Trachoma is the most common infectious cause of vision loss in the world. Approximately 1.9 million people are blinded by trachoma. (Trachoma, 2024) https://www.who.int/news-room/fact-sheets/detail/trachoma It accounts for 1.4% of all blindness worldwide. https://www.who.int/news-room/fact-sheets/detail/trachoma

As a completely preventable cause of blindness, trachoma has been targeted by the World Health Organization (WHO) for elimination through its GET2020 initiative, a global program to stop the cycle of infection with the SAFE strategy: surgery, antibiotics, facial hygiene, and environment improvement.  

As of 2024, massive progress has been made on the initiative: “The number of people affected by blinding trachoma has been reduced by over 90%,” explains Dr. Hugh Taylor, who serves on the Emeritus Board of Directors of Cure Blindness Project. Taylor has studied trachoma internationally for decades and has advised the World Health Organization on eye health. 

Trachoma affected about 1.2 billion when the World Health Organization’s 2020 project started and now there are only about 21 million https://eyewiki.org/Trachoma at risk. Of the 50 countries identified to have trachoma when the GET2020 program started, 21 countries have been certified by WHO as having eliminated trachoma. https://www.who.int/news-room/fact-sheets/detail/trachoma

Trachoma Symptoms

As a recurring infection to the surface of the eye, trachoma leads to conjunctival inflammation, ocular scarring, in-turned eyelashes and trichiasis. https://eyewiki.org/Trachoma Trachoma usually affects both eyes. https://www.merckmanuals.com/professional/eye-disorders/conjunctival-and-scleral-disorders/trachoma At its worst, trachoma disease can cause the eye’s cornea to become scarred and opaque, blocking sight.

Most individuals have various mild trachoma symptoms or can be asymptomatic. https://eyewiki.org/Trachoma Symptoms, if present, include chronic redness, discomfort, tearing, light sensitivity, and mucopurulent discharge. https://eyewiki.org/Trachoma When the irritated eyelids swell and scar on the inner surface of the lid, they cause the eyelashes to turn in and touch the eye. This then leaves scratches and scarring of the cornea. https://eyewiki.org/Trachoma Blindness from corneal opacity is a late-stage outcome of trachoma.

 

Bacteria Chlamydia is the Cause

Trachoma is caused by the bacterial organism known as Chlamydia trachomatis. Chlamydia may be more commonly known as a bacteria causing genital infections: indeed, the chlamydia strains of serotypes D-K and L1- L3 have this outcome. https://eyewiki.org/Trachoma By contrast, serotypes A, B, and C of chlamydia infect the eyes, and are primarily responsible for trachoma. https://www.sciencedirect.com/science/article/pii/S2452232516300750

“Every species has its own chlamydia,” explains Hugh Taylor, MD. “Chlamydia doesn't cause problems until you crowd together and have repeated episodes of infection. While there's been tremendous improvement in trachoma treatment, we will never be able to eradicate chlamydia.” 

When Trachoma Becomes Blinding Trachoma

Data scientists project that patients likely endure more than 150 infections before the disease becomes blinding. https://www.who.int/health-topics/trachoma#tab=tab_1 When healthy, the surface of the eye protects against microbes, trauma, and toxins. The ocular surface serves as a refractive surface for light to project through the ocular media and it makes sure the cornea remains clear.  

When unhealthy or unstable due to trauma or disease, the ocular surface’s protection function is compromised; this can mean corneal and conjunctival dysfunction ranging from mild abrasions to severe stem cell loss, resulting in decreased vision or blindness. https://www.sciencedirect.com/science/article/pii/S2452232516300750

Trachoma is Infectious, not Highly Contagious

“As an infectious disease, trachoma is not highly contagious. It needs direct or indirect contact of infected eye secretions and nasal secretions,” explains Taylor. “If you wash your hands after you've examined each person with trachoma, you're not going to get it. The transmission route is pretty clear.” 

Trachoma Can Infect Anyone, Anywhere

Trachoma is a public health problem in 38 counties and results in vision loss or irreversible blindness for approximately 1.9 million people. https://www.who.int/news-room/fact-sheets/detail/trachoma Trachoma disappeared from most high-income countries in the past century as living conditions and hygiene improved. Taylor notes that people in the US or Australia get chlamydial eye infection, although it is usually a singular infection, diagnosed as inclusion conjunctivitis, which dissipates within a month without permanent damage.  

However, in low- and middle-income countries, the scenario is less optimistic. “You might have 200 episodes of infection because you are crowded in with your little brother or sister, your little sons and daughters are infecting you all the time, then you get buildup of inflammation leading to scarring that leads to blindness,” Taylor explains. In areas where trachoma is endemic, 60-90% of preschoolers can have the active, inflammatory condition on a recurring basis. https://www.who.int/news-room/fact-sheets/detail/trachoma

Women experience blinding trachoma at a rate that is four times that of men. https://www.who.int/health-topics/trachoma#tab=tab_2 Describing his work in under-resourced countries, Taylor explains this disparity. “Women usually have more scarring and much more trichiasis than men because they're usually infected as young girls,” he observes. “They're looking after their brothers and sisters and then they're looking after their own kids. So they're in the milieu of re-infection while the boys are out there herding the cattle and harvesting the grain.

"The infection is transmitted from one infected eye to another by the eye secretions because the tears drain through the nose. Kids swap the infected eye and nasal secretions amongst themselves when they play together. If the mom uses the same cloth or the hem of a skirt to blow their noses or wash their faces, that can lead to transmission."

