Introduction

Epidemic keratoconjunctivitis (EKC) refers to an infection that causes your eyes to become irritated and inflamed. In EKC, the infection is caused by a virus known as an adenovirus. EKC is highly contagious, and you may contract the virus if you have come into close contact with an infected person or touched surfaces that an infected person has also touched. The virus infects the transparent outer part of the eyeball, specifically the cornea and conjunctiva. The cornea is the transparent membrane that covers the pupil and iris at the front of your eye, whilst the conjunctiva covers the thick outer part (sclera) of the rest of the eyeball and the inside of the eyelids.

This article will take you through epidemic keratoconjunctivitis, giving you more details on how the disease affects your eyes and why it is so contagious.

Overview of EKC

Description of EKC

EKC is a contagious infection of the eye that leads to the reddening of your eyes. It is one of many causes of irritation in the eye. This irritation leads to a feeling of having a foreign object in your eye and also affects your sight. The disease often persists for between 3 and 6 weeks, with the incubation period being about 2-14 days after having come into contact with the virus. The symptoms usually only affect one of your eyes, but in many cases, your other eye may also become affected as your hands transfer virus-containing fluid from your infected eye to your healthy eye.^3,4 This 3 to 6-week window where the disease causes symptoms is said to be the acute phase of the disease. EKC is said to be self-limiting because the adenovirus is eventually removed from the body, and the symptoms go away.^1,5

Why is EKC so contagious?

Adenoviruses are quite resilient. This means that the adenoviruses can stay on surfaces and remain infective for extended periods of time⁵. This is why EKC is so contagious. Therefore, EKC outbreaks are most likely to happen in places that people frequent. This includes schools, hospitals and workplaces. Also contributing to EKC being so contagious is the fact that people who are in the incubation period of the disease may also pass on the virus to healthy people. Infected doctors who have previously treated patients with EKC may unknowingly pass on the disease to healthy patients, or the outbreak may occur amongst school pupils where classrooms and playgrounds are shared. EKC affects people of all demographics alike. In Asia, however, the disease seems to affect children more.

EKC is not the only type of keratoconjunctivitis

In understanding EKC, it is also important to be aware that the word keratoconjunctivitis simply refers to the inflammation or irritation of the eye, even if it is not infected by the adenovirus. The other causes of keratoconjunctivitis, which do not involve the adenovirus infecting your eyes, are described here:^3,4,6

• Allergic keratoconjunctivitis. This type of keratoconjunctivitis may also be referred to as vernal or atopic keratoconjunctivitis. It is caused by allergies
• Keratoconjunctivitis sicca. This type of keratoconjunctivitis is due to dryness in your eyes that is caused by a problem in the system that produces tears in your eyes. This condition is referred to as tear film insufficiency or dry eye syndrome
• Superior limbic keratoconjunctivitis. The cause of this type of keratoconjunctivitis is usually unknown, but trauma to your eyes is thought to also be a contributing factor
• Phlyctenular keratoconjunctivitis. With this type of keratoconjunctivitis, bacterial infections are usually the culprits, especially Staphylococcus aureus, Mycobacterium tuberculosis and Chlamydia

An additional point that needs to be made, for clarity’s sake, is that keratoconjunctivitis is a combination of two types of eye irritation conditions. These conditions are keratitis and conjunctivitis, hence the name keratoconjunctivitis. Conjunctivitis, which is commonly referred to as pink-eye, refers to the involvement of the conjunctiva, whilst keratitis points to the cornea.

