Opisthorchis viverrini infection in Thailand: symptoms and signs of infection—a population-based study

Abstract

A population-based study of the clinical, laboratory and ultrasonographic findings in patients suffering from mild or moderate opisthorchiasis in Prachinburi province, Thailand was conducted in 1990–1992. The effectiveness of treatment with praziquantel at 40 mg/kg body weight was evaluated. After treatment, a longlasting, marked improvement in the well-being of the study group was observed. Symptoms common in opisthorchiasis infection decreased in intensity and the clinical response showed total or partial remission in 98% of all cases studied. Total and direct bilirubin concentrations decreased significantly and remained low up to the end of the follow-up period of 2 years, indicating a reduction in cholestasis. Also, white blood cell counts decreased initially, which can be interpreted as a reduction in inflammation intensity. No relationship was found between intensity of infection and age or clinical findings, Population-based treatment of opisthorchiasis appears to have had a significant impact on public health in north-east Thailand. However, it is also evident that drug therapy alone will not solve the opisthorchiasis problem, as indicated by the reinfection rate of almost 10% at the end of the study.