Global & Disaster Medicine

CDC on Trachoma


Trachoma is an infectious disease of the eye cause by a bacteria called Chlamydia trachomatis. Five hundred forty million people are at risk in 55 countries, and 84 million are already infected. Repeated infections cause the eyelids to turn inward, at which point the eyelashes scrape and permanently scar the cornea. This stage of trachoma infection is called trichiasis and can lead to blindness.

The disease spreads quickly through close personal contact and often is more common in areas where people live close together. Often, whole communities can be affected. For these reasons, trachoma infections are often common in the poorest communities.

Trachoma is particularly common in children who are less than five years of age and in the adults – mainly women – who care for them. In some rural communities, 60 – 90 percent of children are infected.


Trachoma is the world’s leading cause of preventable blindness of infectious origin (1). Caused by the bacterium Chlamydia trachomatis, trachoma is easily spread through direct personal contact, shared towels and cloths, and flies that have come in contact with the eyes or nose of an infected person. If left untreated, repeated trachoma infections can cause severe scarring of the inside of the eyelid and can cause the eyelashes to scratch the cornea (trichiasis). In addition to causing pain, trichiasis permanently damages the cornea and can lead to irreversible blindness. Trachoma, which spreads in areas that lack adequate access to water and sanitation, affects the most marginalized communities in the world (2). Globally, almost 8 million people are visually impaired by trachoma; 500 million are at risk of blindness from the disease throughout 57 endemic countries (1).

The World Health Organization has targeted trachoma for elimination by 2020 through an innovative, multi-faceted public health strategy known as S.A.F.E. (3,4):

  • Surgery to correct the advanced, blinding stage of the disease (trichiasis),
  • Antibiotics to treat active infection,
  • Facial cleanliness and,
  • Environmental improvements in the areas of water and sanitation to reduce disease transmission


The comprehensive SAFE strategy combines measures for the treatment of active infection and trichiasis (S&A) with preventive measures to reduce disease transmission (F&E) (5,6). Implementation of the full SAFE strategy in endemic areas increases the effectiveness of trachoma programs. The F and E components of SAFE (7), which reduce disease transmission, are particularly critical to achieving sustainable elimination of trachoma.

The “F” in the SAFE strategy refers to facial cleanliness. Because trachoma is transmitted through close personal contact, it tends to occur in clusters, often infecting entire families and communities. Children, who are more likely to touch their eyes and have unclean faces that attract eye-seeking flies, are especially vulnerable to infection, as are women (8), the traditional caretakers of the home. Therefore, the promotion of good hygiene practices, such as hand washing and the washing of children’s faces at least once a day with water, is a key step in breaking the cycle of trachoma transmission (9).

The “E” in the SAFE strategy refers to environmental change. Improvements in community and household sanitation, such as the provision of household latrines, help control fly populations and breeding grounds. Increased access to water facilitates good hygiene practices and is vital to achieving sustainable elimination of the disease (10). Separation of animal quarters from human living space, as well as safe handling of food and drinking water, are also important environmental measures that affected communities can take within a trachoma control program.

For more information on trachoma, visit:

For more information on the SAFE strategy, visit:


  1. Resnikoff, S., et al. Global data on visual impairment in the year 2002. Bull World Health Organ, 2004. 82(11): p. 844-51.
  2. Wright, H.R., A. Turner, and H.R. Taylor. Trachoma and poverty: unnecessary blindness further disadvantages the poorest people in the poorest countries. Clin Exp Optom, 2007. 90(6): p. 422-8.
  3. World Health Organization. Alliance for the Global Elimination of Blinding Trachoma by 2020. Report of the 2nd Global Scientific Meeting on Trachoma, Geneva, 25-27 August 2003. (WHO/PBD/GET.03.1). 2003.
  4. Mariotti SP, P.A.. The SAFE strategy. Preventing trachoma: a guide for environmental sanitation and improved hygiene . Geneva: WHO, 2001 (WHO/PBD/GET/00.7/rev.1). 2001. Available at: [PDF – 2.78 mb].
  5. West, S.K.. Blinding trachoma: prevention with the safe strategy. Am J Trop Med Hyg, 2003. 69(5 Suppl): p. 18-23.
  6. Wright, H.R., A. Turner, and H.R. Taylor. Trachoma. Lancet, 2008. 371(9628): p. 1945-54.
  7. Emerson, P.M., et al. Review of the evidence base for the ‘F’ and ‘E’ components of the SAFE strategy for trachoma control. Trop Med Int Health, 2000. 5(8): p. 515-27.
  8. Courtright, P. and S.K. West. Contribution of sex-linked biology and gender roles to disparities with trachoma. Emerg Infect Dis, 2004. 10(11): p. 2012-6.
  9. Ngondi, J., et al., Associations between Active Trachoma and Community Intervention with Antibiotics, Facial Cleanliness, and Environmental Improvement (A,F,E). PLoS Negl Trop Dis, 2008. 2(4): p. e229.
  10. Emerson, P.M. and J. Ngondi, Mass antibiotic treatment alone does not eliminate ocular chlamydial infection. PLoS Negl Trop Dis, 2009. 3(3): p. e394.

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