A faixa etária influi na reinfecção por strongyloides venezuelensis de ratos wistar?

Abstract

Helminths of the genus Strongyloides, causers of intestinal disease strongyloidiasis currently infect an estimated 30-100 million people worldwide, with higher prevalence in tropical and subtropical regions. It is known that factors such as age may influence the immune response of the host, since individuals of the third age tend to have a decrease in the immune response due to certain physiological events. For the understanding of this parasitosis, the species Strongyloides venezuelensis, a natural parasite of rodents, has been widely used as an experimental model due to similarities of biological cycle. Although some studies have already been carried out in this context, little is known about the relationship between age and reinfection. Therefore, the objective of this study was to analyze the parasitological implications of S. venezuelensis reinfection in rats of different ages. This is an experimental study in wistar rats reinfected at 6, 12 and 18 months with infective larvae of S. venezuelensis, recovered using the Baermann-Moraes method. The OPG technique was used to verify the success of the infection and follow it during the experimental period. Data were collected for physiological and morphological analysis, as well as leukocyte count and adult worms to comprehension and analysis of the effects of these mice reinfection. The 6-month-old rats showed better post-infection recovery, and along with the 12-month group had stronger immune response when compared to the group 18 months, this response may be responsible for decreasing the fecundity of the adult worms present in their intestines. It may be concluded that younger rats re-exposed to the parasite tend to respond better to S. venezuelensis reinfection.