Answer:
An encounter with an affected animal
Explanation:
Note:
hormonal changes, changes in diet and immune suppression might lead to a disease caused by an opportunistic pathogen.
Bonus:
An opportunistic pathogen can be bacteria, viruses, fungi, or protozoa that take advantage of an rare opportunity to infect it's due to weakened immune system, a disruption in the host gut microbiota/integumentary barriers.
An opportunistic pathogen can not cause disease Where there is normal immune system in the host
