Abstract
Purpose :
As more countries achieve elimination goals for active trachoma, surveillance is necessary for verification of absence of re-emergence. In Nepal, surveillance surveys in all formerly endemic districts have started. During these pre-validation surveillance surveys, we added a test of infection processed locally, and antibody detection in young children, to the clinical grading of active trachoma to evaluate the possible role of these tools in surveillance programs.
Methods :
15 randomly selected clusters within two districts were chosen (30 clusters). In each cluster, 50 randomly selected children ages 1-9 year olds and 100 adults ≥15 years old were examined for TF±TI and TT respectively (1500 children and 3000 adults). Eye swabs were taken from all children to test for C. trachomatis (CT) using the Cepheid GeneXpert platform (Cepheid, Sunnyvale, CA). Dried blood spots were collected from children 1-4 and 9 years (794 children) to determine antibody positivity to the C. trachomatis antigen pgp3. Blood spots were processed on the Luminex-100 platform following standard procedures. Data were analyzed as simple frequencies, and age stratified proportions.
Results :
Districts were 2 and 4 years from last program activities. In the sampled 1500 children, only 2 TF cases and one CT infection were found. Overall antibody positivity was found in 2.4% of samples with no increase in frequency by age. There was no evidence for clustering of antibody positivity by community.
Conclusions :
There is no evidence of re-emergence in those two districts in Nepal. The absence of an increase in age seroprevalence suggests interruption of transmission of C. trachomatis.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.