Community mass treatment with azithromycin for trachoma: Factors associated with change in participation of children from the first to the second round.

Background: Mass drug administration (MDA) with azithromycin is an important part of trachoma control programs. Maintaining high participation among children is challenging.

Aim: We assessed factors identifying households with a child who changed participation from the first MDA to the second MDA compared to households where all children participated at both MDAs.

Methods: Two case-control comparisons were conducted in 11 Tanzanian communities, which underwent MDA in 2008 and 2009. The first case group (n=165) was a random sample of households with a child who changed from a 2008 non-participant to a 2009 participant (delayed participant). The second case group (n=165) was a random sample of households with a child who went from a 2008 participant to a 2009 non-participant (change to non-participant). Controls (n=330) were a random sample of households where all children participated in both rounds. Risk factors were assessed using questionnaires asked of children's guardians. Logistic models with a random-intercept were used to estimate odds ratios and 95% confidence intervals.

Results: Households with delayed participation were more likely to be in communities with fewer treatment days (OR=2.98, 95% CI=1.80-4.92) and assigned to Community Treatment Assistants (CTA) with a wide area to cover (OR=1.88, 95% CI=1.09-3.23). Households with change to non-participation were more likely to live further from the distribution site (OR=3.17, 95% CI=1.19-8.46), have the guardian born outside the village with short-term residency (OR=2.64, 95% CI=1.32-5.31), and be assigned to a male CTA (OR=1.75, 95% CI=1.08-2.83).

Conclusions: Factors related to program accessibility were associated with delayed participation and maintaining participation.