Assessing bait acceptance of local dogs, oral rabies vaccination success and human contact risk in Bali, Indonesia

Abstract

Aim: The objective of this study was to identify the preferred bait of local dogs in Bali and estimate oral rabies vaccination (ORV) success in locations with varying geographic and demographic conditions. In addition, an evaluation of potential direct and indirect contact with the placebo sachet contents was conducted. Methods: The study was a randomized controlled trial conducted in two pilot areas of Bali using imported and hand-made baits. All dogs were offered a single bait containing a sachet of blue-dyed water using the “hand-out and retrieve” technique. Several methods were used to determine the likelihood of contact with the placebo vaccine. Comparing ORV with capture-vaccinate-release (CVR) methods, field officers were given Google Forms questions to answer. Statistical analysis was performed using univariate contingency table testing, followed by the development of a multiple logistic regression (MLR) model. Results: With 96.9% acceptance, intestine was the most popular bait for local dogs in Bali, and egg bait came in second (81.1%). However, the egg bait was 95.2% effective in releasing the vaccine in the oral cavity, followed by the intestine at 82.6%. 6.1% of surveyed households had direct contact with a dog that had recently consumed a vaccine bait. A survey among field officers also indicated that they preferred ORV over CVR, as the former is more suitable for vaccinating inaccessible dogs and less stressful for the teams and the animals. Conclusion: In Bali, both a locally-made intestine bait and an industrially-produced egg-flavored bait were readily taken up by local dogs. There is a small risk that people can come into contact with dogs previously offered a bait; hence, only vaccines with a high safety profile should be used. ORV can replace the currently used CVR method for vaccinating free-roaming dogs as a complementary tool to increase vaccination coverage.