Table 2 Ability and timeliness of mortality and egg production thresholds to signal highly and low pathogenic avian influenza outbreaks.

From: Effective thresholds for reporting suspicions and improve early detection of avian influenza outbreaks in layer chickens

 

HPAI

LPAI

No. detected/No. tested (%)

Days earlier detection (range)

No. detected/No. tested (%)

Days earlier detection (range)

Mortality

   CUSUM

5/7 (71.4)

2 (0–6)

8/9 (89.0)

6 (0–89)

   Ratio >2.9

5/7 (71.4)

2 (0–6)

7/9 (77.8)

7 (3–89)

   Mortality % >0.08/0.13

5/7 (71.4)

2 (0–5)

6/9 (66.7)

5 (3–89)

   Mortality % >0.25% (2 day)

3/7 (43.0)

0 (0–1)

0/9 (0.0)

 

   Mortality % >0.5% (2 day)

3/7 (43.0)

0 (0–1)

0/9 (0.0)

 

   Mortality % >0.25% (1 day)

6/7 (85.7)

0 (0–2)

0/9 (0.0)

 

Mortality % >0.5% (1 day)

5/7 (71.4)

0 (0–2)

0/9 (0.0)

 

Egg production

   CUSUM

1/6 (16.7)

0

3/6 (50.0)

6 (2–6)

   Ratio <0.94

2/6 (33.3)

0 (0–1)

4/6 (66.7)

6 (1–7)

  1. Data from recent outbreaks (2012–2016) were used for this analysis.