Trachoma is a leading cause of blindness in the developing world and affects an estimated 8 million people. Children are most susceptible to this infectious disease that is caused by exposure to Chlamydia trachomatis, a microorganism which spreads through contact with other infected people and through transmission by flies. After years of repeated infection, the inside of the eyelid becomes severely scarred, causing the eyelid to turn inward. The eyelashes then scrape against the normally transparent cornea, leading to irreversible corneal opacities and blindness. Trachoma is endemic in crowded areas with poor personal hygiene, lack of clean water, absence of toilets, flies, and close proximity to cattle. The World Health Organization has targeted trachoma through intervention programs that rely in part on community-wide distribution of an oral antibiotic, azithromycin. These programs have been successful in areas with moderate levels of infection. However, in severely affected communities, infection returns rapidly after treatment. It is unknown whether repeated, long-term antibiotic treatment can reduce infection rates in these severely affected regions.
An NIH-supported clinical trial demonstrated that six treatments of azithromycin of more than 90 percent of the population in two severely affected Ethiopian communities over a three year period eliminated trachoma. Additional analysis by these investigators showed that treating these villages with azithromycin also sharply reduced childhood mortality. This unexpected effect most likely occurred because of concomitant antibiotic treatment of undiagnosed respiratory infections, gastrointestinal diseases, malaria and other endemic diseases.
Public Impact Statement/Significance:
These results are aligned with the increased NIH focus on global health to improve the quality of life in the developing world. The strategy of local elimination of trachoma in severely affected villages provides evidence that it is possible to eradicate the disease worldwide and significantly improve child health. More than 15 percent of Ethiopian children die before their fifth birthday due largely to diseases and opportunistic infections that are treatable with antibiotics. Although additional work is needed to evaluate the long-term efficacy of antibiotic programs, these results provide further scientific and humanitarian rationale for intervention programs in areas severely affected by trachoma.
Trachoma Amelioration in Northern Amhara (TANA) U10EY016214-06, Eliminating trachoma with mass drug treatment U10EY016214-05S1.
Porco, T.C., et al. Effect of Mass Distribution of Azithromycin for Trachoma Control on Overall Mortality in Ethiopian Children. JAMA. 2009; 302(9): 962-8. PubMed
Biebesheimer, J.B., et al. Complete Local Elimination of Infectious Trachoma from Severely Affected Communities after Six Biannual Mass Azithromycin Distributions. Ophthalmology. 2009; 116(11): 2047-50. PubMed
Last Reviewed: January 2010