Comparing the performance of urine and copro-antigen detection in evaluating Opisthorchis viverrini infection in communities with different transmission levels in Northeast Thailand

Abstract

To combat and eventually eliminate the transmission of the liver fluke Opisthorchis viverrini , an accurate and practical diagnostic test is required. A recently established urine antigen detection test using monoclonal antibody-based enzyme-linked-immunosorbent assay (mAb-ELISA) has shown promise due to its high diagnostic accuracy and the use of urine in place of fecal samples. To further test the utility of this urine assay, we performed a cross sectional study of 1,043 people in 3 opisthorchiasis endemic communities in northeast Thailand by applying urine antigen detection together with copro-antigen detection methods. The quantitative formalin-ethyl acetate concentration technique (FECT) was concurrently performed as a reference method. The prevalence of O . viverrini determined by urine antigen detection correlated well with that by copro-antigen detection and both methods showed 10–15% higher prevalence than FECT. Within the fecal negative cases by FECT, 29% and 43% were positive by urine and copro-antigen detection, respectively. The prevalence and intensity profiles determined by antigen detection and FECT showed similar patterns of increasing trends of infection with age. The concentration of antigen measured in urine showed a positive relationship with the concentration of copro-antigen, both of which were positively correlated with fecal egg counts. The data observed in this study indicate that urine antigen detection had high diagnostic accuracy and was in concordance with copro-antigen detection. Due to the ease and noninvasiveness of sample collection, the urine assay has high potential for clinical diagnosis as well as population screening in the program for the control and elimination of opisthorchiasis.

Performance of Mini Parasep® SF stool concentrator kit, Kato-Katz, and formalin-ethyl acetate concentration methods for diagnosis of opisthorchiasis in Northeast Thailand

“…The stool kit method allows for storage of the sample after preparation, and it can be kept for examination later on; this presents advantages over Kato-Katz, which must be read by technicians within 30 min of slide preparation. Our finding that the stool kit performed equally well to FECT, and better than the KK method, in a parasite survey in Northeast Thailand suggests that it may become the method of choice for future field applications [ 16 , 43 ].…”

Monoclonal Antibodies Targeting an Opisthorchis viverrini Extracellular Vesicle Tetraspanin Protect Hamsters against Challenge Infection

“…Eight mAbs were raised to surface antigens of Schistosoma japonicum , only one of which was an IgM that conferred protection via passive transfer studies in mice [ 24 ]. An IgG mAb was raised to 78 kDa ES protein-protected mice against challenge infection with the livestock liver fluke Fasciola hepatica [ 25 ], but to the best of our knowledge, mAbs raised against human liver fluke antigens have only been used to develop diagnostic tools [ 26 , 27 , 28 , 29 ] and were not shown to confer protective efficacy in passive transfer studies.…”

Public health interventions for preventing re‐infection of Opisthorchis viverrini: application of the self‐efficacy theory and group process in high‐prevalent areas of Thailand

“…One limitation of this study is the quantification of the infection intensity of the liver fluke. Since we worked in the community with limited resources, highly sensitive diagnostic methods, such as copro‐antigen [31] or urine antigen [32] detection, were not possible and stool examination is still a gold standard for diagnosing helminth infection. Quantification of the eggs per gram faeces (EPG) needs more resources.…”

“…Given that the intensity of infection (i.e. EPG) can help to explain the re-infection, most of the re-infected individuals showed less intensity of infection post-treatment [30][31][32]. Both re-infection/ repeated infection and intensity of infection are associated with the risk of developing CCA [6,7].…”