Introduction
Trachoma is a highly infectious ocular infection caused by Chlamydia trachomatis, which is an obligate intracellular bacterium. Trachoma is the main cause of preventable blindness in the world. At the turn of the twentieth century, trachoma was prevalent in Europe and North America, but disappeared by the middle of the century when improvements to living conditions and hygiene practices occurred. However, trachoma is currently a major public health crisis in many of the developing countries of the world. The disease mainly affects the poor, rural populations in these regions. The disease is found predominantly in sub-Saharan Africa, Asia, and parts of the Middle East. Areas of Central and South America are also affected, as well as some areas in Oceania, including Australia. [1][2][3]
Children, especially small children, are the main reservoirs of Chlamydia trachomatis. Trachoma infections are contracted by passing infected eye secretions while in close proximity to each other, such as while sharing a bed or while playing. Sharing household items, such as towels and washcloths, also transmit the infection from one individual to another. In addition, eye-seeking flies, which have been associated with trachoma infection transmission for hundreds of years, transmit the infection from person to person. [1][4][5]
The most prevalent form of the disease is active trachoma. Active trachoma is defined as “papillary and/or follicular inflammation of the tarsal conjunctiva.” [1] Trichiasis is a more serious and progressed form of the disease that is characterized by the eyelids rolling up towards the eyeball and the eyelashes abrading the surface of the eyeball. Without proper interventions, trichiasis can lead to blinding corneal opacification, which is the most severe form of the disease. However, trichiasis alone may not be the only risk factor for the development of blindness; bacterial infection and chronic conjunctival inflammation are also thought to contribute to blinding corneal opacification. [4] In 1987, the World Health Organization (WHO) developed a diagnostic grading system to classify trachoma for trachoma control programs. This system is called The WHO Simplified Trachoma Grading System. The World Health Organization grading system further divides active trachoma into two clinical phenotypes: trachoma inflammation follicular (TF) and trachoma inflammation intense (TI). [1][2] TF is described as “the presence of five or more follicles (>0.5mm) in the upper tarsal conjunctiva” and TI is described as “pronounced inflammatory thickening of the tarsal conjunctiva that obscures more than half of the deep normal vessels.” The WHO grading system also defines trachomatous scarring (TS) as “the presence of scarring in the tarsal conjunctiva,” trachomatous trichiasis (TT) as “at least one lash rubs on the eyeball,” and corneal opacity (CO) as “easily visible corneal opacity over the pupil.” [1]
A resolution passed by the World Health Assembly in 1998 called for the elimination of blinding trachoma by 2020. In response to this resolution, The World Health Organization and the International Agency for the Prevention of Blindness formed the Global Alliance for the Elimination of Blinding Trachoma by 2020 (GET 2020). The main goal of this alliance is not to completely eliminate human infection with Chlamydia trachomatis, but rather to eradicate endemic blinding trachoma. [1][5] In 1998, the Edna McConnell Clark Foundation and the drug manufacturer, Pfizer, created the International Trachoma Initiative, which distributes azithromycin, the recommended antibiotic treatment for trachoma infection. Since 2000, representatives of a small number (7-12) of trachoma-endemic countries have met annually at the Carter Center in Atlanta, Georgia to share information and to discuss the latest developments in research. All of these organizations have adopted the WHO-recommended trachoma control strategy called SAFE (Surgery for trichiasis, Antibiotics, Facial cleanliness, and Environmental improvement). [5] The goal of the SAFE strategy is to treat and prevent trachoma infections. This strategy is based on the best field research available.
