• obligate intracellular parasite. difficult to diagnose and cannot be grown on agar.
• biphasic lifecycle
• multiple serotypes (D-K genital)

Risk factors

• age <25
• sexual partner +ve for chlamydia
• recent change in sexual partner
• coinfection with another STI
• no barrier contraception/lack of consistent use

Infections

• local infection (spread to adjacent cells when EBs released). Site determines nature of disease.
  • adults (autoinoculation)
    • conjunctivitis
    • urethritis/prostatis/cervicitis
  • neonates (acquired at birth)
    • Pneumonia
    • conjunctivitis
• may spread to other sites via lymph/blood
• symptoms from cell destruction and host inflammatory response

Symptoms (STI)

Females

• cervicitis
• abdo cramps