Conjunctivitis in rabbits caused by enterovirus type 70 (EV70).

Area of Science:

• Ophthalmology
• Virology
• Immunology

Background:

• Human enteroviral conjunctivitis is a common, contagious eye infection.
• Enterovirus 70 (EV70) is a significant cause of epidemic keratoconjunctivitis.
• Existing animal models do not fully replicate the human disease course or viral evolution.

Purpose of the Study:

• To develop and characterize a rabbit model of EV70 infection that mimics human enteroviral conjunctivitis.
• To investigate viral kinetics, host immune responses, and potential antigenic variation of EV70 in vivo.
• To establish a platform for evaluating antiviral therapies against EV70.

Main Methods:

• Topical ocular inoculation of rabbits with EV70.
• Clinical assessment of conjunctivitis signs (tearing, redness, swelling, follicles).
• Histopathological examination of ocular tissues.
• Viral load quantification (PFU/ml) in ocular fluids.
• Detection of interferon-beta (IFN-β) in tears.
• Measurement of serum antibody responses to EV70.

Main Results:

• Conjunctivitis developed within 24 hours, characterized by clinical signs and epithelial defects.
• Peak viral titers (10^3–10^6.2 PFU/ml) were observed 1-2 days post-infection, with clearance by 3-5 days.
• Antiserum neutralization suggested antigenic variation in adapted EV70 strains.
• Interferon-beta was detected in tears, and variable serum antibody responses were noted.
• Clinical, virologic, and immunologic findings closely resembled human EV70 conjunctivitis.

Conclusions:

• The rabbit EV70 model accurately replicates human enteroviral conjunctivitis.
• This model is suitable for studying EV70 antigenic variation and ocular host defenses.
• The model provides a valuable system for testing antiviral interventions against enteroviral conjunctivitis.