All members of the household need to be treated for trachoma in order to prevent rapid re-infection, according to a new study published in PLoS Neglected Tropical Diseases.
Trachoma is an infectious eye disease, and the leading cause of the world's infectious blindness. Globally, 84 million people suffer from active infection and nearly 8 million people are visually impaired as a result of this disease.
Community-wide administration of antibiotics is one arm of a four-pronged strategy in the global initiative to eliminate blindness due to trachoma. The potential impact of more efficient, targeted treatment of infected households depends on the relative contribution of community and household transmission of infection, which have not been previously estimated.
A research team which included a number of scientists from the London School of Hygiene & Tropical Medicine, together with colleagues from Imperial College London, Johns Hopkins (US) and the Wilmer Eye Institute, studied prevalence data from four endemic populations in The Gambia and Tanzania. They found the rate of transmission of trachoma within households to be higher than the rate in communities, leading to persistent transmission of the infection within households. In all populations, individuals in larger households contributed more to the incidence of infection than those in smaller households.