Which organism is likely responsible for causing septic arthritis in sexually active adults?

The organism most commonly associated with septic arthritis in sexually active adults is Neisseria gonorrhoeae. This bacterium is a sexually transmitted pathogen that can disseminate throughout the body, leading to complications such as septic arthritis, particularly in young adults and adolescents who are sexually active.

In cases of gonococcal arthritis, the infection often arises from untreated gonorrhea, where the bacteria can migrate from the mucous membranes of the genital tract to the joints, causing inflammation, pain, and swelling. This condition is considered a classic manifestation of disseminated gonococcal infection.

While other organisms like Staphylococcus aureus can cause septic arthritis, they often occur in different contexts, such as in cases of previous joint damage or in individuals with compromised immune systems. Chlamydia trachomatis is also linked to sexually transmitted infections, but its association with septic arthritis is less prominent compared to Neisseria gonorrhoeae. Pseudomonas aeruginosa is typically involved in infections among immunocompromised individuals or in cases of penetrating trauma and is not a major cause of septic arthritis in the sexually active population.

Thus, the likelihood of Neisseria gonorrhoeae being the causative agent in sexually active adults