Final answer:
The #1 cause of septic arthritis in sexually active young adults is Neisseria gonorrhoeae.
Step-by-step explanation:
The number #1 cause of septic arthritis in sexually active young adults is Neisseria gonorrhoeae, a bacterium that causes the sexually transmitted infection (STI) gonorrhea. Gonorrhea is a common STI caused by this bacterium and is most prevalent in individuals aged 15 to 24 years. Infections with Neisseria gonorrhoeae can lead to acute infectious arthritis in sexually active individuals.
Septic arthritis, also known as infectious arthritis, is a serious medical condition characterized by the infection of a joint. It occurs when bacteria, viruses, or fungi invade the joint space, leading to inflammation and, if left untreated, potential joint damage. Septic arthritis commonly affects a single joint, most often the knee, but it can also involve other joints such as the hip, shoulder, ankle, or wrist.