Symptoms of EKC

Listed here are some of the clinical features of EKC:^2,3,5

• Sensitivity to light (photophobia)
• Blurry vision
• Redness
• Pain in the eyes
• Swollen eyelids
• Eye discharge
• In some cases, the discharge from the eyes can make it difficult to open your eyes when you wake up because it may cause the eyelids to stick together
• Preauricular lymphadenopathy, whereby the lymph nodes at the sides of the head swell up
• Flaking or the appearance of crusting on or around the eyes or eyelids
• Symptoms that may be associated with the flu. These include fevers, headaches and fatigue

In a number of people, what is called a pseudomembrane (also referred to as nummuli) can form in the area of the cornea. When the eye is inflamed or infected, this pseudomembrane, which consists of immune cells and waste caused by inflammation, begins to form. The pseudomembranes significantly impair vision and usually last for several weeks. However, the pseudomembranes may persist for longer periods of time, running into years. The formation of this pseudomembrane on the cornea is known as epithelial keratitis. Because of the pseudomembranes, irregular astigmatism may also occur. In irregular astigmatism, the cornea at the front of the eye loses its normal curved shape and takes a random shape, affecting how light enters the eye. This negatively affects vision.²

Diagnosis of EKC

For diagnosis, numerous factors need to be taken into consideration. Adenoviruses are not the only type of virus to cause eye infections. So, there is a need for lab tests that will ensure that adenoviruses are the cause of the infection. There also have to be measures to eliminate the other types of keratoconjunctivitis, which are not due to the adenovirus.

Treatment of EKC

There is no specific medical treatment that is indicated for EKC; the disease goes away in due course. You can, however, apply some measures in order to alleviate symptoms. For example, if you use contact lenses, you need to stop wearing them until symptoms go away. You can also compress your eyes with something cold, like ice. Cycloplegic drugs, which relax the eye muscles, also help in relieving your symptoms. Sunglasses can reduce the amount of light entering your eyes to deal with photophobia. The sunglasses can also act as a physical barrier to prevent irritants such as dust from further aggravating the condition. Also, eyewear can prevent eye rubbing.

Another form of treatment that is still fairly recent or is being considered for EKC is the use of povidone-iodine eyedrops. In clinical studies, these eyedrops reduced the amount of adenovirus and alleviated the symptoms of EKC.²

Prevention of EKC to limit the contagion

Since EKC is a viral disease, hygiene interventions can help in reducing the spread of infection from one person to the next. In clinical practice, ophthalmology practices or units need to make sure that all equipment that a patient comes into contact with is free of possible contamination, which may have come from previous patients. This is done by disinfecting surfaces and medical equipment. In schools and workplaces, people who have EKC should stay away until such a time as it is ascertained that they are no longer having symptoms and that they will not spread the infection.^1,2,5

FAQs

How does EKC spread?

You may contract EKC if you come into close contact with a person who is infected or if you touch surfaces on which a person with EKC could have left the adenovirus.

What causes EKC?

EKC is caused by adenoviruses that infect the cornea and conjunctiva of the eyes.

How can you treat EKC?

There is no specific treatment for EKC. To relieve symptoms, you can compress your eyes with something cold and avoid wearing contact lenses until your eyes get back to their normal condition.

How long does it take for EKC to go away?

Once your eyes come into contact with the virus, it may take up to 14 days for you to get symptoms. The symptoms last for 3 to 6 weeks.

Summary

EKC is an infection of the eyes that is caused by adenoviruses. This infection affects the cornea and the conjunctiva, leading to the eyes becoming red. This leads to your eyes feeling as if there is a foreign object that has entered them, and it may also affect your eyesight. EKC may also cause light sensitivity. The symptoms of EKC last for about 3 to 6 weeks. EKC is very contagious because adenoviruses are able to spread between people by direct contact, or if you touch surfaces that have already been touched by an infected person. Adenoviruses can stay on surfaces for an extended period whilst remaining infective, which makes them more likely to spread to other people. There is no specific treatment, but there are measures you can take to make your eyes feel better. This includes applying cold compresses to your eyes or wearing sunglasses. The spread of this highly contagious disease can be prevented by implementing hygiene measures in healthcare facilities, especially in ophthalmology units or practices. If you have EKC or suspect that you are infected, you should also stay away from public spaces such as schools or workplaces.