Hymenolepis diminuta

Hymenolepis diminuta, also known as the rat tapeworm, is a species of parasitic tapeworm that primarily infects rodents and arthropods. It is one of the most common tapeworms in rats and can also infect humans, although human infection is rare.

Life Cycle

The life cycle of Hymenolepis diminuta involves two hosts. The primary host is typically a rodent, such as a rat, in which the adult tapeworm resides in the small intestine. The secondary host is an arthropod, such as a beetle, which ingests the tapeworm's eggs.

The eggs hatch in the arthropod's intestine, releasing oncospheres that penetrate the intestinal wall and develop into cysticercoid larvae in the body cavity. When the arthropod is eaten by a rodent, the larvae are released in the rodent's intestine, where they attach to the intestinal wall and develop into adult tapeworms.

Morphology

Adult Hymenolepis diminuta are typically 20-60 cm long and consist of a scolex (head), a short neck, and a long body composed of numerous proglottids (segments). The scolex has four suckers but lacks rostellum and hooks, which distinguishes Hymenolepis diminuta from other species of Hymenolepis.

Pathology and Treatment

Infection with Hymenolepis diminuta is usually asymptomatic in rodents. In humans, symptoms can include abdominal pain, diarrhea, headache, and loss of appetite. The infection is diagnosed by finding eggs in the stool.

Treatment typically involves a single dose of the anthelmintic drug praziquantel. Prevention of infection involves good hygiene practices and control of rodent and arthropod populations.

See Also

• Hymenolepis nana
• Cestoda
• Parasitology