Controlling tick borne diseases through domestic animal management: a theoretical approach. Ros Johnson

Transcription

1 Controllng tck borne deae through dometc anmal management: a theoretcal approach Ro Johnon Dr Rachel Norman Dr Lucy Glbert

2 Talk Outlne Background of tck bology Management trategy Model Reult Future plan

3 Loupng Ill Vru (LIV) Tck borne deae Affect heep and groue Sheep vaccnated and dpped 80% mortalty n nfected groue

4 Thouand of egg are lad. Approx egg hatch

5 Thouand of egg are lad. Approx egg hatch Egg hatch nto larvae

6 Thouand of egg are lad. Approx egg hatch Egg hatch nto larvae Larvae quet for blood meal on mall/medum ze hot

7 Thouand of egg are lad. Approx egg hatch Egg hatch nto larvae Larvae leave hot after meal to moult nto nymph Larvae quet for blood meal on mall/medum ze hot

8 Thouand of egg are lad. Approx egg hatch Egg hatch nto larvae Nymph quet for blood meal on any ze hot Larvae leave hot after meal to moult nto nymph Larvae quet for blood meal on mall/medum ze hot

9 Thouand of egg are lad. Approx egg hatch nymph leave hot after meal to moult nto adult Egg hatch nto larvae Nymph quet for blood meal on any ze hot Larvae leave hot after meal to moult nto nymph Larvae quet for blood meal on mall/medum ze hot

10 Adult quet for meal on large hot Thouand of egg are lad. Approx egg hatch nymph leave hot after meal to moult nto adult Egg hatch nto larvae Nymph quet for blood meal on any ze hot Larvae leave hot after meal to moult nto nymph Larvae quet for blood meal on mall/medum ze hot

11 Matng occur. Adult quet for meal on large hot Thouand of egg are lad. Approx egg hatch nymph leave hot after meal to moult nto adult Egg hatch nto larvae Nymph quet for blood meal on any ze hot Larvae leave hot after meal to moult nto nymph Larvae quet for blood meal on mall/medum ze hot

12 Control tratege No tck = no deae Treat/remove wld anmal hot Ethcal/legalty ue Treat dometc hot Sheep tck mop

13 Sheep tck mop Actvely ue heep treated wth acaracde to mop up tck.

14 Sheep Model Reult Model run n Mathematca What effect do heep tck mop have wth dfferent deer dente? What effect doe varyng the effcacy have?

15 Model predcton wth deer T Total tck G Total groue wthout heep tck mop 6 G Infected groue 3 deer 6 deer 7 deer 12 deer T t Total tck t G Total groue wth heep tck mop 6 G t Infected groue t t t A deer number ncreae tck number ncreae and groue number declne Increaed deer number reduce effect of heep tck mop

16 Dfferent effcacy level T Total tck G Total groue 6 G Infected groue t t t Hgh effcacy peed recovery Low effcacy prevent recovery, wore than no heep?

17 Concluon Ung heep tck mop can be effectve If: very few deer hgh level of effcacy

18 Emprcal evdence Game and Wldlfe Conervaton Trut Key Fndng: The ue of heep a tck-mop may reduce tck btng rate on groue chck where deer dente are lower than fve per 100 hectare. Red deer dente of 10 per 100 hectare appear to be too hgh for tck-mop to be effectve. (Are heep tck-mop effectve n Scotland?

19 Future work Seaonalty Deer tck mop Feldwork/collaboraton for valdaton data

20 Thank to : R Norman, L Glbert landowner/hepherd for data NERC Macaulay Development Fund

21 The model dg dt dg dt dg dt dt dt dt dt z = (a = (β = = (a = β γg 2 1 t g + Pβ T)T(β D + (1 d)β T G b t g G)G b g 3 )TG G b T t z 5 - β G ΓG 3 g (β TG - β Pβ S) β TD - β )TG T G TS - dβ 2 where Г=α+b Groue equaton g +γ b T 7 TS t - β 3 T G - β 5 T D - β 6 T S - dβ Tck equaton 7 T S