In Soil-Transmitted Helminth (STH) control programs, microscopic examination is applied as a standard method for detecting the presence and the number of STH eggs. The time limitations of fresh specimen processing, especially for an accurate quantitative diagnosis, cause the specimen processing to be delayed or should be performed at a referral laboratory. This deferment requires preservatives to keep the stool integrity without reducing the accuracy. The aims of this study were: 1) to compare the proportion of positive samples and the intensity of A. lumbricoides, T. trichiura, and hookworm infection based on the examination of fresh samples and stool preserved by 10% formalin for >12 months and 2) to determine the most reliably accurate between Kato-Katz and mini-FLOTAC methods in detecting A. lumbricoides, T. trichiura, and hookworm eggs in preserved stools both qualitatively and quantitatively. Seventy-eight (78) stool samples were examined by mini-FLOTAC, and KatoKatz methods. Proportion of positive samples of A. lumbricoides, T. trichiura, and hookworms in fresh and in >=12 months 10% formalin preserved stools had no significant difference. Helminths density (eggs per gram of stool/EPG) in fresh samples was fewer compared to EPG in preserved samples (p <0.05) which leads to a lower proportion of moderate and high level groups in fresh stools samples compared to those in preserved samples (p <0.05). In preserved samples, as qualitative method, mini-FLOTAC detected more A. lumbricoides and T. trichiura eggs than Kato-Katz, while hookworm eggs were detected more by Kato-Katz than the miniFLOTAC. As a quantitative detection, Kato-Katz showed higher calculation of STH EPG than mini-FLOTAC. Using 10% formalin preservation for stool samples, the STH eggs' morphology could still be well identified. Homogenization process and low number of samples tested, were acknowledged as the limitation of this study.
Liver fluke infection, particularly Opisthorchis viverrini, poses a significant public health risk in Thailand, where it is closely associated with cholangiocarcinoma and contributes to substantial mortality in the northeastern region. Diagnosis of this condition employs various parasitological approaches. This research aims to compare the diagnostic accuracy of three parasitological techniques: the Kato Katz technique (KKT), the formalin-ethyl acetate concentration technique (FECT), and the Fully Automatic Feces Analyzer (FAFA) for O. viverrini identification. A total of 455 fecal specimens were collected from rural areas across five provinces in northeastern Thailand. The specimens were processed according to each method and examined through microscopy for KKT and FECT, and by utilizing an artificial intelligence-based machine for FAFA. Data analysis was conducted to assess parasitic infection rates and observe diagnostic accuracy. The results revealed a parasitic infection rate of 19.34%, with the majority of infections attributed to O. viverrini (18.02%), followed by Strongyloides stercoralis (0.88%). FECT exhibited the highest positive detection of O. viverrini eggs (16.48%), followed by FAFA (10.55%), and KKT (8.57%), respectively. Statistical analysis indicated sensitivity and specificity values for O. viverrini detection by KKT (100% and 89.21%), FECT (98.67% and 97.63%), and FAFA (97.92% and 91.15%). The positive predictive value, negative predictive value, and kappa were reported for FECT (89.16%, 99.73%, 0.92), FAFA (56.63%, 99.73%, 0.67), and KKT (45.78%, 100%, 0.58). Additionally, the preparation time for KKT, FECT, and FAFA was 30, 15, and 10 min, respectively. In conclusion, this study highlights FECT, KKT, and FAFA as comparably sensitive in diagnosing O. viverrini. The FAFA machine emerges as a potentially valuable tool for detecting O. viverrini and other parasitic infections, showcasing promise for clinical use. The findings provide valuable insights into the diagnostic landscape and underscore the potential of FAFA in enhancing efficiency and accuracy in parasitological assessments.
Infections by gastrointestinal parasites are found in a variety of animals worldwide. For the diagnosis of such infections, the flotation method is commonly used to detect parasitic microorganisms, such as oocysts or eggs, in feces. Instead of adding a flotation solution after the final centrifugation step and using a cover slip to collect the parasites, the method using a wire loop for the recovery of the organisms has been reported as one of alternative methods. However, the recovery rates of microorganisms from the flotation method have not been analysed. In the present study, the utility of a flotation method with the use of a wire loop of 8 mm in diameter (the loop method) was evaluated using different numbers of E. tenella oocysts and Heterakis gallinarum eggs, and chicken fecal samples collected at the farms. Consequently, we found that the oocysts and eggs in tubes could be collected at a ratio of 2.00 to 3.08. Thus, our results indicate that the loop method is a simple and time saving method, implicating the application for the estimated OPG/ EPG (Oocysts/Eggs per gram) of the samples.