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.
This study illustrates and quantifies the changes on corneal tissue between the paraffin-embedded and resin-embedded blocks and thus, selects a better target in investigational ophthalmology and optometry via light microscopy. Corneas of two cynomolgus monkeys (Macaca fascicularis) were used in this study. The formalin-fixed cornea was prepared in paraffin block via the conventional tissue processing protocol (4-day protocol) and stained with haematoxylin and eosin. The glutaraldehyde-fixed cornea was prepared in resin block via the rapid and modified tissue processing procedure (1.2-day protocol) and stained with toluidine blue. The paraffin-embedded sample exhibits various undesired tissue damage and artifact such as thinner epithelium (due to the substantial volumic extraction from the tissue), thicker stroma layer (due to the separation of lamellae and the presence of voids) and the distorted endothelium. In contrast, the resin-embedded corneal tissue has demonstrated satisfactory corneal ultrastructural preservation. The rapid and modified tissue processing method for preparing the resin-embedded is particularly beneficial to accelerate the microscopic evaluation in ophthalmology and optometry.
Scrub typhus is a major cause of febrile illness throughout the Asia-Pacific region. It is commonly undiagnosed, partly because of the lack of a simple, reliable diagnostic test which can be used in clinical laboratories. The indirect immunoperoxidase technique, configured into a test kit, was provided to technicians who were trained in its use. They used the kit during a 2 year field trial in their respective clinical hospital laboratories throughout Malaysia. In an evaluation using 1,722 consecutive sera tested in those laboratories, the kit was found to have a median sensitivity for IgG detection of 0.85 (range 0.33-0.95), a median specificity of 0.94 (range 0.88-1.00), reproducibility of 0.86, and efficiency of 0.92 when compared to the reference laboratory. In a proficiency survey in which 10 laboratories received 3 coded test samples, all but 2 laboratories had results within 1 dilution of the reference laboratory in quantitating specific IgG, whereas 7 laboratories were within 1 dilution in quantitating IgM. The shelf life of the kit was at least 1 year at 4 degrees C.