Epidemiology of Taenia saginata taeniosis/cysticercosis: A systematic review of the distribution in central and western Asia and the Caucasus

Background The zoonotic parasite Taenia saginata transmits between humans, the definitive host (causing taeniosis), and bovines as the intermediate host (causing cysticercosis). Central and western Asia and the Caucasus have large cattle populations and beef consumption is widespread. However, an overview of the extent of human T. saginata infection and bovine cysticercosis is lacking. This review aims to summarize the distribution of T. saginata in this region. Methods A systematic review was conducted, that gathered published and grey literature, and official data concerning T. saginata taeniosis and bovine cysticercosis in central and western Asia and the Caucasus published between January 1st, 1990 and December 31st, 2018. Where no data were available for a country within this period, published data from 1985–1990 were also accessed. Results From 10,786 articles initially scanned, we retrieved 98 full-text articles from which data were extracted. In addition, two unpublished datasets were provided on the incidence of human taeniosis. Data for human taeniosis and bovine cysticercosis were found for all countries except Turkmenistan. Human taeniosis prevalence varied from undetected to over 5.3%, with regional variations. Where bovine cysticercosis was detected, prevalences varied from case reports to 25%. Conclusions The public health burden of T. saginata is assumed to be small as the parasite is of low pathogenicity to humans. However, this review indicates that infection continues to be widespread and this may result in a large economic burden, due to the resources utilized in meat inspection and condemnation or processing with subsequent downgrading of infected carcasses.