When is conjunctivitis no longer infectious?

When is Conjunctivitis No Longer Infectious

Conjunctivitis is typically no longer infectious when symptoms have resolved, which usually occurs within 4-7 days for viral conjunctivitis and within 24-48 hours after starting appropriate antibiotic treatment for bacterial conjunctivitis. 1

Infectious Period by Type of Conjunctivitis

Viral Conjunctivitis

• Typically self-limiting and resolves within 4-7 days 1
• Most contagious during the first 3-5 days after symptoms appear
• Signs of resolution include:
  • Decreased redness/injection of the conjunctiva
  • Reduction in watery discharge
  • Decreased discomfort
  • Reduced eyelid swelling 1
• Patients can generally return to work/school when symptoms have significantly improved

Bacterial Conjunctivitis

• Most uncomplicated cases resolve in 1-2 weeks if untreated 2
• With topical antibiotic treatment:
  • Generally considered non-infectious 24-48 hours after starting appropriate antibiotics
  • Treatment allows earlier return to work/school 1, 2
• Signs of resolution include:
  • Decreased mucopurulent discharge
  • Reduced eyelid matting
  • Decreased conjunctival injection 1

Special Cases with Extended Infectious Periods

Gonococcal Conjunctivitis

• Requires both systemic and topical antibiotic treatment 1
• Considered an ophthalmological emergency 1
• May remain infectious until 24-48 hours after appropriate systemic antibiotic therapy

Chlamydial Conjunctivitis

• In neonates: May manifest 5-19 days after birth and can persist for 3-12 months if untreated 3
• Requires systemic treatment in addition to topical therapy 1
• Generally considered non-infectious after 7 days of appropriate antibiotic therapy

Prevention of Transmission During Infectious Period

To prevent transmission while conjunctivitis is still infectious:

• Practice strict personal hygiene with frequent handwashing 1, 4
• Avoid sharing towels, pillowcases, and cosmetics
• Avoid touching or rubbing the eyes
• Dispose of tissues immediately after use
• Change pillowcases daily until infection resolves
• Discard eye cosmetics that may have been contaminated

When to Seek Medical Attention

Return for medical evaluation if:

• No improvement after 7-10 days
• Worsening pain or vision changes
• Development of light sensitivity
• Increased eye discharge after initial improvement 1
• Signs of corneal involvement 1

Common Pitfalls in Determining Infectiousness

1. Premature Return to Work/School: Returning before the infectious period has ended can lead to outbreaks, especially in schools and daycare settings.

2. Misdiagnosis: Viral conjunctivitis misdiagnosed as bacterial may lead to unnecessary antibiotic use, while bacterial conjunctivitis misdiagnosed as viral may lead to prolonged infectiousness due to lack of appropriate treatment 1.

3. Incomplete Treatment: Stopping antibiotics prematurely for bacterial conjunctivitis can result in continued infectiousness and potential recurrence.

4. Contact Lens Use: Resuming contact lens wear too soon can prolong the infection or lead to complications. Wait until the eye is completely white and symptom-free for at least 24 hours.

Remember that allergic conjunctivitis is never infectious, regardless of how severe the symptoms appear 5.