**Core Concept**
Epidemic keratoconjunctivitis (EKC) is a highly contagious and infectious eye disease characterized by inflammation of the cornea and conjunctiva. It is often associated with adenovirus infections, which can lead to outbreaks and epidemics in susceptible populations.

**Why the Correct Answer is Right**
Adenovirus, particularly serotypes 8, 19, and 37, are the primary causative agents of EKC. These viruses infect the conjunctiva and cornea, leading to symptoms such as redness, discharge, and vision impairment. The viral replication in the conjunctival epithelium triggers an intense inflammatory response, which can cause significant morbidity. Adenovirus EKC is highly contagious and can spread through direct contact with an infected individual or contaminated surfaces.

**Why Each Wrong Option is Incorrect**
**Option B:** Enteroviruses, such as Coxsackie A and B viruses, are primarily associated with gastrointestinal infections and various neurological disorders, but they are not commonly linked to EKC.

**Option C:** Coxsackie virus is a type of enterovirus and, as mentioned earlier, is not typically associated with EKC.

**Option D:** Herpes viruses, such as herpes simplex and herpes zoster, can cause ocular infections, but they are not the primary cause of epidemic keratoconjunctivitis.

**Clinical Pearl / High-Yield Fact**
To differentiate EKC from other conjunctival infections, look for the characteristic "limbal infiltrate" – a visible, band-like infiltrate at the junction of the cornea and conjunctiva. This is a classic finding in adenoviral EKC and can aid in diagnosis.

**✓ Correct Answer: A. Adenovirus**