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Table II.
Scenario tree node values for the different Surveillance System Components (SCC) used for HPAI H5N1 surveillance in wild waterbirds on Lake Constance. Branch probabilities are either a single point value or a distribution; @RISK distributions are shown when appropriate, otherwise the expected value is shown. Where applicable, branch probabilities are shown for the different wild waterbird groups: diving ducks, grebes and mergansers as one group (D/G/M), Swans and Other. The relevant scenario trees are shown in Figures 1–3.
| Tree | Node name | Branch name | Branch probability |
|---|---|---|---|
| All SSC: May–August | Bird group | Swans | 0.0177 (number of birds 208) |
| D/G/M | 0.189 (number of birds 2 943) | ||
| Other | 0.797 (number of birds 12 633, 16% dabbling ducks and 58% Gulls (Laridae)) | ||
| All SSC: September–April | Bird group | Swans | 0.0143 (number of birds 1 912) |
| D/G/M | 0.541 (number of birds 72 620) | ||
| Other | 0.444 (number of birds 59 525, 30% dabbling ducks, 56% Eurasian Coots (Fulica atra)) | ||
| All trees | Unit infection status | Infected | 0.01 |
| All trees | Bird dies | Dies | Swan ~ Uniform (0.8, 0.99); D/G/M ~ Uniform (0.2, 0.8); Other ~ Uniform (0.2, 0.6) |
| Bycatch, Swan Catch, Hunt & Trap | Test positive | Yes | BetaPert (0.7, 0.8, 0.9) – for live birds |
| Found dead | Test positive | Yes | Uniform (0.9, 0.99) – for dead birds |
| September–April trees | |||
| Bycatch | Bird sampled | Sampled | Swan = 0; D/G/M = 1.89E−5; Other = 2.31E−5 |
| Trap | Bird sampled | Sampled | Swan = 3.27 E−4; D/G/M = 6.20 E−5; Other = 4.82 E−5 |
| Swan Catch | Bird sampled | Sampled | Swan = 0.197; D/G/M = 0; Other = 0 |
| Found dead | Bird sampled | Sampled | Expected values: Swan = 0.0123; D/G/M = 1.46 E−4; Other = 5.23 E−4 |
| Hunt | Bird sampled | Sampled | Expected values: Swan = 9.81 E−4; D/G/M = 5.16 E−5; Other = 5.24 E−5 |
| Sentinel | Mallards | Yes | 0.154 (number of Mallard ducks 9 206) |
| Bird visits sentinel | Visits | Expected values: Swan = 0.003; D/G/M = 0: Non_Mallard = 5.0E−4; Mallard = 0.0348 | |
| Infects sentinel Expert 1 or Expert 2 | Yes | Swan ~ Betapert (0.2, 0.5, 0.8) or Betapert (0.2, 0.7, 1); D/G/M ~ Betapert (0.1, 0.2, 0.5) or BetaPert (0.2, 0.4, 1); Other_Non_Mallard ~ Betapert (0.1, 0.2, 0.5) or Betapert (0.2, 0.6, 1); Other_Mallard ~ Betapert (0.2, 0.5, 1) or Betapert (0.2, 0.9, 1) | |
| Flock test positive | Yes | Expected value: 0.999 | |
| May–August trees | |||
| Bycatch | Bird sampled | Sampled | Swan = 0; D/G/M = 0; Other = 1.98 E−5 |
| Trap | Bird sampled | Sampled | Swan = 2.68 E−3; D/G/M = 8.49 E−4; Other = 1.35 E−3 |
| Swan Catch | Bird sampled | Sampled | Swan = 6.08 E−3; D/G/M = 0; Other = 6.29 E−6 |
| Found dead | Bird sampled | Sampled | Expected value: Swan = 0.0714; D/G/M = 3.80 E−3; Other = 5.45 E−3 |
| Hunt | Bird sampled | Sampled | Swan = 0; D/G/M = 0; Other = 0 |
| Mallard | Yes | 0.150 (number of Mallard ducks 1 898) | |
| Sentinel | Bird visits sentinel | Visits | Expected value: Swan = 0; D/G/M = 0; NonMallard = 1.4 E−3; Mallard = 0.12 |
| Infects sentinel | Yes | As for sentinel September–April | |
| Flock test positive | Yes | As for sentinel September–April | |