Cousin diagnosis with reactive arthritis after admitted to hosp with extreme toe swelling and high fever. What infections might cause? Bacterial? Viral?

Reactive arthritis. The most common triggers are intestinal infections (with salmonella, shigella or campylobacter) and sexually transmitted infections (with chlamydia trachomatis or neisseria gonorrheae). It represents an autoimmune reaction to the infection. Many times the initial infection may have resolved.
Bacterial. Typical bacteria that cause reactive arthritis include salmonella, campylobacter, shigella, chlamydia, or yersinia. The initial infection may actually have begun in the intestines, urinary tract or genitals and may have been mild or asymptomatic. Usually anti-inflammatory medications and antibiotics are given for treatment.