The phrase "infection sets" refers to groups or collections of infectious agents, such as bacteria or viruses, that have the potential to spread and cause illnesses.
Sentences with «infection sets»
Sometimes secondary infections set in and antibiotics are required. (cat-health-guide.org)
Medical attention is needed should bacterial infection set in. (petsmagazine.com.sg)
In either case, when infection sets in, eczema can worsen and become more difficult to treat. (health.com)