Commission Decision of 12 May 1993 laying down the criteria for classifying third countries with regard to avian influenza and Newcastle disease in relation to imports of live poultry and hatching eggs (repealed)

ANNEX A U.K. DEFINITIONS OF ‘AVIAN INFLUENZA’ AND ‘NEWCASTLE DISEASE’

CHAPTER I U.K. Avian influenza

‘Avian influenza’ means an infection of poultry caused by any influenza A virus which has an intravenous pathogenicity index (IVPI) in six-week-old chickens greater than 1,2 or any infection with influenza A virus of H5 or H7 sub-type for which nucleotide sequencing has demonstrated the presence of multiple basic amino acids at the cleavage site of the haemagglutinin.

The IVPI has to be determined according to the following method:

Intravenous pathogenicity index (IVPI) U.K.

1. Infective allantoic fluid from the lowest passage level available, preferably from the initial isolation without any selection, is diluted 10¹ in sterile isotonic saline. U.K.

2. 0,1 ml diluted virus is injected intravenously into each of 10 six-week-old chickens (specific pathogen free birds should be used). U.K.

3. Birds are examined at 24 hour intervals for 10 days. U.K.

4. At each observation each bird is recorded normal (O), sick (1), severely sick (2) or dead (3). U.K.

5. Record results and calculate index as shown in this example: U.K.

a This has to be a subjective clinical judgement but normally this would involve birds showing more than one of the following signs: respiratory involvement, depression, diarrhoea, cyanosis of exposed skin or wattles, oedema of face and/or head, nervous signs.
Index = mean score per bird per observation =
Clinical Signs	Days after inoculation (number of birds)										Total	Score
	1	2	3	4	5	6	7	8	9	10
Normal	10	2	0	0	0	0	0	0	0	0	12 × 0	= 0
Sick	0	4	2	0	0	0	0	0	0	0	6 × 1	= 6
Severely sicka	0	2	2	2	0	0	0	0	0	0	6 × 2	= 12
Dead	0	2	6	8	10	10	10	10	10	10	76 × 3	= 228
Total = 246

CHAPTER II U.K. Newcastle disease

‘Newcastle disease’ means an infection of poultry caused by any avian strain of the paramyxovirus 1 with an intracerebral pathogenicity index (ICPI) in one-day-old chicks greater than 0,7.

The ICPI has to be determined according to the following method:

Intracerebral pathogenicity index text (ICPI) U.K.

1. Infective freshly harvested allantoic fluid (HA titre must be greater than 2⁴) is diluted 1:10 in sterile isotonic saline (antibiotics must not be used). U.K.

2. 0,05 ml of the diluted virus is injected intracerebrally into each 10 one-day-old chicks (i.e. 24 - 40 hours after hatching). The chicks should be hatched from eggs obtained from a specific pathogen-free flock. U.K.

3. The birds are examined at intervals of 24 hours for eight days. U.K.

4. At each observation each bird is scored: 0 = normal; 1 = sick; 2 = dead. U.K.

5. The index is calculated as shown in the following example: U.K.

Index = is a mean score per bird of observation =
Clinical signs	Days after inoculation (number of birds)								Total	Score
	1	2	3	4	5	6	7	8
Normal	10	4	0	0	0	0	0	0	14 × 0	= 0
Sick	0	6	10	4	0	0	0	0	20 × 1	= 20
Dead	0	0	0	6	10	10	10	10	46 × 2	= 92
Total = 112