Current status of the treatment of paragonimiasis

Abstract

Paragonimiasis, a foodborne trematodiasis is caused by various Paragonimus species endemic in Asia, Africa, and the Americas. Human infection occurs through consuming improperly cooked freshwater crustaceans, crabs or crayfish, eating raw meat of paratenic hosts or by ingesting metacercariae from contaminated hands and cooking utensils. More than 292 million persons worldwide are at risk. The morbidity associated with paragonimiasis includes acute febrile illness and chronic pleuro-pulmonary manifestations which may be confounded with tuberculosis or lung cancer. Ectopic manifestations mostly involve the central nervous system, heart, or subcutaneous tissues. Objectives: to evaluate the efficacy and safety of currently available drugs praziquantel (PZQ) and triclabendazole (TCZ). Methods: a PubMed and Google Scholar search and reference selection was performed according to the the Preferred Reporting Items for Systematic Reviews protocol using a combination of the terms “paragonimiasis” AND “treatment” OR “therap*” from 01/2000 to 02/2022. Results: no randomized controlled trials were identified. Five open trials on 487 patients treated with PZQ showed 81%-100% parasite clearance depending on dosage and duration. Three open trials on 226 patients with TCZ showed a 99.6% efficacy. A quantitative comparison was not applicable to retrospective analyses of hospital records, case series and case reports because of surgical interventions, various co-morbidities and -medications and definitions of cure. Some patients treated with PZQ required multiple courses or re-treatment with TCZ, whereas one patient treated with TCZ required re-treatment with PZQ. Conclusions: PZQ and TCZ are usually effective for treating paragonimiasis. Controlled randomized trials are required to compare the safety, efficacy and applicability of PZQ versus TCZ and to evaluate combined PZQ-TCZ therapy.