A risk factor is something that increases your chances of getting a disease or condition. Each of the multiple kinds of chlamydial infection has a different set of risk factors and can be considered a separate disease entity.

Sexually transmitted chlamydial infections are transferred from one person to another by direct contact with genital tissues. Chlamydia is highly contagious and the most common sexually transmitted disease.

Risk factors for chlamydial STDs :

  • Age: 15-25 years old
  • Gender: Chlamydia trachomatis is more common in females; Lymphogranoloma venereum is six times more common in males
  • Multiple sex partners
  • Having sex without a condom
  • History of sexually transmitted diseases

Neonatal chlamydia is the same organism transmitted during childbirth from an infected mother to her baby. It accounts for 30%-50% of newborn conjunctivitis and is so common that every newborn in the United States is treated to prevent it. Infants born to infected mothers are at risks of developing chlamydial conjunctivitis (in 25% of cases) and chlamydial pneumonia (in 16% of cases).

Risk factors for neonatal chlamydia :

  • A pregnant woman with chlamydia in her birth canal

Chlamydia bacteria that infect the respiratory system are a different species and enter the body when they are inhaled. These germs in spore form are wafted into the air from infected birds. The risk is limited to those in contact with infected birds.

Risk factors for respiratory chlamydia :

  • Contact with birds, especially psittacines (parrots, parakeets, budgies), but also barnyard birds (ducks, chickens, and turkeys), pigeons, and most other kinds.

Trachoma is yet another chlamydial infection by a different strain of this group of germs. Trachoma causes ocular chlamydia. The germ is carried from one person to another by direct contact or by intermediate objects known as fomites.

The risk of acquiring trachoma is high in endemic areas such as Africa, India, Southeast Asia, and the Middle East, and especially for children.

Risk factors for ocular chlamydia :

  • Flies in developing countries, also objects that can transmit germs—such as towels, washcloths, and fingers.