Epidemic keratoconjunctivitis

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].

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].

1. 1 Gonzalez 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/
2. 2 González-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/
3. 3 Jhanji 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/