Accuracy of the Kato-Katz method and formalin-ether concentration technique for the diagnosis of Clonorchis sinensis, and implication for assessing drug efficacy

Abstract

BackgroundClonorchiasis is a chronic neglected disease caused by a liver fluke, Clonorchis sinensis. Chemotherapy is the mainstay of control and treatment efficacy is usually determined by microscopic examination of fecal samples. We assessed the diagnostic accuracy of the Kato-Katz method and the formalin-ether concentration technique (FECT) for C. sinensis diagnosis, and studied the effect of diagnostic approach on drug efficacy evaluation.MethodsOverall, 74 individuals aged ≥18 years with a parasitological confirmed C. sinensis infection at baseline were re-examined 3 weeks after treatment. Before and after treatment, two stool samples were obtained from each participant and each sample was subjected to triplicate Kato-Katz thick smears and a single FECT examination.ResultsThirty-eight individuals were still positive for C. sinensis according to our diagnostic ‘gold’ standard (six Kato-Katz thick smears plus two FECT). Two FECT had a significantly lower sensitivity than six Kato-Katz thick smears (44.7% versus 92.1%; p <0.001). Examination of single Kato-Katz and single FECT considerably overestimated cure rates.ConclusionsIn settings where molecular diagnostic assays are absent, multiple Kato-Katz thick smears should be examined for an accurate diagnosis of C. sinensis infection and for assessing drug efficacy against this liver fluke infection.

TLR2 signal influences the iNOS/NO responses and worm development in C57BL/6J mice infected with Clonorchis sinensis

“…Recently we found that C. sinensis were able to mature and release eggs in BALB/c mice [ 9 ]. In this study, fecal examination was also performed by modified Kato-Katz egg counting technique [ 9 , 29 ] to further confirm the egg production capacities of the worms. However, no eggs were found in the faeces from both TLR2 wild-type and mutant mice after the infection.…”

“…Stool samples were collected from each infection group every other day and were mixed together every 20 days. Eggs were counted by the Kato-Katz egg counting technique [ 29 ]. For perfect blending, 1 ml of pure water was added into 1 g of stool of each sample.…”

Pathological Lesions and Inducible Nitric Oxide Synthase Expressions in the Liver of Mice Experimentally Infected with &lt;i&gt;Clonorchis sinensis&lt;/i&gt;

“…The stool samples were thoroughly mixed after complete humidification. Triplicate Kato-Katz thick smears using standard 41.7 mg templates [ 24 ] were prepared from each stool sample. The number of C. sinensis eggs was counted and presented as the geometric mean of eggs per 1 g of stool (GM EPG).…”

Comparison of two diagnostic techniques to determine the prevalence of <i>Schistosoma mansoni</i> infections in Cameroonian school children

“…Contradictory results have been reported in the literature on the effectiveness of Kato-Katz and Formolether techniques in the detection of gastrointestinal parasites in faeces. Some authors have noted that the Kato-Katz technique was better and significantly more sensitive than the other method (18)(19) while others have reported that the Formol-ether technique had a better sensitivity than the Kato-Katz method (20)(21). According to Knight et al, (22), the concentration of eggs in the faeces enabled the detection of more patients infected with S. mansoni when the Formol-ether technique was used.…”