| Autor: |
de Souza RP; Laboratório de Biologia Parasitária, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil., Pascoal VF; Laboratório de Biologia Parasitária, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil., Vilches TN; Agent-Based Modelling Laboratory, York University, Toronto, ON, Canada., Bittencourt HR; Escola Politécnica, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil., Utz LRP; Laboratório de Ecologia Aquática, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil., Graeff-Teixeira C; Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, ES, Brazil. |
| Abstrakt: |
Schistosoma mansoni is the main causative agent of intestinal schistosomiasis which affects millions of people worldwide. At the larval stage, miracidia are released into bodies of water where they utilize their motility to successfully infect their intermediate host, snails. Here, we revisit the motility and survival of S. mansoni miracidia throughout its life span. Briefly, miracidia motility was monitored at 30-min and 60-min intervals under the presence/absence of natural/artificial light. Based on a subjective evaluation of activity, body shape and transparency, 6 categories of miracidia activity were established from its fully active stage to its immobile larva stage. The estimated life span of miracidia was 5.8 and 3.5 h in the experiments with 60-min and 30-min observation intervals, respectively. Death was defined by an absence of cilia and body movement. When mobility was used as a proxy for infectivity, infective miracidia were detected at 2.5 and 4.5 h, respectively. The present miracidia motility and survival re-evaluation supports parameters optimization for computational modelling of schistosomiasis transmission dynamics. Target control interventions, especially at late stages next to transmission interruption, may greatly benefit from improved modelling studies. |
