Final answer:
Parasitic infections are rare in North America due to limited exposure to vectors, widespread vaccination, and efficient healthcare systems.
Step-by-step explanation:
Parasitic infections are rare in North America due to a combination of factors. One reason is limited exposure to vectors, such as mosquitoes and ticks, that transmit parasites. Additionally, widespread vaccination against certain infectious diseases has helped prevent their spread. Efficient healthcare systems and improved sanitation have also played a role in minimizing the occurrence of parasitic infections.