91探花

Dr. Annette Boerlage, Candidate for Post Doctoral Position in Aquatic Epidemiology-Infectious Diseases in the Canada Excellence Research Chair Program will present 鈥淭ransmission, dynamics and control of fish-borne zoonotic trematodes.鈥� Fish-borne zoonotic trematodes (FZTs) are among the most neglected tropical diseases. The life-cycle involves aquatic snails, fish and final hosts which can be humans or reservoir hosts like pigs and cats. Final hosts get infected if they eat raw or undercooked fish. Objective was to give recommendations on control. Transmission experiments were performed to quantify the effect of fish size, water volume and bottom surface on transmission of FZTs to common carps. Conclusion was that transmission was independent of cercariae density, implying that pond dimensions in aquaculture are less important with regard to FZT transmission. Small fish had a much higher probability to get infected than larger fish, therefore a delay in stocking of fish in ponds might lead to lower FZT levels in fish. An experiment to quantify survival of FZTs in fish showed that in aquaculture, FZTs outlive fish. The grow-out period of fish should be extended for a few years to lead to substantially lower FZT levels in harvestable fish. A mathematical model was developed based on the life-cycle of FZTs on integrated agriculture-aquaculture farming systems in Nam Dinh province, Vietnam, using results of the experiments and literature. Control measures were compared using the basic reproduction ratio. FZTs persist in the absence of control. Application of chemotherapy to humans, as is currently the core intervention method, might not lead to complete FZT elimination without complementary measures. In conclusion, FZT control in aquaculture by delayed stocking of fish in ponds can lead to FZT control, but a combination of control measures, e.g. human chemotherapy, delayed stocking and snail control might be more effective. Everyone is welcome to attend.