Risk-based inspection as a cost-effective strategy to reduce human exposure to cysticerci of Taenia saginata in low-prevalence settings

Abstract

BackgroundTaenia saginata cysticercus is the larval stage of the zoonotic parasite Taenia saginata, with a life-cycle involving both cattle and humans. The public health impact is considered low. The current surveillance system, based on post-mortem inspection of carcasses has low sensitivity and leads to considerable economic burden. Therefore, in the interests of public health and food production efficiency, this study aims to explore the potential of risk-based and cost-effective meat inspection activities for the detection and control of T. saginata cysticercus in low prevalence settings.MethodsBuilding on the findings of a study on risk factors for T. saginata cysticercus infection in cattle in Great Britain, we simulated scenarios using a stochastic scenario tree model, where animals are allocated to different risk categories based on their age, sex and movement history. These animals underwent different types of meat inspection (alternative or current) depending on their risk category. Expert elicitation was conducted to assess feasibility of scenarios and provide data for economic analysis. The cost-effectiveness of these scenarios was calculated as an incremental cost-effectiveness ratio, using the number of infected carcasses detected as the technical outcome.ResultsTargeting the high-risk population with more incisions into the heart while abandoning incisions into the masseter muscles was found to reduce the total number of inspections and cost, while simultaneously increasing the number of infected carcasses found.ConclusionsThe results suggest that, under reasonable assumptions regarding potential improvements to current inspection methods, a more efficient and sensitive meat inspection system could be used on animals categorised according to their risk of harbouring T. saginata cysticercus at slaughter. Such a system could reduce associated cost to the beef industry and lower microbial contamination of beef products, improving public health outcomes.

Bovine cysticercosis outbreak in an indoor beef finisher farm in the North of England

“…The main procedure for the diagnosis of cysticercosis in animals is meat inspection and postmortem examination. Depending on the level of infection, the current meat inspection procedures detect only about 10 per cent–50 per cent of the animals that are actually infected 9. Light infections are easily missed.…”

Systematic review and meta-analysis of bovine cysticercosis in Brazil: current knowledge and way forward

“…No studies have been performed assessing the sensitivity of the Brazilian meat inspection system. Some authors have been suggesting to perform meat inspection on animals categorized according to their risk of harboring cysticerci, because it is thought more efficient and sensitive than traditional methods [93,94]. This risk-based system could be assessed for Brazil, as there are several risk factors and associated variables described for BCC in this country ( Table 2).…”

Seroprevalensi Bovine Cysticercosis pada Sapi Bali di Nusa Tenggara Barat, Indonesia (SEROPREVALENCE OF BOVINE CYSTICERCOSIS AT BALI CATTLE IN WEST NUSA TENGGARA, INDONESIA)

“…Manusia terinfeksi cacing pita bila mengonsumsi daging sapi yang tidak dimasak atau dimasak kurang matang yang mengandung C. bovis. Sebaliknya, sapi terinfeksi larva cacing pita bila menelan telur T. saginata yang dikeluarkan manusia lewat feses (Prakashbabu et al, 2018).…”

“…Sistiserkus kadang-kadang dapat dideteksi pada otot di sekitar pipi dan pada lidah sapi dengan melakukan palpasi, teraba adanya benjolan/nodul di bawah jaringan kulit atau intramuskuler. Namun, cara deteksi seperti ini sensitivitasnya rendah, terutama pada hewan yang terinfeksi ringan (Gonzalez et al, 2006;Silva et al, 2015;Prakashbabu et al, 2018).…”