The Epidemiology of Trachoma in the Five Northern Districts of Sierra Leone

Abstract

Purpose: In 2008, a trachoma prevalence survey was conducted in the five northern districts of Sierra Leone to determine if and where specific components of the SAFE strategy (Surgery, Antibiotics, Face washing, Environmental change) should be initiated.

Methods: A cross-sectional survey at district level was implemented using two-stage random cluster sampling: probability proportionate sampling was used to select villages in the first stage and compact segment sampling of households in the second stage. Both eyes of 16,780 individuals were examined using the World Health Organization simplified trachoma grading system. Data were also collected on village- and household-level behavior and environmental factors related to trachoma.

Results: Prevalence of trachomatous inflammation-follicular (TF) in children aged 1–9 years was highest in Kambia at 3.52% (95% Confidence Interval (CI): 2.28–4.75%), while the prevalence of trachomatous trichiasis (TT) in persons over 15 years of age was highest in Port Loko at 0.27% (95% CI: 0.03–0.50%). Across all districts, the percentage of households reporting washing children’s faces less than once per day was very low, while latrine coverage and accessible and safe water sources were not highly prevalent.

Conclusions: In all districts but Koinadugu, TT prevalence was greater than the WHO elimination threshold, indicating the need for 1,016 TT surgeries to prevent blindness. District TF prevalence rates did not warrant mass antibiotic distribution. Although not required given the low prevalence of TF, we recommend the construction of 35,941 household latrines and provision of water sources within a 30-minute walk roundtrip for 17,551 households to bring Sierra Leone closer to reaching Millennium Development Goal 7.

Keywords::

• Trachoma
• Environmental change
• Sierra Leone
• Neglected tropical diseases
• Water and sanitation

ACKNOWLEDGMENTS

This study was made possible through technical support from Sight Savers International, the Government of Sierra Leone, Research Triangle Institute International, Helen Keller International, and funding from the United States Agency for International Development and does not necessarily reflect the views of these organizations, the United States Agency for International Development, or the United States Government. The authors gratefully acknowledge the survey team who were employees of the Government of Sierra Leone’s National Eye Care Programme, the Ministry of Health in Guinea who hosted the survey team for the practical training session, and data entry personnel who were staff members of the National Neglected Tropical Disease Control Programme and Helen Keller International. We thank Yaobi Zhang who contributed greatly to the refinement of this paper. Finally, we thank the thousands of households in the five northern districts of Sierra Leone who participated in this survey and thus allowed us to gain a greater understanding of trachoma epidemiology in this region.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.