Epidemic keratoconjunctivitis is a severe, highly contagious adenoviral ocular disease caused primarily by Human adenovirus species D (HAdV-D) types 8, 37, and 64, with emerging recombinant types 53, 54, and 56 increasingly identified as etiologic agents [1]. It is one of two well-defined adenoviral keratoconjunctivitis clinical syndromes, distinguished from pharyngoconjunctival fever by the absence of systemic symptoms and by its propensity for corneal involvement [2].
Disease overview
Epidemic keratoconjunctivitis
流行性角结膜炎
Evidence-backed informationEN 5/7 applicable sections · ZH 5/7 applicable sectionsUpdated Sep 3, 2026
Epidemic keratoconjunctivitis (EKC) is a highly contagious infectious ocular disease caused by adenovirus that presents as severe conjunctival inflammation involving the cornea, potentially leading to corneal opacities and blurred vision that can persist for months [1]. It is one of two well-defined adenoviral keratoconjunctivitis clinical syndromes and is the most severe form of ocular adenoviral infection [2][3]. EKC is responsible for outbreaks worldwide and is characterized by high transmissibility through direct contact and fomites [1][3]. Cases are more frequent during warmer months, though exact incidence remains unknown [2].
Read the full clinical and epidemiological profile6
EKC presents with watery discharge, conjunctival hyperemia, chemosis, and ipsilateral lymphadenopathy [3]. Corneal involvement includes keratitis nummularis and subepithelial infiltrates that can lead to corneal opacities and prolonged blurred vision [2][1]. Pseudomembranes occur with higher frequency than in other forms of conjunctivitis [2]. The majority of cases are self-limited, though complications affecting vision may persist for months [2][1].
Exact incidence of adenoviral conjunctivitis is unknown, but cases are more frequent during warmer months [2]. EKC is highly contagious and responsible for outbreaks worldwide, making accurate diagnosis and rapid containment imperative [1]. Recombinant HAdV-D types 53, 54, and 56 have emerged as additional etiologic agents and may have been underdiagnosed as sources of new outbreaks [1].
EKC is transmitted through direct hand-to-eye contact, contact with fomites, respiratory droplets, and ocular secretions [2][3]. The virus is extremely resistant to different physical and chemical agents, facilitating environmental spread [2]. Transmission can also occur through contact with ophthalmic care providers and their medical instruments [3].
Prevention is the most reliable way to control this contagious infection given that no treatment appears completely effective [2]. Rigorous hand hygiene, proper disinfection of ophthalmic instruments, and isolation of affected individuals are essential preventive measures [2]. The extreme resistance of the virus to physical and chemical agents necessitates careful environmental decontamination [2].
- 1Gonzalez G et al. Challenges in management of epidemic keratoconjunctivitis with emerging recombinant human adenoviruses. J Clin Virol. 2019 Mar. PMID: 30654207. doi: 10.1016/j.jcv.2019.01.004.PubMed: https://pubmed.ncbi.nlm.nih.gov/30654207/
- 2González-López JJ et al. Adenoviral keratoconjunctivitis: an update. Arch Soc Esp Oftalmol. 2013 Mar. PMID: 23473088. doi: 10.1016/j.oftal.2012.07.007.PubMed: https://pubmed.ncbi.nlm.nih.gov/23473088/
- 3Jhanji V et al. Adenoviral keratoconjunctivitis. Surv Ophthalmol. 2015 Sep-Oct. PMID: 26077630. doi: 10.1016/j.survophthal.2015.04.001.PubMed: https://pubmed.ncbi.nlm.nih.gov/26077630/
Coverage
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Data access
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Official sourcesAuthority, cadence, notes1
JP NIID Weekly
Japan
Japan weekly infectious disease surveillance via NIID/JIHS.