Chanika Worasith1,2, Chompunoot Wangboon3, Kulthida Y Kopolrat2, Chutima Homwong2, Jiraporn Sithithaworn4, Anchalee Techasen2,5, Raynoo Thanan2,6, Narong Khuntikeo2,7, Paiboon Sithithaworn1,2. 1. Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. 2. Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen 40002, Thailand. 3. School of Preclinical Science, Institute of Science, Suranaree University of Technology, Nakhon Rachasima 30000, Thailand. 4. Faculty of Medicine, Mahasarakham University, Mahasarakham 44150, Thailand. 5. Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand. 6. Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. 7. Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
Abstract
BACKGROUND: A urine antigen assay was applied to evaluate chemotherapeutic outcomes and reinfection patterns of opisthorchiasis in Thailand. METHODS: We used a prospective study design by following opisthorchiasis subjects at baseline and post-treatment using a urine antigen assay and faecal examination by the formalin-ethyl acetate concentration technique (FECT). RESULTS: The antigen of Opisthorchis viverrini in urine diminished within 4 weeks after praziquantel treatment. Concurrent faecal examinations by FECT showed that faecal eggs were negative at 4 weeks after treatment. In a subsequent study, reinfection rates and intensity patterns of O. viverrini were evaluated at 48 weeks after praziquantel treatment. Within a group of subjects with curative treatment (n=137), 16.8% became reinfected according to FECT and 27.7% according to the urine antigen assay (p<0.05). There were significant correlations in intensity of infection between pretreatment and at 48 weeks post-treatment in both faecal egg counts and antigen levels in urine. CONCLUSIONS: The results suggested that in addition to screening, the urine antigen assay is an efficient tool for monitoring outcomes of drug treatment and reinfection in opisthorchiasis. Due to the ease of urine sample collection and handling, the urine assay becomes an alternative method to faecal examination for diagnosis and monitoring of opisthorchiasis.
BACKGROUND: A urine antigen assay was applied to evaluate chemotherapeutic outcomes and reinfection patterns of opisthorchiasis in Thailand. METHODS: We used a prospective study design by following opisthorchiasis subjects at baseline and post-treatment using a urine antigen assay and faecal examination by the formalin-ethyl acetate concentration technique (FECT). RESULTS: The antigen of Opisthorchis viverrini in urine diminished within 4 weeks after praziquantel treatment. Concurrent faecal examinations by FECT showed that faecal eggs were negative at 4 weeks after treatment. In a subsequent study, reinfection rates and intensity patterns of O. viverrini were evaluated at 48 weeks after praziquantel treatment. Within a group of subjects with curative treatment (n=137), 16.8% became reinfected according to FECT and 27.7% according to the urine antigen assay (p<0.05). There were significant correlations in intensity of infection between pretreatment and at 48 weeks post-treatment in both faecal egg counts and antigen levels in urine. CONCLUSIONS: The results suggested that in addition to screening, the urine antigen assay is an efficient tool for monitoring outcomes of drug treatment and reinfection in opisthorchiasis. Due to the ease of urine sample collection and handling, the urine assay becomes an alternative method to faecal examination for diagnosis and monitoring of opisthorchiasis.