Chlamydia is a common bacterial sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis. While it is generally treatable with antibiotics, a single infection does not lead to lasting natural immunity. This means that individuals can be reinfected with chlamydia multiple times, highlighting the importance of understanding its transmission and prevention.
How Chlamydia Spreads and Affects Cells
Chlamydia trachomatis primarily spreads through sexual contact, including vaginal, anal, and oral sex. The bacterium infects the columnar epithelial cells lining various mucous membranes, such as the urethra, cervical canal, anus, throat, and conjunctiva. It is an obligate intracellular bacterium, meaning it must live and replicate inside host cells.
The infection begins when an elementary body, the infectious form of the bacterium, enters a host cell. Once inside, it transforms into a reticulate body, which replicates within a specialized vacuole. As this vacuole grows, the host cell is destroyed, releasing new elementary bodies that can then infect other cells.
The Absence of Natural Immunity
Despite the body mounting an immune response during a chlamydia infection, this response is often insufficient to provide lasting protection against future infections. The bacterium’s intracellular nature allows it to evade the immune system by hiding within host cells. Chlamydia can also manipulate host cellular functions to aid its replication.
The immune system’s efforts to clear the infection can be hampered by the bacteria’s ability to interfere with immune processes. Immunity acquisition can be a slow process, with the organism potentially persisting. This incomplete or delayed immunity contributes to the high rates of reinfection, with approximately 20% of people experiencing reinfection.
Preventing Future Chlamydia Infections
Since natural immunity does not develop, preventing new and recurrent chlamydia infections relies on consistent protective measures. Using latex condoms consistently and correctly during vaginal, anal, and oral sex significantly reduces the risk of transmission. For oral sex, dental dams or cut-open condoms can be used for mouth-to-genital or oral-anal contact.
Regular screening is also important, especially for sexually active individuals, including women aged 25 and younger, and anyone with new or multiple sexual partners. If diagnosed, completing the full course of prescribed antibiotics is important to clear the infection and prevent complications. Informing and ensuring that all sexual partners from the previous 60 days also get tested and treated is important to break the chain of transmission and avoid reinfection.