Treatment of Trachoma in Low- and Middle-Income Countries

The poorest and most remote regions of Africa, Central and South America, Asia, Australia and the Middle East experience hyperendemic incidences of trachoma. https://www.who.int/news-room/fact-sheets/detail/trachoma

WHO’s SAFE Strategy

The World Health Organization championed the four-step 'SAFE' strategy in 1993 and launched GET2020 (Global Elimination of Trachoma by the year 2020), later resetting the target date to 2030.  

SAFE strategy steps are:

S: Surgery for Trichiasis
A: Antibiotics for C. trachomatis infection
F: Facial cleanliness
E: Environmental change to improve sanitation and increase access to clean water. 

Surgery for Trichiasis

Trichiasis, a complication of trachoma, causes scarring of the eyelid and turns the eyelashes inward, scratching and eventually scarring the cornea. Surgery is uncomplicated and effective. Under local anesthesia, the patient’s eyelid is flipped inside out. An incision is made through the tarsal plate where the scarring is. The sutures in the lid change its contour, directing the eyelashes outward. The 15-minute procedure can be performed by trained ophthalmic nurses, ophthalmic support personnel or paramedics. 

Taylor, who has studied trachoma in five continents for decades, stresses the permanence of this type of blindness. “Once someone is blinded with the cornea scarring, there's really nothing you can do. Treatable trachoma becomes more or less irreversible trichiasis. Usually, the cornea cannot be repaired.” Corneal transplantation for trachoma sufferers, notes Taylor, is “pretty tricky”, requiring close supervision by a corneal specialist. “Even then, the chance of success is 50/50,” he reports.  

Having local people on the ground who can detect the in-turned lashes and treat them is very important. “Recognition in the community, by community people is crucial,” Taylor advocates. “Timely surgery will stop trichiasis patients from going blind if it is done early enough.” 

Timely surgery will stop trichiasis patients from going blind if it is done early enough. Dr. Hugh Taylor

Trachoma Treated with Antibiotics

In early stages, trachoma treatment addresses the chlamydia bacterial infection. Chlamydia has not become resistant to any antibiotic that's been used, from the first antibiotics (sulfonamides) in the 1930s to tetracyclines in 1948 to today’s azithromycin.  

“We have got a much better antibiotic than we had when I first started,” notes Taylor. “At first, we had to give people a sulfa drug Septrin twice a day for 28 days. Today, progress is made with just one dose of azithromycin. And azithromycin has been given out in hundreds of millions of doses.”

A single dose of azithromycin is 78 to 95% effective. https://www.merckmanuals.com/professional/eye-disorders/conjunctival-and-scleral-disorders/trachoma#Diagnosis_v1152237 “An antibiotic doesn't eliminate all the infection, but it reduces the level of infection dramatically, but if nothing else is changed, the infection rates will build up over the next year or so,” explains Taylor. “Local trachoma teams go around once a year and treat everybody in the communities with antibiotics.”

The International Trachoma Initiative and Pfizer have delivered more than one billion Zithromax® doses, and ITI’s global program has also reduced the need for azithromycin by more than 160 million doses through other SAFE measures. https://www.trachoma.org/

Facial Cleanliness to Prevent Trachoma

With his extensive experience treating trachoma, Taylor observes that the world's efforts to eliminate trachoma tend to emphasize surgery, antibiotic distribution, pit latrines and hand washing.

“However, to my mind, there has not been an emphasis on facial cleanliness, the final bottom line,” the ophthalmologist states.  

In areas where trachoma has disappeared, 95% of all children under the age of 15 have clean faces. However, Taylor applies the 30-60-90 rule in the areas where trachoma is a problem. He has found that only 30% of the 1- to 4-year-olds have a clean face, 60% of the 5- to 9-year-olds, and 90% of 10- to 15-year-olds. In some cases, they all live in the same house. They all have the same distance to the water supplies. It's really the cultural awareness and recognition of the importance of keeping the faces of young children clean. 

“We did a study in Tanzania years ago where water is carried in hollowed-out gourds,” recalls Taylor. “Collectively, we discovered that 15 faces could be washed with one gourd full of water. You don't actually need a lot of water. And you need to have clean faces to have safe eyes.”

Environmental Improvements and Clean Water

“Improving living conditions improves facial hygiene,” Taylor points out. “That's how trachoma disappeared in New York, in Mississippi, among the American Indian people in the southwest and among the Australian Aboriginal people.”  

Solutions include fly control and latrine sanitation, because flies may also play some role in transmission. Families in areas where trachoma is endemic have limited access to water. Accessible water means the kids can bathe and wash their faces. “If you had to walk an hour to carry a bucket of water, you're not going to waste it on washing your two-year-old's face so having water is important,” states Taylor. 

How Cure Blindness Project is Treating Trachoma

Trachoma is a public health problem in 38 countries https://www.who.int/news-room/fact-sheets/detail/trachoma and all of this burden can be eliminated. Cure Blindness Project, a global non-profit organization, treats trachoma in underserved communities in 30 nations across sub-Saharan Africa, South Asia and South America.

The care model of Cure Blindness Project begins with bringing high quality ophthalmology to those who need it and continues to address eye diseases through prevention measures and well-trained local capacity. Its volunteer ophthalmologists with partners have performed more than 1.6 million sight-restoring surgeries and more than 16.5 million eye screenings. 

Cure Blindness Project frequently combines its efforts with other sight-restoring organizations. Recently, Cure Blindness Project partnered with The Carter Center in surgical outreaches targeting trachomatous trichiasis (TT) and other eye diseases in South Sudan, preventing blindness for people experiencing vision loss there.  “We've taken the rate of trachoma to 10 percent of what it once was. Where there was a problem is now no longer a problem,” notes Taylor. “But there are still millions at risk, so we must not lose our momentum to stop the cycle of infection and eradicate trachoma completely.”