Wisetmora Ampas, Artchayasawat Atchara, Laummaunwai Porntip, Pitaksakulrat Opal, Wattanawong Oranard, Boonmars Thidarut
Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
Division of General Communicable Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, 11000, Thailand.
Vet World. 2024 Jan;17(1):99-107. doi: 10.14202/vetworld.2024.99-107. Epub 2024 Jan 8.
Parasitic infections are a public health problem worldwide, including in Thailand. An epidemiological survey for helminthiasis based on stool examination uses the Kato-Katz method as recommended by the World Health Organization. Limitations of this method include the need for fresh stool, time requirement, and lack of quality control. The aim of this study was to enhance the efficiency of the Kato-Katz technique using formalin and glycerol solutions and to implement specimen preparation in fieldwork.
For the Kato-Katz method, stool samples were divided into formalin-fixed and unfixed groups at various time points and processes. Fresh echinostome eggs were added to each stool group. Incubation with glycerol increased the clearing process. Each group was observed and photographed using a light microscope. Parasite eggs were imaged and compared using the standard Kato-Katz method.
Visualization of echinostome eggs from formalin-fixed stool slides was significantly better than that from unfixed stool slides (p < 0.01). Stool samples fixed for 7 days retained normal echinostome eggs morphology. Incubation with glycerol for 1 h resulted in increased Kato-Katz performance by digesting the stool content and enhancing egg observation. Moreover, the results of the Kato-Katz method using fixed and fixed stool plus glycerol for natural helminth infection showed good quality of and egg visualization and normal morphology with a clear background of slides.
Formalin-fixed stool could be more suitable than fresh stool for the Kato-Katz method.
寄生虫感染是包括泰国在内的全球公共卫生问题。基于粪便检查的蠕虫病流行病学调查采用世界卫生组织推荐的加藤厚涂片法。该方法的局限性包括需要新鲜粪便、耗时以及缺乏质量控制。本研究的目的是使用福尔马林和甘油溶液提高加藤厚涂片技术的效率，并在实地工作中实施标本制备。
对于加藤厚涂片法，在不同时间点和过程将粪便样本分为福尔马林固定组和未固定组。向每组粪便中添加新鲜棘口吸虫卵。用甘油孵育可加快透明过程。每组使用光学显微镜进行观察和拍照。对寄生虫卵成像，并与标准加藤厚涂片法进行比较。
福尔马林固定粪便玻片上棘口吸虫卵的可视化效果明显优于未固定粪便玻片（p < 0.01）。固定7天的粪便样本保留了正常的棘口吸虫卵形态。用甘油孵育1小时可通过消化粪便内容物和增强虫卵观察来提高加藤厚涂片法的效果。此外，使用固定粪便和固定粪便加甘油进行自然蠕虫感染的加藤厚涂片法结果显示，虫卵可视化质量良好，形态正常，玻片背景清晰。
对于加藤厚涂片法，福尔马林固定的粪便可能比新鲜粪便更合适。
