Microbiology Practice Exam

What is the primary cause of trachoma, an eye infection that can lead to blindness?

1. Chlamydia

2. Neisseria gonorrhoeae

3. Staphylococcus epidermidis

4. Influenza virus

The correct answer is: Chlamydia

Trachoma is predominantly caused by Chlamydia trachomatis, a bacterium that can lead to inflammation and scarring of the eyelids, which may ultimately result in blindness if not treated effectively. This organism is highly transmissible and spreads through direct contact or indirectly via flies that carry the bacteria from the eyes of an infected person to the eyes of a healthy individual. The infection is particularly prevalent in areas with inadequate sanitation and hygiene practices. Other organisms listed do not cause trachoma: Neisseria gonorrhoeae is associated with gonorrheal infections and can lead to conjunctivitis but is not the primary cause of trachoma. Staphylococcus epidermidis is generally a skin commensal and does not have a primary association with eye infections, particularly trachoma. The influenza virus, meanwhile, is primarily responsible for respiratory illnesses and can cause viral conjunctivitis but does not contribute to the disease process of trachoma. Thus, the key recognition of Chlamydia trachomatis as the causative agent is essential in understanding the disease's epidemiology and pathology.