Back to Homepage

Diagnosis, Management

and Therapy










Management and Therapy


Heterophyid infection can be diagnosed by the identification of eggs in fecal matter. However, the eggs of M. yokogawai are essentially identical to those of Heterophyes heterophyes (the slight difference in size observed between the two species' does not appear to significant or consistent enough to be considered diagnostic). The eggs also bear a great similarity to those of other worms, namely species of Clonorchis and Opisthorchis. In addition, because adult M. yokogawai have limited egg-laying capacities, fecal matter may need to be concentrated in order for eggs to be isolated in light infections. 

Therefore, in order to definitively make the diagnosis of M. yokogawai infection (as distinct from other heterophyid infections), adult flukes must be identified in the feces after their evacuation by a suitable anthelmithic drug.



The drug of choice to attack M. yokogawai is Praziquantel (Biltricide). It has proven very effective, both in reducing the number of eggs in infected patients, and in killing adult worms. Its precise mechanism of action is unknown. Praziquantel is rapidly taken up by the parasite, and appears to increase the permeability of its cell membrane, leading to a loss of intracellular calcium. This results in massive contractions, and paralysis of the parasite's musculature.

Studies by the Department of Parasitology and Institute for Tropical Endemic Diseases in Korea University's College of Medicine found Praziquantel to be 100% effective in completely curing M. yokogawai infection, without any recorded side effects. However, studies in rats and rabbits have shown the drug to increase abortion rates and to have teratogenic effects when given in doses that exceed the recommended human dose. In addition, Praziquantel is excreted in breast milk, and so should not be used while a mother is breastfeeding.

Despite the risk of side effects, however, Praziquantel is by far the most effective drug available to treat M. yokogawai infection. It is administered orally, and does not require heavy dosage. Its potential applications for mass therapy are promising.

Prophylactic treatment should also be coupled with therapy to address secondary clinical symptoms. Particularly in children, and with heavy infections, rehydration and electrolyte therapy should be administered to counter fluid and salt losses due to diarrhea.