Definitive host: Humans
Intermediate host: Dogs and cat fleas.
Prevalence & Distribution: It is the common parasite of the domestic dog. The distribution of dog tapeworm cannot be restricted to one particular country but is seen to affect humans when they are in close association with the animal.
Mode of infection: The eggs of the dog tapeworm are present in the dog's feces, which are consumed by the fleas. The eggs hatch out and the larvae (cysticerci) grow in to the immature tapeworm within the body of the flea. These fleas then bite the dogs, which swallow them. Once the cysticerci reach the dog's intestine, they grow into adult tapeworms. Sometimes the fleas harbor the segments containing the eggs, which are ingested by the dogs and are capable of limited movements. This result in intense itching and the dog drag their backsides along the ground to relive the itching, which crushes the segments and releases the eggs out in the environment. Human beings get infected with the larval stage of the tapeworm by accidentally swallowing the fleas. This usually occurs when they allow the dogs to lick them and while crushing the fleas in between the fingernails. Once inside the human they grow into adult tapeworms.
Mostly it is asymptomatic but some people, especially those with low immunity show symptoms of gastrointestinal discomfort, weakness, fatigue etc.
Tapeworm Infections - References
- MEDIC8 - (http://www.medic8.com/)