How does this pathogen infect humans?

He became distrustful of other people due to his past experiences.

Due to the impact of the new coronavirus, the number of tourists has decreased sharply.

Due to the impact of the new coronavirus, the number of tourists has decreased rapidly.

He asserted his opinion.

We conducted a field survey and procured the necessary materials on site.

This project requires local procurement.

He confidently affirmed that the plan would succeed.

He affirmed with full confidence.

What does this wording mean?