Surgery
The objective of trachoma surgery is to correct trichiasis, or the rolling of the eyelashes. Even though trichiasis surgery is an important component to the SAFE strategy, it does have problems with high trichiasis recurrence rates and effective local service delivery. The recurrence rates are quite variable, from 5% to 40% recurrence 1 year after surgery. Recurrence of trichiasis may be expected because of the progressive character of trachoma, but the main causes are frequently due to inadequate surgical technique, recurrent infection with Chlamydia trachomatis, additional bacterial infections, conjunctival inflammation, and residing in high-risk regions. Other factors that may contribute to the high recurrence rates of trichiasis surgery include the severity of trichiasis before the operation, varying surgical techniques, and the surgeons themselves. To address some of these issues, it is recommended that trichiasis surgery be performed during the early stages of the disease, with standardized and accountable procedures. A large majority of people requiring trichiasis surgery do not seek medical help. The barriers to trichiasis surgery include being unaware that trichiasis causes blindness and that surgery is available; fear of surgery and of unfavorable outcomes; and fear of the direct (surgery and transportation) and indirect costs (missing work, childcare) of surgery. In order to address these barriers to surgery, it is recommended that improved community awareness of the need for and existence of trichiasis surgery be implemented, accessibility be improved by providing village-based surgery, and equipment shortages be dealt with. [4]
Antibiotics
The reasons for using antibiotics for trachoma control are to treat the individual infections with the hope of reducing the risk for the development of significant conjunctival scarring, and to reduce the transmission of trachoma infection to others. The mass drug administration of antibiotics to an entire endemic community is considered a reasonable method of treatment because many infected individuals are asymptomatic during examination. The “Azithromycin in Control of Trachoma” study published in 1999 was conducted in order to compare the effect of azithromycin with tetracycline when used for mass drug administration. This was a significant study in the development of global trachoma control because it “established the efficacy and safety of mass treatment with azithromycin,” provided the basis for the development of the International Trachoma Initiative, and strengthened the newly formed GET 2020 initiative. [5]
Facial cleanliness and environmental improvement
The facial cleanliness and environmental improvement components to the SAFE strategy are often discussed together because they are both preventative measures rather than treatment methods. Facial cleanliness is considered by some to be the most important aspect of the SAFE strategy because it is the “final common pathway” for each of the environmental-associated risk factors for trachoma infection, such as overcrowded living conditions that lead to the spread of “infected ocular secretions” found on dirty faces; dirty faces result from inadequate access to clean water or the ineffective use of water; inadequate access to latrines, improper waste disposal, and living with livestock all cause an increase in eye-seeking flies that are more attracted to dirty faces rather than clean ones. [4] As this list demonstrates, the recommended environmental improvements to living conditions includes such sanitary interventions as access to clean water, latrines, proper waste disposal sites, and proper housing of livestock away from living areas. Additional environmental improvement recommendations include insecticidal spray to control eye-seeking flies and community health education as well as personal and environmental hygiene education. There are several studies that have reported a correlation between inadequate facial hygiene and trachoma infection rates. In Sudan, a 3-year follow-up study of the SAFE strategy reported a greater decrease in the occurrence of active trachoma in areas where a larger number of facial cleanliness and environmental improvement practices were implemented. [6] study was conducted in the Gambia that found that there was a decrease in risk for trachoma infection when households used a larger percentage of their water supply for hygienic purposes compared with those who did not. [5]
Each component of the SAFE strategy is considered successful as evidenced in current published data. [1] There are many reasons for the success of the SAFE strategy. One important advantage to SAFE is its simplicity; the program is uncomplicated and easily implemented. The distribution of most of the services outlined in the SAFE strategy (eg, antibiotics distribution, latrine distribution/promotion) is effectively and affordably carried out by non-specialists. Azithromycin is well tolerated and has the added advantages of being effective against malaria and respiratory and skin infections. There has not been any reported evidence of resistance to azithromycin by Chlamydia trachomatis. Azithromycin is donated and distributed to trachoma-endemic countries. Mass drug administration of azithromycin is effective, practical, and accepted by communities. Some governments of trachoma-endemic countries have stepped up their commitment to trachoma control efforts based on the advocacy and involvement of nongovernmental organizations worldwide. Frequent meetings between and within programs permit effective exchange of information and quick implementation of new ideas and practices. [5] The combination of each of these factors has lead to the success of the SAFE strategy.
Statistic
- Trachoma is endemic in 57 countries.
- Trachoma contributes 4% of global blindness, which is down from 15% in 1995.
- Trachoma is the eighth most common infectious blinding disease in the world.
- Approximately 1.3 million people are blind resulting from trachoma.
- Approximately 1.8 million people have low vision (“visual acuity of less than 6/18 (20/60) but equal to or better than 3/60 in the better eye with best possible correction” ) [1] resulting from trachoma infection.
- Approximately 40 million people have active trachoma.
- Approximately 8.2 million people have trichiasis.
- An estimated 50% of the world burden of trichiasis is found in China, Ethiopia, and Sudan.
- Ethiopia and Sudan have the highest occurrence of trachoma, with 50% of children younger than 10 years of age having active trachoma and 19% of adults having trichiasis.
- Approximately 90% of people who have trichiasis do not seek medical help. [1][4]
Signs and Symptoms
The following list does not insure the presence of this health condition. Please see the text and your healthcare professional for more information.
