Trachoma

Trachoma is an eye disorder caused by Chlamydia trachomatis infection. It is the most common cause of blindness due to infection in the world.

The infection spreads through contact with the eye discharge, nose discharge or throat discharge of someone with active disease.

The contact can be direct or indirect via fomites (commonly touched surfaces like lift buttons and doorknobs), bedclothes, handkerchiefs and other shared items.

It can also spread via hands, which is why maintaining hand hygiene is crucial to avoid this infection. It is also a good idea to avoid touching your face and eyes, to prevent all kinds of infection.

Flies can also transmit the infection, by transferring eye, nose and throat discharge from infected persons to healthy ones.

In places where there is poor personal hygiene, researchers have also linked the spread of infection among children to dirty faces (because any discharge from the eye stays there for longer).

In places where hygiene is generally poor and the infection is common, infection tends to spread from older family member to younger ones.

Preschool-aged children are the most susceptible to fresh infections.

In places where trachoma is endemic, the chances of repeated infections are very high. While the body is usually equipped to handle one-off infections by Chlamydia trachomatis, repeat infections can scar the inside of the eyelids (trachomatous conjunctival scarring) so they turn inwards. This affects the direction of the eyelashes (trachomatous trichiasis) which, in turn, can scratch and scar the eyeball. People who have had repeated episodes of trachoma infection tend to have increased light sensitivity, eye pain and cornea problems.

Untreated infections can cause blindness, as the scarring of the eye can cause opacities to build up.

In 2017, India declared itself trachoma-free. According to the WHO, though, as of 10 September 2020, only 10 out of 53 countries across Africa, Asia and Central and South America had eliminated trachoma as a public health threat. These countries are Cambodia, China, Islamic Republic of Iran, Lao People’s Democratic Republic, Ghana, Mexico, Morocco, Myanmar, Nepal and Oman. The WHO defines “elimination of trachoma as a public health problem” as meeting the following three criteria:

• Less than 0.2% of the population aged 15 and above has trachomatous trichiasis “unknown to the health system”. That is roughly one case per 1000 total population
• Two years or more in which fewer than 5% of children between one and nine years of age have the first stage of trachoma—trachomatous inflammation-follicular—without resorting to mass treatments with antibiotics. The WHO checks each district where the infection was endemic (present continually at low levels) to validate
• There should be a system in place to identify and manage any cases of trachomatous trichiasis, with properly outlined and funds to prevent the resurgence of infections in the area

According to the World Health Organization (WHO), there are five stages of trachoma:

• Stage 1: Small white bumps containing lymphocytes (white blood cells) appear on the inner surface of the upper eyelid. These bumps are visible under magnification.
• Stage 2: There is active infection with intense inflammation and irritation in the eye. There may be swelling or thickening in the upper eyelid.
• Stage 3: The inner surface of the eyelids becomes scarred as a result of repeated infections. In some patients, the eyelids may also turn in, a condition known as entropion.
• Stage 4: As the upper eyelids become scarred and start to turn inwards (entropion), the eyelashes too turn in towards the eyeball. When the eyelashes rub against the eyeball, they can scratch the cornea (outermost covering of the eye).
• Stage 5: The cornea becomes cloudy because of eyelid inflammation and continued scratching by the ingrown eyelashes (trichiasis) or eyelashes that are turned inward.

As the condition advances, a thick line can sometimes appear on the eyelids that is visible from the outside. This happens because of scarring, a natural response of the body to inflammation.

Trachoma is an eye disorder that typically affects both eyes together. The incubation period is six to 12 days, meaning it takes six to 12 days for symptoms to show up after someone contracts the Chlamydia trachomatis bacteria. Some of the symptoms of this bacterial infection of the eyes are:

• Mild eye irritation and conjunctivitis like symptoms in the early stages
• Eye discharge that could contain mucus or pus
• Eye pain
• Light sensitivity
• Swelling in eyelids
• Thickening of eyelids
• Trichiasis or eyelashes that are turned abnormally
• In more advanced stages, the upper eyelid could become deformed and the eyelashes could turn inward, scratching the cornea. This is what leads to clouding of the cornea

In areas where the infection is widespread, it tends to affect young children. Where treatment with antibiotics and surgery is not available, patients can go blind, often by the time they are 30-40 years old.

Trachoma is caused by a bacteria called Chlamydia trachomatis. In areas where the infection is endemic, it typically affects young children. Often, children get the infection from older family members. Direct or indirect contact with patients spread the infection. Flies, too, can transmit the bacteria.

Repeat cases of infection are common in endemic areas—this repetition makes things worse for patients. In the absence of treatment with antibiotics or surgery, patients would develop symptoms like entropion (eyelids turning), trichiasis (misdirection of eyelashes), clouding of the cornea and eventually blindness. A common complication of this infection is corneal ulcers.

Currently, there is no vaccine for trachoma. However, the WHO has a SAFE protocol to prevent trachoma. SAFE stands for 

• Surgery to prevent blindness if the disease has progressed to trachomatous trichiasis or stage 4-5
• Antibiotics to treat the infection. In areas where the infection is endemic (especially where more than 10% of children in a community have the infection), mass treatment with azithromycin may be advised
• Facial cleanliness: Especially in children, as they are more prone to infection and ocular or eye discharges can stay on the face for a long time unless they are cleaned.
• Environmental improvement: Improving hygiene and access to clean water and sanitation can go a long way to contain the infection.

Prevention is linked to maintaining good hygiene and practices that deter the spread of infectious diseases. Some of the steps to prevent infection include:

• Observing good hand hygiene by cleaning hands with soap and water (or alcohol-based hand sanitizer) often for at least 20 seconds.
• Avoiding touching your face. This can help prevent many infections, as we have mucus membrane in our eyes, nose and throat that can become the entry point for pathogens into the body.
• Trachoma mostly affects young children in areas where it is endemic. Children’s faces can become dirty quickly. If you have children, it is important to keep their hands and faces clean and talk to them about the importance of hygiene and how to maintain it.
• If you live in an area where trachoma is widespread, do not ignore cases of conjunctivitis and eye irritation. See a doctor at the earliest.
• Checking the growth of flies in the area can also reduce the risk of transmission.

A doctor can diagnose trachoma after a physical examination. He or she may also send a sample of your eye discharge to a lab for testing.

The treatment for trachoma depends on the stage at which it is diagnosed. In the earlier stages, the doctor may give a tetracycline (antibiotic) based eye ointment or azithromycin.

In cases where repeated infections have caused scarring of the inner eyelids and turning of the eyelashes, surgery may be necessary to prevent blindness.

1. Trachoma surgery