Working group 1

Epidemiology

Transmission dynamics: from prevalence to incidence data

Understanding the transmission dynamics of Taenia spp. is essential to develop ad hoc cost-effective prevention and control programmes. To this end, studies evaluating the yearly risk of infection with T. saginata/T. solium by beef/pork consumption, and the rate of exposure of cattle/pigs to tapeworm eggs are highly needed. Once available, these parameters can be incorporated in Epidemiological Compartmental Models to simulate the spatio-temporal spread and transmission of the parasite. These models will also allow assessing and comparing the effects of control interventions on the parasite life cycle. WG 1 will first focus on gathering and critically assessing available epidemiological data on taeniosis and cysticercosis. Based on expert elicitation, these data will be adjusted for underreporting and underestimation due to diagnostic test inaccuracy. Conducting this data collection in the framework of the Action will allow a standardization of the data mining and adjustment approaches used. A solid database will be the basis of the other activities of the WG.

Assessing the economic and health burden of Taenia spp.

Assessing the economic and health burden of Taenia spp. is important to set up public health and veterinary public health priorities at national and European level. As mentioned above, a good control programme should be cost-effective. Despite the fact that millions of Euros are yearly allocated to bovine cysticercosis prevention, the parasite is still endemic in Europe and other regions of the world applying the same control measures. Similarly, only few studies addressed the cost-effectiveness of T. solium control programmes in endemic areas. Assessing the monetary and health burden of these human and animal diseases will be the first step in developing a valid evaluation of intervention strategies considering both costs and benefits. The Action will allow a large scale standardized burden assessment in order to provide an evidence-based opinion on the real impact of bovine, porcine and human cysticercosis, and to evaluate cost-effectiveness of control measures. Assessing the risk factors linked to Taenia spp. within and outside the EU

Some risk factors for bovine, porcine and human cysticercosis are well known i.e. eating habits, sanitation and farming systems. On the other hand, new or not well known potential risks of transmission such as the increased organic pig farming (re-introduction of an active life cycle), backyard farming, illegal meat import or the increased number of (illegal) immigrants/travellers have been identified but never properly assessed within and outside European countries. Moreover, infection routes for pigs, cattle and human such as the origin and demographic characteristics of NCC cases in Europe (importance of human-to-human transmission) still need to be completely understood.

The Action will allow launching new initiatives for the identification of emerging risk factors favouring the maintenance and/or the (re-) emergence of Taenia spp. infections within and outside Europe.

Proposing efficient taeniosis/cysticercosis surveillance systems

Among Taenia spp. infections, only official meat inspection data are notifiable. In animals, ante- mortem testing at farm level is inexistent. Taeniosis and human cysticercosis are not notifiable diseases. In order to avoid the re-emergence of human cysticercosis inside the EU as it occurred in the US (Southwest), European countries should develop efficient surveillance systems. Experts of the Action will analyse the European situation and propose the most appropriate surveillance pathways in order to avoid an increase or the (re-) emergence of Taenia spp. infections.