Symptoms of trachoma infection include pain, tearing, swollen eyelids, discharge, sensitivity to light, and the growth of follicles on the conjunctivae of the upper eyelids. If the infection goes untreated, these follicles will develop into large yellow/gray pimples. Recurrent infection with Chlamydia trachomatis results in chronic inflammation that causes scar tissue within the conjunctiva. When this scar tissue builds up it contracts, which causes the eyelids to roll up towards the eye as well as the eyelashes to scratch the surface of the eye (called trichiasis). Untreated trichiasis can ultimately result in permanent blindness. [4][7]
Treatment Options
Conventional
The current World Health Organization treatment guidelines for the treatment of trachoma is either a single, oral dose of azithromycin (20 mg/kg; not exceeding 1g) or 1% topical tetracycline ointment applied to both eyes daily for 6 weeks. Annual mass drug administration is recommended for entire endemic communities if the prevalence of follicular trachoma in 1- to 9-year old children is greater than or equal to 10%. It is recommended that annual mass drug administration should continue annually for at least 3 years or until the prevalence level is less than 5%. [1][4] The World Health Organization recommends the surgical procedure bilateral tarsal rotation to correct trichiasis, without regard to number of eyelashes touching the eye or the position of the eyelashes. [4]
Nutritional Supplementation
Vitamin A
Most research regarding nutrition and eye diseases evaluates the link between Vitamin A status and risk of blindness from various causes including Trachoma. [8][9][10][11][12] Vitamin A belongs to a class of compounds called retinoids, which only occur in animal products. Retinoids with vitamin A activity occur in nature in three different forms: a) the alcohol, retinol, b) the aldehyde, retinal or retinaldehyde, and c) the acid, retinoic acid. Vitamin A requires fats as well as minerals in order to be properly absorbed from the digestive tract. Substantial amounts of vitamin A are stored in the liver, and therefore, it does not need to be supplied in the diet on a daily basis.
Herbal Supplementation
Many cultures who have populations that are at risk for Trachoma seek traditional medicine therapies as a first line of treatment. [13][14][15] In most instances, these therapies are in the form of eyewashes or compresses and are made using the botanicals that are listed below. This list is not all-encompassing but rather represents a general sampling of those botanicals that are used to treat and relieve the symptoms of various eye conditions such as Trachoma.
Goldenseal
Goldenseal has a long history of use globally as a medicinal herb. It was initially used by tribal cultures and gained popularity with the eclectic medical movement from the 1850’s to the 1940’s. It has been used for GI disturbances, as an anti-infective, to stimulate bile flow, and as an eye wash. The isoquinoline alkaloid, berberine, is contained in goldenseal and is responsible for some of the pharmacological activity
Yarrow
Achillea millefolium, or Yarrow, is an herbaceous flowering plant found throughout the Northern hemisphere to an elevation of 3,500m. Growing to a height of 1m, Yarrow has pubescent leaves ranging from 5 to 20cm long, with the larger leaves located toward the bottom and middle of the plant. The diminutive flowers grow as a crown at the top of the plant from May to June, ranging from white to lavender in color. Thought to originate in Europe, Yarrow has flourished in the North American grasslands due to its ability to withstand drought. Yarrow’s traditional use as an anti-inflammatory agent has been supported in laboratory settings indicating its potential use as a non steroidal anti-inflammatory agent.
Chickweed
Stellaria media, or Chickweed, is a member of the Caryophyllaceae family and is easily recognizable by its numerous, delicate, star-shaped white flowers and oval leaves. It is an ancient plant, likely pre-neotlithic, and has been used as food and as medicine. It has been consumed in salads, as cooked greens, and has been fed to poultry to increase the output of eggs. Traditionally, Chickweed has been used to treat a variety of internal and external ailments including inflammatory and cutaneous disorders.
Calendula
Used since ancient times as a healing agent, Calendula is mentioned in herbal books that date back to 1373. The name Calendula refers to the plant’s tendency to bloom in accordance with the calendar – every month in some regions of the Mediterranean, or during the new moon. Used historically as “poor man’s saffron,” Calendula was used both as a culinary herb and spice as well as a medicinal agent. Extracts of Calendula flowers are popular as ingredients in various first aid and cosmetic formulations in Europe. Calendula is listed in the German Commission E Monographs for use as a mouthwash for the oral and pharyngeal mucosa as well as topically for the skin. Calendula is often used in compresses and in topical ‘washes’ both alone and in combination with other botanicals.
Clinical Notes
The current laboratory tests that produce the highest sensitivity and the most precise results in the detection of trachoma are nucleic amplification tests, such as polymerase chain reaction (PCR). However, the cost of such tests and the poor accessibility to these tests in regions where trachoma is endemic has caused some experts to suggest that diagnosis of trachoma in the field should be conducted using clinical methods, such as the World Health Organization grading system, even though this system can lead to an overestimation of individuals who need antibacterial treatment. [4]
References
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- J. Ngondi, A. Onsarigo, F. Matthews. Effect of 3 years of SAFE (surgery, antibiotics, facial cleanliness, and environmental change) strategy for trachoma control in southern Sudan: a cross-sectional study. The Lancet 2006; 368: 589-595.
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- F.O. Abessolo, E. Kuissi, J.C. Nguele, G.J. Lémamy, Z. Ndong, E. Ngou-Milama. Vitamin A in Gabonese children not receiving supplements: relation to ocular and nutritional diseases. Sante. Jan-Mar2009;19(1):29-33.
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