemia (rarely) may also occur.
Stool examination The diagnosis depends on the demonstration of eggs in stool specimens. Concentration techniques and repeated examinations will increase the likelihood of detecting light infections. Eggs of Hynemolepis nana are oval or sub-spherical and smaller than those of H. diminuta. Their size is 40 - 60 µm x 30 - 50 µm. On the inner membrane, there are two poles, from which 4-8 polar filaments spread out between the two membranes. The oncosphere inside the egg has six hooks Stool examination
The diagnosis depends on the demonstration of eggs in stool specimens. Concentration techniques and repeated examinations will increase the likelihood of detecting light infections. Eggs of Hynemolepis nana are oval or sub-spherical and smaller than those of H. diminuta. Their size is 40 - 60 µm x 30 - 50 µm. On the inner membrane, there are two poles, from which 4-8 polar filaments spread out between the two membranes. The oncosphere inside the egg has six hooks

Management - Supportive

Fact Explanation
Prevention Prevention is difficult due to the direct transmission and single host requirement. Improvement of the hygienic habits of children, environmental sanitation and treating the infected persons may be effective. Prevention
Prevention is difficult due to the direct transmission and single host requirement. Improvement of the hygienic habits of children, environmental sanitation and treating the infected persons may be effective.

Management - Specific

Fact Explanation
Praziquantel Praziquantel as a single dose (25 mg/kg) is the current treatment of choice for hymenolepiasis and has an efficacy of 96%. Frequently occurring side effects are dizziness, headache, and malaise. Approximately 90% of all patients have abdominal pain or cramps with or without nausea and vomiting. Praziquantel
Praziquantel as a single dose (25 mg/kg) is the current treatment of choice for hymenolepiasis and has an efficacy of 96%. Frequently occurring side effects are dizziness, headache, and malaise. Approximately 90% of all patients have abdominal pain or cramps with or without nausea and vomiting.
Niclosamide The mitochondrial oxidative phosphorylation and glucose uptake in the parasite is inhibited. & day treatment is recommended. 2g during the first day and 1g/day in next 6 days is the recommended regimen. Children up to 2 years are given one fourth of the adult dose
Children from 2-6 years of age are given half of the adult dose.
Niclosamide
The mitochondrial oxidative phosphorylation and glucose uptake in the parasite is inhibited. & day treatment is recommended. 2g during the first day and 1g/day in next 6 days is the recommended regimen. Children up to 2 years are given one fourth of the adult dose
Children from 2-6 years of age are given half of the adult dose.
Nitazoxanide It is an alternative for Praziquantel and Niclosamide and not as effective as them. Nitazoxanide
It is an alternative for Praziquantel and Niclosamide and not as effective as them.

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