Phylogenetic relationships and pathogenicity variation of two Newcastle disease viruses isolated from domestic ducks in Southern China

Table 6 Virus titers in cloacal and oropharyngeal swabs from ducks

Strains		Days post-inoculation (log₁₀EID₅₀/0.1 mL) ± SD^a
		3 Day		5 Day		7 Day		9 Day		11 Day
		Oropharyngeal swabs	Cloacal swabs	Oropharyngeal swabs	Cloacal swabs	Oropharyngeal swabs	Cloacal swabs	Oropharyngeal swabs	Cloacal swabs	Oropharyngeal swabs	Cloacal swabs
SS-10	Infected ^b	1.96 ± 0.60(4/6)	1.89 ± 0.76(2/6)	ND^d (0/3)	ND (0/3)	ND (0/3)	ND (0/3)	ND (0/3)	ND (0/3)	ND (0/3)	ND (0/3)
SS-10	Contact ^c	1.75 ± 0.43(1//3)	ND (0/3)	2.25 ± 1.30(1/3)	2.00 ± 0.43(2/3)	ND (0/3)	1.83 ± 0.57(1/3)	ND (0/3)	ND (0/3)	ND (0/3)	ND (0/3)
NH-10	Infected	2.17 ± 1.04 (2/6)	2.17 ± 1.04 (2/6)	ND (0/3)	1.58 ± 0.14(1/3)	ND (0/3)	1.58 ± 0.14(1/3)	ND(0/3)	ND(0/3)	ND(0/3)	ND(0/3)
NH-10	Contact	1.58 ± 0.14(1/3)	ND (0/3)	ND (0/3)	ND (0/3)	ND(0/3)	ND(0/3)	ND(0/3)	ND(0/3)	ND(0/3)	ND(0/3)

^aFor statistical purposes, a value of 1.5 was assigned if virus was not detected from the undiluted sample in three embryonated hen’s eggs [17].
^bDucks inoculated with virus.
^cNaive contact ducks housed with those inoculated.
^dNo detected.

ISSN: 1743-422X