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A chronic keratoconjunctivitis caused by Chlamydia trachomatis is the leading cause of infectious blindness in the world.
Causes 15% of global blindness, making it the second major cause of blindness after cataracts.
Has disappeared from the developed world, but remains endemic in poor rural areas of 55 countries, mostly in Africa and Asia.
A prevalence rate of less than 5% among children 1 to 9 years is thought to eliminate blindness risk.
Estimated that 146 million individuals worldwide need treatment for trachoma to prevent blindness.
Estimated by the WHO that 7.6 million individuals have potentially blinding sequelae and 1.3 million are blind.
In early stages few symptoms exist.
Signs that occur include roughened conjunctiva secondary to subconjunctival lymphoid follicles apparent on the everted upper eyelid.
As older children and adults have repeated episodes the infection can lead to conjunctival fibrosis distorting the lid margin and causing lashes to rub against the cornea, which then causes blindness due to corneal opacities.
Chlamydia trachomatis is spread from eye to eye and from person to person by fingers, flies, shared clothing and towels.
Control includes improved hygiene and mass treatment with antibiotics to eradicate the reservoir of infection.
Active disease is controlled by contribution of surgery, anabiotic‘s facial cleanliness, and environmental improvement.
A single dose of oral azithromycin cures ocular C. trachomatis.
After one course of antibiotics infection often returns unless coverage is high and the population movement is limited.
Mass azithromycin administration where active trachoma is present in at least 5% of children age 1 to 9 years is a preventive strategy.
WHO recommends treatment with topical tetracycline or oral azithromycin for all children and women with follicular inflammation and or intense inflammation in areas of prevalence of 20% or greater, treatment in school children with follicular inflammation and or intense inflammation and their households in areas with a prevalence of 10-20% and individual treatment for follicular inflammation and or intense inflammation in areas of prevalence of less than 10%.
WHO recommends at least 3 rounds of annual mass treatment to highly affected communities and the annual treatment be continued until the prevalence in children aged 1-9 years is less than 10%.
A single mass treatment of oral azithromycin dramatically reduces prevalence of C trachomatis infection in a community (Schlacter).
Repeated mass treatment wit azithromycin progressives reduces and even eliminate ocular chlamydia.