Scoring System for Lesions Induced by Different Strains of Newcastle Disease Virus in Chicken

Table 5

Numbers and percentages of different vNDV-infected tissues stained with HE in which lesions appeared from hr 2 pi till day 6 pi.

(a)

	Trachea	Caecal Tonsil	Provent-riculus	Spleen	Kidney	Lung
No. of positive tissues^∗	23 (24)	19 (24)	13 (24)	13 (24)	12 (24)	10 (24)
Percentage of positive tissues^∗	95.83 %	79.167%	54.17%	54.167%	50.00%	41.67%

(b)

	Liver	Thymus	Heart	Bursa of Fabricius	Intestine	Brain
No. of positive tissues^∗	10 (24)	9 (24)	9 (24)	8 (24)	7 (24)	3 (24)
Percentage of positive tissues^∗	41.67%	37.50%	37.50%	33.33%	29.17%	12.50%

Note. Values in brackets represent the whole number of SPF chickens which were infected with vNDV from hour 2 pi till day 6 pi. Positive tissue indicates tissue in which one lesion or more were detected. Lesions were not detected in tissues of control group chickens.