Reduction and Return of Infectious Trachoma in Severely Affected Communities in Ethiopia
Open Access
- 10 February 2009
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLoS Neglected Tropical Diseases
- Vol. 3 (2), e376
- https://doi.org/10.1371/journal.pntd.0000376
Abstract
Antibiotics are a major tool in the WHO's trachoma control program. Even a single mass distribution reduces the prevalence of the ocular chlamydia that causes trachoma. Unfortunately, infection returns after a single treatment, at least in severely affected areas. Here, we test whether additional scheduled treatments further reduce infection, and whether infection returns after distributions are discontinued. Sixteen communities in Ethiopia were randomly selected. Ocular chlamydial infection in 1- to 5-year-old children was monitored over four biannual azithromycin distributions and for 24 months after the last treatment. The average prevalence of infection in 1- to 5-year-old children was reduced from 63.5% pre-treatment to 11.5% six months after the first distribution (PP = 0.0004). In the next 18 months, infection returned to 25.2%, a significant increase from six months after the last treatment (P = 0.008), but still far lower than baseline (P<0.0001). Although the prevalence of infection in any particular village fluctuated, the mean prevalence of the 16 villages steadily decreased with each treatment and steadily returned after treatments were discontinued. In some of the most severely affected communities ever studied, we demonstrate that repeated mass oral azithromycin distributions progressively reduce ocular chlamydial infection in a community, as long as these distributions are given frequently enough and at a high enough coverage. However, infection returns into the communities after the last treatment. Sustainable changes or complete local elimination of infection will be necessary. ClinicalTrials.gov NCT00221364 Trachoma is one of the leading causes of blindness in the developing world. The World Health Organization has a multi-pronged approach to controlling the ocular chlamydial infection that causes the disease, including distributing antibiotics to entire communities. Even a single community treatment dramatically reduces the prevalence of the infection. Unfortunately, infection returns back into communities after treatment, at least in severely affected areas such as rural Ethiopia. Here, we assess whether additional scheduled treatments in 16 communities in the Gurage area of Ethiopia further reduce infection, and whether the disease returns after distributions are stopped. In communities with the highest levels of trachoma ever studied, we find that repeated mass oral azithromycin distributions gradually reduce the prevalence of trachoma infection in a community, as long as these treatments are given frequently enough and to enough people in the community. Unfortunately, infection returns into the communities after the last treatment. Sustainable changes or complete local elimination of infection will be necessary to stop the return of ocular chlamydial in communities with very high prevalence of the disease.Keywords
This publication has 35 references indexed in Scilit:
- A rationale for continuing mass antibiotic distributions for trachomaBMC Infectious Diseases, 2007
- Impact of Mass Distribution of Azithromycin on the Antibiotic Susceptibilities of Ocular Chlamydia trachomatisAntimicrobial Agents and Chemotherapy, 2005
- Mass Treatment with Single-Dose Azithromycin for TrachomaNew England Journal of Medicine, 2004
- New Steps toward Eliminating Blinding TrachomaNew England Journal of Medicine, 2004
- Impact of Azithromycin Administration for Trachoma Control on the Carriage of Antibiotic-Resistant Streptococcus pneumoniaeAntimicrobial Agents and Chemotherapy, 2003
- Disappearance of Trachoma from Western NepalClinical Infectious Diseases, 2002
- Adverse and Beneficial Secondary Effects of Mass Treatment with Azithromycin to Eliminate Blindness Due to Trachoma in NepalClinical Infectious Diseases, 2002
- Pooling of Chlamydia laboratory tests to determine the prevalence of ocular Chlamydia trachomatis infectionOphthalmic Epidemiology, 2001
- A Prospective Study of the Impact of Community-Based Azithromycin Treatment of Trachoma on Carriage and Resistance of Streptococcus pneumoniaeClinical Infectious Diseases, 1997
- Animal Aggregations: A Study in General Sociology.Journal of Educational Sociology, 1931