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MYCOBACTERIUM AVIUM INFECTION STUDY IN A SWINE POPULATION BY MATHEMATICAL MODELING

ABSTRACT

The present work studied, by mathematical modeling, the Mycobacterium avium infection dynamics in a swine population. In order to describe M. avium transmission dynamics, a compartmental model was elaborated. Since the model was aimed to estimate the relationship between infection rate and the rate of swine that presented lesions resulting from M. avium infection, detected at slaughter of 150-day-old animals, it was considered that the disease dynamics could be described by two compartments of animals: susceptible to the infection, and infected that could present lesions. The simulation’s results showed that for a certain force of infection, the proportion of infected animals at the end of the nursery stage (those that would present lesions at the slaughter) remains constant over time, not being subject to seasonal changes. The mathematical simulation of the disease, considering horizontal transmission as the major means of condemnation at slaughter due to granulomatous lymphadenitis, is inconsistent with what is observed within the population. Therefore, the environmental component plays a major/preponderant role in the mycobacterial infection dynamics of swine raised on farms in Brazil.

KEY WORDS
Mycobacterium avium ; swine; mathematical modeling

Instituto Biológico Av. Conselheiro Rodrigues Alves, 1252 - Vila Mariana - São Paulo - SP, 04014-002 - São Paulo - SP - Brazil
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