Acidification of drinking water inhibits indirect transmission, but not direct transmission of Campylobacter between broilers

In this study the effect of acidification of the drinking water of broiler chickens on both direct and indirect transmission of Campylobacter was evaluated. In the direct transmission experiment both susceptible and inoculated animals were housed together. In the indirect transmission experiment the susceptible animals were spatially separated from the inoculated animals and no direct animal to animal contact was possible. The transmission parameter β was estimated for the groups supplied with acidified drinking water and for the control groups. The results showed that acidification of the drinking water had no effect on direct transmission (β = 3.7 day−1 for both control and treatment). Indirect transmission however was influenced by acidification of the drinking water. A significant decrease in transmission was observed (p < 0.05), with control vs. treatment point estimates being β = 0.075 day−1 vs. β = 0.011 day−1.Apart from providing quantitative estimations of both direct and indirect transmission of Campylobacter in broilers, this study also demonstrates the use of an experimental setup for indirect transmission of Campylobacter between broilers to assess the efficacy of candidate measures to reduce transmission.