A Mathematical Model for the Epidemiological Analysis of Trichinella - Infection in Pigs

Trichinella spp. is one of the most widespread parasite infecting humans, mammals, and birds all over the world. Despite of the efforts made by public health specialists to control and eradicate it, trichinellosis is considered a re-emerging zoonosis in many areas. Romania is recognized asone of the countries with the highest prevalence of trichinellosis in Europe. With respect to Trichinella-infections in pigs, our country accounted 51.5% of all positive findings in 2012, a similar situation as in 2010 and 2011; with an overwhelming majority, these Trichinella-positive findings originated from pigs raised in backyards. This work aimed to set and implementa mathematical model able to predict the future evolution of Trichinella-infection incidence in pigs. Our analysis was based on the data collected between 1997 and 2013 from pigs raised both in controlled (farms) and non-controlled housing conditions (backyards). The implemented mathematical model showed two main lines of prediction related to the evolution of Trichinella-infection incidence, depending on the origin of pigs. For pigs raised in controlled systems (farms), the mathematical models predict a trend tow ard zero of the incidence in the next period of time (considering that in the last 4 years included in the study(2009-2013), few positive cases were registered). In the case of pigs raised in extensive systems (uncontrolled conditions), the mathematical models generally predict an ascending trend in Trichinella-infections incidence, this trend reflecting the high incidence of Trichinella-in fectionsin pigs raised in backyards in recent years. In conclusion, statistical processing of the parasitological data may provide a useful modality for understanding the biological processes and the interpretation of epidemiological data.