Infectious agents could be organisms or viruses. You observe a case of conjunctivitis. Thisillness could be caused by an organism (Chlamydia trachomatis) or by Adenovirus. Both of these etiologic agents are obligate intracellular pathogens. Explain why one is a virus the other one is not by applying the criteria suggested by AndreLwof . Discuss how the two pathogens differ at each point covered in le

Explanation:

Conjunctivitis can be caused by either a bacteria or a virus or even sometimes due to allergic reactions.

According to Andrelwof, viruses are classified based

i. on nature of DNA or RNA,

ii. nature of nucleocapsid ,

iii. symmetry of nucleocapsid,

iv. diameter of nucleocapsid with helical symmetry

So Chlamydia trachomatis is a bacteria, they have a nucleocapsid. They are just a single cell. But Adenovirus is a virus, that has a head and tail, contains nucleocapsid.

Chlamydia is Gram negative obligate intracellular pathogen. They can spread through direct or indirect contact through fomites, hand, contaminated towels. They affect both the eyes and symptoms include itching, irritation, discharge, swelling of eyelids, photophobia, and pain.

Laboratory diagnosis can be done by direct detection of inclusion bodies with Giemsa staining of conjunctival smears.

Adenoviruses are the most important and most frequent cause of follicular epidemic keratoconjunctivitis . The major mode of transmission is by direct inoculation by fingers. symptoms include itching, tearing, burning and foreign body sensation as well as photophobia.

the best method for diagnosis is the quantitative real-time polymerase chain reaction (PCR) and Enzyme immunoassays which are a cheaper and faster option with a high sensitivity.