infects humans when infected triatomine vector excreta contaminate breaks in skin or mucosal surfaces. T. cruzi
insect‑derived metacyclic trypomastigotes (IMT) invade through gastric mucosa after oral challenges without any visible inflammatory changes, while cutaneous and conjunctival infections result in obvious local physical signs. In this study we compared the infectivity of T. cruzi
IMT in mice after cutaneous and oral contaminative challenges simulating natural infections. The 50% infective dose (ID50
) for oral challenge was 100 fold lower than the ID50
for cutaneous challenge, indicating that oral mucosal transmission is more efficient than cutaneous transmission.