In keratoconjunctivitis epidemica (KCE) – colloquially called epidemic conjunctivitis or eye flu – (thesaurus synonyms: Adenovirus conjunctivitis; epidemic keratoconjunctivitis; infectious keratoconjunctivitis; keratitis due to adenoviruses; keratoconjunctivitis due to adenoviruses; Sanders syndrome; shipyard keratoconjunctivitis; ICD-10-GM B30.0: Keratoconjunctivitis due to adenoviruses; ICD-10-GM H19. 2: Keratitis and keratoconjunctivitis in other infectious and parasitic diseases classified elsewhere) is a viral disease of the conjunctiva and cornea (Latin: cornea, Greek: keratos) of the eye.
The disease is caused by adenoviruses of serotypes 8, 19, 37; follicular conjunctivitis, on the other hand, is caused by serotypes 3, 4 and 7. The virus belongs to the Adenoviridae family.
Humans currently represent the only relevant pathogen reservoir.
Occurrence: The infection occurs worldwide.
The contagiousness of the pathogen is very high. The adenoviruses are particularly resistant in the environment and may be infectious for weeks at room temperature.
Transmission of the pathogen (route of infection) occurs predominantly by smear infection (= direct contact), occasionally by droplet infection. Transmission through contaminated instruments (= indirect contact) in medical practices and hospitals is also possible.
The pathogen enters the body via the mucosa (mucous membrane) of the nasopharynx (nasopharynx) and the conjunctiva (conjunctiva).
Human-to-human transmission: Yes.
The incubation period (time from infection to onset of disease) is usually 5-12 days.
The incidence (frequency of new cases) in Germany ranges from 1 case per 100,000 inhabitants per year (in Saxony-Anhalt) to about 5 cases per 100,000 inhabitants per year (in Mecklenburg-Western Pomerania). The number of new cases varies greatly each year.
Infectivity (contagiousness) usually exists in the first two to three weeks after infection. It probably begins before the onset of clinical symptoms.
Course and prognosis: It is not uncommon for keratoconjunctivitis epidemica to be preceded by nonspecific symptoms (e.g., mild fever, myalgia (muscle pain), diarrhea). However, the actual keratoconjunctivitis occurs suddenly. Patients complain of unilateral (painful) eye discomfort associated with marked eyelid swelling, epiphora (“watering”; lacrimation), burning sensation, and foreign body sensation. After a short time (usually within 2-7 days), there is usually milder involvement of the second eye. One to two weeks after the onset of the acute phase, the chronic phase begins, which is characterized by subepithelial infiltrates of the cornea (nummuli). Depending on the localization of the infiltrates, the patient suffers from reduced visual acuity and photophobia for about three to six weeks. The infiltrates usually resolve spontaneously in the further course without scarring. In up to 50% of patients, a prolonged persistence is described, which can last up to two years.
Typically, KCE does not recur.
In Germany, the detection of the pathogen in the conjunctival smear is notifiable according to the Infection Protection Act (IfSG). In Thuringia and Saxony-Anhalt, clinical suspicion is also reportable.
