Trachoma is caused by repeated infection of the eyes with the bacterium Chlamydia trachomatis, which is spread mainly through eye and nose secretions, contaminated objects, and eyeā€‘seeking flies in areas with poor hygiene and crowded living conditions.

Core medical cause

  • Trachoma is an infectious eye disease caused by specific strains (serovars A, B, C) of the bacterium Chlamydia trachomatis, which infect the conjunctiva (the thin membrane lining the eyelids and eye surface).
  • Repeated or chronic infections over years trigger inflammation and scarring of the inner eyelid, which can eventually cause the eyelashes to turn inward and scratch the cornea, leading to vision loss or blindness.

How trachoma spreads

  • Transmission happens through direct contact with eye or nose discharge from an infected person, for example via hands, faceā€‘toā€‘face contact, or caring for infected children.
  • Indirect spread occurs via contaminated towels, clothing, bed linen and other fomites, and via eyeā€‘seeking flies that land on infected ocular or nasal secretions and then on another personā€™s face.

Environmental and lifestyle risk factors

  • Crowded housing, limited access to clean water, and poor sanitation all increase the risk of transmission, especially when childrenā€™s faces are not washed frequently and eye discharge is common.
  • Communities in rural, remote and impoverished settings, particularly in some parts of Africa, the Middle East, Asia, Latin America and Indigenous communities in Australia, remain most affected because of high fly density, inadequate latrines and lower health service access.

Who is most at risk

  • Young children are usually the main reservoir of infection, experiencing repeated bouts of active trachoma; adults, especially women who care for children, are often the ones who later develop scarring and blinding complications.
  • Households where many people share limited washing facilities, towels or bedding, or where faces are not cleaned regularly, see more frequent infection and reinfection.

Quick prevention context

  • Because the root cause is bacterial infection plus repeated transmission in unhygienic, crowded environments, key prevention focuses on the WHO ā€œSAFEā€ package: Surgery for advanced scarring, Antibiotics to clear infection, Facial cleanliness, and Environmental improvement (water, sanitation, fly control).
  • Regular faceā€‘washing for children, safe water, improved sanitation, and reducing fly breeding around human waste are critical to breaking the cycle of infection and preventing trachomaā€‘related blindness.

Information gathered from public forums or data available on the internet and portrayed here.