Hygiene-related Diseases


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, Pascolini D, Etya’ale D, Kocur I, Pararajasegaram R, Pokharel GP, Mariotti SP. Global data on visual impairment in the year 2002.external icon Bull World Health Organ. 2004;82(11):844–51.
  2. Wright HR, Turner A, Taylor HR. Trachoma and poverty: unnecessary blindness further disadvantages the poorest people in the poorest countries.external icon Clin Exp Optom. 2007;90(6):422-8.
  3. WHO. Alliance for the Global Elimination of Blinding Trachoma by 2020.external icon 2003.
  4. Mariotti SP, Pruss A. The SAFE strategy. Preventing trachoma: a guide for environmental sanitation and improved hygiene. pdf icon[PDF – 36 pages]external icon 2001.
  5. West SK. Blinding trachoma: prevention with the safe strategy.external icon Am J Trop Med Hyg. 2003;69(5 Suppl):18-23.
  6. Wright HR, Turner A, Taylor HR. Trachoma.external icon Lancet. 2008;371(9628):1945-54.
  7. Emerson PM, Cairncross S, Bailey RL, Mabey DC. Review of the evidence base for the ‘F’ and ‘E’ components of the SAFE strategy for trachoma control.external icon Trop Med Int Health. 2000;5(8):515-27.
  8. Courtright P, West SK. Contribution of sex-linked biology and gender roles to disparities with trachoma.external icon Emerg Infect Dis. 2004;10(11):2012-6.
  9. Ngondi J, Matthews F, Reacher M, Baba S, Brayne C, Emerson P. Associations between active trachoma and community intervention with antibiotics, facial cleanliness, and environmental improvement (A,F,E).external icon PLoS Negl Trop Dis. 2008;2(4):e229.
  10. Emerson PM, Ngondi J. Mass antibiotic treatment alone does not eliminate ocular chlamydial infection.external icon PLoS Negl Trop Dis. 2009;3(3):e394.
Page last reviewed: November 3, 2021