Table 2.

Number of directly inoculated or contact exposed chickens shedding virus detected by real-time RT-PCR, percent of birds infected within dose groups for each isolate, mean bird infectious dose (calculated from the inoculated birds), and seroconversion.

	Inoculated birds					Contact exposed birds
Isolate	Dose^a	Virus detection^b		Antibody^c	% infected^d	50% BID^e	Virus detection^b		Antibody	% infected
		OP	CL	Antibody^c	% infected^d	50% BID^e	OP	CL	Antibody	% infected
	6	2/5	0/5	0/5	40		0/3	0/3	0/3	0
Dk/PA/14	4	0/5	0/5	0/5	0	>6.0	0/3	0/3	0/3	0
	2	0/5	0/5	0/5	0		0/3	0/3	0/3	0
	6	4/5	0/5	4/5	80		0/3	0/3	0/3	0
Ck/NY/16	4	0/5	0/5	0/5	0	5.3	0/3	0/3	0/3	0
	2	0/5	0/5	0/5	0		0/3	0/3	0/3	0
	6	1/5	0/5	2/5	20		0/3	0/3	0/3	0
Ck/CT/17	4	0/5	0/5	0/5	0	>6.0	0/3	0/3	0/3	0
	2	0/5	0/5	0/5	0		0/3	0/3	0/3	0
	6	1/5	0/5	1/5	20		0/3	0/3	0/3	0
CK/NY/02471/18	4	0/5	0/5	0/5	0	>6.0	0/3	0/3	0/3	0
	2	0/5	0/5	0/5	0		0/3	0/3	0/3	0
	6	13/13	12/13	12/13	100		3/3	3/3	3/3	100
Ck/NY/042097/18	4	2/5	0/5	1/5	40	4.3	0/3	0/3	0/3	0
	2	1/5	0/5	1/5	20		0/3	0/3	0/3	0
	6	13/13	11/13	13/13	100		3/3	2/3	3/3	100
Ck/NY/2019	4	5/5	4/5	5/5	100	2.8	3/3	3/3	3/3	100
	2	0/5	0/5	1/5	20		0/3	0/3	0/3	0

^a.

Log10 50% egg infectious dose per bird.

^b.

Number of chickens shedding virus / total number of birds

^c.

Number of chickens positive for antibody / total number of birds

^d.

Birds were considered infected if viral RNA was detected in oropharyngeal (OP) and cloacal (CL) swabs at any timepoint and/or the chickens was positive for antibodies by hemagglutination inhibition assay at 14 days post inoculation.

^e.

Log10 50% bird infectious dose (BID) per mL.