Control of clonorchiasis by repeated treatments with praziquantel

Abstract

The present study aimed to evaluate control efficacy of clonorchiasis by two schemes of repeated treatment with praziquantel at two endemic villages in China. Residents of one village at Guangxi Autonomous Region were treated and examined 6-monthly and of another at Liaoning Province 12-monthly. In residents that took 25 mg/kg x 3 (total 75 mg/kg) of praziquantel every 6 months for one year the egg positive rate showed a significant drop from 69.0% to 17.1%. In contrast, a group of same praziquantel medication once showed a slight marginal decrease in the egg rate from 18.9% to 12.2% after one year. Of 39 subjects examined 3 times, 56.4% were cured, 7.7% persistently positive, one (2.6%) reinfected after cure or newly infected, but 25.6% were persistently negative. The present finding suggests that 6-monthly medication with 75 mg/kg of praziquantel should effectively lower the prevalence but incomplete for control of clonorchiasis in heavy endemic areas.

Clonorchis Sinensis Infection and Increasing Risk of Cholangiocarcinoma in the Republic of Korea

“…In addition to the elimination of the consumption of raw, undercooked, or fresh pickled fish and prolonged or repeated chemotherapy of infected individuals, the protection of fish ponds and aquaculture systems from contamination with feces from people and animals should be strengthened for prevention of its infection. 15,16 Furthermore, longitudinal studies to identify the relationship between endemicity of C. sinensis infection and risk of cholangiocarcinoma should be done in the endemic area of Korea.…”

Infection Status of Freshwater Fish with Metacercariae of Clonorchis sinensis in Korea

“…Furthermore, the Korea Center for Disease Control and Prevention (KCDCP) is running a control program of clonorchiasis in endemic areas after the 7th national survey of intestinal parasite infections [8]. Although the control activities have been implemented for more than 20 yr, clonorchiasis is still prevalent throughout the country in Korea because of continuous reinfection [9].…”

Therapeutic evaluation of sustained-releasing praziquantel (SRP) for clonorchiasis: Phase 1 and 2 clinical studies

“…In Korea a single dose of 40 mg/kg PZQ had been applied for mass clonorchiasis control, and this achieved a 25.0% cure rate and an egg reduction rate of 95.5% (Lee, 1984). However, in clonorchiasis control trials, actual cure rate is not as high as expected due to poor compliance with the three dose regimen (Hong et al, 1998(Hong et al, , 2001). In our phase 2 clinical trial, the cure rate achieved using a single dose of 30 mg/kg SRP was unsatisfactory.…”

“…Praziquantel is not always effective in treating C. sinensis infection due to poor compliance of patients although its anthelmintic efficacy is known to be excellent, which is attributed to the need for 3 divided doses at 5 hr intervals (Hong et al, 2001). There is an obvious need for a single dose regimen for successful control of clonorchiasis in endemic areas.…”

“…However, this schedule is difficult to adhere to because of the 5 hr interval requirement, which is essential for cure. Furthermore, second and third doses are frequently forgotten, which resulted in incomplete cure (Hong et al, 2001). In order to overcome this shortcoming, development of an alternative/modified drug, such as sustained-releasing praziquantel (SRP) tablet is highly required .…”