Accurate diagnosis of lesions suspected of being caused by Taenia solium in body organs of pigs with naturally acquired porcine cysticercosis

• Published in: PLoS neglected tropical diseases Vol. 13; no. 6; p. e0007408
• Main Authors: Gauci, Charles G, Ayebazibwe, Chrisostom, Nsadha, Zachary, Rutebarika, Chris, Poudel, Ishab, Sah, Keshav, Singh, Dinesh Kumar, Stent, Andrew, Colston, Angela, Donadeu, Meritxell, Lightowlers, Marshall W
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01-06-2019; Public Library of Science (PLoS)
• Subjects: Agriculture; Animal Structures - parasitology; Animal Structures - pathology; Animal tissues; Animals; Autopsy; Biology and Life Sciences; Body organs; Brain; Care and treatment; Contamination; Cysticercosis; Cysticercosis - diagnosis; Cysticercosis - parasitology; Cysticercosis - pathology; Cysticercosis - veterinary; Cysts; Deoxyribonucleic acid; Detection; Developing countries; Diagnosis; DNA; DNA sequencing; EDTA; Epidemiology; Gene sequencing; Health aspects; Histocytochemistry; Histology; Hogs; Identification; Infections; LDCs; Lesions; Liver; Lungs; Medicine and Health Sciences; Methods; Microscopy; Muscles; Necropsy; Nematodes; Nepal; Nucleotide sequence; Organs; Parasites; PCR; Physiological aspects; Polymerase Chain Reaction; Polymorphism; Polymorphism, Restriction Fragment Length; Research and Analysis Methods; Restriction fragment length polymorphism; Risk factors; Roundworm infections; Roundworms; Sample contamination; Sequence Analysis, DNA; Skeletal muscle; Spleen; Statistics; Swine; Swine Diseases - diagnosis; Swine Diseases - parasitology; Swine Diseases - pathology; Taenia solium; Taenia solium - isolation & purification; Taeniasis; Tissue; Tissue analysis; Tropical diseases; Uganda; Veterinary medicine; Uganda; Nepal; Victoria Australia; Australia
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0007408

The definitive method for diagnosis of porcine cysticercosis is the detection of cysticerci at necropsy. Cysts are typically located in the striated muscle and brain. Until recently Taenia solium cysticerci have not been definitively identified in other tissue locations, despite several comprehensive investigations having been undertaken which included investigation of body organs other than muscle and brain. Recently a study conducted in Zambia reported 27% infection with T. solium in the liver of pigs with naturally acquired porcine cysticercosis, as well as some T. solium infection in the lungs and spleen of some animals. We investigated the cause of lesions in sites other than the muscle or brain in a total of 157 pigs from T. solium endemic regions of Uganda and Nepal which were subjected to extensive investigations at necropsy. Lesions which had the potential to be caused by T. solium were characterised by macroscopic and microscopic examination, histology as well as DNA characterisation by PCR-RFLP and sequencing. Lesions were confirmed as being caused by Taenia hydatigena (both viable and non-viable), by T. asiatica and Echinococcus granulosus (in Nepal) and nematode infections. No T. solium-related lesions or cysticerci were identified in any tissue other than muscle and brain. It is recommended that future evaluations of porcine cysticercosis in aberrant tissue locations include DNA analyses that take appropriate care to avoid the possibility of contamination of tissue specimens with DNA from a different tissue location or a different animal. The use of appropriate control samples to confirm the absence of cross-sample contamination is also recommended.