Abstract

PIP: Many different infections with protozoan and helminthic parasites are common global health problems. Several protozoa are responsible for opportunistic infections in patients with AIDS. The newly developed drug, albendazole, has a strong activity against many nematode and cestode parasites. In the case of echinococcosis, it reduces the viability of protoscolices and cysts. Its hepatic metabolite, albendazole sulfoxide, is active against the larval cestodes. In the case of neurocysticercosis, administration of either the standard treatment, praziquantel, or the newly developed drug, albendazole, reduces or eliminates tapeworm cysts in 80-90% of patients. Patients with numerous cysts and those in whom neurologic symptoms or intracranial hypertension develops after therapy against cysticerci should receive adjunctive therapy with dexamethasone. Mass chemotherapy with single doses of albendazole or the older drug, mebendazole, is feasible for school-age children to treat the soil-transmitted helminthiases (ascariasis, hook-worm infection, and trichuriasis). The newly developed drug, ivermectin, is more effective against chronic strongyloidiasis than albendazole. It has been used most extensively against river blindness. It greatly reduces the number of microfilariae in the skin and eyes but has no effect on sclerosing keratitis or chorioretinitis. Both drugs are available in the US on a compassionate-use basis from their manufacturers. Field trials show that ivermectin is also effective against lymphatic filariasis and Mansonella ozzardi. Praziquantel is effective against many trematode and cestode infections. It is the drug of choice for schistosomiasis. Albendazole was effective against giardiasis in children in Bangladesh but ineffective in adult travelers returning from tropical areas. It appears to effect symptomatic improvement of intestinal microsporidial infections in patients with AIDS. The newly developed drug, fumagillin, can ameliorate ocular microsporidiosis. The newly developed drug, paromycin, treats cryptosporidiosis. Trimethoprim-sulfamethoxazole treats cyclosporiasis and isosporiasis.