[Diagnostic value of the inquiry examination method for taeniasis based on the receiver operating characteristic...

To evaluate the value of inquiry examinations for diagnosis of taeniasis in field investigations, so as to provide insights into improving the efficiency and accuracy of taeniasis control programmes.

Four taeniasis-endemic villages were sampled in Dali Bai Autonomous Prefecture, Yunnan Province in October 2023 as survey sites, and at least 305 permanent residents at ages of over 3 years were randomly sampled from each site. Face-to-face inquiries were performed with structured questionnaires to investigate participants' history and frequency of proglottids release during the past year, consumption of raw or undercooked meat products or pork liver during the past six months, history and time of deworming. Participants' stool samples were collected, and Taenia eggs were detected in stool samples using Kato-Katz technique (two slides of one stool sample). Egg-positive individuals or participants with a history of proglottids release during the past year were given diagnostic deworming with areca nuts and pumpkin seeds. The detection of Taenia eggs using Kato-Katz technique and release of Taenia worms or proglottids following diagnostic deworming served as a gold standard to evaluate the diagnostic efficiency of inquiry examinations for taeniasis. The receiver operating characteristic (ROC) curves of inquiry examinations for diagnosis of taeniasis were plotted, and the area under the curve (AUC) was calculated. In addition, Taenia worms or proglottids released following diagnostic deworming were subjected to multiplex PCR assay and Sanger sequencing for species identification.

A total of 1 842 participants were included, and 1 842 valid questionnaires were recovered. A total of 1 533 stool samples were collected, among which 25 egg-positives were identified. Questionnaire surveys showed that 1 305 respondents had consumed raw or undercooked meat products during the past six months, and 42 respondents had a history of proglottids release during the past year. Diagnostic deworming was given to the aforementioned 25 egg-positive individuals and 42 participants who self-reported a history of proglottids release during the past year, and 33 participants had a release of complete worms. Following exclusion of records of individuals receiving deworming during the past 3 months, during the past year, and all participants with a history of deworming, the AUCs were 0.767 (Z = 4.71, P < 0.001), 0.762 (Z = 4.51, P < 0.001), and 0.762 (Z = 4.52, P < 0.001) for diagnosis of Taenia infections with "self-reported history of proglottids release during the past year", respectively, and pairwise comparisons showed no statistically significant differences (D values, -0.01 to 0.33; all P values > 0.05). Following exclusion of records of individuals receiving deworming during the past 3 months, during the past year, and all participants with a history of deworming, the AUCs were 0.797 (Z = 4.71, P < 0.001), 0.835 (Z = 4.17, P < 0.001), and 0.847 (Z = 3.98, P < 0.001) for diagnosis of Taenia infections with "self-reported history of twice proglottids releases", respectively, and pairwise comparisons showed no statistically significant differences (D values, -0.43 to -0.10; all P values > 0.05). Following exclusion of records of all individuals receiving deworming, the diagnostic sensitivity and specificity of "self - reported history of twice proglottids releases" were 87.50% and 81.82%, respectively. Following exclusion of records of individuals receiving deworming at different intervals, the AUCs were 0.529 to 0.532 for diagnosis of Taenia infections with "self-reported consumption of raw or undercooked meat products or pork liver during the past 6 months" (all P values > 0.05). Among 33 individuals with releases of complete Taenia worms, 31 individuals were identified with T. asiatica infections (93.94%), with a mean worm burden of (1.39 ± 0.72) worms/person, and 2 were identified with T. saginata infections (6.06%), with one worm in each participant.

A history of Taenia proglottids release during the past year as revealed by inquiry examinations exhibit a diagnostic value for taeniasis and may serve as an initial screening tool for field taeniasis screening. Increasing the frequency of Taenia proglottids release during inquiry examinations and exclusion of records of individuals receiving deworming during the analysis may improve the value for diagnosis of taeniasis.